Beyond cancer: The potential application of CD47-based therapy in non-cancer diseases.

The accumulation of mononuclear phagocytes (MP) is one of the hallmarks of age-related macular degeneration (AMD) 178 , 179 . As a pathogenic factor, complement factor H binding with CD11b inhibits TSP1 activation of CD47, whilst inhibiting CD47-mediated MP removal. Naturally, pharmacological activation of CD47 by CD47-activating peptide PKHB1 reversed this effect and exerted an inverse effect that promoted the clearance of MP 13 . Malaria is one of the most prevalent infectious diseases, especially in Africa. Different from virus infection, CD47-based therapies may have distinct contributions to malaria infection. CD47 deletion mice infected by Plasmodium berghei ANKA ( Pb -A) exhibited a more preserved epithelium and better blood–brain barrier (BBB) integrity compared to infected WT mice 180 . In the murine Plasmodium yoelii 17XNL model, CD47 deletion mice had a higher level of CD8 + T cells and macrophages in the spleen, while had a lower serum level of IL-10 of which deletion seems to lead to resistance towards P. yoelii 17XNL 181 . Corresponding with the results from CD47 deletion mice, aCD47 Ab decreased malaria burden from 0.39 ± 0.05% to 0.026 ± 0.008% 181 . And 80% of mice in the aCD47 Ab group did not grow into malaria and survived Pb -A infection 182 . The aCD47 Ab also facilitated the phagocytotic rate of RBCs infected by malaria 182 . Simultaneously, SIRP α fusion protein promoted macrophages to engulf RBCs infected by ring-stage malaria, and LPS and IFN- γ further enhanced engulfment 180 . However, the anti-malaria capacity of aCD47 Ab may not rely on the macrophage, as the survival rate of mice had no change after macrophage and monocyte cleavage in the Pb -A model 182 . As mice treated with aCD47 Ab exhibited more integrated BBB, researchers speculated that aCD47 Ab may contribute to malaria via exerting other biological functions, like protecting BBB, rather than facilitating phagocytosis 182 . The transcription of CD47 was enhanced in cells infected by human respiratory syncytial virus or human parainfluenza virus 3 183 . CD47 seems a negative factor towards the influenza virus as well. CD47 was induced and exposed on the apical surface of nasal and bronchial epithelial cells infected by virus pH1N1 in an NF- κ B/IFN-dependent manner 184 . CD47 deleted mice were better protected from influenza by vaccination, as less weight loss and virus titer in lung 185 . In addition, aCD47 Ab decreased the susceptibility of pH1N1-infected mice to secondary S. aureus infection 184 . In mice infected by lymphocytic choriomeningitis virus (LCMV), aCD47 Ab cleared viremia below the level of detection, while the titer of control groups was 2.8log 10 by eight days post-infection. In addition, kidney virus showed a 27-fold reduction in the aCD47 Ab group in comparison to control group after ten days of infection. Further, aCD47 Ab activated dendritic cells, whilst regulating the activation and proliferation of CD8 + T cells rather than macrophages in LCMV infection 186 . Meanwhile, CD47 neutralizing antibody alleviated clinical scores and calcified myofibers in mice with Theiler's murine encephalomyelitis virus infection 187 . The peripheral monocytes collected from human immunodeficiency virus (HIV) patients also had a higher level of CD47, and CD47 binding partner SIRP α . However, aCD47 Ab only relieved HIV syndromes in one cohort rather than in both two cohorts 186 . The efficacy of aCD47 Ab in HIV infection remains largely obscure but is worthwhile exploring. The more detailed information about the therapeutic effects and mechanisms of CD47-based agents in non-cancer diseases except for that of the circulatory and nervous system is shown in Table 3 13 , 23 , 24 , 25 , 26 , 42 , 44 , 134 , 143 , 155 , 156 , 161 , 163 , 164 , 169 , 175 , 177 , 180 , 181 , 182 , 184 , 186 , 187 and Fig. 4 . Table 3 Pre-clinical studies of CD47-based therapy in diseases other than those of the circulatory and nervous system. Table 3 Disease Target Experimental model Administration design a Main results Ref. Non-alcoholic steatohepatitis (NASH) CD47 Mice fed with diet enriched with fat, fructose, and cholesterol for 20–30 weeks i.p.; q.o.d.; anti-CD47 antibody; MIAP410; 200 μg/mouse; 4 weeks Did not affect hepatic steatosis development; Decreased plasm ALT level; Decreased histology scores of liver inflammation and fibrosis; Decreased hepatic neutrophils infiltration and liver NF- κ B levels; Decreased the level of α -SMA and collagen Ⅰ; Decreased both trichrome and Sirius red positive staining areas; Decreased the number of neutrophils in the blood 134 Hepatic stellate cell Anti-CD47 antibody; N/A; N/A Decreased hepatic stellate cell activation 3D spheroid microtissue (containing human hepatocytes, macrophages, and stellate cells) treated with NASH-inducing media for 5–10 days Anti-CD47 antibody; MIAP410; 20 μg/mL; 5 days Decreased α -SMA and collagen Ⅰ positive staining Non-alcoholic steatohepatitis CD47 necHCs (primary hepatocytes isolated from AAV8-TBG-mRIP3-2xFV mice or hRIP3-2xFV-transduced human hepatocytes to AP20187); Mouse/human macrophages Anti-CD47 antibody; MIAP410; 20 μg/mL Increased necHC uptake; This co-culture medium induced HSC activation genes 25 AAV8-TBG-mRIP3-2xFV transduced mice administrated with AP20187 i.p.; once; anti-CD47 antibody; MIAP410; 200 μg per mouse; N/A Increased the engulfment of RIP3 + necHCs by liver macrophages Fructose-palmitate-cholesterol (FPC) diet-induced NASH for 8 weeks before treatment i.p.; q.3w.; anti-CD47 antibody; MIAP410; 200 μg per mouse; 8 weeks with FPC diet Not altered body weight or liver weight; Increased the engulfment of necHCs by macrophages; Decreased plasm ALT levels and fibrosis High-fat choline-deficient l -amino-defined diet (HF-CDAA)-induced NASH for 2 weeks before treatment i.p.; q.3w.; anti-CD47 antibody; MIAP410; 200 μg per mouse; 6 weeks with HF-CDAA diet Did not alter body weight; Increased the engulfment of necHCs by macrophages; Decreased plasm ALT levels; Did not increase apoptotic cell clearance; Decreased fibrosis; Not changed the number of red blood cells Mice fed with FPC diet for 8 weeks before treatment and a total 16 weeks AAV8-H1-shCD47; N/A Increased the engulfment of necHCs by macrophages; Decreased plasm ALT levels SIRP α necHCs (primary hepatocytes isolated from AAV8-TBG-mRIP3-2xFV mice); Mouse macrophages Anti-SIRP α antibody; cloneP84; 20 μg/mL Increased the engulfment of necHCs by macrophages; FPC diet-inducing NASH for 8 weeks before treatment i.p.; q.3w.; anti-SIRP α antibody; cloneP84; 100 μg per mouse; 8 weeks with FPC diet Did not alter body weight; Increased the engulfment of necHCs by macrophages; Decreased hepatic fibrosis; Decreased plasm ALT levels; Not changed the number of red blood cells HF-CDAA diet-induced NASH for 2 weeks before treatment i.p.; q.3w.; anti-SIRP α antibody; cloneP84; 100 μg per mouse; 6 weeks with HF-CDAA diet Increased the uptake of necHCs by macrophages; Did not alter body weight, liver weight, liver steatosis, and plasm ALT; Decreased hepatic fibrosis and collagen deposition Ulcerative colitis SIRP α CD45RB high CD4 + T cell transfer colitis model s.q.; t.i.w.; agonistic anti-SIRP α antibody; clone 6F2; 250 μg/mice; 12 weeks; initiated right after T cell transfer Decreased body weight loss; Decreased visual colon and histopathology score 26 CD45RB high CD4 + T cell transfer colitis model s.q.; b.i.w.; agonistic anti-SIRP α antibody; 250 μg/mice; 6 weeks; initiated 6 weeks after T cell transfer Increased body weight; Increased visual colon score which reflects colon edema and thickness; Decreased foci of epithelial inflammation, crypt loss, and reactive epithelial hyperplasia; Decreased the ratio of GR1 expressing neutrophil: monocytes in the mucosa and lamina propria regions Crohn disease (CD) SIRP α Mesenteric lymph nodes and intestinal mucosa of CD patients Avidity-improved human CD47 fusion protein (CD47-Var1); 10 μg/mL Selectively identifies CD172a on HLA-DR + cells in intestinal mucosa and mLNs of CD patients 143 T Cells isolated from mesenteric lymph nodes of surgical specimens Avidity-improved human CD47 fusion protein (CD47-Var1); 10 μg/mL Decreased the ability of HLA-DR-CD172a + cells to stimulate memory Th17 responses Inflamed CD tissues Avidity-improved human CD47 fusion protein (CD47-Var1); 10 μg/mL Decreased the production of IL-1 β , IL-6, IL-8, IL-10, TNF, IFN- γ , IL-23, MIP-1 α , and MIP-1 β in the inflamed tissue without significantly affecting the secretion of cytokines by the noninflamed tissues in CD patients Type Ⅰ diabetes CD47 Human islet Anti-CD47 antibody; B6H12; N/A Increased insulin expression 42 Primary murine β cells isolated from mice CD47 siRNA; N/A Increased insulin secretion MIN6 cell A morpholino targeting human CD47; N/A Increased insulin secretion MIN6 cell CD47 siRNA; N/A Increased phosphorylation of Lyn kinase Isolated human islet Anti-CD47 antibody; MIAP301; N/A Increased phosphorylation of Lyn kinase Primary murine β cells isolated from mice CD47 siRNA; N/A Decreased Cdc42 phosphorylation at serine-71 6-week-old nonobese diabetic mice i.p.; N/A; anti-CD47 antibody; MIAP301; 0.4 μg/g; N/A Delayed the onset of hyperglycemia for 3–5 weeks compared to the IgG group; Showed better glucose tolerance over the time course of treatment at 16 and 20 weeks of age 11-week-old nonobese diabetic mice N/A; q.2w.; anti-CD47 antibody; MIAP301; 0.8 μg/g; 5 weeks 50% of the MIAP301-treated mice turned into diabetics while 80% of IgG-treated mice turned into diabetics by 28 weeks Obesity CD47 Mice fed with a high-fat diet for 6 weeks i.p.; q.2w.; antisense oligonucleotide targeting CD47 (CD47 ASO); 25 mg/kg; 8 weeks with HFD Knockdown CD47 in the liver, skeletal muscle, or fat tissues; Decreased high-fat diet-induced weight gain; Decreased fat mass, plasma triglyceride and cholesterol, hepatic steatosis, plasma ALT and AST levels, and Nos2; Decreased the size of adipocytes of epidydimal white fat tissue; Increased glucose tolerance, lipolysis genes in epidydimal white fat tissue, Arg1 expression, oxygen consumption, energy expenditure, and voluntary wheel running distance 24 Genetic obese mice i.p.; q.2w.; CD47 ASO; 25 mg/kg; 8–9 weeks Induced weight loss after 5 weeks of CD47 ASO; Decreased adiposity; Increased glucose tolerance Renal ischemia reperfusion injury (RIRI) SIRP α Vascular smooth muscle cells Anti-SIRP α antibody; N/A; 1 μg/mL Blocked TSP1-mediated phosphorylation of both SIRP α and the downstream signal transducer SHP1; Decreased TSP1-stimulated O 2 ·– generation 155 Vascular smooth muscle cells SIRP α siRNA; N/A Decreased TSP1-stimulated O 2 ·– generation Endothelial-free arteries Anti-SIRP α antibody; clone C20; 1 μg/mL Decreased TSP1-mediated inhibition of NO-stimulated vasodilation Human renal tubular endothelial cell Anti-SIRP α antibody; clone C20; 1 μg/mL Blocked TSP1-mediated phosphorylation of SIRP α and SHP1 Mice with renal IRI i.p.; N/A; anti-SIRP α antibody; clone C20; 0.4 μg/g; 90 min before surgery Decreased subsequent O 2 ·– production; Restored kidney blood flow to near preischemic level after 24 h; Decreased oxidative stress and proinflammation cytokines and chemokines transcript expression ( CCL2 , CXCL2 , IL1b , and TNFa ); Decreased renal tubular injury, neutrophil infiltration, and serum urea and creatinine levels Renal interstitial fibrosis CD47 Mice suffered from unilateral ischemia reperfusion injury followed by contralateral nephrectomy i.p.; q.w.; anti-CD47 antibody; MIAP301; 0.8 μg/g; 3 weeks; a week following injury at the time of nephrectomy Improved histology and fibrosis; Downregulated the expression of TSP1, TGF- β , CTGF, α -SMA, and vimentin 156 Glomerulonephritis CD47 Anti-neutrophil cytoplasmic antibody-induced neutrophil extracellular trap (NET) neutrophils; Macrophages Anti-CD47 antibody; B6H12; 10 μg/mL; pretreated NET Increased the efferocytosis rate of NETs but not altered NET formation 161 Human umbilical vein endothelial cells (HUEhT); Macrophages Anti-CD47 antibody; B6H12; 10 μg/mL; pretreated HUEhT Promoted macrophages to engulf HUEhT SCG/Kj mice developed systemic necrotizing glomerulonephritis with anti-neutrophil cytoplasmic antibody production i.p.; q.5d.; anti-CD47 antibody; MIAP301; 200 μg; 2 weeks Decreased serum creatinine; Decreased kidney injury as glomerular score decreased from 2.8 ± 0.41 (IgG group) to 2.0 ± 0.63; Decreased the area of myeloperoxidase and citH3 double positive NETs in glomeruli; Bound to injured glomerular and not altered the infiltration of neutrophils, macrophages, and lymphocytes in the kidney Endometriosis CD47 Macrophages; ectopic endometrial stromal cells (ESCs) Anti-CD47 antibody; N/A; 2.5 μg/mL Increased engulfment by macrophages 163 Endometriosis CD47 The abdominal endometriosis model was established by injecting ESCs into the abdominal cavity Anti-CD47 antibody; N/A; 4 μg/mL; used to treat ESCs Increased the phagocytosis rate to ectopic ESCs and ectopic ESCs apoptosis 164 Ectopic ESCs; macrophage Anti-CD47 antibody; N/A; 4 μg/mL Increased phagocytosis rate to ectopic ESCs Heterotopic ossification CD47 Mice that underwent burn/tenotomy CD47-activating peptide (p7N3); N/A; 3 weeks Decreased cartilage formation and mature heterotopic ossification formation; Decreased levels of Tgfb1 in macrophages; Decreased the level of Arg1 and Mrc1; Increased iNos expression 169 Rheumatoid arthritis SIRP α K/BxN serum-induced arthritis model N/A; q.o.d.; agonistic anti-SIRP α antibody; clone 6F2; 250 μg/mice; 8 days; start one day before serum transfer Decreased clinical arthritis scores; Decreased synovial and intra-articular inflammation; Decreased articular cartilage erosion and bone remodeling; Decreased the number of neutrophils and inflammatory monocytes from joint synovial fluids; Increased the number of neutrophils and monocytes in the spleen 26 Collagen-induced arthritis model N/A; q.o.d.; agonistic anti-SIRP α antibody; clone 6F2; 250 μg/mice; 18 days; Day 21 post the first immunization Decreased joint swelling, edema, and erythema; Decreased in arthritis severity on histopathology Scleroderma CD47 Peritoneal macrophages from B6 mice; JUN inducible fibroblasts Anti-CD47 antibody; N/A; N/A Increased phagocytosis 175 Immunocompromised mice transplanted with primary mouse dermal fibroblasts under their kidney capsule Anti-CD47 antibody; N/A; N/A Decreased dermal fibroblasts Skins fibrosis induction mice model (i.d.; q.o.d.; doxycycline for 2 weeks) N/A; q.o.d.; anti-IL-6 antibody; 20 μg/kg; 2 weeks N/A; q.o.d.; anti-CD47 antibody; 500 μg/injection; 2 weeks Decreased the skin hydroxyproline content; Increased the fat area and reversed the skin to an almost normal state; Induced an only side-effect that anemic change in bone marrow Jun -induced mice N/A; q.o.d.; anti-CD47 antibody; first dosage was 100 μg, the other is 500 μg; 2 weeks i.p.; b.i.d.; Vismodegib (PD-L1 inhibitor); 30 mg/kg; 2 weeks Decreased the dermal number of CD3 + cells and Ki67 + cells; Decreased the agglomeration of macrophages Jun -induced mice N/A; q.o.d.; anti-CD47 antibody; first dosage was 100 μg, the other is 500 μg; 2 weeks N/A; q.o.d.; anti-IL-6 antibody; 20 μg/kg; 2 weeks Increased dermal fat tissue and fatty area; Decreased the dermal number of CD3 + cells and Ki67 + cells; Decreased the agglomeration of macrophages Pulmonary fibrosis CD47 Mice induced by bleomycin i.p.; q.o.d.; anti-CD47 antibody; MIAP410; 500 μg; 2 weeks i.p.; b.i.w.; anti-IL-6 antibody; clone MP5-20F3; 20 mg/kg; 2 weeks i.p.; q.d.; HAC protein; 250 μg; 2 weeks Decreased fibrosis in the lung 44 Mice induced by bleomycin i.p.; q.o.d.; anti-CD47 antibody; MIAP410; 500 μg; 2 weeks i.p.; q.d.; HAC protein; 250 μg; 2 weeks Decreased fibrosis in the lung Pulmonary fibrosis CD47 Mouse lung fibroblast Mlg cells CD47 inhibitor (RRx-001) Decreased TSP1 overexpression-induced upregulation of α -SMA and fibronectin protein expression; Decreased TSP1 overexpression-induced ROS and ER stress 23 Bleomycin-induced lung fibrosis i.p.; q.d.; RRx-001; 10 mg/kg; 2 weeks Decreased ROS production; Decreased bleomycin-induced upregulation of Grp78 and CHOP; Decreased collagen deposition and preserved pulmonary architecture; Decreased pulmonary levels of hydroxyproline, fibronectin, and α -SMA COVID pulmonary fibrosis CD47 IsI-rtTA Jun mice co-transduced with human ACE2 lentivirus and a SARS-CoV-2 pseudovirus (huACE2/S-protein) in the lung and induced JUN with doxycycline i.p.; b.i.w.; anti IL-6 antibody; clone MP5-20F3; 20 mg/kg; 4 weeks; after 13 days of huACE2/S-protein transduction i.p.; q.o.d.; anti-CD47 antibody; MIAP410; 500 μg; 4 weeks; after 13 days of huACE2/S-protein transduction Restored normal lung morphology; Decreased extracellular matrix/collagen deposition, fibrosis, activated fibroblasts 177 Humanized NOD-SCID- IL2Rg −/− mouse implanted with human lung and transduced with huACE2/S-protein i.p.; b.i.w.; anti-IL-6 antibody; clone MP5-20F3; 20 mg/kg; 4 weeks; after 13 days of huACE2/S-protein transduction i.p.; q.o.d.; anti-CD47 antibody; MIAP410; 500 μg; 4 weeks; after 13 days of huACE2/S-protein transduction Decreased neutrophils and macrophage infiltration, fibrosis-mediated interstitial expansion, and bronchiolization of alveoli Age-related macular degeneration CD47 Mice with laser injury Intravitreally; CD47-activating peptide PKHB1; 200 μmol/L; on Days 4 and 7 Accelerated subretinal mononuclear phagocyte elimination 13 Acute thioglycolate-induced peritonitis i.p.; CD47-activating peptide PKHB1; 500 μmol/L; on Day 1 Increased the elimination of recruited monocyte-derived inflammatory macrophages Malaria CD47 Human MDMs; RBCs infected by P. falciparum (Pf RBCs) SIRP α Fc; 10 μg/mL Increased uptake of ring-stage Pf RBCs 180 SIRP α Human MDMs; Pf RBCs Anti-SIRP α antibody; N/A; 20 μg/mL Increased uptake of ring-stage Pf RBCs Malaria CD47 RBCs from P.berghei ANKA ( Pb -A)-infected mice; Mouse macrophages Anti-CD47 antibody; MIAP410; N/A 4.7-Fold increased parasitized RBCs (pRBCs) phagocytosis; 182 P. falciparum -infected human RBCs; human macrophages Anti-CD47 antibody; Hu5F9G4; N/A 2.3-Fold increased pRBCs phagocytosis Mice infected by Pb -A develop symptoms that resemble the clinical features of human cerebral malaria (CM) i.p.; N/A; anti-CD47 antibody; MIAP410; 100 μg; N/A; initiated on 3 days post injection (dpi) 80% of mice did not develop experimental CM and survived from cerebral phase of infection while all mice in the control group developed experimental CM and succumbed on 6 to 9 dpi; Had intact meningeal architecture; Protected the blood–brain barrier from vascular leakage; Decreased CD8 + T cell migrating into brain tissue; CD8 + T cells in the brain produced less Granzyme B and IFN- γ Malaria CD47 Mice infected by Plasdmodium yoelii i.p.; N/A; anti-CD47 antibody; MIAP301; 100 μg/dose; on the day of GFP- Py NL infection Decreased parasite burden from 0.39 ± 0.05% (isotype) to 0.026 ± 0.008 on Day 3 postinfection 181 Influenza virus-mediated bacterial super-infection CD47 Influenza virus-infected human nasal epithelial cells and human bronchial epithelial cells infected by S. aureus Anti-CD47 antibody; B6H12.2; N/A Decreased paracellular permeability disruption and trans-epithelial electrical resistance; Decreased cytopathogenic effects of super-infection 184 Influenza virus-infected mice infected with S. aureus i.n.; twice in total; anti CD47 antibody; MIAP301; N/A; day 5 and 7 after viral infection (mice were infected by bacteria on Day 7) Decreased body weight loss and increased survival rates; Decreased signs of pneumonia and histological lung injury score; Decreased bacterial adherence and invasion in the lung; Decreased the level of TNF- α and IL-6 in bronchoalveolar lavage fluids Lymphocytic choriomeningitis virus infection CD47 Mice infected with lymphocytic choriomeningitis virus i.p.; q.d.; anti-CD47 antibody; MIAP410; 100 μg; 5 days; initiated at 2 dpi 27-fold reduction in kidney virus compared to mice in the control group at 10 dpi; Increased macrophage activation by 5 dpi and dendritic cell activation by 3 dpi; Increased the number of CD4 + and CD8 + T cells in the spleen by 3 dpi; Increased functional CD8 + T cells 186 Virus-induced myositis CD47 Mice inoculated i.p. with Theiler's murine encephalomyelitis virus i.p.; q.o.d.; anti-CD47 antibody; 100 μg; 9 days; initiated at 5 dpi Decreased clinical disease scores; Decreased calcification of skeletal muscle compared with controls 187 i.p., intraperitoneal; s.q., subcutaneous; i.n., intranasal; q.o.d., every other day; q.3d., every three weeks; t.i.w., three times a week; b.i.w., twice a week; q.2w., every 2 weeks; q.w., once a week; q.5d., every 5 days; q.d., every day. a In vivo assay: administration method; frequency; treatment; (clone of antibody) dosage; duration; others. In vitro assay: treatment; (clone of antibody) dosage; others. Figure 4 The effects of CD47-based therapies on regulating phagocytosis. CD47-based therapies enhanced the ability of macrophages to remove diseased or redundant cells in pathological tissues. On the contrary, CD47 decorated on cells, nanoparticles, extracellular vesicles, and exosomes was beneficial for evading phagocytosis to achieve better therapeutic efficacy. aCD47 Ab, anti-CD47 antibody; SIRP α , signal regulatory protein alpha; aSIRP α Ab, anti-SIRP α antibody; ASOs@CaP-aSIRP α , anti-SIRP α antibody-modified, anti-sense oligonucleotides-loaded calcium phosphate nanoparticles; aCD47@PMSN, anti-CD47 antibody loaded platelet membrane coated mesoporous silicon nanoparticles; aRLP, senescent RBC-mimetic liposomes decorated with an anti-Ly6G antibody; CAR M, chimeric antigen receptor macrophage; CD47 ASO, antisense oligonucleotide targeting CD47; DNPC-aCD47, anti-CD47 antibody-conjugating polydopamine nanoparticles loaded with CY-09; ESC, endometrial stromal cell; MG, microglia; Mø, macrophage; NPC, neural progenitor cell; OPC, oligodendrocyte progenitor cell; RBC, red blood cell; SHP1i, a SHP1 inhibitor; MM@Lips-SHP1i, macrophage membrane-coated SHP1i-liposome nanoparticles; MAC CCR2+MERTK CR -Lipo PEP−20 , C–C chemokine receptor type2 and cleavage-resistant MerTK overexpressed macrophages anchoring liposomes loaded with PEP-20; SIRP α -v Exos, modified exosomal SIRP α variants; SWNT-SHP1i, single-walled carbon nanotubes loaded with a SHP1 inhibitor; S α V-NVs, hybrid nanovesicles, which contain cell-derived nano vesicles overexpressing high-affinity SIRP α variants; TNF- α i, TNF- α inhibitor. Figure 4 Pre-clinical studies of CD47-based therapy in diseases other than those of the circulatory and nervous system. i.p., intraperitoneal; s.q., subcutaneous; i.n., intranasal; q.o.d., every other day; q.3d., every three weeks; t.i.w., three times a week; b.i.w., twice a week; q.2w., every 2 weeks; q.w., once a week; q.5d., every 5 days; q.d., every day. In vivo assay: administration method; frequency; treatment; (clone of antibody) dosage; duration; others. In vitro assay: treatment; (clone of antibody) dosage; others. The effects of CD47-based therapies on regulating phagocytosis. CD47-based therapies enhanced the ability of macrophages to remove diseased or redundant cells in pathological tissues. On the contrary, CD47 decorated on cells, nanoparticles, extracellular vesicles, and exosomes was beneficial for evading phagocytosis to achieve better therapeutic efficacy. aCD47 Ab, anti-CD47 antibody; SIRP α , signal regulatory protein alpha; aSIRP α Ab, anti-SIRP α antibody; ASOs@CaP-aSIRP α , anti-SIRP α antibody-modified, anti-sense oligonucleotides-loaded calcium phosphate nanoparticles; aCD47@PMSN, anti-CD47 antibody loaded platelet membrane coated mesoporous silicon nanoparticles; aRLP, senescent RBC-mimetic liposomes decorated with an anti-Ly6G antibody; CAR M, chimeric antigen receptor macrophage; CD47 ASO, antisense oligonucleotide targeting CD47; DNPC-aCD47, anti-CD47 antibody-conjugating polydopamine nanoparticles loaded with CY-09; ESC, endometrial stromal cell; MG, microglia; Mø, macrophage; NPC, neural progenitor cell; OPC, oligodendrocyte progenitor cell; RBC, red blood cell; SHP1i, a SHP1 inhibitor; MM@Lips-SHP1i, macrophage membrane-coated SHP1i-liposome nanoparticles; MAC CCR2+MERTK CR -Lipo PEP−20 , C–C chemokine receptor type2 and cleavage-resistant MerTK overexpressed macrophages anchoring liposomes loaded with PEP-20; SIRP α -v Exos, modified exosomal SIRP α variants; SWNT-SHP1i, single-walled carbon nanotubes loaded with a SHP1 inhibitor; S α V-NVs, hybrid nanovesicles, which contain cell-derived nano vesicles overexpressing high-affinity SIRP α variants; TNF- α i, TNF- α inhibitor.

Wei-Qing Deng: Writing – review & editing, Writing – original draft, Data curation, Conceptualization. Zi-Han Ye: Writing – review & editing, Writing – original draft. Zhenghai Tang: Writing- review & editing. Xiao-Lei Zhang: Writing – review & editing. Jin-Jian Lu: Writing – review & editing, Supervision, Project administration, Funding acquisition, Data curation, Conceptualization.

Pulmonary fibrosis is a lung ailment characterized by lung destruction and scarring 176 . From the data obtained from clinical samples, over 20% of pulmonary fibrosis cells expressed CD47 44 . More importantly, CD47 inhibitor, RRx-001, preserved pulmonary architecture and reduced collagen deposition in bleomycin-induced pulmonary fibrosis mice model 23 . As there is a subset of pulmonary fibrosis cells co-expressed CD47 and PD-L1, it is conceivable that treatment containing aCD47 Ab, aPD-L1 antibody, and anti-IL-6 antibody displayed the most superior effect on pulmonary fibrosis compared to other combinations. The therapeutic effect of aCD47 Ab was supported by CT scan results and other indexes like decreased PD-L1 + CD47 + fibroblasts and a lower level of collagen 44 . These observations are in agreement with a study focusing on coronavirus disease 2019 (COVID-19) lung fibrosis. The aCD47 Ab in combination with anti-IL-6 antibody ameliorated the severe immune infiltration and fibrotic expansion in humanized mice with COVID lung fibrosis, suggesting the promising applicability of CD47-based therapies in pulmonary fibrosis including that in response to COVID-19 infection 177 .

The authors declare no conflicts of interest.

Diabetes is characterized by insulin absolute lack caused by islet β cell injury or inadequate insulin of dysfunctional β cell 145 . Streptozotocin-induced diabetic mice have less CD47 in their islets 146 . However, emerging evidence suggested that CD47 was downregulated in islets of patients with type 1 diabetes endotypes 2, and reversely upregulated in β cells of patients with type 1 diabetes endotypes 1 147 . Though the level of CD47 in diabetic islets is still uncertain, it was observed that CD47 had a bias in expression against β cells. It was further reported that the islet's CD47 level increased during the transition from nondiabetic to diabetic in nonobese diabetic mice 42 . CD47 signaling may be responsible for insulin secretion. si-CD47 and morpholino targeting CD47 effectively induced the secretion of insulin in murine islets and human islets stimulated by glucose, respectively. Granules docking and exocytosis were enhanced in CD47-deficient β cells. It was proposed that CD47 may modulate insulin secretion via regulating the docking and exostosis of granules in a Cdc42-dependent pathway 42 . CD47 targeting agents may delay the onset of diabetes by elevating insulin secretion. The aCD47 Ab delayed the initiation of hyperglycemia in mice for 3–5 weeks, and may further postpone when tripled the dosage 42 . Moreover, 80% of euglycemic nonobese diabetic mice in the isotype group were diagnosed with diabetes after 4 weeks, while only half of the mice in the aCD47 Ab group developed into diabetes 42 . The therapeutic efficacy of aCD47 Ab in diagnosed type 1/2 diabetes patients is still largely unknown. According to the regulatory role of CD47 in insulin secretion, aCD47 Ab or other CD47-based therapy may be beneficial to type 2 diabetes patients. After conventional therapeutic approaches fail, transplantation of allogeneic islets will be the ultimate therapeutic modality for patients with diabetes 148 , 149 . However immunological rejection restricts its broad applicability. Nevertheless, CD47 overexpression-endowed hypoimmune HLA class I- and class II-deficient pseudoislets have the capability of escaping innate and adaptive immune attack 31 , 150 , 151 . These transgenetic pseudoislets successfully survived in humanized mice for 30 days and in rhesus monkeys for 40 weeks 31 , 150 . In addition to controlling glucose levels in humanized mice with diabetes within 2 weeks, a most recent study demonstrated that this transgenetic psedoislet achieved curative diabetic treatment in cynomolgus monkeys without immunosuppression medication 151 . Concomitantly, aCD47 Ab could accelerate the clearance of pseudoislets when necessary, suggesting the safety of transplantation 31 . Obesity is a multi-caused disease, which leads to a series of comorbidity, like cardiovascular disease, diabetes, and heart failure 152 , 153 . Early observations in Cd47 −/− mice demonstrated that CD47 deletion protected mice from HFD-induced-obesity by decreasing inflammation and enhancing fat utilization 154 . Not only did CD47 regulate the progression of obesity, but also CD47 was recently considered to be a potential target for obesity. An antisense oligonucleotide targeting CD47 (CD47 ASO) was proven to effectively knock down CD47 in metabolic tissues, including liver, muscle, and fat tissue. CD47 ASO inhibited body weight increase both in HFD-induced obesity mice and genetically-engineered obesity mice 24 . In epidydimal white fat tissue of HFD-induced-obesity mice, CD47 ASO decreased the size of lipid cells and increased fat degradation-related genes, suggesting that CD47 ASO enhanced lipid degradation. In addition, CD47 ASO seems to boost the exercise motivation of mice 24 .

More and more studies have emphasized the property of CD47 and its binding partners in non-cancer disease progression. For instance, the plaque area and neointima area were smaller in Cd47 −/− mice induced by western diet 76 . CD47 deficiency seems to protect mice from EAU 188 . Mice injected by blood from Cd47 −/− mice rather than WT mice tended to have slighter brain swelling and less neurological deficits 102 . Inhibition of CD47 and/or its binding partners may therefore be beneficial in non-cancer diseases. To uncover the wider applicability of CD47-based therapy, we summarized the applications of CD47-related agents in non-cancer diseases in this decade ( Fig. 1 ). In addition to conventional agents like anti-CD47 antibody and anti-SIRP α antibody, some novel agents like CD47 fusion protein, ASO targeting CD47, SIRP α -activating peptide, were utilized in these studies as well. The beneficial effects of aCD47 Ab on cardiovascular diseases were widely reported. aCD47 Ab was found to accelerate the clearance of atherosclerosis plaque and brain hematoma 41 , 43 , 102 . The property of CD47-related agents in treating metabolic disorder diseases was also mentioned. The secretion of insulin was induced by aCD47 Ab in islet β cells. The aCD47 Ab decreased the incidence of diabetes in nonobese diabetic mice 42 . Conversely, HO and AMD were alleviated by CD47-activating peptide 13 , 169 . Similarly, the SIRP α -activating peptide mitigated the symptoms in mice with UC and RA 26 . More detailed information about the applications of CD47-related agents has been summarized in Figure 1 , Figure 2 , Figure 3 , Figure 4 and Table 1 , Table 2 , Table 3 . Among non-cancer diseases, atherosclerosis is one of the most high-profile diseases with the most pre-clinical studies and clinical trials ( Fig. 2 and Table 1 ). CD47-based agents may have broad applicability to different stages of atherosclerosis. BRB-002, a kind of aCD47 Ab, was reported to exert a preventative role towards atherosclerosis in mice with HFD induction 54 . After the formation of plaques, CD47 was served as a biomarker and target 41 . A CD47-targeting nanoparticle identified the plaque in a very early stage 75 . aCD47 Ab, aSIRP α Ab, and SHP1i reduced the plaque area by stimulating the process of efferocytosis 59 , 62 , 63 . And combination therapy could further enhance their therapeutic efficacy. Apart from enhancing dying cells removal, CD47-based therapy may also reduce vessel inflammation to achieve preventative and curative effects on atherosclerosis. SWNT-SHP1i reduced aortic 18 F-FDG uptake in mice 59 . In a phase Ib/II clinical trial, it was found that patients treated with aCD47 Ab magrolimab had lower arterial uptake of 18 F-FDG, as maximum standardized uptake values decreased from 2.68 ± 0.59 to 2.06 ± 0.52, suggesting inflammation in arteria was ameliorated 189 . It was proposed that magrolimab or SWNT-SHP1i may relieve vascular inflammation which is a core risk factor towards atherosclerosis to narrow plaques. Even though, aCD47 Ab may have inverse effects on atherosclerosis with JAK2 V617F ( JAK2 VF ) mutation 190 . RBCs from Jak2 VF mice had a lower CD47 level, while RBCs from humans with JAK2 VF mutation had a higher level of calreticulin 190 , 191 . Macrophages preferred to swallow mutant RBCs rather than apoptotic cells within plaques in Jak2 VF mice with atherosclerosis 191 . aCD47 Ab may further enhance the clearance of RBCs rather than plaques in Jak2 VF mice 190 . Stroke is another promising indication of CD47-related agents ( Fig. 3 and Table 1 ). The investigations on the role of CD47 in stroke date back to ten years ago. Researchers have estimated the benefits of targeting CD47 therapy in treating stroke by different animal models, including mice, rats, and piglets 103 , 104 , 107 , 108 , 109 . Three subtypes of stroke, ICH, IVH, and SAH could all be alleviated by CD47-related therapy. No matter aCD47 Ab or exosomal SIRP α variant exerted potential clinical efficacy towards ICH 103 , 104 , 107 , 108 , 109 . In a more recent study, researchers further confirmed the association between the TSP1–CD47 axis and SAH by single-cell RNA sequencing and spatial transcriptomics 43 . Targeting CD47 therapy, especially aCD47 Ab, is believed to lead stroke-induced hematoma to fade via regulating the capacity of macrophages and microglia or protecting the function of mLVs in the present studies 43 , 103 , 105 , 107 . Generally, exogenous macromolecules including antibodies rarely penetrate BBB 192 , 193 . It may be a potential explanation as to why aCD47 Ab was delivered across BBB by invasive technology in preclinical studies. Researchers will premix blood with aCD47 Ab to inject into animals’ brains to construct a model together with drug administration 103 , 104 , 106 , 107 , 109 . In addition, aCD47 Ab could be invasively administrated by direct cisterna magna injection 105 . However, it is reported that the integrity of BBB is impaired following stroke 194 , making it possible to deliver antibodies by systemic administration. Then, it may raise concern that aCD47 Ab leakage caused by systematic administration or impaired BBB may facilitate the removal of RBCs around the body rather than only enhancing the clearage of brain hematoma. Additionally, considering the upregulation of CD47 on neurons, oligodendrocytes, microglia, and macrophages, one would imagine potent side effects of antibody blocking CD47 195 . Fortunately, aCD47 Ab is generally given once a time when treating stroke in studies 104 , 105 . Apart from the two potential indications mentioned above, fibrotic disease is another promising candidate. aCD47 Ab was able to ameliorate pulmonary fibrosis and scleroderma 23 , 44 , 175 . Moreover, both aCD47 Ab and aSIRP α Ab decreased liver fibrosis in mice with NASH 25 . It is worth mentioning that potent non-cancer indications in recent clinical trials partially matched with pre-clinical studies. By far, there have been three CD47-based therapy are approved for clinical trials of non-cancer diseases. The first one is sB24M, a CD47/TNF- α antibody. Researchers speculated that sB24M may facilitate impaired tissue epithelialization via the CD47/TNF- α axis. A clinical trial of sB24M for purulent pyoderma has been completed ( NCT04895566 ). Secondly, it is BRB-002, an aCD47 Ab comprising of CD47 binding region and inactive Fc domain. BRB-002 presented both preventative and therapeutic efficacy in animal atherosclerosis model 54 . It is undergoing phase I clinal trial being in charge by Bitterroot Bio (ACTRN12624000405516). The last one is IMC-002 (CD47 × CD20 mAb-Trap). IMC-002 was designed to target both CD47 and CD20. IMC-002 was pronounced to exert a great effect on inducing B cell exhaustion without inducing severe side effects in a phase I clinical trial for lymphoma 196 . B cell elimination therapy was reported to achieve durable autoimmune disease remission 197 . The applications of IMC-002 clinical trials for B cell-associated autoimmune diseases including systemic lupus erythematosus (CTR20242914) and neuromyelitis optica spectrum disorders (CTR20243045) were therefore applied and have been approved by the National Medical Products Administration this year 173 , 196 . At this point, despite extensive effort, we do not have access to study the unpublic results of these clinical trials. But it is certain that preclinical studies did encourage the researchers to be confident about launching clinical trials and contribute to the evaluation of CD47-based therapeutic strategies for non-cancer diseases. Simultaneously, new clinical studies in more non-cancer diseases are needed to be done to confirm the action of CD47-based treatments. Meanwhile, understanding the potential side effects of CD47-based therapies in non-cancer diseases is an essential step. Drawing lessons from clinical trials of cancer, drug-induced anemia probably retarded the development of CD47-based agents 34 . CD47 on healthy RBCs functions as a “bell” to remind macrophages not to engulf. Once CD47 is blocked, RBCs will be rapidly eliminated by macrophages and natural killer cells, due to CD47–SIRP α axis blockage and Fc/Fc γ R interaction 32 , 198 . In recent years, investigations of reducing the toxicity of CD47-based agents have increased tremendously. These studies have shown that therapeutic modalities, such as selective antibody 36 , SIRP α fusion protein 22 , and bispecific fusion protein 39 are reasonable to reduce side effects in clinical trials. Concomitantly, strategies used in preclinical studies may be beneficial for reducing the rate of side effects. For example, BRB-002, aCD47 Ab used in atherosclerosis studies, was endowed with inactive Fc fragment which restricts Fc/Fc γ R interaction 54 . Besides, low-dose aCD47 Ab was used in diabetes studies 42 . Orthotopic drug delivery and nanomaterial targeting drugs may also contribute to the increased safety of CD47-based therapies 63 , 105 . After clarifying promising non-cancer indications of CD47-based therapy, a deeper comprehension of the mechanisms of CD47-related agents on non-cancer diseases is worthwhile. Increasing evidence in pre-clinical studies brings it to light. There are three major mechanisms. Firstly, CD47-based therapy promotes the phagocytotic capacity of macrophages and other phagocytes. Phagocytosis of apoptotic cells was amplified. Both aCD47 Ab and SHP1i promoted efferocytosis of apoptotic cells containing atherosclerotic plaques, and that decreased the volume of plaques and the necrotic area 41 , 59 . Concomitantly, the uptake of necrotic hepatocytes was enhanced by blockade of CD47 or SIRP α 25 . In addition to dying cells, CD47-related agents drove phagocytic cells to internalize oligodendrocyte progenitor cells and neural progenitor cells with 16p11.2 deletion, fibroblasts, and RBCs in brain hematoma, and so on 103 , 175 , 199 . Notably, aCD47 Ab may not elicit its role in malaria depending on enhancing phagocytosis as usual 182 . It was speculated that CD47 blockade may promote the engulfment of myelin fraction, and that disturbs the recovery of MS 121 . By contrast, nanoparticles, extracellular vesicles, and exosomes will be modified with CD47 to achieve immune evasion as cancer cells did 28 , 29 , 30 . CD47 overexpression pseudoislets failed to elicit an innate and adaptive immune response, ultimately surviving in recipient 31 , 150 , 151 . Moreover, mutant CD47 expressed on cells may present fewer adverse effects than wild-type ones, as evidenced by hematopoietic stem cell function and endothelial cell angiogenesis were reported to not be affected by membrane-expressed mutant CD47 200 ( Fig. 4 ). Secondly, CD47-based therapy influenced other immune cells besides macrophages. CD47-based therapy decreased the infiltration of neutrophils in focus of non-cancer diseases, like RA and NASH 25 , 26 . In LCMV infecting mice, it was observed that aCD47 Ab activated dendritic cells and CD8 + T cells 186 . Thirdly, the secretion of cytokines and chemokines was also influenced by CD47-related agents. For instance, CD47 fusion protein and aCD47 Ab downregulated the level of inflammatory cytokines in Crohn disease and autoimmune valvular carditis, respectively 73 , 143 . Similarly, CD47-activating peptide p7N3 may relieve HO via inhibiting macrophage-secreting TGF- β 1 169 . However, whether the effects of CD47-based therapy on other immune cells and the regulation of cytokines are residue effects of phagocytosis is uncertain. Notably, the property of CD47-based therapy on regulating the CD47–TSP1 axis may be associated with its capacity in some non-cancer diseases as well. TSP1 was reported to increase the level of ROS and superoxide production in arterioles, subsequently promoting PH 70 , 84 . Moreover, overexpression of TSP1 may lead to pulmonary fibrosis through increasing ROS production and inducing endoplasmic reticulum stress 23 . Blocking CD47 by antibody improved TSP1-inhibited vasodilation in PH 69 . TSP1-induced HDAC3 upregulation was correlated with LVHF. Profoundly, aCD47 Ab abrogated the effect of TSP1 in LVHF 72 . There may be direct interaction between CD47 and TSP1. CD47-activating peptide was used to rectify TSP1–CD47 interaction to relieve AMD 13 . Disrupting TSP1–CD47 interaction may be meaningful during SAH 43 . TSP1 which is highly expressed in platelet α -granules also plays an important role in thrombus formation 201 . TAX2 is a peptide targeting TSP1. Moreover, the peptide binds TSP1 at CD47-binding site 202 . TAX2 peptide suppressed human blood platelet aggregation induced by ADP and collagen by 28 ± 8.7% and 36.8 ± 6.9% compared to scrambled peptide, respectively. The process of vascular occlusion was delayed in arterioles from FeCl 3 -induced mice treated with TAX2 peptide, meanwhile, this peptide did not influence tail bleeding time 203 . Recent advances have shown that CD47-based agents ameliorated defective phagocytosis to remove diseased cells and cell debris, regulating T cells, dendritic cells, and neutrophils, and regulating the secretion of cytokines and chemokines, whilst preventing and/or treating non-cancer diseases. Yet there are some lurking suspicions. For example, the residual effects of phagocytosis could be harmful. Toxic products would be released during polymorphonuclear leukocyte and eosinophils degranulating after phagocytic contact and uptake 204 . Besides, overactivated macrophages may engulf illegitimate targets, whilst causing excessive injuries on the surrounding healthy but fragile cells and reversely deteriorating diseases 205 , 206 , 207 . Moreover, epithelial CD47 may facilitate rather than suppress intestine mucosal repair 208 . Whereas, more basic research on the underlying mechanisms and more clinical trials on the therapeutic efficacy regarding to CD47-related agents are pivotal. The gap could be filled in the following four aspects: agents’ selection, drug administration, biological function, and indication. First, select the right agents. Most studies emphasized the therapeutic effect of aCD47 Ab, while CD47-activating peptide may have more important applications for age-related macular degeneration and heterotopic ossification 13 , 169 . Besides, agonistic aSIRP α Ab had a plethora of beneficial and irreplaceable effects as a treatment in autoimmune diseases 26 . Nonetheless, most of the studies paid attention to one or two CD47-related agents. The differences in therapeutic efficacy, side-effects, and detailed mechanisms among different CD47-related modalities remain largely obscure. In terms of the structure of antibodies, the role of the Fc domain of antibodies won considerable attention. Emerging data from the study on cancer demonstrated that aCD47 Ab elicits anti-cancer activities relying on its Fc part, through interacting with Fc receptors on macrophages 209 . Concomitantly, an active Fc domain is required in aSIRP α Ab-driving immune migration. Further study to clarify the role of the Fc domain of antibodies in treating non-cancer diseases is also needed 26 . It is also necessary to select CD47-based agents according to the different binding modes of CD47 in diverse pathological situations. In most instances, trans interaction between CD47 (on diseased cells) and SIRP α (on macrophage) is implicated as a major mechanism that suppresses phagocytosis. However, cis interaction between CD47 (on macrophage) and SIRP α (on macrophage) was reported 210 . And most recent study provided evidence that CD47 is capable of inhibiting phagocytosis in a SIRP α -independent manner. CD47 (on tumor cell) cis interacts with SLAMF7 (on tumor cell) to interrupt the trans interaction between SLAMF7 on tumor cell and SLAMF7 on the macrophage, thereby instigating the inhibition of phagocytosis 211 . Second, adjust drug administration. CD47-based agents were intraperitoneally administrated in most studies. Complicate approaches of administration, like orthotopic injection and target-specific drug delivery systems, were also utilized. It may be necessary to consider efficacy, convenience, and clinical transformation difficulty when selecting a drug delivery method. The dosage of agents is another significant factor. In a murine ICH study, they identified that a medium dosage of aCD47 Ab exerted the best effect, while a low dosage had limited effect and a high dosage may induce cell apoptosis 105 . In addition, researchers constructed the ICH model together with antibody treatment in an overwhelming majority of studies 103 . And the expression of CD47 in hematoma decreased with time. These evidenced suggested the necessity of selecting the optional time for treatment 98 . Besides, it is worth mentioning that combination therapy enhanced the therapeutic efficacy of aCD47 Ab in atherosclerosis, scleroderma, and myocardial infarction, as in cancer. For instance, TNF- α inhibitors and NLRP3 inhibitors enhanced the therapeutic effectiveness of aCD47 Ab in atherosclerosis 41 , 63 . Third, investigate the role of CD47 and its binding partners in other normal cells, except for diseased cells. CD47 also expresses on macrophages. It was found that expression of CD47 in M1-like macrophages may be a potential explanation as to why some macrophages in atherosclerosis plaques lost their opsonin-sensing ability. CD47-deficient BMDMs polarized into the M1-state may have a higher phagocytic rate of latex beads than the control. It hints the critical role of CD47 in macrophages 58 . Besides, recent studies have implicated the roles of CD47 blockade in suppressing T cell transmigration and LTB4-indued-bone marrow-derived neutrophils migration 137 . And TSP1–CD47 axis was reported to suppress IFN- γ production in NK cells by activating the JAK–STAT pathway 212 . Further studies are needed to answer the question of whether CD47 has a direct role in other cells, especially immune cells. Fourth, further enrich the applicability of CD47-based therapy. CD47-based agents may have important applications for postponing cell senescence. Emerging data from studies highlighted the critical effect of the CD47/TSP1 axis on senescence. TSP1 was reported to mediate senescence in endothelial cells by regulating CD47 213 . Meanwhile, senescent cells are likely to evade removal via CD47–QPCT/L axis 214 . Accordingly, it was demonstrated that TSP1 blockade activated aged muscle cells and restored muscle strength in vivo 215 . Along with cell senescence, the effect of CD47-based therapy on neural diseases cannot be underestimated. In the hippocampus of Alzheimer's disease patients, upregulated CD47 protein was found to co-localize with PHF-tau protein 216 . Similarly, CD47 mRNA was elevated in the hippocampus in mice with schizophrenia 217 . Based on the aberrantly higher level of CD47 and its binding partners, attenuating CD47 expression may be a potential therapeutic strategy for cell senescence-associated diseases and various nervous system disorders. Some immune diseases, like lethal inflammation that occurred in Ptpn6 spin mice and autoimmune uveitis, were mild in the corresponding animal model with CD47 deficiency 218 . The therapeutic effect of CD47-related agents on these immune diseases warrants further investigation. Nevertheless, CD47 was downregulated in focal cortical dysplasia type IIb tissue, hippocampus of patients with perioperative neurocognitive disorders, and tuberous sclerosis complex tissue 219 , 220 . Activating agents rather than inhibitors may reversely relieve these illnesses.

In this review, we summed up CD47-based therapies in treating non-cancer diseases and highlighted atherosclerosis and stroke as two remarkable candidate indications. The efficacy of CD47-based therapy in relieving these non-neoplastic diseases may be attributed to regulating the immune system and adjusting the biological roles of CD47. However, further work will now be necessary to compare the therapeutic efficacy among different CD47-based therapies and to figure out suitable drug administration. It is also worthwhile devoting much effort to exploring the role of CD47 and its binding partners in cells except for diseased cells and more potent indications of CD47-based therapy.

CD47, a 50-kDa protein, is a ubiquitously expressed transmembrane glycoprotein 1 , 2 . CD47 is originally termed an integrin-associated protein, owing to an interaction between integrin and CD47 3 . CD47 was reported to regulate phagocytosis, cell death, and cancer cell spreading when interacting with Integrin α v β 3 4 , 5 . Besides integrin, signal regulatory protein alpha (SIRP α ) is another famous binding partner of CD47. Binding with CD47 stimulated aggregation of SIRP α at the phagocytotic synapse of macrophages, which phosphor-activate the immunoreceptor tyrosine-based inhibitory motif of SIRP α and later recruit tyrosine phosphatases, like Src homology region 2 domain-containing phosphatase 1 or 2 (SHP1/2), with subsequent downstream regulation, inhibits macrophage phagocytosis 6 , 7 , 8 , 9 . In addition to binding with SIRP α , CD47 is reported to interact with a typical member of the thrombospondin family of glycoprotein extracellular matrix protein thrombospondin 1 (TSP1), whilst taking part in regulating platelet aggregation, blood flow, angiogenesis, inflammation, and so on 10 , 11 , 12 , 13 . CD47 is well-known as a ‘don't eat me’ signal, especially in cancer. CD47 is highly expressed in extensive tumors, suggesting that a wide range of cancers adopt it to achieve immune escape 14 , 15 , 16 , 17 . Therefore, CD47-based agents were explored as anti-cancer modalities 18 , 19 , 20 , 21 . CD47-based therapies encompass a spectrum of agents targeting factors involved in the CD47–SIRP α axis, as well as CD47-decorated subjects. Concretely, targeting CD47 modalities includes anti-CD47 antibody (aCD47 Ab), SIRP α fusion protein 22 , CD47 inhibitor 23 , CD47-activating peptide 13 , antisense oligonucleotide targeting CD47 24 , and so on. Likewise, agents targeting other participants of the CD47–SIRP α axis, such as anti-SIRP α antibody (aSIRP α Ab) 25 , agonistic aSIRP α Ab 26 , and SHP1 inhibitor (SHP1i) 27 , were also referred to as CD47-based therapies. Simultaneously, CD47-decorated nanoparticles 28 , exosomes 29 , extracellular vesicles 30 , and cells 31 are implicated as a subtype of CD47-based agents. In addition to monotherapy, therapy combining CD47-based agents and other therapeutic modalities was incorporated into our discussion. Despite growing interest in developing CD47-based therapy, clinical translation of aCD47 Ab remains hindered by side effects, especially hematotoxicity and limited efficacy of monotherapy 19 , 20 , 32 , 33 , 34 , 35 . Researchers have made extensive efforts to cope with this threat, albeit with a few twists and turns. To mitigate the adverse effect of aCD47 Ab, TJ011133 with negligible binding to red blood cells (RBCs) was screened out 36 . Besides, a SIRP α fusion protein IMM01 was developed with restricted erythrocyte conjugation 22 . Preliminary results showed that IMM01 led to a 65.6% objective response rate in classic Hodgkin lymphoma patients ( n  = 32) 37 . Phase IIII trials of IMM01 in classic Hodgkin lymphoma are ongoing ( NCT06465446 and CTR20241938). IMM0306, a fusion protein of aCD20 Ab with CD47 binding domain, was also reported to rarely bind to RBCs 38 . As of November 21, 2023, the objective response rate was 30.3% ( n  = 33) in phase I study of IMM0306 in relapsed or refractory CD20-positive B-cell non-Hodgkin lymphoma patients ( NCT05805943 ) 39 . Distinguishing from the conventional application, a recent study proposed that aCD47 Ab could be developed into a safety switch removing chimeric antigen receptor (CAR) T-cells when necessary, hinting that there is a lot of overlooked possibility in the era 40 . Recently, the therapeutic effects of CD47-based agents were highlighted in studies focusing on non-cancer diseases 13 , 41 , 42 , 43 ( Fig. 1 ). The viewpoint from non-cancer diseases may pave a new way to optimally exploit the immune checkpoint CD47 as a target in human diseases. Apart from cancers, abnormalities of CD47 and its binding partners were commonly observed across non-tumor excrescence, inflamed tissue, dysfunctional organs, and other diseased regions 41 , 44 . High levels of CD47 were detected in benign lesions including atherosclerosis plaque and ectopic endometrium 41 , 45 . Inflamed tissue like human non-alcoholic steatohepatitis (NASH) liver also had abundant expression of CD47 on necrotic liver cells 25 . Variation of CD47 level between normal and diseased states highlights the probability for CD47-based therapy in treating non-cancer diseases. Indeed, there is an increasing number of studies probing the therapeutic effect of CD47-based therapy. There is a clinical trial exploring the application of the CD47/TNF- α antibody sB24M in purulent pyoderma patients ( NCT04895566 ). Figure 1 The potential applications of CD47-based therapy. The increasing number of pre-clinical studies highlight the effect of different CD47-based therapies in treating non-cancer diseases. aCD47 Ab, anti-CD47 antibody; SIRP α , signal regulatory protein alpha; aSIRP α Ab, anti-SIRP α antibody; ASOs@CaP-aSIRP α , anti-SIRP α antibody-modified, anti-sense oligonucleotides-loaded calcium phosphate nanoparticles; aCD47@PMSN, anti-CD47 antibody loaded platelet membrane coated mesoporous silicon nanoparticles; aRLP, senescent RBC-mimetic liposomes decorated with an anti-Ly6G antibody; CAR M, chimeric antigen receptor macrophage; CD47 ASO, antisense oligonucleotide targeting CD47; DNPC-aCD47, anti-CD47 antibody-conjugating polydopamine nanoparticles loaded with CY-09; SHP1i, a SHP1 inhibitor; MM@Lips-SHP1i, macrophage membrane-coated SHP1i-liposome nanoparticles; MAC CCR2+MERTK CR -Lipo PEP−20 , C–C chemokine receptor type2 and cleavage-resistant MerTK overexpressed macrophages anchoring liposomes loaded with PEP-20; SIRP α -v Exos, modified exosomal SIRP α variants; SWNT-SHP1i, single-walled carbon nanotubes loaded with a SHP1 inhibitor; S α V-NVs, hybrid nanovesicles, which contain cell-derived nano vesicles overexpressing high-affinity SIRP α variants; TNF- α i, TNF- α inhibitor. Figure 1 The potential applications of CD47-based therapy. The increasing number of pre-clinical studies highlight the effect of different CD47-based therapies in treating non-cancer diseases. aCD47 Ab, anti-CD47 antibody; SIRP α , signal regulatory protein alpha; aSIRP α Ab, anti-SIRP α antibody; ASOs@CaP-aSIRP α , anti-SIRP α antibody-modified, anti-sense oligonucleotides-loaded calcium phosphate nanoparticles; aCD47@PMSN, anti-CD47 antibody loaded platelet membrane coated mesoporous silicon nanoparticles; aRLP, senescent RBC-mimetic liposomes decorated with an anti-Ly6G antibody; CAR M, chimeric antigen receptor macrophage; CD47 ASO, antisense oligonucleotide targeting CD47; DNPC-aCD47, anti-CD47 antibody-conjugating polydopamine nanoparticles loaded with CY-09; SHP1i, a SHP1 inhibitor; MM@Lips-SHP1i, macrophage membrane-coated SHP1i-liposome nanoparticles; MAC CCR2+MERTK CR -Lipo PEP−20 , C–C chemokine receptor type2 and cleavage-resistant MerTK overexpressed macrophages anchoring liposomes loaded with PEP-20; SIRP α -v Exos, modified exosomal SIRP α variants; SWNT-SHP1i, single-walled carbon nanotubes loaded with a SHP1 inhibitor; S α V-NVs, hybrid nanovesicles, which contain cell-derived nano vesicles overexpressing high-affinity SIRP α variants; TNF- α i, TNF- α inhibitor. To comprehensively understand the feasible contributions of CD47-based therapy in human diseases, we summarize the promising applications of CD47-based agents in non-cancer diseases, especially the usage of targeting CD47 agents. Related papers published between 2013 and 2024 were screened through ( n  = 2168). Excluding cancer studies which took the highest proportion, there remained 544 papers of which only 50% focus on CD47-based therapy application. The studies ultimately involved in the discussion were screened based on eligibility, reliability, and representativeness of the literature. Referred to the International Classification of Diseases 11th revision, the main text was divided into 9 sections 46 . The sections and the content in each section were arranged in descending order of importance. Afterward, we conclude the major underlying mechanisms of CD47-based agents affecting non-cancerous disease progression. Perspectives were also presented here in terms of four aspects: agents’ selection, drug administration, biological function, and indications.