Host Factor PLAC8 is Required for Pancreas Infection by SARS-CoV-2

Background: Although COVID-19 initially caused great concern about respiratory symptoms, mounting evidence shows that also the pancreas is productively infected by SARS-CoV-2. However, the severity of pancreatic SARS-CoV-2 infection and its pathophysiology are still under debate. Here we investigated the consequences of SARS-CoV-2 pancreatic infection and the role of the host factor Placenta-associated protein (PLAC8).Methods: We analyzed plasma levels of pancreatic enzymes and inflammatory markers in a retrospective cohort study of 120 COVID-19 patients distributed in 3 severity-stratified groups. We studied the expression of SARS-CoV-2 and PLAC8 in the pancreas of deceased COVID-19 patients as well as in non-infected donors. We performed pseudovirus infection experiments in PLAC8 knock-out PDAC cell lines and validated results with SARS-CoV-2 virus.Findings: We found that analysis of circulating pancreatic enzymes aided the stratification of patients according to COVID-19 severity and predict outcomes. Interestingly, we found an association between PLAC8 expression and SARS-CoV-2 infection in postmortem analysis of COVID-19 patients. Functional experiments demonstrated the requirement of PLAC8 in SARS-CoV-2 pancreatic infection by pseudovirus. Furthermore, using full SARS-CoV-2 infectious virus inoculum from Wuhan-1 and BA.1 strains, we demonstrated that PLAC8 is necessary for productive infection of PDAC cell lines. Finally, we observed an overlap between PLAC8 and SARS-CoV-2 immunoreactivities of the pancreas of deceased patients.Interpretation: Our data indicate the human pancreas as a SARS-CoV-2 target with plausible signs of injury and demonstrate that the host factor PLAC8 is required for SARS-CoV-2 pancreatic infection, thus defining new target opportunities for COVID-19-associated pancreatic pathogenesis.Funding: This work was funded by the Instituto de Salud Carlos III (ISCIII) and Programa de Investigación en Salut—ISCIII (PI20/01267), by Fondo COVID19-ISCIII (COV20/00571), by Fundació La Marató (MARATÓ 167-C-2021 51), co-funded by the European Union and through the Programa Miguel Servet (MS19/00100) co-funded by the European Regional Development Fund/European Social Fund, "A way to make Europe"/"Investing in your future" (CB); TECH fellowship program, Impost turisme sostenible/Govern de les Illes Balears (TECH19/03) (LI-G); . Ministerio de Ciencia e Innovación MCIN/AEI /10.13039/501100011033 / FEDER, UE (PID-2021-123810OB-I00) and the European Commission – NextGenerationEU (Regulation EU 2020/2094), through Spanish National Research Council (CSIC)'s Global Health Platform (PTI Salud Global, CSIC-COV19-012/012202020E086) (MLD); “. The project that gave rise to these results received the support of a fellowship from “la Caixa” Foundation (ID 100010434). The fellowship code is LCF/BQ/DR22/11950020, awarded to DLG (DLG); Ministerio de Ciencia e Innovación (RYC2021-031776-I) (APU), the Deutsche Forschungsgemeinschaft (DFG, German Research foundation). Ulm University Hertha Nathorff and Medical Scientist Program funding (SH).Declaration of Interest: The authors disclose no conflicts of interest.Ethical Approval: Sections of human tissue from 1 patient were executed according to the guidelines of the Ethics Committee of the Federal General Medical Council and approved by the Ethics Committee of the University of Ulm (vote for usage of archived human material 03/2014). Patient tissue for immunofluorescence analysis were received from the pathology institutes with the respective approval of local ethics committees and collected in the frame of the German Registry for COVID-19 Autopsies (DeRegCOVID). Written informed consent to perform autopsies and to use the tissues for research purposes were obtained from patient relatives. We performed a retrospective conducted in agreement with the Good Clinical Practice principles and the Declaration of Helsinki for ethical research. Ethical approval for this project (IB 4172-20 PI, 26 May 2020) was obtained from the ethics committee of the Balearic Islands and waived the requirement for informed consent, due to the emergency situation.