IPSE, a parasite-derived host immunomodulatory protein, is a promising therapeutic for hemorrhagic cystitis

Chemotherapy-induced hemorrhagic cystitis is characterized by bladder pain and voiding dysfunction caused by hemorrhage and inflammation. Of currently available therapies, prophylactic 2-mercaptoethanesulfonic acid (MESNA) has limited efficacy and cannot treat pre-existing lesions. Therefore, novel therapeutic options to treat hemorrhagic cystitis are needed. We previously reported that systemic administration of the Schistosomiasis haematobium -derived protein H-IPSE H06 (IL-4-inducing p rinciple from S chistosoma mansoni e ggs), is superior to 3 doses of MESNA in alleviating hemorrhagic cystitis. Based on prior reports by others on S. mansoni IPSE and additional work by our group, we reasoned that H-IPSE H06 mediates its effects on hemorrhagic cystitis by binding IgE on basophils and inducing IL-4 expression, promoting urothelial proliferation, and translocating to the nucleus to modulate expression of genes implicated in relieving bladder dysfunction. We speculated that local bladder injection of the S. haematobium IPSE ortholog IPSE H03 , hereafter called H-IPSE H03 , might be more efficacious in preventing hemorrhagic cystitis compared to systemic administration of IPSE H06 . We demonstrate herein that H-IPSE H03 is a promising therapeutic for the treatment of voiding dysfunction and bladder pain in hemorrhagic cystitis. Namely, it attenuates ifosfamide-induced increases in bladder wet weight in an IL-4-dependent fashion. H-IPSE H03 relieves hemorrhagic cystitis-associated allodynia. Finally, H-IPSE H03 drives increased urothelial cell proliferation. This indicates that IPSE induces bladder healing mechanisms, which suggests that it may be a novel non-opioid analgesic to treat bladder pain syndromes.