Project description:This study is designed to compare and contrast the temporal and spatial changes in bone formation rates and transcriptional profiles in cortical and cancellous bone cell populations enriched by laser capture microdissection (LCM) in ovariectomized rats administered Scl-Ab by subcutaneous injection for up to 26 consecutive weeks, followed by a recovery period of up to 18 weeks.
Project description:Recombinant cytokines have limited anti-cancer efficacy mostly due to narrow therapeutic window and systemic adverse effects. IL-18 is an inflammasome induced proinflammatory cytokine that enhances T and NK cell activity and stimulates IFNg production. The activity of IL-18 is naturally blocked by a high affinity endogenous binding protein (IL-18BP). IL-18BP is induced in the tumor microenvironment (TME) in response to IFNg upregulation in a negative feedback mechanism. In this study we found that IL-18 is upregulated in the TME compared to the periphery across multiple human tumors and most of it is bound to IL-18BP. Bound IL-18 levels were largely above the amount required for T cell activation in vitro, implying that releasing IL-18 in the TME could lead to potent T cell immune activation. To restore the activity of endogenous IL-18 we generated COM503, a high affinity anti-IL-18BP antibody (Ab), that blocks the IL-18BP:IL-18 interaction and displaces pre-complexed IL-18 to enhance T cell and NK cell activation. In vivo, administration of a surrogate anti-IL-18BP Ab, either alone or in combination with anti-PD-L1 Ab, resulted in significant tumor growth inhibition and increased survival across multiple mouse tumor models. Moreover, anti-IL-18BP Ab induced pronounced TME-localized immune modulation including an increase in polyfunctional non-exhausted T and NK cell numbers and activation. In contrast, no increase in inflammatory cytokines and lymphocyte numbers or activation state was observed in serum and spleen. Taken together, blocking IL-18BP using an Ab is a promising novel approach to harness cytokine biology for the treatment of cancer.