Abstract 113: Generation and validation of a novel humanized IL-31/IL-31RA/OSM/OSMR mouse model

Abstract Oncostatin M (OSM) and interleukin-31 (IL-31) are two pleiotropic cytokines that share a common signaling receptor subunit, the OSM receptor beta (OSMR). Both cytokines are released by monocytes, macrophages, dendritic cells and T lymphocytes in inflammatory situations, and upon binding to their respective receptors, induce the production of inflammatory cytokines (such as IL-6), chemokines, and other cellular growth factors during tissue repair, mainly via the JAK/STAT signal pathway. As OSM and IL-31 are reported to be involved in a variety of physiological and pathological processes, targeting IL-31 or OSM signaling is of therapeutic interest. To provide a novel preclinical platform for testing novel modulators of these signaling axes, a humanized IL-31/IL-31RA/OSM/OSMR mouse model was generated. First, single gene knock-in mice were constructed by gene editing technology; multigenic knock-in mice were then obtained by breeding, yielding a quadruple humanized model in which the murine cytokine sequences were replaced by full-length human cytokine sequences in situ, while the murine receptor sequences were replaced by chimeric sequences comprised of the human extracellular region and murine intracellular regions in situ. mRNA expression confirmed expression of IL-31, IL-31RA, and OSMR in this model, while ELISA confirmed expression of human OSM protein in the model without evidence of murine OSM expression. Next, the signaling capacity of the humanized OSMR receptor was confirmed: mouse embryonic fibroblasts (MEFs) isolated from humanized B-hOSM/hOSMR mice were capable of responding to human OSM to release IL-6, while wild-type MEFs could only respond to murine OSM. Subsequently, the ability of IL-31RA antibodies to alleviate scratching was tested in a chemically induced model of atopic dermatitis. Compared to mice receiving control antibodies, scratching frequency in humanized B-hIL31/hIL31RA/hOSMR mice treated with nemolizumab was attenuated (analog antibody was generated in-house). Finally, blood counts and flow cytometric profiling indicates that the humanized mice have a normal frequency of leukocytes and lymphocytes. Taken together, this quadruple humanized IL-31/IL-31RA/OSM/OSMR mouse model is a promising preclinical tool that can be used to evaluate novel modulators of this signaling pathway prior to clinical development. Citation Format: Linlin Wang, Lei Zhao, Meiqi Zhang, Zhi Zhang, Zhen Chen, Mari Kuraguchi, Jingjing Lian, Jiansu Zhang. Generation and validation of a novel humanized IL-31/IL-31RA/OSM/OSMR mouse model abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts) ; 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84 (6Suppl): Abstract nr 113.