Involvement of the interleukin‐2 receptor γ subunit in interleukin‐4‐dependent activation of mouse hematopoietic cells and splenic B cells

摘要

AbstractInterleukin‐4 (IL‐4) has various activities on B cells and on hematopoietic cells. We previously reported that TUGm2, a monoclonal antibody to the γ subunit of the IL‐2 receptor (IL‐2Rγ), inhibited IL‐4‐dependent proliferation of CTLL2, a cytotoxic T cell line. We proposed that IL‐2Rγ is required for the functional IL‐4 receptor (IL‐4R) in T cells. In the present work, we further examined whether or not IL‐2Rγ is involved in IL‐4R function in mouse myeloid cell lines and splenic B cells. TUGm2 suppressed the IL‐4‐induced proliferation of BA/F3 or IC2 cells, as well as of purified splenic B cells. TUGm2 partially suppressed proliferation of B cells induced by the combination of IL‐4 and anti‐immunoglobulin M (IgM) antibody. In contrast, TUGm2 had no effect on proliferation of B cells induced by anti‐IgM antibody alone or lipopolysaccharide (LPS). TUGm2 also inhibited IgE production induced by IL‐4 of LPS‐stimulated B cells. The induction of major histocompatibility complex class II molecules or CD23 by IL‐4 was virtually unaffected by TUGm2 antibody. These results indicate that IL‐2Rγ is differentially