Induction and Regulation of CD30 Expression on Murine B Lymphocytes by Non-specific Stimulation

Nam, Sang Yun

Abstract

An activation antigen, CD30 was initially identified on Hodgkin and Reed-Sternberg (H-RS) cells. CD30 expression is observed on activated, but not on resting, T and B lymphocytes. Despite of numerous studies, the functions of CD30 in physiological condition remains open question. Moreover, CD30 expression of normal B lymphocytes has been poorly documented. In this study, CD30 expression of murine B lymphocytes and its regulation was analyzed. Murine splenic B (SP-B) cells obtained by adherence were used for activation with LPS or plate-bound anti-mouse IgM. LPS stimulation resulted in B cell proliferation. However, stimulation with plate-bound anti- mouse IgM (pb anti-mlgM) induced blast cell formation but did not increase cell number. Both stimulation induced minimal expression of CD30. Substantial CD30 expression of SP-B cells was induced by IL 4, which upregulated both of proliferation and CD30 expression of activated SP-B cells. Highest level of CD30 expression was detected at day 3 of stimulation. IL 2 enhanced B cell proliferation but not CD30 expression and rather reduced IL 4-mediated upregulation of CD30 expression. These data suggest that the signaling pathway for B cell proliferation is different from that for induction of CD30 expression and IL 4 exerts a pivotal role in CD30 expression of both T and B cells. In addition, T and B cells may show distinct response to other cytokines such as IL 2 in CD30 expression.