The response of selected human B cell lines to B cell growth and differentiation factors

Fifteen human B cell lines were tested for their ability to respond to B cell growth and differentiation factors present in phytohemagglutinin-conditioned medium. Five lines responded significantly: CESS showed an increase in IgG production only, HFB1 and BALM1 showed an increase in proliferation only and L4 and BALM4 showed an increase in both IgG production and proliferation. When four of the responding lines (CESS, HFB1, L4 and BALM4) were cultured with human recombinant-derived interleukin 1, interleukin 2, interleukin 4 or interferon-gamma no significant response was seen. CESS, L4 and BALM4 all increased IgG production in response to partially purified B cell growth factor (Cellular Products, Inc., Sera-Lab., Crawley Down, GB) and B cell differentiation factor-containing supernatant from the T24 bladder carcinoma cell line. HFB1, L4 and BALM4 all showed increased tritiated thymidine incorporation in response to purified B cell growth factor but not in response to B cell differentiation factor-containing supernatant. These lines may prove useful in the study of B cell growth and differentiation factors and their receptors.