title: Demonstration of up-regulated IL 2 receptor expression on an in vitro cloned BCL1 subline.
abstract: We have established BCL1 CL-3 cells capable of responding to B15-TRF and interleukin 2 (IL 2). This clone has both high affinity and low affinity receptors for IL 2 (IL 2R), but IL 2 by itself did not stimulate either proliferation or immunoglobulin (Ig) secretion. B15-TRF, which possesses both growth and differentiation activity, causes an increase in size of CL-3 cells and renders CL-3 cells responsive to IL 2, including an increased expression of IL 2R (eight-fold to 10-fold) and the differentiation of CL-3 cells into Ig secretion (60 to 80% of cultured cells). CL-3 cells pretreated with B15-TRF for 12 hr become competent to respond to IL 2 by up-regulation of IL 2R within 12 hr. In contrast CL-3 cells pretreated with IL 2 for 12 hr required 24 hr B15-TRF stimulation to result in IL 2R up-regulation. Thus the ordered action of B15-TRF and IL 2 is the most effective operational pathway for the up-regulation of IL 2R. This IL 2-mediated IL 2R up-regulation and induction of Ig synthesis depends upon the concentration of IL 2 in the culture. Both responses seem to be caused by IL 2 molecules bound to high affinity IL 2R. However, the possibility of involvement of low affinity IL 2R can not be vigorously excluded. In fact the level of IL 2 required for a response is far higher than that needed for activated T cell proliferation. This cloned BCL1 subline promises to be a useful tool for studying the regulation and mechanisms of B cell responses.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation; D002460:Cell Line; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000494:pharmacology*; D051379:Mice; D011971:Receptors, Immunologic / Q000276:immunology*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors
chemical_list: D007376:Interleukin-2; D008222:Lymphokines; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2