Recombinant T cell replacing factor (interleukin 5) acts with antigen to promote the growth and differentiation of single hapten-specific B lymphocytes.
The role of murine recombinant T cell replacing factor (rTRF) (interleukin 5) in the early activation, proliferation, and antibody-forming cell (AFC) clone formation of single fluorescein (FLU)-specific B cells was examined in vitro. FLU-specific B cells were selected by their adherence to FLU-gelatin and then cultured in 10-microliters wells with or without rTRF in the presence or absence of the T-independent antigen FLU-polymerized flagellin (FLU-POL). rTRF acting alone was unable to induce early B cell activation as assessed by significant cell enlargement after 24 hr in culture. When acting in the presence of FLU-POL, however, a greater number of B cells were induced to enlarge than with FLU-POL alone. When FLU-specific B cells were cultured in the presence of FLU-POL, the addition of rTRF markedly increased the frequencies of both proliferating clones and AFC clones above that induced by FLU-POL alone. Furthermore, in the presence of FLU-POL, the activity of rTRF was comparable to that seen with the mixture of B cell growth and differentiation factors contained within the supernatant from concanavalin A-stimulated EL4 cells. However, rTRF exerted little activity when acting alone in contrast to the medium conditioned by concanavalin A-stimulated EL4 cells which showed some activity in the absence of FLU-POL. rTRF acting with FLU-POL also promoted AFC clone development among single B cells stimulated in the presence of 3T3 fibroblast filler cells. Thus rTRF can be added to the list of B cell active factors (including recombinant murine interleukin 1 and recombinant human interleukin 2) that act in the concomitant presence of antigen to induce both growth and differentiation among single hapten-specific murine splenic B cells. This stands in contrast to the activity seen with interleukin 4 (formerly termed B cell stimulatory factor 1) which acts to promote early activation and proliferation but not IgM secretion.
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects; D000941:Antigens / Q000276:immunology*; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation; D002455:Cell Division; D019793:Fluorescein; D005452:Fluoresceins / Q000276:immunology; D006241:Haptens; D015848:Interleukin-5; D007378:Interleukins / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D011994:Recombinant Proteins / Q000494:pharmacology
D000941:Antigens; D005452:Fluoresceins; D006241:Haptens; D015848:Interleukin-5; D007378:Interleukins; D011994:Recombinant Proteins; D019793:Fluorescein