title: Helper signals in the plaque-forming cell response to protein-bound haptens.
abstract: We have demonstrated the ability of a series of murine T cell hybridomas to deliver an antigen-specific, B cell I-region-restricted helper signal in the generation of specific PFC responses to protein-bound haptens. With some hybridomas the elicitation of optimal PFC responses required the addition of nonspecific factors provided by culture supernatants of concanavalin A-stimulated (Con A SN) spleen cells. Using hapten-primed B cells depleted of both T cells and macrophages (Mphi) we have now demonstrated a requirement for three nonspecific factor preparations to substitute for spleen Con A SN in the elicitation of optimal PFC responses. The first preparation was the interleukin 1 containing culture supernatant of the Mphi tumor cell line P388D1, the second the interleukin 2 (IL-2) and B cell growth factor containing Con A SN of the T cell hybridoma FS6-14.13, and the third, the gamma interferon containing Con A SN of the T cell hybridoma FS7-20.6.18. The P388D1 and FS6-14.13 factor preparations were most effective when added at the initiation of culture, while the FS7-20.6.18 factor preparation was most effective when added at 24 h of culture. The activity of FS6-14.13 Con A SN was depleted by incubation with the IL-2-dependent T cell line HT-2. The activity of FS7-20.6.18 Con A SN was abrogated by incubation at pH 2. The results suggest that the generation of PFC responses to protein-bound haptens require at least three nonspecific factors in addition to an antigen/Ia specific helper signal.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D003208:Concanavalin A / Q000502:physiology; D000939:Epitopes; D006183:H-2 Antigens / Q000235:genetics; D006241:Haptens / Q000276:immunology*; D006462:Hemolytic Plaque Technique; D006825:Hybridomas / Q000276:immunology; D007371:Interferon-gamma / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D007700:Kinetics; D008211:Lymphocyte Cooperation; D008222:Lymphokines; D051379:Mice; D008810:Mice, Inbred C57BL; D011485:Protein Binding; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D000939:Epitopes; D006183:H-2 Antigens; D006241:Haptens; D007376:Interleukin-2; D008222:Lymphokines; C021649:concanavalin A-induced helper factors; D003208:Concanavalin A; D007371:Interferon-gamma