Functions of accessory cells in B cell responses to thymus-independent antigens.
The functions of adherent accessory (A) cells in thymus-independent (TI) B cell activation were investigated using homogeneous A cell lines with distinct cell surface and functional characteristics, as well as inhibitors of antigen processing and interleukin 1 (IL 1) secretion. B cell responses to both type 1 and type 2 TI antigens were found to be strictly A cell dependent. Only A cells capable of IL 1 secretion could restore responsiveness in A cell-depleted spleen cells, regardless of Ia expression or antigen-processing capability. Moreover, recombinant IL 1 completely replaced A cell function in B cell responses to both TI 1 and TI 2 antigens. Finally, T cell depletion did not diminish the reconstitution by IL 1. Thus in contrast to T cell activation, IL 1 secretion is the only A cell function required in TI B cell activation, and the data are consistent with a direct role for IL 1 in B cell activation.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology* / Q000378:metabolism; D000941:Antigens / Q000276:immunology*; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D002460:Cell Line; D007375:Interleukin-1 / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects; D051379:Mice; D008808:Mice, Inbred CBA / Q000276:immunology; D008811:Mice, Inbred DBA / Q000276:immunology; D013154:Spleen / Q000166:cytology
D000941:Antigens; D007375:Interleukin-1