In vitro analysis of allogeneic lymphocyte interaction. VIII. Characterization of helper components of allogeneic effect factor (AEF) that activate Lyb5+ and Lyb5- B cells to respond to thymus-dependent and thymus-independent antigens.
We analyzed the ability of an allogeneic effect factor (AEF), produced using alloactivated A.SW (H-2s) responder T cells and irradiated A/WySN (H-2a) T cell-depleted stimulator spleen cells, to enhance the responsiveness of Lyb5+ and Lyb5- B cells to thymus-dependent (TD) and thymus-independent type 1 (TI-1) and type 2 (TI-2) antigens. We found that normal adult male CBA/CaHN (Lyb5+ + Lyb5-) B cells are activated by unfractionated AEF in primary in vitro IgM antibody responses to the SRBC (TD), TNP-LPS (TI-1), and TNP-Ficoll (TI-2) antigens. Adult male xid CBA/N (Lyb5-) B cells are activated by unfractionated AEF to respond to TNP-LPS but to neither SRBC nor TNP-Ficoll. Gel filtration of AEF on ACA 54 resolves several helper components. One component, which is I-Ak restricted in its activity and may represent a secreted form of an Ia antigen T cell receptor, interacts with histocompatible and functionally competent CBA/CaHN or CBA/N antigen-presenting cells to activate a primary anti-SRBC response of CBA/CaHN B cells but not of CBA/N B cells. A second antigen-nonspecific and H-2-nonrestricted AEF component, which consists of interleukin 2 and possibly also interleukin 1, activates anti-SRBC and anti-TNP-Ficoll responses of both CBA/CaHN B cells and CBA/N B cells. Such CBA/N B cell responses were potentiated by this AEF component only after its biochemical fractionation and only in the presence of a limiting number of T cells. These data indicate that both Lyb5+ and Lyb5- B cells are responsive to TD, TI-1, and TI-2 antigens in the presence of ancillary antigen-nonspecific help. They are also consistent with the notion that T helper cell activation of Lyb5+ B cells is H-2 nonrestricted and that T helper cell activation of Lyb5- B cells is H-2 restricted.
D000818:Animals; D000950:Antigens, Ly / Q000235:genetics / Q000276:immunology; D000955:Antigens, T-Independent / Q000235:genetics / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D005591:Chemical Fractionation; D006183:H-2 Antigens / Q000235:genetics; D007375:Interleukin-1 / Q000502:physiology; D007376:Interleukin-2 / Q000502:physiology; D007519:Isoantigens / Q000235:genetics / Q000276:immunology*; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008222:Lymphokines / Q000032:analysis / Q000502:physiology*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D010641:Phenotype
D000950:Antigens, Ly; D000955:Antigens, T-Independent; D006183:H-2 Antigens; D007375:Interleukin-1; D007376:Interleukin-2; D007519:Isoantigens; D008222:Lymphokines; C022780:allogenic effect factor