title: Evaluation of accessory cell heterogeneity. I. Differential accessory cell requirement for T helper cell activation and for T-B cooperation.
abstract: Several Ia+ tumor cell lines and peritoneal exudate macrophages were tested as accessory cells (AC) for the activation of antigen-specific T cells and for T-B cooperation. The macrophages and all the Ia+ tumor lines tested induced the release of lymphokines from T cells in a major histocompatibility complex (MHC)-restricted fashion and reconstituted the antibody responses of AC-depleted spleen cells or of purified T and B cells. However, only the normal macrophages but none of the tumor lines induced carrier-specific T helper (Th) cells which help B cells for specific antihapten antibody responses by linked recognition. For T-B cooperation accessory cells were also required, but in contrast to Th cell activation any type of Ia+ AC (e.g. macrophage or tumor line) was effective. Strong MHC-restriction between the lymphocytes and the AC was seen if antigen-pulsed AC were added into the AC-depleted T-B cooperation cultures. If the AC and antigen were concomitantly added to the AC-depleted T-B cultures, MHC-restriction was less obvious. Concanavalin A supernatant reconstituted the response of AC-depleted T-B cultures provided antigen-specific Th cells and the hapten-carrier conjugate were present. If, however, tumor line-activated T cells were added instead of macrophage-induced Th cells, no cooperation with B cells took place even in the presence of Con A supernatant. The results obtained demonstrate a differential AC requirement for the induction of Th cells depending on the differentiation stage of the Th cells.
authors.forename: G
authors.initials: G
authors.lastname: Ramila
authors.forename: S
authors.initials: S
authors.lastname: Studer
authors.forename: M
authors.initials: M
authors.lastname: Kennedy
authors.forename: I
authors.initials: I
authors.lastname: Sklenar
authors.forename: P
authors.initials: P
authors.lastname: Erb
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000938:Antigen-Presenting Cells / Q000145:classification / Q000166:cytology / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology; D002454:Cell Differentiation; D002460:Cell Line; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D007941:Leukemia P388 / Q000276:immunology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008222:Lymphokines / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000378:metabolism
chemical_list: D000949:Histocompatibility Antigens Class II; D008222:Lymphokines