title: Two independent pathways of helper activity provided by a single T cell clone.
abstract: Data presented in this paper demonstrate the existence of two separate pathways by which a single T cell clone can induce B cell differentiation. With the use of high doses of antigen, a T cell clone can induce a primary antibody response in unprimed B cells. With the use of low doses of antigen, the same T cell clone can induce an immunoglobulin (Ig)G response in primed B cells. The primary response is accompanied by T cell proliferation and lymphokine production (interleukin 2, B cell growth factor, B cell differentiation factor for immunoglobulin M, and B cell differentiation factor for immunoglobulin G). The secondary response does not require proliferation and occurs independently of detectable lymphokine production. Variants of the wild type T cell helper clone have been isolated. One variant can provide help to unprimed B cells when high doses of antigen are used. This variant cannot provide help to primed B cells when low doses of antigen are used, nor can it provide help to CBA/N "xid" B cells at any antigen concentration tested. Additional variants have been isolated that proliferate on antigen-pulsed-presenting cells, but fail to secrete detectable lymphokines and do not induce B cell differentiation. These results suggest that a single T cell helper clone has multiple functional activities that can be independently expressed.
authors.forename: M
authors.initials: M
authors.lastname: Shigeta
authors.forename: S
authors.initials: S
authors.lastname: Takahara
authors.forename: S J
authors.initials: SJ
authors.lastname: Knox
authors.forename: T
authors.initials: T
authors.lastname: Ishihara
authors.forename: E S
authors.initials: ES
authors.lastname: Vitetta
authors.forename: C G
authors.initials: CG
authors.lastname: Fathman
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D002999:Clone Cells / Q000145:classification / Q000276:immunology / Q000378:metabolism; D004306:Dose-Response Relationship, Immunologic; D005260:Female; D006241:Haptens / Q000276:immunology; D006433:Hemocyanins / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis; D008213:Lymphocyte Activation; D008222:Lymphokines / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology* / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D006241:Haptens; D007074:Immunoglobulin G; D008222:Lymphokines; D014301:Trinitrobenzenes; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin