title: The role of accessory molecules in T-helper activation induced by antigen, lectin, or CD3 antibodies.
abstract: We examined the role of L3T4 and LFA-1 molecules in T-helper-cell activation, under conditions where the physical stability of T helper-accessory cell interactions was not an issue. T-helper hybridomas were activated by accessory cells coated either with concanavalin A (Con A) or with CD3 antibodies. Activation of the T helper cells was measured by microtubule-organizing center (MTOC) reorientation as an early activation event, and by interleukin-2 (IL-2) production as an indication of a fully matured response. Both parameters were strongly blocked by L3T4 and LFA-1 antibodies in the case of Con A activation. In the case of stimulation with accessory cell-bound CD3 antibody, activation was blocked by LFA-1 but not L3T4 antibody. These results support the notion that L3T4 and LFA-1 molecules play more than a simple adhesion role in T-cell activation. The differential effect of L3T4 antibody in the case of Con A activation vs CD3 activation is consistent with the possibility that L3T4 and the alpha/beta portions of the T-cell receptor must interact during antigen- and lectin-stimulated T-cell activation.
authors.affiliation: Department of Biology, University of California, Los Angeles 90024.
authors.forename: B E
authors.initials: BE
authors.lastname: Torbett
authors.forename: W R
authors.initials: WR
authors.lastname: Clark
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D000941:Antigens; D000943:Antigens, Differentiation / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D017252:CD3 Complex; D007376:Interleukin-2 / Q000378:metabolism; D037102:Lectins; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1; D051379:Mice; D008870:Microtubules / Q000648:ultrastructure; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology* / Q000648:ultrastructure
chemical_list: D000936:Antigen-Antibody Complex; D000941:Antigens; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D007376:Interleukin-2; D037102:Lectins; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell