title: The cell biology of T-dependent B cell activation.
abstract: The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells includes multipoint intermolecular interactions that probably involve aggregation of both polymorphic and monomorphic T cell surface molecules. Such aggregations have been shown in vitro to markedly enhance and, in some cases, induce T cell activation. The production of T-derived lymphokines that have been implicated in B cell activation is dependent on the T cell receptor for antigen and its associated CD3 signalling complex. T-dependent help for B cell activation is therefore similarly MHC-restricted and involves T-B intercellular interaction. Recent reports that describe antigen-independent B cell activation through coculture with T cells activated by anti-T-cell receptor or anti-CD3 antibodies suggest that cellular interaction with T cells, independent of antigen presentation or lymphokine secretion, induces or triggers B cells to become responsive to T-derived lymphokines, and that this may be an integral component of the physiological, antigen- and MHC-restricted T-dependent B cell activation that leads to antibody production.
authors.affiliation: Department of Medicine, McGill University, Montreal, Que., Canada.
authors.forename: T
authors.initials: T
authors.lastname: Owens
authors.forename: R
authors.initials: R
authors.lastname: Zeine
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002450:Cell Communication; D006801:Humans; D008213:Lymphocyte Activation / Q000276:immunology*; D008285:Major Histocompatibility Complex / Q000276:immunology; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D000941:Antigens