title: Antigen-specific T-cell activations distinguished by in vivo anti-CD4 antibody treatment.
abstract: This study identifies activation characteristics of PPD-responsive T-cells that emerge after treatment with anti-CD4 monoclonal antibody (Mab). PPD-stimulated T-cell proliferations, OX40 phenotype and protein tyrosine phosphorylations involving p56lck (pp56lck) were compared to Con A stimulations using T-cells isolated from spleen and draining lymph node of CFA/PPD-immunized rats either untreated or treated in vivo with anti-CD4 Mab. Splenocytes stimulated by concanavalin A (Con A) showed correlated increases in proliferation, levels of pp56lck, and OX40 expression; these parameters were not correlated in splenocytes after PPD-stimulations. T-cells isolated from lymph nodes draining the site of CFA/PPD immunization proliferated in response to stimulation by either PPD or Con A, but only PPD-responsive cells showed correlation to the OX40 activation phenotype and increased levels of pp56lck. CD4+ T-cells isolated from either tissue compartment after anti-CD4 Mab treatments showed higher background and PPD-stimulated proliferations, and expressed lower levels of OX40. In contrast, anti-CD4 Mab treatments reduced (60%) and abolished Con A-stimulated proliferations of splenocytes and lymph node T-cells, respectively. The effects of anti-CD4 Mab treatment on pp56lck levels correlated only to the changes observed for Con A stimulations of splenocytes. These results demonstrate that PPD antigen-specific T-cell populations recovered from different tissue compartments were resistant to in vivo anti-CD4 Mab treatments and did not show the activation changes characteristics of CD4+ T-cells after Con A stimulation.
authors.affiliation: Department of Pharmacology, Oregon Health Sciences University, Portland 97201, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Morrison
authors.forename: N J
authors.initials: NJ
authors.lastname: Kennedy
authors.forename: H
authors.initials: H
authors.lastname: Offner
authors.forename: A A
authors.initials: AA
authors.lastname: Vandenbark
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D015704:CD4 Antigens / Q000276:immunology*; D003208:Concanavalin A / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes / Q000276:immunology*; D005620:Freund's Adjuvant / Q000276:immunology; D008213:Lymphocyte Activation; D011505:Protein-Tyrosine Kinases / Q000276:immunology; D051381:Rats; D011917:Rats, Inbred Lew; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D014373:Tuberculin / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D000939:Epitopes; D014373:Tuberculin; D003208:Concanavalin A; D005620:Freund's Adjuvant; D011505:Protein-Tyrosine Kinases