title: CD2 (OKT11) augments CD3-mediated intracellular signaling events in human T lymphocytes.
abstract: CD2 (LFA-2) is expressed on thymocytes, natural killer cells, and virtually all peripheral T cells. CD2 binds to its primary ligand CD58 (LFA-3) on antigen presenting cells (APC) and stabilizes the T cell-APC interaction; this stable interaction then optimizes Ag-specific T-cell activation. We assessed whether CD2-cross-linking by mAb augments the process of T-cell stimulation through the TCR/CD3 complex. Plate-bound anti-CD2 or anti-CD3 mAb alone had no measurable effect on any of the assessed activation parameters of resting T cells. However, concomitant signaling through both CD2 and CD3 by plate-bound antibodies resulted in marked increases in CD69 expression on the T-cell surface and T-cell-cellular metabolism, as assessed by the ability of the cell to reduce 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxylmethoxyphenyl)-2-( 4-sulphophenyl)- 2H-tetrazolium (MTS) to formazen. In addition, simultaneous cross-linking of CD2 and CD3 caused a significant (P < 0.001) increase in phosphatidylinositol hydrolysis in resting T cells compared to stimulation with anti-CD3 mAb alone and anti-CD3 mAb plus anti-CD2 isotype control antibody. These results indicate that CD2 augments signaling through CD3, and consequently functions as a costimulatory molecule for resting T cells in the initial activation step.
authors.affiliation: Department of Medicine, LSU School of Medicine at Shreveport 71130-3932, USA. sberne@lsumc.edu
authors.forename: S M
authors.initials: SM
authors.lastname: Berney
authors.forename: T
authors.initials: T
authors.lastname: Schaan
authors.forename: R E
authors.initials: RE
authors.lastname: Wolf
authors.forename: H
authors.initials: H
authors.lastname: van der Heyde
authors.forename: T P
authors.initials: TP
authors.lastname: Atkinson
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000378:metabolism; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism; D018801:CD2 Antigens / Q000378:metabolism*; D017252:CD3 Complex / Q000378:metabolism*; D006801:Humans; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D051379:Mice; D010716:Phosphatidylinositols / Q000378:metabolism; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D000099192:CD69 Antigens
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D017252:CD3 Complex; D037181:Lectins, C-Type; D010716:Phosphatidylinositols; D000099192:CD69 Antigens