title: Specific down-regulation of proliferative T cell alloresponsiveness by interference with CD2/LFA-3 and LFA-1/ICAM-1 in vitro.
abstract: T cell activation requires Ag contact with the TCR in the presence of costimulatory signals provided by APCs. When Ag is presented without costimulation, T cells are functionally inactivated. Here we demonstrate that interference with distinct adhesion molecules during Ag contact using mAbs leads to Ag-specific functional inactivation of alloreactive T cells. We found that the presence of a mixture of mAbs specific for CD2, LFA-3, LFA-1 alpha- and beta-chain, and ICAM-1 during primary MLC leads to down-regulation of secondary proliferative responses to Ag from the donor used for priming. Cells from pretreated cultures proliferated well, however, when stimulated with Ag from third party donors, mitogens, or mitogenic CD3 mAb. Because specific reactivity could be restored by addition of IL-2 to restimulation cultures, altered secondary responsiveness appeared to be caused by anergy and not by elimination of specific clones. Furthermore, specific down-regulation of alloresponsiveness was prevented by addition of IL-2 to primary cultures in the presence of mAb. Interference by mAb with either CD2/LFA-3, LFA-1/ICAM-1, CD2/LFA-1, or LFA-3/ICAM-1 had a substantial, though less pronounced effect on secondary responsiveness. After pretreatment with the Ab mixture, CTL generation was substantially but incompletely down-regulated against the original and third party donors. Because a decrease in the reactivity of unstimulated responders by culture was also observed, these findings might be explained by the loss of cytotoxic precursors after culturing under nonstimulating conditions. In conclusion, our data demonstrate that T cells enter a state of anergy when T cell activation is modulated by simultaneous interference with distinct adhesion molecules during Ag contact, which thus might reflect at least partly overlapping functions of particular receptor-ligand pairs in T cell costimulation.
authors.affiliation: Institute of Immunology, University of Vienna, Austria.
authors.forename: G A
authors.initials: GA
authors.lastname: Böhmig
authors.forename: J
authors.initials: J
authors.lastname: Kovarik
authors.forename: W
authors.initials: W
authors.lastname: Holter
authors.forename: E
authors.initials: E
authors.lastname: Pohanka
authors.forename: G J
authors.initials: GJ
authors.lastname: Zlabinger
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D018801:CD2 Antigens; D018968:CD58 Antigens; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007108:Immune Tolerance; D007156:Immunologic Memory; D066298:In Vitro Techniques; D018799:Intercellular Adhesion Molecule-1; D007376:Interleukin-2 / Q000494:pharmacology; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D018968:CD58 Antigens; D015815:Cell Adhesion Molecules; D007376:Interleukin-2; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D018799:Intercellular Adhesion Molecule-1