title: Monoclonal antibodies to CD2 and lymphocyte function-associated antigen 3 inhibit human thymic epithelial cell-dependent mature thymocyte activation.
abstract: Recent study of human thymocyte-thymic epithelial (TE) cell interactions has demonstrated that thymocytes bind to TE cells, and a consequence of this binding is the provision of accessory cell signals by TE cells for phytohemagglutinin (PHA)-induced mature thymocyte activation. In this paper we report on studies of the molecules involved in TE cell-dependent mature thymocyte activation. TE-thymocyte interactions necessary for PHA-induced thymocyte activation were inhibited by monoclonal antibodies against the cluster of differentiation (CD)2 antigen on thymocytes and lymphocyte function-associated (LFA)-3 antigen on TE cells. Inhibition of TE accessory cell signals by antibodies against CD2 (alpha CD2) and LFA-3 (alpha LFA-3) antigens occurred early on during thymocyte activation and prevented thymocyte interleukin 2 receptor expression. Further, alpha CD2 and alpha LFA-3 inhibited PHA-induced thymocyte activation in whole thymic explant cultures suggesting a significant role of the CD2 and LFA-3 antigens in thymocyte activation when accessory cell signals for PHA-induced thymocyte triggering were delivered by cells within an intact thymic microenvironment.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology*; D000954:Antigens, Surface / Q000276:immunology*; D004848:Epithelium / Q000502:physiology; D006801:Humans; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1; D011971:Receptors, Immunologic / Q000276:immunology; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000502:physiology*; D013997:Time Factors
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D016169:Lymphocyte Function-Associated Antigen-1; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2