Engagement of major histocompatibility complex class II molecules induces sustained, lymphocyte function-associated molecule 1-dependent cell adhesion.
Antigenic stimulation is associated with enhanced adhesion between T cells and antigen-presenting cells (APC). Binding of ligands to the T cell antigen receptor activates the adhesion function of lymphocyte function-associated molecule 1 (LFA-1; CD11a/CD18). We demonstrate here that ligand binding to major histocompatibility complex class II (Ia) molecules also activates LFA-1 function, providing a reciprocal mechanism for the induction of adhesion between T cells and Ia+ APC. Adhesion was affected by a qualitative change in LFA-1 molecules and was reversed by the protein kinase C inhibitor sphingosine. These results define a novel role for Ia molecules as signal transducing receptors that regulate LFA-1-dependent adhesion via a putative, Ia-coupled protein kinase(s).
Mourad
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W
Division of Immunology, Children's Hospital, Boston, Massachusetts 02115.
Geha
R S
RS
Chatila
T
T
D000911:Antibodies, Monoclonal / Q000276:immunology; D001402:B-Lymphocytes / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D002448:Cell Adhesion / Q000187:drug effects; D004789:Enzyme Activation / Q000502:physiology; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000502:physiology*; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology*; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D011493:Protein Kinase C / Q000502:physiology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D015854:Up-Regulation / Q000502:physiology
D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell; D011493:Protein Kinase C