title: Direct evidence for a receptor-ligand interaction between the T-cell surface antigen CD2 and lymphocyte-function-associated antigen 3.
abstract: The recognition of foreign antigen by T lymphocytes requires direct contact with cells expressing the antigen. It has recently become clear that T lymphocytes can form conjugates with other cells in the absence of foreign antigen expression. Studies using monoclonal antibodies (mAbs) to inhibit conjugate formation have suggested that a portion of the antigen-dependent adhesion is mediated by T lymphocytes interacting with cells expressing lymphocyte-function-associated antigen 3 (LFA-3), a widely distributed cell surface protein. We have investigated antigen-independent adhesion by incorporating affinity-purified LFA-3 into the lipid membrane of an artificial target cell (ATC; a nylon-matrix vesicle with a lipid membrane). These vesicles are similar in size and density to intact cells, so that conjugates between cells and ATCs may be seen by light microscopy. ATCs expressing a density of LFA-3 similar to that on intact cells were found to form conjugates with T cells, but only if the T cells expressed the sheep erythrocyte receptor, CD2 (T11; LFA-2). Previous studies using mAbs have implicated the CD2 molecule in both adhesion and T-cell activation. ATCs prepared without surface protein or with purified HLA class I protein failed to interact with the CD2-positive T cells, indicating that the adhesion found was mediated by the LFA-3 molecule. Furthermore, mAb against LFA-3 or CD2 was able to block the LFA-3-mediated vesicle-cell interaction, whereas mAb against LFA-1 or HLA failed to inhibit the interaction. These results provide direct evidence that LFA-3 functions as an adhesion molecule by serving as a ligand for the CD2 molecule on T cells.
authors.affiliation: Department of Pathology, Dana-Farber Cancer Institute, Boston, MA.
authors.forename: Y
authors.initials: Y
authors.lastname: Takai
authors.forename: M L
authors.initials: ML
authors.lastname: Reed
authors.forename: S J
authors.initials: SJ
authors.lastname: Burakoff
authors.forename: S H
authors.initials: SH
authors.lastname: Herrmann
mesh_terms: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology* / Q000302:isolation & purification; D000954:Antigens, Surface / Q000276:immunology* / Q000302:isolation & purification; D002448:Cell Adhesion; D002460:Cell Line; D006801:Humans; D016169:Lymphocyte Function-Associated Antigen-1; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D016169:Lymphocyte Function-Associated Antigen-1