CLONING AND SEQUENCING OF CDNA-ENCODING MOUSE CYTOHESIN-1

Lymphocyte function-associated antigen-1 (LFA-1; aL beta 2; CD11a/CD18 ) is a member of the integrin family of cell surface adhesion receptor s, and binds to the widely-expressed intercellular adhesion molecules -1, -2, and -3 (ICAM-1, -2, -3). LFA-1-ICAM interactions play critical roles in T-lymphocyte immune responses, mediating firm adhesion to an tigen-presenting cells and target cells and additionally providing co- stimulatory signals for T-cell activation (Diamond and Springer 1994; Gahmberg 1997). The importance of LFA-1-ICAM interactions to cells inv olved in an immune response is emphasized by the fact that individuals with a CD18 gene defect lack functional cell surface beta 2 chains an d suffer from leukocyte adhesion deficiency, a potentially fatal disea se characterized by recurrent pathogenic infections (Anderson and Spri nger 1987).