A HIERARCHY FOR INTEGRIN EXPRESSION AND ADHESIVENESS AMONG T-CELL SUBSETS THAT IS LINKED TO TCR GENE USAGE AND EMPHASIZES V-DELTA-1(-DELTA T-CELL ADHERENCE AND TISSUE RETENTION() GAMMA)

To define the relationship between T cell phenotype and adhesiveness, we examined T cell adhesion to endothelial cell, fibroblast, and epith elial cell monolayers as well as extracellular matrix proteins (collag en and fibronectin) using a three-color flow cytometry-based adherence assay that minimizes basal adhesion levels and facilitates quantitati ve lymphocyte subtyping. Regardless of monolayer type, monolayer stimu lation conditions, or T cell activation status, we found that the gamm a delta-TCR-bearing T cells adhered more efficiently than alpha beta T cells. The difference was based predominantly on increased levels of activatable LFA-1 (and to a lesser degree VLA-4) because: 1) it correl ated precisely with inhibitability by anti-LFA-1 (and VLA-4) mAbs and the levels of LFA-1 (and VLA-4) on the cell surface, and 2) it persist ed after maximal LFA-1 (and VLA-4) activation with phorbol dibutyrate. In contrast to most cases of alpha beta T cell behavior, gamma delta T cell adhesion to cell monolayers was not linked to memory status, i. e., there was no difference between naive V delta 1(+) and memory V de lta 2(+) populations in levels of LFA-1 (or VLA-4) expression or LFA-1 - (or VLA-4-) dependent adhesion to cell monolayers. However, V delta 1(+) cells exhibited higher levels of VLA-5 that correlated with an in creased adhesiveness to fibronectin acid to a 120-kDa fibronectin frag ment (FN-120) that contains only the VLA-5-binding domain but not to t ype I collagen or to a fibronectin fragment (FN-40) that binds only VL A-4. Taken together, the results define a hierarchy for integrin (LFA- 1, VLA-4, and VLA-5) expression and consequent adhesion among T cell s ubsets that is linked to TCR gene usage (but not necessarily linked to memory status) and may thereby help to explain the accumulation and r etention of V delta 1(+) + gamma delta T cells in epithelial and conne ctive tissues.