Adhesion molecule phenotype of T lymphocytes in inflamed CNS

The phenotype of T cells in the central nervous system (CNS) in two models of chronic inflammation (experimental allergic encephalomyelitis and Corynebacterium parvum-induced inflammation) was compared to that of T cells in gut and chronically inflamed subcutaneous tissue and lung. CNS T cells display a similar phenotype in both inflammatory models, and are phenotypically unique compared to T cells from the other inflamed tissues. T cells from inflamed CNS are mainly CD4(+) and are the only population examined that express a typical activated/memory phenotype: CD44(high)/LFA-1(high)/ICAM-1(high)/CD45RB(low). The CNS T cells are alpha(4) beta(7)-integrin(negative), but express alpha(4)-integrin and activated beta(1) integrin, suggesting expression of the alpha(4) beta(1)-heterodimer in an activated state. In contrast, most T cells in gut express low levels of activated beta(1) integrin. The CNS T cells lack expression of alpha(6) and alpha(E) integrin chains and L-selectin. in inflamed CNS and inflamed subcutaneous tissues approximately 50% of T cells express high affinity ligands for P-selectin while fewer than 10% express high affinity ligands for E-selectin. Ln summary, our data show that, independent of the inflammatory stimulus, T cells recruited into the inflamed CNS are phenotypically distinct from T cells in other inflamed tissues. This finding leads us to hypothesize the existence of a phenotypically distinct 'CNS-seeking' T lymphocyte population. (C) 1998 Elsevier Science B.V.