The intrinsic migratory capacity of memory T cells contributes to their accumulation in rheumatoid synovium

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Abstract
Objective. Mechanisms controlling the infiltration of T cells into rheumatoid synovium have not been fully characterized. These studies were undertaken to investigate the relationship between T cell phenotype and migratory capacity, so as to elucidate mechanisms that might contribute to the accumulation of T cells at inflammatory sites.Methods. The characteristics of in vivo migrating cells were studied by dual‐immunofluorescence FACS (fluorescence‐activated cell sorter) analysis of rheumatoid synovial and peripheral blood T cells. Migratory cells were also characterized using a recently developed in vitro assay, wherein peripheral blood T lymphocytes (PBTL) with the capacity to migrate through endothelial cell monolayers were retrieved and assessed.Results. Migratory CD4+ T cells from rheumatoid arthritis (RA) and normal individuals were characterized as being CD45RA‐, CD29bright, CD11abright, L‐selectin‐, CD54+, and CD58+. Migrating RA PBTL (compared with normal PBTL), however, were significantly enriched in activated HLA—DR+ T cells. RA synovial tissue lymphocytes exhibited a similar phenotype, but with decreased surface density of CD4 and an increase in HLA‐DR and VLA‐1. RA synovial lymphocytes exhibited a 2–3‐fold increase in migratory capacity over normal and RA PBTL.Conclusion. These studies demonstrate the inherent migratory proficiency of CD4+ T cells that express a memory phenotype (CD29bright, CD11abright, and CD58+). In addition, enhanced transendothelial migration was observed for CD4+ T cells that were CD54+ and L‐selectin—. These studies demonstrate that the migratory patterns of circulating lymphocytes may be correlated with their surface phenotype and that the intrinsic migratory capacity of memory T cells is one component contributing to their accumulation in the rheumatoid synovium.