Lymphocytes expressing α1β1 integrin (very late antigen-1) in peripheral blood of patients with arthritis are a subset of CD45RO+ T-cells primed for rapid adhesion to collagen IV

Abstract We report that very late antigen-1 (VLA-1 + ) CD3 + CD45RO + T-cells are selectively segregated from VLA-1 − peripheral blood (PB) mononuclear cells (MC), in which CD3 + T-cells are evenly CD45RO + and CD45RO − , when PBMC are stained with a monoclonal antibody (mAb) to VLA-1 and passaged on immunomagnetic columns. In contrast, both VLA-1 + and VLA-1 − MC isolated from synovial fluid (SF) are mainly CD45RO + CD3 + T-cells. VLA-1 + MC formed 13 ± 5.3% of MC eluting from columns loaded with PBMC of patients with seropositive rheumatoid arthritis ( n = 6) and 2.3 ± 1.6% of patients ( n = 4) with other arthritides ( P + MC from PB and SF adhered to collagen IV upon triggering with phorbol 12-myristate 13-acetate. Moreover, adhesion and migration on collagen IV were preferentially maintained in lines cultured from VLA-1 + T-cells, and both were inhibited by mAb to the VLA-1 α1 I domain. These results suggest that VLA-1 + CD45RO + T-cells in patients with arthritis could play a role in both systemic and local inflammation by rapidly adhering to collagen IV.