Antigen-specific expansion of TCR Vβ3⁺CD4⁺ T cells in the early stage of collagen-induced arthritis and its arthritogenic role in DBA/1J mice

To investigate type II collagen (CII)-specific CD4⁺ T cell receptors involving in Collagen-induced arthritis (CIA) in DBA/1J mice as a model of rheumatoid arthritis in humans, TCRVβ usage in draining lymph nodes (dLNs) was assessed by flow cytometric analysis at 3, 5, and 8 weeks after bovine CII immunizations. In the early stage of CIA, the draining lymph node CD4⁺ T cells from CIA mice showed a higher proportion of CD4 ⁺ Vβ3⁺subsets compared with those from control mice. The CD4⁺ Vβ3⁺ T cells were specifically and primarily expanded by antigen-specific stimulation in in vitro culture of dLNs lymphocytes and splenocytes from CIA mice. In addition, CII-reactive response was observed when CD4⁺ Vβ3⁺ T cells were added to a non-responding T cell population. The adoptive transfer of CD4⁺ Vβ3⁺ T cells produced exaggerated arthritis compared with that in the control group. Our results indicate that CD4⁺Vβ3 ⁺ T cells, which were selectively expanded in dLN of CIA mice, play a pivotal role in CIA pathogenesis.