The Restricted Usage Of T Cell Receptor Vβ And Biological Function In CD4～+ T Lymphocytes From Peripheral Blood With Graves Disease

Objective: To evaluate if there is a restricted usage of TCR VJ3 gene segment in CD4+ CD28+ and CD4+CD28~ T cell subsets from peripheral blood with Graves disease, and the biological function of these two subsets. Methods: We detected the expression level of TCR Vp in CD4+CD28 + and CD4+CD28~T subset with real-time quantitative PCR(RQ-PCR) in ten Graves disease patients, the intracytoplasmic level of IFN-y and IL-4 in the two short-term cell lines using Flow Cytometer. Furthermore, the function of agonistic anti-CD40mAb, antagonistic anti-CD40LmAb and antagonistic anti-B7-lmAb to the interaction of thyrocyte with these two subsets also be primarily assessed by 3H-TdR incorporation. Results: There were overexpression of CD4+CD28-T cell subset in these 10 patients for 12 times, and only 6 times of CD4+CD28+T cell subset in these 8 patients(two patients not detected). The usage of V(3 in these two subsets is partially different. The intracytoplasmic level of IFN-y( 27.9 15.9% )in CD4+CD28-T cell subset show marked higher than that in CD4+CD28+T cell subset (10.3 + 12.1%, P<0.001) of the same patient, while the intracytoplasmic level of IL-4 in these two subset has no different significance (7.8 + 9.2% and 13.5 + 18.7% respectively, P>0.05) . The promoting proliferation effect of agonistic CD40mAb could be found in the CD4+CD28+T cell group rather than CD4+CD28-; the proliferation of both groups could be inhibited by antagonistic CD40LmAb; the antagonistic B7-lmAb could only restrain the proliferation of CD4+CD28+T cell group, but not CD4+CD28- group. Conclusion: The restricted usage of TCR Vp gene segment suggests that oligoclonal proliferation happened in both subsets, CD4+CD28-T cell subset maybe belong to Th1, and both of them probably playdifferent role in pathogenesis and activation of Graves disease. All of agonistic CD40mAb, antagonistic CD40LmAb and antagonistic B7-lmAb have relavative effects on these two T cell subsets.