The role of CD8+ Granzyme B+ T cells in the pathogenesis of Takayasu's arteritis.

Abstract

T cell-mediated immune response plays a key role in Takayasu arteritis (TAK). Although previous studies have showed the roles of CD4+T cell and its subsets in TAK, the change of CD8+ T cell subsets remains unclear. This study investigated the role of CD8+ T cell subsets in TAK. The study consisted of 56 TA patients and 51 healthy controls. The percentages of CD8+T cells, CD8+GranzymeB+ T cells, CD8+Perforin+ T cells, and CD8+IFN-γ+ T cells in blood samples were analyzed by flow cytometry. We found that the percentages of CD8+GranzymeB+ T cells (P = 0.030), CD8+Perforin+ T cells (P = 0.000), and CD8+IFN-γ+ T cells (P = 0.002) in CD8+T cells were higher in TAK patients compared to control group. After 6months of treatment, the proportion of CD8+T cells in lymphocytes were significantly lower in TAK patients than the baseline assessment (P = 0.033). A lower ratio of CD8+GranzymeB+ T cells/CD8+ T cells were showed in TAK patents after treatment compared with TAK patients before treatments (P = 0.011). The change of CD8+GranzymeB+ T cells/CD8+ T cells ratio was positively correlated with the change of ITAS (r = 0.721, P = 0.002) and ITAS-A (r = 0.637, P = 0.008). Finally, the immunofluorescence staining showed the infiltration of CD8+ Granzyme B + cells in the aortic tissue of TAK patients. Our results disclose that the CD8+ T lymphocytes may play a role in TAK pathogenesis. Targeting CD8+GranzymeB+ T lymphocytes or Granzyme B inhibitors could be a potential therapeutic approach for the treatment of TAK. Key Points • Our study investigated role the of CD8+ T cell subsets in TAK. • We found the percentages of CD8+GranzymeB+ T cells, CD8+Perforin+ T cells, and CD8+IFN-γ+ T cells in CD3+CD8+T cells were higher in TAK patients. • The proportion of CD8+T cells in lymphocytes and the ratio of CD8+GranzymeB+ T cells/CD8+ T cells were significantly lower in TAK patients after treatment.