Mycobacterium avium complex症患者のCD4^+ αβとγδT細胞機能に関する検討 : 増殖能, IFN-γ, IL-10産生能

Abstract

Several cytokines play a crucial role in host defense immunity against Mycobacterium tuberculosis. But in patients with non-tuberculous mycobacterial disease, the function of both CD4^+ αβ T cells and γδ T cells and the cytokine production of these cells have not yet been assessed. In this study, to elucidate the protective immune mechanism against M. avium complex (MAC) infection, I examined IFN-γ and IL-10 production in supernatants of coculture of infected monocytes and highly purified CD4^+ T or γδ T cells obtained from patients and healthy subjects. IFN-γ productions by CD4^+ T and γδ T cells were significantly higher in healthy subjects than those in patients: mean ng /ml of IFN-γ in supernatants was 11.90±1.38 in controls and 4.61±3.10 in patients for CD4^+ T cells (p＜0.01), and 4.41±2.10 in controls and 1.27±1.38 in patients for γδ T cells (p＜0.001), respectively. CD4^+ T cells produced significantly higher amounts of IFN-γ than did γδ T cells in patients and healthy subjects (p＜0.01). In remarkable contrast, IL -10 production in the coculture of infected monocytes and CD4^+ T cells was significantly higher in patients than in healthy subjeCts: mean pg/ml of IL-10 in supernatants was 220± 105 in patients and 136±39 in controls (p＜0.05), respectively. These results suggest that the profile of those cytokines produced by CD4^+ T and γδ T cells may be closely related to pathogenesis of MAC disease.