absence of both il-7 and il-15 severely impairs the development of cd8+ t cell response against toxoplasma gondii缺乏il-7和il-15严重损害发展针对刚地弓形虫的cd8 + t细胞反应.pdfVIP

Absence of Both IL-7 and IL-15 Severely Impairs the Development of CD8+ T Cell Response against Toxoplasma gondii 1 2 1 Rajarshi Bhadra , Hongbing Guan , Imtiaz A. Khan * 1 Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington, D. C., United States of America, 2 Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, United States of America Abstract CD8+ T cells play an essential role in the protection against both acute as well as chronic Toxoplasma gondii infection. Although the role of IL-15 has been reported to be important for the development of long-term CD8+ T cell immunity against the pathogen, the simultaneous roles played by both IL-15 and related c-chain family cytokine IL-7 in the generation of this response during acute phase of infection has not been described. We demonstrate that while lack of IL-7 or IL-15 alone has minimal impact on splenic CD8+ T cell maturation or effector function development during acute Toxoplasmosis, absence of both IL-7 and IL-15 only in the context of infection severely down-regulates the development of a potent CD8+ T cell response. This impairment is characterized by reduction in CD44 expression, IFN-c production, proliferation and cytotoxicity. However, attenuated maturation and decreased effector functions in these mice are essentially downstream consequences of reduced number of antigen-specific CD8+ T cells. Interestingly, the absence of both cytokines did not impair initial CD8+ T cell generation but affected their surviv