アクティブボード・２００９年　７月
　　　　　・・・・・２００９年　７月　３日更新・・・・・

研究発表を行った学会；
・Keystone Symposia
HIV Immunobiology: From Infection to Immune Control (X4).
　２００９年　３月２２日〜２７日（Keystone,Denver,U.S.A.）

タイトル；Killing of HIV-1-infected macrophages by HIV-1 Nef-specific CD4+ CTLs.
　
発表者；　Nan Zheng　氏
　　　（熊本大学　エイズ学研究センター　ウイルス制御分野）
Abstract；
Increasing evidences showed that HIV-1 specific CD4+ T cells play important roles against infection. In the recent study, we investigated the ability of HIV-1-specific CD4+ T cells to kill HIV-1-infected target cells. We identified two CD4+ T cell epitopes on nef protein, Nef37-53 and Nef187-203, which were restricted by HLA-DRB1*0403 and HLA-DRB1*0803, respectively. Both two epitope peptides induced strong specific IFN-gamma responses of CD4+ T cells in the cultured PBMC from HIV-1-infected donors. Nef187-203-specific CD4+ T cell clones derived from an infected donor showed strong cytotoxic activity for pulsed or recombinant HIV-1 nef vaccinia-infected autologous EBV transformed B lymphoblastoid cells (B-LCLs), whereas Nef37-53-specific CD4+ T cell clones did not. Nef187-203-specific CD4+ T cell clones expressed perforin, granzyme A and granzyme B, while they secreted substantial amounts of IFN-gamma and MIP-1beta but only low levels of TNF-alpha, IL-2 and IL-4 after stimulation with HIV-1-infected macrophages as well as stimulated with peptide-pulsed B-LCLs, indicating the existence of a perforin-mediated cytotoxicity of HIV-1 Nef-specific CD4+ T cells. These clones could effectively lyse macrophages infected with HIV-1, implying the direct roles of HIV-1-specific CD4+ T cells in controlling HIV-1 infection.
.