Analysis for the pathogenesis of concomitant infection in AIDS and murine AIDS

LP-BM5murine leukemia virus(MuLV)injection is a causative of murine AIDS(MAIDS)，characterized by a variety of functional abnormalities of immunocompetent cells and susceptibility to various infectious with Mycobacterium avium or M.bovis BCG as assessed by survival rate and bacterial counts.The expression of IL-15 in the peritoneal macrophages was severely impaired in MAIDS mice following infection with M.bovis BCG。NK cells were increased in the peritoneal cavity of normal mice at earl stage after BCG infection，whereas such increases were not evident in MAIDS mice。Serum IFN-γlevel was also depressed in MAIDS mice following BCG infection.The production IFN-γby T cells from the MAIDS mice infected with M.bovis BCG was significantly lower in response to PPD than that of normal mice infected with M.bovis BCG。These results suggested that depressed IL-15 production in MAIDS mice might be involved in susceptibility against M.bovis BCG.To elucidate the protective roles of IL-15in the progression of MAIDS，we constructed transgenic mice using IL-15cDNA under the control of an MHC class I promoter.The IL-15 Tg mice constitutionally produced a significant level of IL-15 protein and had markedly increased numbers of memory type(CD 44 I D 1 high e D 1 Ly 6C I D 1+I D 1)of CD 8 I D 1+D 1 T cells in the LN.These mice showed resistance to LP-BM5infection accompanied by increases in NK cells and memory CD8 I D1+ii D1T cells and enhanced IFN-γproduction.Thus，these findings suggest that IL-15 production is partly responsible for MAIDS progression and that IL-15may be protective for MAIDS and presumably AIDS progression.

LP-BM5 murine leukemia virus (MuLV) injection is a causative of murine AIDS (MAIDS), characterized by a variety of functional abnormalities of immunocompetent cells and susceptibility to various infectious with Mycobacterium avium or M. bovis BCG as assessed by survival rate and bacterial counts. The expression of IL-15 in the peritoneal macrophages was severely impaired in MAIDS mice following infection with M. bovis BCG. NK cells were increased in the peritoneal cavity of normal mice at earl stage after BCG infection, whereas such increases were not evident in MAIDS mice. Serum IFN-γ level was also depressed in MAIDS mice following BCG infection. The production IFN-γ by T cells from the MAIDS mice infected with M. bovis BCG was significantly lower in response to PPD than that of normal mice infected with M. bovis BCG. These results suggested that depressed IL-15 production in MAIDS mice might be involved in susceptibility against M. bovis BCG.To elucidate the protective roles of IL-15 in the progression of MAIDS, we constructed transgenic mice using IL-15 cDNA under the control of an MHC class I promoter. The IL-15 Tg mice constitutionally produced a significant level of IL-15 protein and had markedly increased numbers of memory type (CD44ィイD1highィエD1 Ly6CィイD1+ィエD1) of CD8ィイD1+ィエD1T cells in the LN. These mice showed resistance to LP-BM5 infection accompanied by increases in NK cells and memory CD8ィイD1+ィエD1 T cells and enhanced IFN-γ production. Thus, these findings suggest that IL-15 production is partly responsible for MAIDS progression and that IL-15 may be protective for MAIDS and presumably AIDS progression.