title: Proliferative activation up-regulates expression of CD4 and HIV-1 co-receptors on NK cells and induces their infection with HIV-1.
abstract: NK cells play important roles in immune surveillance against malignancy and virus-infected cells. NK cell functions are affected in patients infected with HIV-1; however, whether there is direct interaction between NK cells and HIV-1 remains controversial. In this study the expression of CD4, an important receptor for HIV-1, was up-regulated on NK cells co-cultured with an NK cell-selective stimulating cell line, HFWT, and rIL-2. Although the level of CD4 was lower on NK cells than on CD4+ T cells, expression of the HIV-1 co-receptor CCR5 was clearly up-regulated on CD4+ NK cells. CD4+ NK cells expressed higher levels of HLA-DR and CD25 than CD4- NK cells, suggesting that they were highly activated. Cell-free HIV-1 could not infect the NK cells, but NK cells were infected when co-cultured with HIV-1-infected T cells. Using this co-culture system, we can better understand how HIV-1 infects NK cells and how NK cell functions are affected in AIDS.
authors.affiliation: Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, Kumamoto, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Harada
authors.forename: Yumi
authors.initials: Y
authors.lastname: Goto
authors.forename: Tadao
authors.initials: T
authors.lastname: Ohno
authors.forename: Shinya
authors.initials: S
authors.lastname: Suzu
authors.forename: Seiji
authors.initials: S
authors.lastname: Okada
mesh_terms: D015704:CD4 Antigens / Q000276:immunology* / Q000378:metabolism; D049109:Cell Proliferation; D018920:Coculture Techniques; D005434:Flow Cytometry; D015658:HIV Infections / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology* / Q000472:pathogenicity; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology* / Q000821:virology; D008213:Lymphocyte Activation / Q000276:immunology*; D019713:Receptors, CCR5 / Q000096:biosynthesis; D011991:Receptors, Virus / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology / Q000821:virology; D015854:Up-Regulation
chemical_list: D015704:CD4 Antigens; D019713:Receptors, CCR5; D011991:Receptors, Virus