title: Natural killer (NK) cells prevent virus production in cell culture.
abstract: Natural killer (NK) cells (CD3-/CD16+/CD56+ lymphocytes) play an important role in early immune defense against viral infection, a fact which is of prime significance for heavily immunosuppressed patients after bone marrow transplantation. In this study we demonstrate that NK cells preferentially lyse human colon adenocarcinoma (Colo-205) tumor cells infected with herpes simplex virus type 1 (HSV-1) and vaccinia virus (VV) and autologous T cells infected with VV. This phenomenon was assessed by the viral infectious center (IC) method and compared with the results obtained by means of the standard 51Cr-release assay. Using the IC assay, we found that NK cells lyse virus infected cells at an early stage of infection, thereby preventing viral dissemination to neighboring cells. 51Cr-release assay verified by propidium iodide (PI) penetration showed that the early effects of NK mediated anti-viral activity are not the result of membrane damage. The effect of NK cells on HSV-1 infected Colo-205 cells appears to be independent of the level of expression of major histocompatibility complex (MHC) class I molecules while the killing of autologous VV-infected T cells correlates with a reduction in MHC class I expression. Our results suggest that additional factors besides MHC play a role in the regulation of NK cell-mediated lysis of virus infected cells. This may be of clinical importance in patients who are heavily immunosuppressed after bone marrow transplantation.
authors.affiliation: Department of Bone Marrow Transplantation, Hadassah University Hospital, The Hebrew University-Hadassah Medical School, Jerusalem, Israel.
authors.forename: L
authors.initials: L
authors.lastname: Baraz
authors.forename: E
authors.initials: E
authors.lastname: Khazanov
authors.forename: R
authors.initials: R
authors.lastname: Condiotti
authors.forename: M
authors.initials: M
authors.lastname: Kotler
authors.forename: A
authors.initials: A
authors.lastname: Nagler
mesh_terms: D000956:Antigens, Viral; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D006561:Herpes Simplex / Q000276:immunology*; D018259:Herpesvirus 1, Human / Q000276:immunology*; D015395:Histocompatibility Antigens Class I; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology* / Q000821:virology; D014615:Vaccinia / Q000276:immunology*; D014616:Vaccinia virus / Q000276:immunology*
chemical_list: D000956:Antigens, Viral; D015395:Histocompatibility Antigens Class I