title: NK cell-like behavior of Valpha14i NK T cells during MCMV infection.
abstract: Immunity to the murine cytomegalovirus (MCMV) is critically dependent on the innate response for initial containment of viral replication, resolution of active infection, and proper induction of the adaptive phase of the anti-viral response. In contrast to NK cells, the Valpha14 invariant natural killer T cell response to MCMV has not been examined. We found that Valpha14i NK T cells become activated and produce significant levels of IFN-gamma, but do not proliferate or produce IL-4 following MCMV infection. In vivo treatment with an anti-CD1d mAb and adoptive transfer of Valpha14i NK T cells into MCMV-infected CD1d(-/-) mice demonstrate that CD1d is dispensable for Valpha14i NK T cell activation. In contrast, both IFN-alpha/beta and IL-12 are required for optimal activation. Valpha14i NK T cell-derived IFN-gamma is partially dependent on IFN-alpha/beta but highly dependent on IL-12. Valpha14i NK T cells contribute to the immune response to MCMV and amplify NK cell-derived IFN-gamma. Importantly, mortality is increased in CD1d(-/-) mice in response to high dose MCMV infection when compared to heterozygote littermate controls. Collectively, these findings illustrate the plasticity of Valpha14i NK T cells that act as effector T cells during bacterial infection, but have NK cell-like behavior during the innate immune response to MCMV infection.
authors.affiliation: Department of Molecular Microbiology and Immunology and Graduate Program in Pathobiology, Division of Biology and Medicine, Brown University, Providence, Rhode Island, United States of America.
authors.forename: Johnna D
authors.initials: JD
authors.lastname: Wesley
authors.forename: Marlowe S
authors.initials: MS
authors.lastname: Tessmer
authors.forename: Deanna
authors.initials: D
authors.lastname: Chaukos
authors.forename: Laurent
authors.initials: L
authors.lastname: Brossay
mesh_terms: D000818:Animals; D002452:Cell Count; D020868:Gene Silencing; D007113:Immunity, Innate; D007371:Interferon-gamma / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018146:Muromegalovirus / Q000502:physiology*; D020825:T-Box Domain Proteins / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000821:virology*; D014779:Virus Replication; D000098815:T-bet Transcription Factor
chemical_list: D053645:Interleukin-2 Receptor alpha Subunit; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D007371:Interferon-gamma