title: Type I NKT cells protect (and type II NKT cells suppress) the host's innate antitumor immune response to a B-cell lymphoma.
abstract: Natural killer T (NKT) cells are a T-cell subpopulation known to possess immunoregulatory functions and recognize CD1d molecules. The majority of NKT cells express an invariant T-cell receptor (TCR) alpha chain rearrangement (Valpha14 Jalpha18 in mice; Valpha24 Jalpha18 in humans) and are called type I NKT cells; all other NKT cells are type II. In the current study, we have analyzed the roles for these NKT-cell subsets in the host's innate antitumor response against a murine B-cell lymphoma model in vivo. In tumor-bearing mice, we found that type I NKT cells conferred protection in a CD1d-dependent manner, whereas type II NKT cells exhibited inhibitory activity. Pro- and anti-inflammatory cytokines secreted by splenocytes from tumor-bearing mice correlated with tumor progression. Myeloid cells (CD11b(+)Gr1(+)) were present in large numbers at the tumor site and in the spleen of tumor-bearing type I NKT-deficient mice, suggesting that antitumor immunosurveillance was inhibited by CD11b(+)Gr1(+) cells. Overall, these data suggest that there are distinct roles for NKT-cell subsets in response to a B-cell lymphoma in vivo, pointing to potential novel targets to be exploited in immunotherapeutic approaches against blood cancers.
authors.affiliation: Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202-5181, USA.
authors.forename: Gourapura J
authors.initials: GJ
authors.lastname: Renukaradhya
authors.forename: Masood A
authors.initials: MA
authors.lastname: Khan
authors.forename: Marcus
authors.initials: M
authors.lastname: Vieira
authors.forename: Wenjun
authors.initials: W
authors.lastname: Du
authors.forename: Jacquelyn
authors.initials: J
authors.lastname: Gervay-Hague
authors.forename: Randy R
authors.initials: RR
authors.lastname: Brutkiewicz
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D001201:Ascites / Q000276:immunology; D045744:Cell Line, Tumor; D016207:Cytokines / Q000378:metabolism; D005260:Female; D007167:Immunotherapy; D007694:Killer Cells, Natural / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D016393:Lymphoma, B-Cell / Q000276:immunology* / Q000401:mortality / Q000628:therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D022423:Myeloid Cells / Q000276:immunology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D015996:Survival Rate; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism
chemical_list: D016207:Cytokines; D016693:Receptors, Antigen, T-Cell, alpha-beta