title: CD1d-independent NKT cells in beta 2-microglobulin-deficient mice have hybrid phenotype and function of NK and T cells.
abstract: Unlike CD1d-restricted NK1.1(+)TCRalphabeta(+) (NKT) cells, which have been extensively studied, little is known about CD1d-independent NKT cells. To characterize their functions, we analyzed NKT cells in beta(2)-microglobulin (beta(2)m)-deficient B6 mice. They are similar to NK cells and expressed NK cell receptors, including Ly49, CD94/NKG2, NKG2D, and 2B4. NKT cells were found in normal numbers in mice that are deficient in beta(2)m, MHC class II, or both. They were also found in the male HY Ag-specific TCR-transgenic mice independent of positive or negative selection in the thymus. For functional analysis of CD1d-independent NKT cells, we developed a culture system in which CD1d-independent NKT cells, but not NK, T, or most CD1d-restricted NKT cells, grew in the presence of an intermediate dose of IL-2. IL-2-activated CD1d-independent NKT cells were similar to IL-2-activated NK cells and efficiently killed the TAP-mutant murine T lymphoma line RMA-S, but not the parental RMA cells. They also killed beta(2)m-deficient Con A blasts, but not normal B6 Con A blasts, indicating that the cytotoxicity is inhibited by MHC class I on target cells. IL-2-activated NKT cells expressing transgenic TCR specific for the HY peptide presented by D(b) killed RMA-S, but not RMA, cells. They also killed RMA (H-2(b)) cells that were preincubated with the HY peptide. NKT cells from beta(2)m-deficient mice, upon CD3 cross-linking, secreted IFN-gamma and IL-2, but very little IL-4. Thus, CD1d-independent NKT cells are significantly different from CD1d-restricted NKT cells. They have hybrid phenotypes and functions of NK cells and T cells.
authors.affiliation: Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors.forename: Motoi
authors.initials: M
authors.lastname: Maeda
authors.forename: Ashleen
authors.initials: A
authors.lastname: Shadeo
authors.forename: Anna M
authors.initials: AM
authors.lastname: MacFadyen
authors.forename: Fumio
authors.initials: F
authors.lastname: Takei
mesh_terms: D000818:Animals; D018949:Antigens, CD1 / Q000502:physiology*; D055610:Antigens, CD1d; D002454:Cell Differentiation / Q000276:immunology; D019070:Cell Lineage / Q000235:genetics / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D004306:Dose-Response Relationship, Immunologic; D006822:Hybrid Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D016130:Immunophenotyping; D007376:Interleukin-2 / Q000494:pharmacology; D015979:Killer Cells, Lymphokine-Activated / Q000166:cytology / Q000276:immunology; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008213:Lymphocyte Activation / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000172:deficiency* / Q000235:genetics*
chemical_list: D018949:Antigens, CD1; D055610:Antigens, CD1d; D007376:Interleukin-2; D001613:beta 2-Microglobulin