CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although alpha-galactosylceramide (alpha-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-gamma by NKT cells, concomitant with a decreased level of IL-4, in the circumstance of co-culture of DCs and B Cells. Remarkably, the response promoted by B cells was dependent on CD1d expression of B cells.
Antigen-Presenting Cells ; B-Lymphocytes* ; Coculture Techniques ; Dendritic Cells ; Galactosylceramides ; Interleukin-4 ; Natural Killer T-Cells*

Animals ; Anti-Bacterial Agents ; administration & dosage ; Escherichia coli ; Female ; Galactosylceramides ; immunology ; Gastric Mucosa ; pathology ; Gastritis, Atrophic ; pathology ; Helicobacter Infections ; complications ; drug therapy ; Helicobacter pylori ; pathogenicity ; Humans ; Inflammation ; pathology ; Intestines ; microbiology ; Levofloxacin ; Lymphocyte Activation ; Male ; Natural Killer T-Cells ; microbiology ; Ofloxacin ; administration & dosage ; Sphingomonas ; Stomach ; pathology

PURPOSE: Invariant natural killer T (iNKT) cells may play an important role in the pathogenesis of asthma in mice and humans. Thus, an agent that modulates the function of iNKT cells may have therapeutic potential to control asthma. We hypothesized that lipopolysaccharide (LPS)-, flagellin-, or CpG-induced changes in the cytokine milieu may modify and even inhibit the function of airway iNKT cells in asthma. METHODS: Because increased alpha-galactosylceramide (GalCer)-induced airway hyperreactivity (AHR) reflects the presence of airway iNKT cells, alpha-GalCer-induced AHR, as well as inflammatory cells and cytokines in bronchoalveolar lavage (BAL) fluid, were determined 24 hours after in vivo treatment with LPS, flagellin, or CpG in naive BALB/c mice. Intracellular IL-4 and IFN-gamma were measured in spleen iNKT cells after in vitro treatment with LPS, flagellin, or CpG. A role for IL-12 following the treatments was determined. RESULTS: Intranasal administration of LPS, flagellin, or CpG reduced development of alpha-GalCer-induced AHR, eosinophilic airway inflammation, and Th1 and Th2 cytokine responses in BAL fluid, while producing IL-12 in BAL fluid. Intraperitoneal administration of IL-12 mAb blocked the suppressive effect of LPS, flagellin, or CpG. In vitro treatment with LPS, flagellin, or CpG reduced production of IL-4 and IFN-gamma from alpha-GalCer-stimulated spleen iNKT cells; these effects were ameliorated by addition of anti-IL-12 mAb. CONCLUSIONS: TLR4, 5, and 9 agonists may suppress the function of airway and spleen iNKT cells via IL-12-dependent mechanisms. Anergy of iNKT cells by IL-12 might play a role in suppression by these TLR agonists.
Administration, Intranasal ; Animals ; Asthma ; Bronchoalveolar Lavage ; Cytokines ; Eosinophils ; Flagellin ; Galactosylceramides ; Humans ; Inflammation ; Interleukin-12 ; Interleukin-4 ; Mice ; Natural Killer T-Cells ; Spleen

BACKGROUNDActivation in vitro of natural killer T (NKT) cells in systemic lupus erythematosus (SLE) with α-galactosylceramide (α-GalCer) and dendritic cells (DC) may affect the immunoregulatory role of NKT cells. This study was designed to compare the number of NKT cells in patients with SLE to the number in healthy volunteers and measure the cytokines secreted from these NKT cells in vitro.

METHODSThree sets of culture conditions using (i) α-GalCer, (ii) DC, or (iii) both α-GalCer and DC (α-GalCer+DC) were adopted to expand NKT cells from peripheral blood mononuclear cells (PBMC) of patients with SLE and healthy volunteers. Flow cytometry was used to assess the levels of interleukin (IL)-4, IL-10, interferon (IFN)-γ and tumor necrosis factor (TNF)-α produced by the Vα24(+)Vβ11(+) NKT cells.

RESULTSAfter 14 days in culture, the total cell count and percentage of Vα24(+)Vβ11(+) NKT cells were increased under all conditions but were highest in the α-GalCer+DC group. The level of IL-4 and IL-10 secreted by Vα24(+)Vβ11(+) NKT cells from patients with active SLE was found to be higher than that of inactive patients and the control group (P < 0.05), while the levels of IFN-γ and TNF-α were lower than those found in the inactive and control groups (P < 0.05).

CONCLUSIONSVα24(+)Vβ11(+) NKT cells showed the greatest expansion in vitro with α-GalCer and DC. Th2-type cytokines from Vα24(+)Vβ11(+) NKT cells are the predominant type in patients with SLE, while Th1 cytokines predominate in the control group. This evolution of NKT cell function during the progression of the disease may have important implications in understanding the mechanism of SLE and for the development of possible therapies using NKT cell agonists.

Adolescent ; Adult ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cytokines ; metabolism ; Dendritic Cells ; metabolism ; Female ; Flow Cytometry ; Galactosylceramides ; pharmacology ; Humans ; Interferon-gamma ; metabolism ; Interleukin-10 ; metabolism ; Interleukin-4 ; metabolism ; Lupus Erythematosus, Systemic ; immunology ; metabolism ; Male ; Middle Aged ; Natural Killer T-Cells ; cytology ; drug effects ; metabolism ; Receptors, Antigen, T-Cell ; metabolism ; Receptors, Antigen, T-Cell, alpha-beta ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; Young Adult

Animals ; Female ; Galactosylceramides ; metabolism ; Graft vs Host Disease ; metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; T-Lymphocytes ; cytology ; Th2 Cells ; cytology

OBJECTIVETo explore the effect of α- galactosyleramide( α-GalCer ) on immune reconstitution under acute graft-versus-host disease (aGVHD).

METHODSBALB/c mice were transplanted wit hallogeneic C57BL/6 bone marrow cells and splenocytes (both 1×10(7))after receiving lethal total-body irradiation. α-GalCer (100 ug/kg) or vehicle (dimethylsulfoxide) was administered intraperitoneally immediately after transplantation. The effects of α-GalCer on immune reconstitution,proliferation of T cells and B cells, hematopoiesis,and thymic microenvironment were assessed.

RESULTSThe α-GalCer group exhibited higher percentages of CD3(+),CD4(+), CD8(+), B220(+), CD40(+), and CD86(+)cells compared with the vehicle group . The number of colony forming unit per 1000 CD34(+) cells in the α-GalCer group was higher than in the vehicle group ( P=0.0012).In vitro proliferation assays showed that the α-GalCer group had higher percentages of CD3(+), CD4(+), CD8(+),and B220(+) cells compared with the vehicle group. As for the results of in vivo proliferation assays, the numbers of CD3(+), CD4(+), CD8(+), and B220(+)cells were higher in the α-GalCer group than in the normal group ,especially the number of B220(+) cells ( P=0.007).Significant difference was not found in thymocyte count between the α-GalCer group and the vehicle group, nor in the percentages of CD3(+), CD4(+), and CD8(+) cells.

CONCLUSIONAdministration of α-GalCer after allogeneic bone marrow transplantation may promote immune reconstitution in the presence of aGVHD.

Animals ; B-Lymphocytes ; drug effects ; immunology ; Bone Marrow Transplantation ; immunology ; Female ; Galactosylceramides ; pharmacology ; Graft vs Host Disease ; immunology ; Hematopoietic Stem Cells ; drug effects ; Lymphocyte Activation ; drug effects ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; T-Lymphocytes ; drug effects ; immunology ; Transplantation, Homologous

Natural killer T (NKT) cell is a special type of T lymphocytes that has both receptor of natural killer (NK) cell (NK1.1, CD161c) and T cell (TCR) and express a conserved or invariant T cell receptor called Valpha14Jalpha18 in mice or Va24 in humans. Invariant NKT (iNKT) cell recognizes lipid antigen presented by CD1d molecules. Marine-sponge-derived glycolipid, alpha-galactosylceremide (alpha-GalCer), binds CD1d at the cell surface of antigen-presenting cells and is presented to iNKT cells. Within hours, iNKT cells become activated and start to secrete Interleukin-4 and interferon-gamma. NKT cell prevents autoimmune diseases, such as type 1 diabetes, experimental allergic encephalomyelitis, systemic lupus erythematous, inflammatory colitis, and Graves' thyroiditis, by activation with alpha-GalCer. In addition, NKT cell is associated with infectious diseases by mycobacteria, leshmania, and virus. Moreover NKT cell is associated with asthma, especially CD4+ iNKT cells. In this review, I will discuss the characteristics of NKT cell and the association with inflammatory diseases, especially asthma.
Animals ; Antigen-Presenting Cells ; Asthma ; Autoimmune Diseases ; Colitis ; Communicable Diseases ; Encephalomyelitis, Autoimmune, Experimental ; Galactosylceramides ; Humans ; Interferon-gamma ; Interleukin-4 ; Mice ; Natural Killer T-Cells ; Receptors, Antigen, T-Cell ; T-Lymphocytes ; Thyroid Gland ; Thyroiditis ; Viruses

Immune reconstitution is crucially relevant for patients receiving hematopoietic stem cell transplantation (HSCT). This study was purposed to investigate the ability of α-GalCer (α-galactosylceramide), a well-known activator of natural killer T cells (NK-T), to enhance immune and hematological reconstitution. Lethally irradiated BALB/c mice were transplanted with allogeneic C57BL/6 bone marrow cells and splenocytes. α-GalCer was administered immediately after HSCT. After transplantation, the weight, activity, hairs, diarrhea and survival time of mice were observed daily; the blood routine test was performed once weekly; the donor chimeras, amount of mononuclear cells in spleen (MNC) and relative levels of CD3(+), CD4(+), CD8(+), B220(+), CD11c(+), CD40(+), CD86(+) and CD80(+) cells were detected by FACS on day 2, 7, 14, 27, 70 after transplantation. The results indicated that the MNC counts and relative levels of CD3(+) and CD4(+) in group treated with α-GalCer on day 2 after transplantation were higher than those in control group; at the same time, the detected donor chimeras were complete recipient type chimeras, then gradually transformed into donor type, on day 7 - 14 donor chimeras in α-GalCer group were enhanced significantly as compared with control group, on day 27 the chimeras in two groups were complete donor type chimeras thereafter to day 70, the MNC count and relative levels of CD3(+), CD4(+), CD8(+), B220(+), CD40(+), CD86(+) cells in α-GalCer group were obviously higher than those in control group, at the same time, the hematopoietic reconstitution in α-GalCer group was accelerated as compared with control group. It is concluded that the α-GalCer administration after allogeneic bone marrow transplantations accelerates immune and hematological reconstitution.
Animals ; Bone Marrow Transplantation ; immunology ; methods ; Chimera ; Female ; Galactosylceramides ; pharmacology ; Leukocyte Count ; Lymphocyte Activation ; drug effects ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Natural Killer T-Cells ; drug effects ; immunology ; Postoperative Period

Invariant natural killer T (iNKT) cells develop in the thymus upon recognition of CD1d expressed on developing thymocytes. Although CD4 and CD8 coreceptors are not directly involved in the interaction between CD1d and the T cell receptors (TCRs) of iNKT cells, a conspicuous lack of CD8+ iNKT cells in mice raised the question of whether CD8+ iNKT cells are excluded due to negative selection during their thymic development, or if there is no lineage commitment for the development of murine CD8+ iNKT cells. To address this question, we analyzed iNKT cell-specific TCR Valpha14+ transgenic mice, where the Valpha14 transgene forces the generation of iNKT cells. This allows detailed study of the iNKT cell repertoire. We were able to identify CD8+ iNKT cells which respond to the NKT cell-specific glycolipid ligand alpha-galactosylceramide. Unlike conventional iNKT cells, CD8+ iNKT cells produce predominantly IFN-gamma but not IL-4 upon antigen stimulation. We also confirmed the presence of CD8+ iNKT cells in wild type mice. Our results suggest that CD8+ NKT cells do exist in mice, although their population size is quite small. Their Th1-skewed phenotype might explain why the population size of this subtype needs to be controlled tightly.
Animals ; CD8-Positive T-Lymphocytes/*immunology/metabolism ; Galactosylceramides/immunology ; Interferon-gamma/immunology ; Interleukin-4/immunology ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Natural Killer T-Cells/*immunology/metabolism ; Receptors, Antigen, T-Cell, alpha-beta/*genetics ; Transgenes

This study was purposed to investigate the phenotype, in vitro expansion and cytokine secretion profile of Valpha24(+) NKT cells from cord blood (CB), peripheral blood (PB), and granulocyte colony stimulating factor-mobilized peripheral blood mononuclear cells (G-PBMNCs). Fresh mononuclear cells (MNCs) were isolated by the method of gradient centrifugation and then cultured with alpha-GalCer (100 ng/ml), IL-2 (50 U/ml), IL-15 (50 ng/ml) for 12 days. Valpha24(+) NKT cells were purified by anti-Vbeta11 TCR McAb and goat anti-mouse IgG magnetic beads. The phenotype and purity of Valpha24(+) NKT cells were determined by flow cytometry. Cytokine production was analyzed by ELISA. The results showed that Valpha24(+) NKT cells in CB, PB and G-PBMNCs were expanded by 221.5 (95 - 501), 456.5 (101 - 2207), and 756.38 (82 - 20373)-fold respectively. After stimulation by phorbol-12-myristate-13-acetate (PMA) for 24 hours, IL-4 and IFN-gamma produced by Valpha24(+) NKT cells from CB and PB were 180.33 (144.67 - 2253.48) vs 190.67 (110.07 - 6060.16) ng/ml, 864.33 (401.33 - 3386.67) vs 508.49 (253.82 - 8840.00) ng/ml respectively, with IL-4/IFN-gamma ratio of 0.503 +/- 0.642 vs 0.455 +/- 0.562 respectively. After expansion of Valpha24(+) NKT cells from G-PBMNCs, IL-4 and IFN-gamma produced by Valpha24(+) NKT cells at day 9 and day 12 were 139.08 (7.62 - 606) vs 89.3 (0 - 729.2) ng/ml, 14264.8 (1168 - 18059) vs 14488 (1041 - 18261) ng/ml respectively, with IL-4/IFN-gamma ratio of 0.0531 +/- 0.1081 vs 0.0376 +/- 0.1148 respectively. It is concluded that in presence of IL-2 and IL-15, alpha-GalCer can facilitate the rapid short-term expansion of Valpha24(+) NKT cells from CB, PB, and G-PBMNCs. Valpha24(+) NKT cells from G-PBMNCs show much high potential of expansion in comparison to the counterparts from CB or PB (p < 0.05). The activated Valpha24(+) NKT cells can secrete IFN-gamma and IL-4 in large amounts, with IFN-gamma in particular.
Cell Culture Techniques ; Fetal Blood ; cytology ; Galactosylceramides ; pharmacology ; Humans ; Interferon-gamma ; secretion ; Interleukin-15 ; pharmacology ; Interleukin-2 ; pharmacology ; Interleukin-4 ; secretion ; Leukocytes, Mononuclear ; cytology ; Lymphocyte Activation ; Natural Killer T-Cells ; metabolism