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1.
A novel lymphocyte, NKT cells bearing an invariant V(alpha)14 antigen receptor, specifically recognizes alpha-galactosylceramide (alpha-GalCer) exclusively presented by mouse CD1d (mCD1d). However, the precise molecular interaction remains unclear. For the basis of functional analyses, a docking model of alpha-GalCer with the crystal structure of mCD1d was constructed. Possible residues involved in the alpha-GalCer--mCD1d interaction were found to be Arg79, Glu83 and Asp80 for carbohydrate recognition, and Asp153 for interaction with the amide group on the fatty acyl chain. The alpha-GalCer-presenting ability of various transfectants expressing mutant mCD1d was completely abrogated if a single amino acid mutation was induced at positions 79, 80, 83 or 153, suggesting that the polar amino acids above the F' pocket are crucial for alpha-GalCer presentation to activate V(alpha)14 NKT cells. The possibility that Glu83 is a contact site for the NKT cell receptor is also discussed.  相似文献   

2.
A monoclonal antibody against V14+ alpha-chain of murine T cell receptor (TCR) was established by fusing spleen cells from a rat immunized with a soluble chimeric TCR/IgG3 protein containing murine TCR V alpha 14J alpha 281 in place of the VHDHJH of an IgG3. lambda 1, and subjected to screening on a human transfectant (Jurkat variant) expressing the murine V14J281 alpha-chain. The anti-mouse V alpha 14 antibody precipitated TCR alpha beta molecules from Triton X-100-solubilized extracts of 125I-labeled murine thymocytes and spleen cells. Unexpectedly, the antibody showed cross-reactivity to the human CD3 epsilon molecule and detected a disulfide-linked 20 kDa dimeric form of human CD3 epsilon, which is a novel family component of the CD3 complex and is associated closely with the CD3 zeta-zeta homodimer as well as TCR alpha beta or TCR gamma delta.  相似文献   

3.
Two cytokines IL-4 and IL-12 are known to determine the balance between T(h)1 and T(h)2 development. In addition to IL-4 production of V(alpha)14(+) NKT cells, they have recently been demonstrated to have the capacity to stimulate IL-12 production by antigen-presenting cells (APC). This study demonstrates that IFN-gamma is absolutely required for the NKT cell-stimulated IL-12 production. Culture of B cell-depleted spleen cells from C57BL/6 mice with alpha-galactosylceramide (alpha-GalCer) capable of selectively stimulating V(alpha)14/J(alpha)281(+) NKT cells resulted in the production of IL-12 together with IL-4. Whereas IL-4 production occurred in culture of IFN-gamma(-/-) C57BL/6 splenocytes, the same culture failed to generate IL-12 production. While IL-12 production induced during culture of V(alpha)14(+) NKT cells and APC depended on the interaction between CD40 ligand on NKT cells and CD40 on APC, the expression levels of these key molecules were comparable in cells from wild-type and IFN-gamma(-/-) mice. Addition of rIFN-gamma to alpha-GalCer stimulated IFN-gamma(-/-) splenocyte culture, and administration of rIFN-gamma to alpha-GalCer-injected IFN-gamma(-/-) mice resulted in the restoration of IL-12 production in vitro and in vivo. These results illustrate a mandatory role for IFN-gamma in V(alpha)14(+) NKT cell-stimulated IL-12 production by APC.  相似文献   

4.
BACKGROUND: Elevated maternal serum levels of interleukin-2 soluble receptor-alpha (IL-2 sRalpha), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) have been associated with pregnancy loss. The aim of our study was to evaluate the predictive value of these cytokines in the outcome of early IVF pregnancies. METHODS: One hundred and fifty-nine consecutive IVF patients who were subsequently diagnosed to have a biochemical pregnancy (n = 23), a first-trimester miscarriage (n = 19) or a normal term delivery (n = 117) were included in this study. Serum was collected from the initial pregnancy test, 11 days after a day 3 embryo transfer, and all samples were analysed for IL-2 sRalpha, TNF-alpha and IFN-gamma by commercially available enzyme-linked immunosorbent assay (ELISA) kits. RESULTS: IL-2 sRalpha levels were significantly higher in patients with an early pregnancy loss compared with patients with a normal term delivery (849.5 +/- 69.6 versus 693.5 +/- 31.2 pg/ml, P = 0.02), and a cut-off point of IL-2 sRalpha >1000 pg/ml predicted a poor pregnancy outcome (44.4 versus 22.7% pregnancy loss, IL-2 sRalpha >or=1000 versus IL-2 sRalpha <1000 pg/ml; P = 0.02). IFN-gamma-positive patients had twice the risk for poor IVF pregnancy outcome compared with IFN-gamma-negative subjects (40.8 versus 20.0%, respectively; P < 0.02), including a significantly lower implantation rate (37.6 +/- 0.05 versus 50.0 +/- 0.03%, respectively; P = 0.02). There was no difference in pregnancy outcome based upon serum levels, or the ability to detect the presence of TNF-alpha. No differences in levels of these cytokines were found based on the aetiology of the patients' infertility. CONCLUSIONS: Elevated maternal serum levels of IL-2 sRalpha and IFN-gamma as early as 11 days after embryo transfer are associated with poor IVF pregnancy outcome.  相似文献   

5.
In vivo administration of NKT cell ligand, alpha-galactosylceramide (alpha-GalCer), caused the activation of NKT cells to induce a strong NK activity and cytokine production by CD1d-restricted mechanisms. Surprisingly, we also found that alpha-GalCer induced the activation of immunoregulatory cells involved in acquired immunity. Specifically, in vivo administration of alpha-GalCer resulted in the induction of the early activation marker CD69 on CD4(+) T cells, CD8(+) T cells and B cells in addition to macrophages and NKT cells. However, no significant induction of CD69 was observed on cells from CD1d- or V(alpha)14 NKT-deficient mice, indicating an essential role for the interaction between NKT cells and CD1d-expressing dendritic cells (DC) in the activation of acquired immunity in response to alpha-GalCer. Indeed, in vivo injection of alpha-GalCer resulted not only in the activation of NKT cells but also in the generation of CD69(+)CD8(+) T cells possessing both cytotoxic T lymphocyte (CTL) activity and IFN-gamma-producing ability. Tumor-specific CTL generation was also accelerated by alpha-GalCer. The critical role of CD40-CD40 ligand (CD40L)-mediated NKT-DC interaction during the development of CD69(+)CD8(+) CTL by alpha-GalCer was demonstrated by blocking experiments using anti-CD40L mAb. These findings provide direct evidence for a critical role of CD1d-restricted NKT cells and DC in bridging innate and acquired immunity.  相似文献   

6.
7.
BACKGROUND: In September 2002, an outbreak of toxoplasmosis was noted in a male boarding high school on the Aegean coast of Turkey. We have focused our efforts to investigate the sex hormones in this population. METHODS: Blood samples were collected from 40 male patients, 17-18 years old, who also had positive titres of antibody to Toxoplasma gondii. Serum FSH, LH, free testosterone (FT), total testosterone (TT), interferon-gamma (IFN-gamma), interleukin-1beta (IL-1beta) and macrophage-inflammatory protein-1alpha (MIP-1alpha) concentrations were measured in all patients and 20 control subjects. Initially, the patients were divided on the basis of the levels of sex hormones into the following groups: patients who had normal sex hormone levels (n = 31) as group A and patients with low sex hormone levels (n = 9) as group B. RESULTS: IL-1beta levels were found to be higher in group B patients than group A. The levels of IL-1beta correlated significantly in a negative manner with FSH, LH, FT and TT in all patients with acute toxoplasmosis (n = 40). CONCLUSIONS: Acute toxoplasma infection may cause temporary hypogonadotrophic gonadal insufficiency regardless of the course of the disease.  相似文献   

8.
Tumour necrosis factor- (TNF-) and interleukin-1 (IL-1) areimportant mediators of cell signalling in the uterus. Prostaglandins(PG) have been implicated in the increase of endometrial vascularpermeability which occurs during the implantation process. Thisstudy evaluates the effect of these two pleiotropic cytokineson PGF2 and PGE2 release from human luteal phase endometrialglandular epithelial cells (GEC) and stromal cells (STC) inculture. Basal PGF and PGE release did not differ significantlyfrom each other or among cell types, and declined significantlywith increasing number of days in culture. On day 3, basal PGrelease had decreased to half of that on day 1 of culture. However,both cell types were still able to respond to the addition ofexogenous arachidonic acid (5 µM) on day 3 of culture,with PG release by GEC being elevated 7- to 10-fold and by STCmoderately, but still significantly, on day 4. The permissiveeffect of arachidonic acid on the stimulation of PG releasemay indicate the down-regulation of phospholipase A2 with continuedtime in culture. However, the addition of arachidonic acid (5µM) on day 0 of culture, while able to cause significantlyincreased PG release from GEC, had no effect on STC. In contrast,the addition of a combination of arachidonic acid (5 µM),and either recombinant human TNF- (10 µg rhTNF-/I) or10 µg rhlL-1/I, had a synergistic action and caused thesignificantly increased release of PGF and PGE from both celltypes, compared with that achieved with either arachidonic acidor the cytokine alone (although GEC responded more than STC).During the first 24 h after the addition of rhTNF- or rhlL-1,both cytokines stimulated PG release from both cell types ina dose- and time-dependent fashion. Neither cycloheximide (10µM) nor actinomycin D (10 µM) affected basal PGrelease, but both blocked cytokine-induced PG release from bothcell types. These results suggest that there is a differentialcontrol of human endometrial cell PG biosynthesis, and thatPG release may be regulated through gene activation.  相似文献   

9.
Hepatitis C virus (HCV) has evolved complex strategies to evade host immune responses and establish chronic infection. Since human Vgamma9Vdelta2 T lymphocytes play a critical role in the immune response against viruses, we analyzed their antiviral functions on Huh7 hepatoma cells carrying the subgenomic HCV replicon (Rep60 cells). In a transwell culture system, Rep60 cells were co-cultured with either PBMCs or highly purified gammadelta T cells stimulated by non-peptidic antigens. Vgamma9Vdelta2 T cell activation was associated with a dramatic reduction of HCV RNA levels. Neutralizing antibodies targeting IFN-gamma revealed a critical role for this cytokine in the inhibition of HCV replication. Interestingly, drugs already in clinical use, such as Phosphostim and Zoledronate, known to activate gammadelta T cells, were shown to induce the inhibition of HCV replication mediated by Vgamma9Vdelta2 T cells of HCV patients. Our data suggest that the therapeutic activation of Vgamma9Vdelta2 T lymphocytes may represent an additional strategy to inhibit HCV replication and to restore a Th1-oriented immune response in HCV-infected patients.  相似文献   

10.
We have investigated the involvement of adhesion molecules inthe lymphocyte infiltration associated with acute intestinalgraft-versus-host disease (GVHD) induced by injection of C3Hlymph node cells into irradiated (C3H x DBA/2)F1 mice. Firstwe analyzed the expression profile of adhesion molecules including1, 2, 4, 5, 6, L and ß7 integrins, CD44 and L-selectinof lymphocytes from lymph nodes and gut mucosa in normal mice.In normal mice, intraepithelial lymphocytes (IEL) and laminapropria lymphocytes (LPL) uniquely showed increased expressionof 1, 2 and ß7 integrins, and decreased expressionof L-selectin compared with that of lymphocytes of the lymphnodes and Peyer's patches. In mice with GVHD, IEL and LPL ofdonor lymph node cells origin underwent phenotyplc changes characterizedby the increased expression of 1, L and ß7 integrins,and the loss of L-selectin. The expression profile of adhesionmolecules on IEL and LPL of GVHD mice resembled that of normalmice except for the lack of 2 integrin. Treatment of GVHD micewith anti-1,-4 or-ß7 integrin antibody alone partiallyprevented the mucosal pathology of intestinal GVHD, whereasonly mice treated with anti-1 showed reduced donor lymphocyticinfiltration into the intestinal mucosa. In contrast, treatmentwith anti-L or anti-CD44 antibody did not affect the intestinalGVHD. Furthermore, dual blockade of both 1 and 4 integrins completelyinhibited the mucosal pathology and donor lymphocyte infiltrationof intestinal GVHD. These results indicate that 1 and 4 integrinsplay an important role in the pathology of intestinal GVHD.  相似文献   

11.
The high-affinity receptor for IgE (FcRI) has a tetrameric structurecomposed of one, one ß, and two disulfide-linked subunits, of which the subunit binds IgE with high affinity.A recombinant soluble form of the ectodomain of the human FcRIsubunit (rsFcRI) was recently generated by gene engineeringand was verified to bind IgE with an affinity as high as thatof native FcRI on the cell surface. rsFcRI was prepared on alarge scale in order to analyze its biological function. rsFcRIcompletely inhibited IgE binding to the cell surface, resultingin abrogation of the chemical mediator release from RBL-2H3cells. Furthermore it completely abolished the passive cutaneousanaphylaxis (PCA) response by trapping IgE specifically whenitwas administered into rats prior to IgE sensltizatlon. Evenafter IgE sensitizatlon, treatment of rsFcRI substantially reducedthe PCA response. It was finally shown that rsFcRI inhibitedIgE binding to human peripheral blood basophils and the histaminerelease from them. In this paper we address the ability of rsFcRIto specifically prevent the IgE-mediated allergic reaction.  相似文献   

12.
BACKGROUND: The central role of estrogens and androgens in the male reproductive system has focused attention on the presence and distribution of their cognate receptors [estrogen receptor (ER) alpha, ERbeta and androgen receptor (AR)] in male reproductive tissues and cells. Since the presence of steroid hormone receptors in mitochondria of mammalian cells has been well documented, we investigated the possibility of mitochondrial localization of sex steroid hormone receptors in sperm. METHODS AND RESULTS: Applying immunofluorescence labelling and confocal laser scanning microscopy we show that the estrogen receptor beta and the AR of human sperm are specifically enriched in the midpiece, at the site of the mitochondria, which were visualized by labelling with the vital dye CMX. Nuclear and mitochondrial localization of AR was also detected in LnCap human prostate cancer cells. Differentially, most of the ERalpha immunostaining is in the form of a compact zone at a region corresponding to the equatorial segment of the upper post-acrosomal region of the sperm head. Immunoblotting experiments using sperm extracts revealed the presence of a 66 and a 45 kDa protein reacting with the ERalpha antibody, one 64 kDa protein reacting with the ERbeta antibody and a 110 and a 90 kDa protein reacting with the antibody against AR. CONCLUSIONS: Our findings suggest that the differential localization of AR and ER isoforms in human sperm reveals distinct roles of these receptors in the physiology of sperm cells and, perhaps, also in the process of fertilization.  相似文献   

13.
Mitogenic anti-CD28 antibody stimulates all peripheral T cells to proliferate in the absence of TCR ligation, providing an exception to the two-signal requirement of T cell responses. This antibody preferentially recognizes a mobilized signaling-competent form of CD28, normally induced following TCR ligation, thus providing a unique non-physiological tool to dissect CD28-specific signals leading to T cell proliferation. The protein kinase C (PKC)theta-NF-kappaB pathway has recently been shown to integrate TCR- and CD28-derived signals in co-stimulation. We now demonstrate that this pathway is activated by mitogenic anti-CD28 antibody stimulation. In contrast to conventional anti-CD28 antibody, mitogenic anti-CD28 antibody induced activation of phospholipase Cgamma and Ca(2+) flux in peripheral rat T cells despite no or low levels of inducible tyrosine phosphorylation of TCRzeta chain, TCRzeta-associated protein of 70 kDa (ZAP-70) or linker for activation of T cells (LAT)-critical components of the TCR signaling machinery. Nevertheless, PKCtheta kinase activity in vitro was increased following mitogenic anti-CD28 antibody stimulation, as was membrane association of both PKCtheta and Bcl10. As downstream targets of PKCtheta activation, NF-kappaB components translocated to the nucleus at levels comparable to those after TCR-CD28 co-stimulation. NF-kappaB translocation was diminished by PKCtheta inhibition, as was induction of the NF-kappaB/AP-1 responsive activation marker CD69. We propose that co-stimulation is a sequential process in which appropriate TCR engagement is required to mobilize CD28 into a signaling-competent form which then activates the PKCtheta-NF-kappaB pathway necessary for IL-2 production and proliferation.  相似文献   

14.
BACKGROUND: Age at menarche has a strong genetic influence. We reported recently an association between the XbaI (351A-->C)and PvuII (397T-->C) polymorphisms of the estrogen receptor (ER)alpha gene with the age of menarche in Greek adolescents. In the present study, we examined whether ERbeta genotypes alone, or in combination with ERalpha genotypes, may also influence onset of menarche. METHODS: We performed genotyping for the single nucleotide polymorphisms 1730A-->G and 1082G-->A of the ERbeta gene and examined their association with the age of menarche in the same cohort of 145 Greek girls. We then looked for a possible effect of combined ERalpha and beta genotypes on the age of menarche. RESULTS: Menarche occurred 7 months later in girls with the AA genotype of the 1730A-->G polymorphism than in girls with the AG genotype (mean +/- SD: 13.23 +/- 1.24 versus 12.66 +/- 1.26 years, respectively; P = 0.005). The 1082G-->A polymorphism was not detected in any of the girls examined. A significant effect of combined ERalpha and beta genotypes was also apparent. Menarche occurred 11 months later in girls bearing the AA/TT,AA (ERalpha, ERbeta) genotypes compared with girls with the CC/CC,AG genotype (13.30 +/- 1.27 nersus 12.41 +/- 1.28 years; P = 0.042). The difference remained significant after adjusting for body mass index (P = 0.034). CONCLUSION: Combined ERalpha and ERbeta polymorphisms may influence the age of menarche.  相似文献   

15.
The third subunit, the so-called common (c) chain, of the IL-2receptor is shared among the receptors for IL-2, IL-4, IL-7and IL-15, and dysfunction of the c chain is thought to causeX-linked severe combined immunodeficiency (XSCID) ascribed toimpairment of early T cell development. However, cytokines linkedto XSCID are as yet unidentified. A mAb specific for the c chain,TUGm2, profoundly inhibited cell proliferation in response toIL-9. Another mAb, TUGm3, immunoprecipltated [125I]IL-9 cross-linkedwith either the IL-9 receptor or the c chain. These resultsdemonstrate that the c chain is included in the functional receptorcomplex for IL-9, which was initially characterized as a T cellgrowth factor and is essential for IL-9-dependent growth signaltransductlon.  相似文献   

16.
Plasmacytoid dendritic cells (pDCs) are an important source of IFN-alpha/beta in response to a variety of viruses in vivo, including murine cytomegalovirus (MCMV). However, the respective contributions of various infected organs, and within these of pDCs, conventional dendritic cells and other cells, to the systemic production of IFN-alpha/beta or other innate cytokines during viral infections in vivo is largely unknown. Whether a specialization of pDC subsets in the production of different patterns of innate cytokines exists in vivo in response to a viral infection has not been investigated. Here, by analyzing for the first time directly ex vivo, at the single-cell level, the simultaneous production of up to three cytokines in pDCs isolated from MCMV-infected mice, we show that (i) pDCs are the quasi-exclusive source of IFN-alpha/beta, IL-12 and tumor necrosis factor (TNF)-alpha, early during MCMV infection, in two immunocompetent mouse lines and with two viral strains, (ii) pDC activation for IFN-alpha/beta production is organ specific and (iii) a significant proportion of pDCs simultaneously produce IFN-alpha/beta, TNF-alpha and IL-12, although TNF-alpha and IFN-alpha/beta appear more often co-expressed with one another than each of them with IL-12. Altogether, these results show a broad and non-redundant role of pDCs in early innate detection of, and defense against, viral infection. The data also show differences in the responsiveness of pDCs from different tissues and suggest distinct molecular requirements for pDC production of various cytokines. These observations must be taken into account when designing new antiviral vaccination strategies aimed at harnessing pDC responses.  相似文献   

17.
The numbers, phenotype, and tissue distribution of gamma delta T cells in cattle were studied using two monoclonal antibodies (mAbs) which react with the bovine gamma delta T cell receptor (TCR). Both mAbs stained 20-40% of T cells in peripheral blood, and immunoprecipitated molecules of 44 and 36 kd (reduced) and 70-80 kd (non-reduced). In cattle the majority of circulating gamma delta T cells showed a distinct surface phenotype; they expressed T19, a 215 kd molecule described in sheep and cattle which marks only gamma delta T cells. Bovine gamma delta T cells were also CD2-, CD4-, and mostly CD8-, and failed to express CD6, a molecule possibly involved in T cell activation. The distribution of gamma delta T cells in cattle lymphoid tissues differed markedly from that in humans, in that bovine gamma delta T cells were concentrated around lymph node trabeculae and were usually sparse or absent from the B cell and T cell domains of lymph nodes. Like most other species studied, gamma delta T cells in cattle were localized to epithelial surfaces, particularly within the skin and intestine, indicating that it was at these sites where gamma delta T cells functioned. Our results provide further evidence for the unusual localization, recirculation pattern, and phenotype of gamma delta T cells, and also show that some features of gamma delta T cells can differ quite markedly from species to species.  相似文献   

18.
In this study, we report the RFLP of the human T cell receptor (TCR) alpha chain variable gene segments. Using DNA samples from 20 individuals and three restriction endonucleases (BamHI, EcoRI and HindIII), the degree of RFLP of a number of different V gene segments was defined. Half of the V alpha subfamilies (6/12) were characterized by a predominant hybridization pattern, with only a few individuals displaying a second pattern. However, one particular V gene family, V alpha 6, has at least five allelic forms that segregated consistently in familial studies. The V alpha polymorphisms revealed in this study, together with those exhibited by V beta gene subfamilies, should prove useful in studying possible associations between TCR gene usage and disorders of the immune system.  相似文献   

19.
The high-affinity IgE receptor (Fc epsilonRI) and the low-affinity IgG receptor (Fc gammaRIII) on mast cells are the key molecules involved in triggering the allergic reaction. These receptors share the common beta subunit (FcRbeta) which contains an immunoreceptor tyrosine-based activation motif and transduces the signals of these receptors' aggregation. In rodents, FcRbeta is essential for the cell surface expression of the Fc epsilonRI. In humans, the FcRbeta gene was reported to be one of the candidate genes causing atopic diseases. However, the role of FcRbeta in vivo still remains ambiguous. To elucidate the functions of FcRbeta, we developed the mice lacking FcRbeta [FcRbeta(-/-)]. The FcRbeta(-/-) mice lacked the expression of the Fc epsilonRI on mast cells and IgE-mediated passive cutaneous anaphylaxis (PCA) was not induced in FcRbeta(-/-) mice as was expected. In these mice, the expression of IgG receptors on mast cells was augmented but the IgG-mediated PCA reaction was attenuated. Although with bone marrow-derived cultured mast cells from FcRbeta(-/-), adhesion to fibronectin and Ca2+ flux upon aggregation of IgG receptors were enhanced, mast cells co-cultured with 3T3 fibroblasts exhibited impaired degranulation on receptor aggregation. These observations indicate that FcRbeta accelerates the degranulation of mature mast cells via the IgG receptor in connective tissues.  相似文献   

20.
Fertilization and oocyte cleavage rates have previously been demonstrated to be lower for women with endometriosis undergoing IVF compared with controls. This might be related to impaired oocyte function, possibly due to an inflammatory milieu in the pelvis of these women, where an elevated concentration of many cytokines is documented. The aim of this study was to examine whether granulosa cells from women with endometriosis deviated with respect to production of the inflammatory cytokines interleukin-1beta, interleukin-6, interleukin-8 and tumour necrosis factor alpha (TNFalpha) compared with granulosa cells from healthy women, undergoing IVF for male infertility. The effect of human chorionic gonadotrophin on cytokine production was also investigated. Granulosa cells in follicular fluid were obtained at oocyte retrieval for IVF. Incubated cell culture media were analysed by enzyme-linked immunosorbent assay. The basal production of all four cytokines was higher in cells from women with endometriosis when compared to controls, although the increase was only significant for TNFalpha. Chorionic gonadotrophin had no significant effect, although it had a tendency to suppress cytokine release in both patient categories. Whether aberrant cytokine production in granulosa cells from women with endometriosis may disturb fertilizing capacity of oocytes requires study.  相似文献   

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