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1.
Autoantibodies to inosine monophosphate dehydrogenase-2 (IMPDH2), an enzyme involved in de novo biosynthesis of guanine nucleotides, are observed in a subset of hepatitis C virus (HCV) patients receiving interferon alpha (IFN-α) plus ribavirin. Anti-IMPDH2 antibodies display a peculiar cytoplasmic “rod/ring” (RR) pattern in IIF-HEp-2. We examined the dynamics of anti-RR autoimmune response with respect to immunoglobulin isotypes, titer, avidity, and protein targets in 80 sequential samples from 15 HCV patients (plus 12 randomly selected anti-RR-positive, totalizing 92 samples) collected over an 18-month period, including samples collected before, during, and after IFN-α + ribavirin treatment. Immunoprecipitation showed reactivity with the 55 kDa IMPDH2 protein in 12/15 patients (80 %) and 11/15 (73 %) reacted with IMPDH2 in a sandwich ELISA. During treatment, anti-IMPDH2 autoantibodies hit their highest levels after 6–12 months of treatment and decreased post-treatment, while anti-HCV antibodies levels were stable over time. Anti-IMPDH2 IgM levels increased up until the sixth month of treatment and remained stable thereafter, while IgG levels increased steadily up to the twelfth month. Both IgG and IgM decreased during the post-treatment period. IgG avidity increased steadily up to the twelfth month of treatment. In conclusion, this study showed that the temporal kinetics of IFN-α + ribavirin-induced humoral autoimmune response to IMPDH2 exhibited a considerably delayed pace of increase in antibody levels and avidity as well as in isotype class switch in comparison with a conventional humoral response to infectious agents. These unique findings uncover intriguing differences between the autoimmune response and the immune response to exogenous agents in humans.  相似文献   

2.
Adult worm extract from Ascaris suum (Asc) has immunosuppressive activity and elicits Th2/IL-4/IL-10 response. This study evaluated the prophylactic and therapeutic effect of Asc in a murine model of concanavalin A (ConA)-induced autoimmune hepatitis (AIH). BALB/c mice received ConA, iv, (20 mg/kg), and three groups of animals were formed: (1) AIH, received only ConA; (2) AIH + Asc prophylactic, treated with Asc (1 mg/ml), ip, 30 min before of the AIH; and (3) AIH + Asc therapeutic, treated with Asc 2 h after the AIH. Plasma transaminase and immunoglobulins (measured at 8 and 24 h and 7 days after treatment) and cytokine production (IL-4, IL-10, IL-13, and IFN-γ) by splenocytes upon ConA and Asc stimulus were compared. The livers were weighed and examined histologically. In the AIH group, there was an increase in liver weight, transaminase levels, and total immunoglobulins. These parameters were reduced by 8–24 h and 7 days in the prophylactic group, but in the therapeutic group, only on day 7. The survival rate of mice in the AIH group was 38.5 %, compared to 67 % in the therapeutic Asc group. The survival rate of the animals with AIH that were prophylactically treated with Asc was 100 %. A decrease of cellular infiltration and high levels of IL-4, IL-10, and IL-13 were induced by Asc. An increase of liver fibrosis was also observed, but with less intensity with prophylactic treatment. Thus, the Ascaris components have an inhibitory effect on AIH, with an intense Th2 immune response.  相似文献   

3.
Non-alcoholic steatohepatitis (NASH) is a primary cause of cirrhosis and hepatocellular carcinoma. Dipeptidyl peptidase (DPP)-4 inhibitors are established therapies for type 2 diabetes and although DPP-4 inhibitors can reduce hepatic steatosis, their impact on local inflammation and fibrosis in NASH remains unknown. Using two different experimental treatment regimens (4- and 2-week treatments) in streptozotocin-treated neonatal mice on a high-fat diet, we show that the DPP-4 inhibitor linagliptin (10 and 30 mg/kg) significantly attenuated the NAS score from 4.9 ± 0.6 to 3.7 ± 0.4 and 3.6 ± 0.3, respectively, in the 4-week study. In the 2-week study, linagliptin 10 mg/kg significantly reduced NAS score from 4.1 ± 0.4 to 2.4 ± 0.4. Telmisartan was used as a positive control in both studies and lowered NAS score to 1.9 ± 0.7 and 1.4 ± 0.3, respectively. Due to streptozotocin treatment, elevated glucose levels were unchanged by either drug treatment. Further, linagliptin 10 mg/kg significantly reduced mRNA levels of SOCS-3 (from 1.68 ± 0.2 to 0.83 ± 0.08), IFN-γ (from 4.0 ± 0.5 to 2.3 ± 0.3), and TNF-α (from 5.7 ± 0.5 to 2.13 ± 0.3). The latter observation was confirmed by immunohistochemistry of TNF-α in liver specimens. In addition, using microautoradiography, we showed that the distribution of radiolabeled linagliptin was heterogeneous with the highest density associated with interlobular bile ducts and portal tracts (acini). In conclusion, these studies confirm that linagliptin has high exposure in hepatic tissue and has both anti-inflammatory and anti-steatotic activity in NASH.  相似文献   

4.
Primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) present with distinct clinical features. The term “PBC–AIH overlap syndrome (OS)” has been adopted to describe the condition characterized by occurrence of both PBC and AIH, although this clinical entity is difficult to define. This study aimed to assess the utility of IgG, IgM, and CD138 immunohistochemistry in the evaluation of AIH, PBC, and OS. Immunohistochemistry was performed with anti-human IgG, IgM, and CD138 to detect specific plasma cells in the liver. Predominant IgG staining was observed in AIH (85.7 %), while equivocal (46.1 %) or predominant (38.5 %) IgM staining was observed in PBC. In OS, equivocal (20 %) or predominant (80 %) IgG staining was observed. The IgM/IgG ratio was significantly higher in PBC than in AIH or OS (P < 0.005). Histological findings revealed significantly higher IgM expression in PBC at cholangitis activity grades 2–3 compared to those at cholangitis activity grades 0–1. In contrast, a significantly higher IgG expression was observed in PBC at hepatitis activity and fibrosis grades 2–3 compared to those at hepatitis activity and fibrosis grades 0–1. Taken together, periportal plasmacytic infiltrates with variable immunohistochemistry patterns of IgG and IgM expression characterized different autoimmune liver diseases.  相似文献   

5.
Maternal pertussis-specific antibodies are passively acquired by infants during pregnancy. An IgG pertussis toxin (IgG-PT) concentration of >20 U/ml is considered to protect neonates against pertussis. To evaluate the IgG concentration at birth and during the first two months of life, we examined the IgG-PT concentration in the umbilical cord blood and three times during the neonatal and early infant period. IgG-PT was measured by validated IgG-specific enzyme-linked immunosorbent assays (ELISA) in umbilical cord blood and in Guthrie card blood samples of umbilical cord blood in 2,790 children, born between 1 August 2006 and 1 December 2008. These measurements were comparable. All children with concentrations of IgG-PT >30 U/ml were included. IgG-PT was also measured in Guthrie card blood samples, when the neonates or early infants were 5 days, 1 month and 2 months old. The mean concentrations of IgG-PT were calculated. The mean concentration of IgG-PT in umbilical cord blood was 60.1 U/ml (LN 4.1; 0.6 SD; n?=?103). At the age of 5 days, 1 month and 2 months, the mean concentration of IgG-PT was 40.6 U/ml (LN 3.7; 0.5 SD; n?=?103), 20.7 U/ml (LN 3.0; 0.7 SD; n?=?62) and 16.7 U/ml (LN 2.8; 0.9 SD; n?=?61), respectively. Four percent of the neonates had a concentration of IgG-PT >30 U/ml in umbilical cord blood, which declined to levels around the concentration needed for protection against pertussis (>20 U/ml) in the first two months of life. Hence, it is of great importance to further investigate the safety of maternal immunisation during pregnancy to prevent life-threatening pertussis in newborns.  相似文献   

6.
Heat-shock protein 60 (Hsp60) has been shown to provoke inflammation, and anti-Hsp60 may facilitate the development of atherosclerosis. In this study, we have investigated 30 patients with mixed connective tissue disease (MCTD) and assessed anti-Hsp60 and their relationship to cardiovascular diseases (CVD). Out of 30 patients with MCTD, 15 had CVDs. Anti-Hsp60 antibody was determined by enzyme-linked immunosorbent assay. Since endothelial dysfunction and accelerated atherosclerosis are characteristic to MCTD, a wide array of MCTD-, endothelial dysfunction- and CVD-associated parameters was investigated: serum lipid levels, paraoxonase activity (PON1), rich nuclear ribonucleoprotein U1 (anti-U1RNP), anti-endothelial cell antibodies, anti-cardiolipin and anti-β2-glycoprotein I antibody isotypes (anti-CL and anti-β2GPI), endothelin-1 (ET-1) levels, also intima–media thickness (IMT), a quantitative indicator of atherosclerosis. In MCTD, anti-Hsp60 antibody levels were significantly higher than in healthy individuals (p < 0.02). MCTD patients with CVD had significantly higher levels of anti-Hsp60 compared to MCTD without CVD (p = 0.001). Patients with MCTD had significantly lower high-density lipoprotein cholesterol (p = 0.02) and PON activity (p < 0.001), and significantly increased systolic (p < 0.0002) and diastolic (p < 0.001) blood pressure compared to healthy individuals. Anti-U1RNP levels (p < 0.002) and IMT were higher in patients compared to controls (p = 0.002). The CVD-positive MCTD patients had increased anti-Hsp60 (p < 0.0013), anti-CL IgG (p = 0.0005), ET-1 serum concentration (p < 0.05) and IMT levels (p < 0.001) compared to MCTD patients without CVD. Anti-Hsp60 showed a strong correlation with anti-oxLDL (r = 0.36, p = 0.01) and serum ET-1 (r = 0.62, p < 0.001) and negative correlation with PON activity (r = ?0.47, p = 0.01). Anti-Hsp60 indicates endothelial injury, CVD, and can function as a novel atherosclerotic risk factor, also a valuable diagnostic marker in patients with MCTD.  相似文献   

7.
The aim of this study was to evaluate the expression of human T cell immunoglobulin domain and mucin-3 (Tim-3) in renal tissue from patients with immunoglobulin A nephropathy (IgAN) and without IgAN and to evaluate the difference in Tim-3 expression between them. A total of 71 patients with IgAN as IgA group and 13 patients without IgAN as control group were enrolled in the present study. Patients in IgAN accepted percutaneous renal biopsy. We examined the expression of Tim-3 in renal tissue and the serological parameters in serum from all enrolled cases. The expression of Tim-3 and serological parameters were compared between the different groups. Positive staining of Tim-3 protein was seen in 94.3 % patients with IgAN (67 out of 71), but only 15.4 % (2 out of 13) in the cases without IgAN were positive staining of Tim-3. There were significant differences between two groups in almost all serological markers, which reflect IgAN activity. There was a nearly positive correlation between pathological manifestations and expression degree of Tim-3. High immuno-reactivity of Tim-3 was found to be significantly correlated with serological grade (p < 0.001) in IgA group, but there was no such phenomenon in control group. The results showed that there was the expression of Tim-3 in renal tissue from the patients with IgAN, but rarely expression in cases without IgAN. Expression of Tim-3 was associated with the diseases’ activity.  相似文献   

8.
The Spirometra mansoni antigenic polypeptide (SmAP) gene was expressed in Escherichia coli, and its characteristics and value as an antigen for the serodiagnosis of sparganosis were investigated. The recombinant SmAP protein (rSmAP) has the molecular weight of 28.7 kDa. On Western blotting analysis, the rSmAP strongly reacted with the sera of mice infected with spargana, but not with normal sera; the anti-rSmAP serum obviously recognized the 28.7-kDa band in the crude antigens and excretory–secretory (ES) antigens of spargana. The immunofluorescence test (IFT) results showed that the positive staining was observed at different stages of spargana from the infected frogs and mice, but not adult worm of S. mansoni. An immunolocalization analysis identified SmAP in the teguments and parenchymal tissues of spargana. ELISA with rSmAP antigen or sparganum ES antigens were evaluated for the serodiagnosis of sparganosis. The results showed that the sensitivity of rSmAP-ELISA and ES-ELISA was 83.3 % (25/30) and 100 % (30/30), respectively, for the detection of anti-sparganum IgG antibodies in sera of the experimentally infected mice (P?>?0.05), the specificities of both ELISA were 100 % (67/67). It is suggested that the rSmAP might be a potential candidate antigen for serodiagnosis of sparganosis.  相似文献   

9.
10.
Ischemic postconditioning (PoCo) reduces infarct size following myocardial ischemia/reperfusion. To protect, PoCo must be performed early during reperfusion, and causal cardioprotective signaling must occur then. The role of microRNA (miRNA) in PoCo is unclear. Anesthetized pigs were subjected to 60 min left anterior descending coronary artery (LAD) occlusion and 180 min reperfusion. Immediate full reperfusion (IFR, n?=?5) was compared to PoCo (four cycles of 60 s/60 s reperfusion/reocclusion, n?=?5). Transmural myocardial biopsies from the LAD territory were sampled at baseline, 60 min ischemia, 10 and 180 min reperfusion. RNA was isolated. The expression of 11 miRNAs, including muscle-specific (miRNA-1, -133a, -206, -208b, -214, and -499), fibrosis- (miRNA-21, -24, and -29b), neovascularization- (miRNA-92a), and inflammation-associated (miRNA-146b) candidates, was quantified using real-time PCR (RT-PCR). mRNA expression at baseline and 180 min reperfusion was quantified and validated (microarray and RT-PCR). PoCo reduced infarct size from 44.9?±?7.7 to 34.8?±?5.3 % of the area at risk. The expression of miRNA-1, -24, -29b, -133a, -146b, -208b, and -499 was increased at 10 min reperfusion with PoCo vs. IFR; however, that of miRNA-1, -24, -208b, and -499 was already increased at 60 min ischemia and probably reflects falsely positive results. Five mRNAs were different with PoCo vs. IFR. In silico analysis identified a tentative connection between three miRNAs and five mRNAs with the biological functions “cell death”, “inflammatory response” and/or “glucose metabolism”. If at all, only miRNA-29b, -133a, and -146b fulfill the minimal temporal requirements for a potential causal involvement in cardioprotection by PoCo.  相似文献   

11.
Gene silencing and large-scale small RNA analysis can be used to develop RNA interference (RNAi)-based resistance strategies for Plum pox virus (PPV), a high impact disease of Prunus spp. In this study, a pPPViRNA hairpin-inducing vector harboring two silencing motif-rich regions of the PPV coat protein (CP) gene was evaluated in transgenic Nicotiana benthamiana (NB) plants. Wild-type NB plants infected with a chimeric PPV virus (PPV::GFP) exhibited affected leaves with mosaic chlorosis congruent to GFP fluorescence at 21 day post-inoculation; transgenic lines depicted a range of phenotypes from fully resistant to susceptible. ELISA values and GFP fluorescence intensities were used to select transgenic-resistant (TG-R) and transgenic-susceptible (TG-S) lines for further characterization of small interfering RNAs (siRNAs) by large-scale small RNA sequencing. In infected TG-S and untransformed (WT) plants, the observed siRNAs were nearly exclusively 21- and 22-nt siRNAs that targeted the whole PPV::GFP genome; 24-nt siRNAs were absent in these individuals. Challenged TG-R plants accumulated a full set of 21- to 24-nt siRNAs that were primarily associated with the selected motif-rich regions, indicating that a trans-acting siRNAs process prevented viral multiplication. BLAST analysis identified 13 common siRNA clusters targeting the CP gene. 21-nt siRNA sequences were associated with the 22-nt siRNAs and the scarce 23- and 24-nt molecules in TG-S plants and with most of the observed 22-, 23-, and 24-nt siRNAs in TG-R individuals. These results validate the use of a multi-hot spot silencing vector against PPV and elucidate the molecules by which hairpin-inducing vectors initiate RNAi in vivo.  相似文献   

12.
13.
Isospora greineri sp. n. and Isospora superbusi sp. n. are described from captive superb glossy starlings, Lamprotornis superbus, from the Toronto Zoo succumbing to visceral coccidiosis. Sequence data from nuclear 18S recombinant DNA (rDNA) and mitochondrial cytochrome c oxidase subunit I (COI) loci from sporulated oocysts and infected tissues (liver, lung, or spleen) demonstrated two distinct Isospora sp. genotypes that varied in their relative abundance. In the tissues of one affected bird, as well as its associated fecal sample, two distinct COI sequences (1.7 % divergence) and two distinct 18S rDNA sequences (0.6 % divergence) were found at almost the same abundance; in other specimens, one of the 18S and one of the COI sequences were less abundant than the other. In the tissues of some birds, only a single COI and single 18S sequence were present. In all cases, the same pair of 18S rDNA and COI sequences fluctuated in abundance in parallel, indicating that there were two distinct species present rather than one species with more than one COI or 18S locus. The oocysts of these new species cannot be differentiated morphologically. Sporulated oocysts of both were spherical to subspherical measuring 17.7?±?0.22 μm by 17.1?±?0.20 μm with a mean L/W ratio of 1.03?±?0.004. Sporocysts were ovoid measuring 13.5?±?0.17 μm by 9.3?±?0.15 μm with a mean L/W ratio of 1.4?±?0.02. Sporocysts had a small Stieda body with indistinct sub-Stieda body; each sporocyst had a compact residuum. Two morphologically similar but genetically divergent Isospora species were shown to cause simultaneous enteric and extraintestinal infections in captive superb glossy starlings.  相似文献   

14.
Gamma delta (γδ) T cells are mainly present in mucosa-associated lymphoid tissues, which play an important role in mucosal immunity. In this study, C57BL/6 mice were infected by Schistosoma japonicum and lymphocytes were isolated from the mesenteric lymph node (MLN) to identify changes in the phenotype and function of γδ T cells using flow cytometry. Our results indicated that the absolute number of γδ T cells from the MLNs of infected mice was significantly higher compared with normal mice (P?P?+ γδ T cells (P?IFN-γ), interleukin (IL)-4, IL-9, and IL-17 in response to propylene glycol monomethyl acetate (PMA) plus ionomycin simulation, and the levels of IL-4, IL-9, and IL-17 increased significantly after S. japonicum infection (P?S. japonicum infection could induce γδ T cell activation, proliferation, and differentiation in the MLN. Moreover, our results indicated that the expression of NKG2D (CD314) was not increased in γδ T cells after infection, suggesting that other mechanisms are involved in activating γδ T cells. Furthermore, higher expression of programmed death-1 (CD279) but not IL-10 was detected in the γδ T cells isolated from infected mice (P?S. japonicum infection.  相似文献   

15.
During the current century, 88 species of parasites have been recorded in Bison bonasus. These are 22 species of protozoa (Trypanosoma wrublewskii, T. theileri, Giardia sp., Sarcocystis cruzi, S. hirsuta, S. hominis, S. fusiformis, Neospora caninum, Toxoplasma gondii, Cryptosporidium sp., Eimeria cylindrica, E. subspherica, E. bovis, E. zuernii, E. canadensis, E. ellipsoidalis, E. alabamensis, E. bukidnonensis, E. auburnensis, E. pellita, E. brasiliensis, Babesia divergens), 4 trematodes species (Dicrocoelium dendriticum, Fasciola hepatica, Parafasciolopsis fasciolaemorpha, Paramphistomum cervi), 4 cestodes species (Taenia hydatigena larvae, Moniezia benedeni, M. expansa, Moniezia sp.), 43 nematodes species (Bunostomum trigonocephalum, B. phlebotomum, Chabertia ovina, Oesophagostomum radiatum, O. venulosum, Dictyocaulus filaria, D.viviparus, Nematodirella alcidis, Nematodirus europaeus, N. helvetianus, N. roscidus, N. filicollis, N. spathiger, Cooperia oncophora, C. pectinata, C. punctata, C. surnabada, Haemonchus contortus, Mazamastrongylus dagestanicus, Ostertagia lyrata, O. ostertagi, O. antipini, O. leptospicularis, O. kolchida, O. circumcincta, O. trifurcata, Spiculopteragia boehmi, S. mathevossiani, S. asymmetrica, Trichostrongylus axei, T. askivali, T. capricola, T. vitrinus, Ashworthius sidemi, Onchocerca lienalis, O. gutturosa, Setaria labiatopapillosa, Gongylonema pulchrum, Thelazia gulosa, T. skrjabini, T. rhodesi, Aonchotheca bilobata, Trichuris ovis), 7 mites (Demodex bisonianus, D. bovis, Demodex sp., Chorioptes bovis, Psoroptes equi, P. ovis, Sarcoptes scabiei), 4 Ixodidae ticks (Ixodes ricinus, I. persulcatus, I. hexagonus, Dermacentor reticulatus), 1 Mallophaga species (Bisonicola sedecimdecembrii), 1 Anoplura (Haematopinus eurysternus), and 2 Hippoboscidae flies (Lipoptena cervi, Melophagus ovinus). There are few monoxenous parasites, many typical for cattle and many newly acquired from Cervidae.  相似文献   

16.
Species of the Metastrongylus genus, the lung nematodes of pigs that require an intermediate host (earthworm) to complete their cycle, pose a potential risk to both livestock and humans. This parasite which can result in lung pathology and mixed infections with other pathogens (e.g. viruses) can be fatal to pigs. Although this genus is distributed worldwide, there are no classification keys for identifying this common parasite species. In this work, we take advantage of parasitological surveys of wild boar (Sus scrofa) in northern and central Spain and southern Poland to develop a morphological identification key for the five most common Metastrongylus species (Metastrongylus apri, Metastrongylus pudendotectus, Metastrongylus salmi, Metastrongylus confusus and Metastrongylus asymetricus). In addition, we provide the first record of M. confusus in Spain, probably unidentified until now due to the lack of appropriate identification keys. We hope that this user-friendly identification key will enable parasitologists and veterinary practitioners to avoid further misclassifications of Metastrongylus species.  相似文献   

17.
Hyaluronan (HA) regulates malignant tumor growth, invasion, and metastasis. However, few studies have focused on the roles of HA in tumorigenicity in malignant peripheral nerve sheath tumors (MPNST). In this study, we sought to clarify the prognostic value of HA in patients with MPNST. Specimens obtained from 15 patients with neurofibroma and 30 with MPNST were subjected to HA staining and scored as three grades. Protein expressions of HA synthase 1–3 were examined in the 22 MPNST tissue samples available. Statistically higher HA positivity was observed in MPNST as compared with neurofibroma (P = 0.020). The univariate analysis revealed that increased HA expression, age, neurofibromatosis type 1 (NF1) status, large tumor size, and histological grade were significantly associated with reduced overall survival of patients with MPNST; while increased HA expression, NF1 status, tumor size, and histological grade were correlated with disease-free survival. However, HA synthase 1–3 expression related to neither overall survival nor disease-free survival of these patients. In multivariate analysis, large tumor size (P = 0.022) was an independent prognostic factor for overall survival, and HA expression (P = 0.028) and tumor size (P = 0.002) were independent prognostic factors for disease-free survival. Statistically higher levels of HA in the human MPNST cells were observed compared with neurofibroma cells in vitro. Our results demonstrate that HA expression can be a useful marker in differentiating MPNST from neurofibroma, and in identifying patients with a poor prognosis. Hyaluronan-targeting therapy for patients with MPNST may have potential as a therapeutic tool.  相似文献   

18.
Dermatophagoides farinae, a domestic mite species, produces some of the most potent allergens that contribute to allergy in China and worldwide. We sought to clone and express the group 8 allergen of D. farinae (Der f 8) to investigate its IgE-binding reactivity. The full-length cDNA encoding Der f 8 was generated by using RT-PCR and 5′ RACE, cloned into pCold-TF expression vector, confirmed by nucleotide sequencing, sub-cloned into pET-28b (+), and transfected into E. coli BL21 cells for expression. After purification by nickel affinity chromatography and identified by SDS-PAGE, the recombinant Der f 8 bound with sera from 40.9 % (9/22) of mite-allergic patients according to ELISA testing. Analysis of the recombinant DNA sequence revealed a 231 amino acid open reading frame encoding a protein with a derived molecular mass of 26.4 kDa and an isoelectric point of 6.84. The deduced amino acid sequence has nine phosphorylation sites, displaying strong homology with glutathione S-transferase, and its secondary structure comprises alpha helix (45.5 %), extended strand (11.3 %), and random coils (43.3 %). BLAST through the National Center for Biotechnology Information database and alignment identified similarity with group 8 allergens or glutathione S-transferases of Dermatophagoides pteronyssinus, Suidasia medanensis, Lepidoglyphus destructor, Glycyphagus domesticus, and Aleuroglyphus ovatus (64, 65, 53, 53, and 50 %, respectively). The first recombinant Der f 8 protein produced in full length successfully bound with patient IgE, demonstrating the importance of Der f 8 in mite allergy.  相似文献   

19.
Emerging evidence supports a key role for endothelin-1 (ET-1) and the transactivation of the epidermal growth factor receptor (EGFR) in angiotensin II (Ang II) action. We aim to determine the potential role played by endogenous ET-1, EGFR transactivation and redox-dependent sodium hydrogen exchanger-1 (NHE-1) activation in the hypertrophic response to Ang II of cardiac myocytes. Electrically paced adult cat cardiomyocytes were placed in culture and stimulated with 1 nmol l-1 Ang II or 5 nmol l-1 ET-1. Ang II increased ~45 % cell surface area (CSA) and ~37 % [3H]-phenylalanine incorporation, effects that were blocked not only by losartan (Los) but also by BQ123 (AT1 and ETA receptor antagonists, respectively). Moreover, Ang II significantly increased ET-1 messenger RNA (mRNA) expression. ET-1 similarly increased myocyte CSA and protein synthesis, actions prevented by the reactive oxygen species scavenger MPG or the NHE-1 inhibitor cariporide (carip). ET-1 increased the phosphorylation of the redox-sensitive ERK1/2-p90RSK kinases, main activators of the NHE-1. This effect was prevented by MPG and the antagonist of EGFR, AG1478. Ang II, ET-1 and EGF increased myocardial superoxide production (187?±?9 %, 149?±?8 % and 163.7?±?6 % of control, respectively) and AG1478 inhibited these effects. Interestingly, Los inhibited only Ang II whilst BQ123 cancelled both Ang II and ET-1 actions, supporting the sequential and unidirectional activation of AT1, ETA and EGFR. Based on the present evidence, we propose that endogenous ET-1 mediates the hypertrophic response to Ang II by a mechanism that involves EGFR transactivation and redox-dependent activation of the ERK1/2-p90RSK and NHE-1 in adult cardiomyocytes.  相似文献   

20.
Natural killer T (NKT) cells from mouse and human play a protective role in the immune responses against the infection of Mycobacterium tuberculosis. However, the characteristic of CD3+TCRvβ11+ NKT cells at the local site of M. tuberculosis infection remains poorly defined. In the present study, we found that the numbers of CD3+TCRvβ11+ NKT cells in pleural fluid mononuclear cells (PFMCs) were significantly lower than those in peripheral blood mononuclear cells (PBMCs). However, CD3+TCRvβ11+ NKT cells from PFMCs spontaneously expressed high levels of CD69 and CD25 and effector memory phenotypes of CD45ROhighCD62LlowCCR7low. After stimulation with the antigens of M. tuberculosis, CD3+TCRvβ11+ NKT cells from PFMCs produced high levels of IFN-γ. Sorted CD3+TCRvβ11+ NKT cells from PFMCs cultured with antigen presenting cells (APCs) produced IFN-γ protein and mRNA. The production of IFN-γ could be completely inhibited by AG490 and Wortmannin. In addition, CD3+TCRvβ11+ NKT cells from PFMCs expressed higher levels of Fas (CD95), FasL (CD178) and perforin but lower levels of granzyme B compared with those from PBMCs. Taken together, our data demonstrated for the first time that M. tuberculosis-specific CD3+TCRvβ11+ NKT cells participated in the local immune responses against M. tuberculosis through the production of IFN-γ and the secretion of cytolytic molecules.  相似文献   

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