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1.
Mol Immunol ; 66(2): 290-8, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25910959

RESUMO

T cell activation leads to the induction of genes that are required for appropriate immune responses. This includes CRTAM (Class-I MHC-restricted T cell associated molecule), a protein that plays a key role in T cell development, proliferation, and generating cell polarity during activation. We previously characterized the CRTAM promoter and described how AP-1 family members are important for inducing CRTAM expression upon antigenic activation. Here, we show that CRTAM is a molecular target for ZEB1 (zinc finger E-box-binding protein), a homeodomain/Zn finger transcription factor. Overexpression of ZEB1 repressed CRTAM promoter activity, as well as endogenous CRTAM levels in human T cells. ZEB1-mediated transcriptional repression was abolished when E-box-like elements in the CRTAM promoter are mutated. In summary, ZEB1 functions as a transcriptional repressor for the CRTAM gene in both non-stimulated and stimulated T cells, thereby modulating adaptive immune responses.


Assuntos
Regulação da Expressão Gênica/imunologia , Proteínas de Homeodomínio/genética , Imunoglobulinas/genética , Fatores de Transcrição/genética , Imunidade Adaptativa , Sítios de Ligação , Genes Reporter , Proteínas de Homeodomínio/imunologia , Humanos , Imunoglobulinas/imunologia , Células Jurkat , Luciferases/genética , Luciferases/metabolismo , Ativação Linfocitária , NF-kappa B/genética , NF-kappa B/imunologia , Regiões Promotoras Genéticas , Ligação Proteica , Transdução de Sinais , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/imunologia , Fatores de Transcrição/imunologia , Transcrição Gênica , Homeobox 1 de Ligação a E-box em Dedo de Zinco
2.
Artigo em Inglês | MEDLINE | ID: mdl-23118784

RESUMO

Epidemiological studies correlate low levels of vitamin D with the osteoarthritis (OA) progression. Cytokines and metalloproteases play a major role in OA promoting the inflammation and degradation of the cartilage and can be induced through the Toll-like receptor (TLR) pathway. The aim of this study was to evaluate the protective effect of vitamin D supplementation on the development of osteoarthritis (OA) through examining the genetic regulation of TLRs, cytokines, and metalloproteases in chondrocytes as well as the wideness of cartilage in rats with OA. Our results demonstrate that the signaling through TLR-4 is a proinflammatory mechanism in osteoarthritis that drives the upregulation of MMP-3, IL-1ß, and TNF-α gene expression, leading to cartilage degradation and inflammation. Vitamin D supplementation had a protective effect during the onset but not during the chronic stage of OA in the rat model.

3.
Res Vet Sci ; 93(3): 1132-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22483318

RESUMO

The aim of the present study was to determine the bacteriological prevalence of subclinical non-typhi Salmonella infections in zoo animals and to determine the most frequently isolated serovars of the bacteria. A total of 267 samples were analyzed, including fecal samples from zoo animals and rodents, insects (Musca domestica and Periplaneta americana) and samples of the zoo animal's food. Salmonella was detected in 11.6% of the samples analyzed. Characterization of the isolates was performed with serotyping and pulsed-field gel electrophoresis. The following serovars were isolated: S. San Diego, S. Oranienburg, S. Weltevreden, S. Braenderup, S. Derby, S. 6,7, H:en x:- and S. 3,10, H:r:-. The isolates showed seven pulsed-field gel electrophoresis patterns with a Jaccard coefficient≥0.75 indicating a possible common origin. The prevalence of asymptomatic infections caused by Salmonella spp. in zoo animals was high. These findings demonstrate the diversity of Salmonella serovars in several captive wild animal species.


Assuntos
Animais de Zoológico , Salmonelose Animal/microbiologia , Salmonella/classificação , Salmonella/isolamento & purificação , Animais , Fezes/microbiologia , México/epidemiologia , Salmonelose Animal/epidemiologia
4.
Poult Sci ; 89(3): 495-500, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20181865

RESUMO

The current studies were undertaken to assess the ability of humoral immune response in breeding hens to provide protective maternal antibody in the progeny. A highly purified outer membrane protein, 34 kDa, was isolated from a virulent strain of Salmonella Gallinarum. Cross-reactivity was observed between this protein and Salmonella Typhi porins; thus we consider this outer membrane protein as a Salmonella Gallinarum porin. To evaluate passive immunity against Salmonella Gallinarum, 200 broiler breeder hens were immunized with either 10 microg of Salmonella Gallinarum porins, 30 microg of Salmonella Gallinarum porins, or PBS without porins as a control group. Anti-Salmonella Gallinarum porin antibodies were detected in broiler breeder serum and in fertile eggs (P < 0.05). Consequently, chickens from immunized broiler breeder hens were protected between 53 to 70% against challenges of 20 to 500 half-maximal lethal dose of Salmonella Gallinarum (P < 0.001) when compared with control hens that were injected with PBS. These results suggest that Salmonella Gallinarum porins, as those of other Salmonella species, participate in the induction of the passive protective immunity, and the humoral immune response may be one of the mechanisms involved in the establishment of this protection.


Assuntos
Galinhas , Imunidade Humoral/fisiologia , Porinas/imunologia , Doenças das Aves Domésticas/prevenção & controle , Salmonella/metabolismo , Animais , Relação Dose-Resposta a Droga , Feminino , Doenças das Aves Domésticas/imunologia
5.
Vaccine ; 25(27): 5071-85, 2007 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-17543427

RESUMO

Attenuated Salmonella strains are used widely as live carriers of antigens because they elicit both mucosal and systemic immunity against passenger antigens. However, they generally evoke poor cytotoxic T cell (CTL) responses because Salmonella resides within vacuolar compartments and the passenger antigens must travel to the cytosol and be processed through the MHC class I-dependent pathway to simulate CTLs. To address this problem, we designed a fusion protein to destabilize the phagosome membrane and allow a dengue epitope to reach the cytosol. The fusion protein was displayed on the bacterial surface of Salmonella enterica serovar Typhimurium SL3261 through the beta domain of the autotransporter MisL. The passenger alpha domain contained, from the N-terminus, a fusogenic sequence, the NS3 protein 298-306-amino acid CTL epitope from the dengue virus type 2, a molecular tag, and a recognition site for the protease OmpT to release it to the milieu. Display of the fusion protein on the bacterial surface was demonstrated by IFA and flow cytometry using antibodies against the molecular tag. Cleavage of the fusogenic protein-dengue peptide was demonstrated by flow cytometry using OmpT+ Escherichia coli strains. The recombinant Salmonella strains displaying the fusogenic-dengue peptide were able to lyse erythrocytes, induced specific proliferative responses, and elicited CTL responses. These results suggest that the recombinant fusion proteins containing fusogenic sequences provide a promising system to induce CTLs by live vector vaccines.


Assuntos
Vacinas contra Dengue/biossíntese , Vacinas contra Dengue/imunologia , Salmonella enterica/metabolismo , Linfócitos T Citotóxicos/imunologia , Animais , Sequência de Bases , Linhagem Celular Tumoral , Proliferação de Células , Cromo/metabolismo , Dengue/imunologia , Vacinas contra Dengue/genética , Vírus da Dengue/imunologia , Epitopos/imunologia , Eritrócitos/efeitos dos fármacos , Escherichia coli/metabolismo , Citometria de Fluxo , Imunofluorescência , Hemólise/efeitos dos fármacos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos BALB C , Oligonucleotídeos , Plasmídeos , Salmonella enterica/genética , Ovinos , Vacinas de Subunidades Antigênicas/biossíntese , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Proteínas Virais de Fusão/biossíntese , Proteínas Virais de Fusão/imunologia
6.
Immunology ; 103(1): 41-8, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11380691

RESUMO

Macrophages can process and present exogenous antigens on major histocompatibility complex (MHC) class I molecules through an alternative mechanism involving the internalization of antigens and the secretion of peptides loading MHC class I molecules at the cell surface. In this paper, we found that interferon-gamma (IFN-gamma) -activated macrophages infected with Salmonella typhimurum secreted peptides able to load empty MHC Kb molecules on co-cultured TAP-2-deficient RMA-S cells, added as targets for peptide loading. The increase in class I Kb on the RMA-S cells, resulting from the macrophage-derived peptides, exhibited a comparable stability as the direct addition of an exogenous Kb-binding peptide (OVA257-264) to the RMA-S cells. In both cases, the Kb complexes were stable for at least 3 hr after separating the RMA-S cells from the macrophages. The endosomal inhibitors, leupeptin and ammonium chloride, did not inhibit the release of peptides and the increase in Kb staining on the RMA-S cells in the co-culture systems. Brefeldin A also had no effect. P815 cells previously co-cultured with Salmonella-infected macrophages became targets for cytotoxic T lymphocytes isolated from Salmonella-infected BALB/c mice. Taken together, our data suggest that IFN-gamma-activated macrophages process exogenous antigens in an intracellular compartment where serine proteases generate peptides released to the external environment for loading empty MHC class I molecules at the cell surface. This TAP-independent mechanism for the MHC class I presentation may be involved in priming cytotoxic T lymphocytes against intracellular pathogens in vivo.


Assuntos
Apresentação de Antígeno/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Interferon gama/imunologia , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Animais , Brefeldina A/farmacologia , Linfócitos T CD8-Positivos/imunologia , Técnicas de Cultura de Células , Endossomos/imunologia , Feminino , Macrófagos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Peptídeos/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , Infecções por Salmonella/imunologia , Salmonella typhimurium
8.
Mol Biochem Parasitol ; 108(2): 199-206, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10838222

RESUMO

We identified here a 576 bp rab-like gene (EhrabB) in Entamoeba histolytica. EhrabB is located 332 bp upstream from the start codon of the Ehcp112 encoding gene, but is transcribed from the complementary strand. The EhrabB open reading frame predicts a 192 amino acid polypeptide (EhRabB) with 40-42% identity to Rab proteins, involved in vesicle docking regulation in endo and exocytic pathways of eukaryotic cells. Transcripts of 0.6 and 0.97 kb were detected by the EhrabB probe in northern blot assays. Using specific antibodies, EhRabB was located in small cytoplasmic vesicles by confocal microscopy. During phagocytosis, EhRabB was initially translocated to the plasma membrane and to the phagocytic mouths. The protein diminished after 10 min phagocytosis, suggesting that EhRabB could be participating in the regulation of the endocytosis process.


Assuntos
Entamoeba histolytica/genética , Entamoeba histolytica/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Anticorpos Antiprotozoários , Transporte Biológico , Northern Blotting , Western Blotting , Membrana Celular/metabolismo , Citoplasma/metabolismo , Genes de Protozoários , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Microscopia Confocal , Dados de Sequência Molecular , Fagocitose , Proteínas Recombinantes/imunologia , Transcrição Gênica , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/imunologia
9.
Mol Reprod Dev ; 55(3): 270-81, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10657046

RESUMO

The differential quantitative participation of apoptosis and necrosis in ewe antral follicles of two different sizes, separated in four stages of atresia using macroscopic, histologic, and esteroid quantification methods was assessed. Annexin V binding and propidium iodide (PI) uptake was used to detect healthy live cells (Annexin V negative/PI negative), early apoptotic cells (Annexin V+/PI-), and necrotic or late apoptotic cells (PI+). Additionally we used internucleosomal DNA fragmentation as a quantitative estimate of apoptosis. Presence and distribution of lysosomal enzymes in follicular fluid and granulosa cells was used as a measure of necrotic cell death. DNA flow cytometry and gel electrophoresis were positively correlated with the progression of atresia, small atretic follicles tend to have higher percentages of internucleosomal cleaved DNA than follicles >6 mm. Annexin/PI binding also indicates that apoptosis and necrosis increase with atresia progression, generally apoptosis outweighs necrosis in small follicles. Acid phosphatase and glucosaminidase in follicular fluid of 3-6 mm follicles showed no significant modifications between healthy and initially atretic follicles, and only a small, but significant increase in activity in advancedly atretic follicles. On the contrary, lysosomal enzyme activity in follicles >6 mm showed positive correlation between atresia stages and the activities of acid phosphatase and glucosaminidase in follicular fluid. A similar size-differential behavior was found in free or membrane-bound lysosomal enzyme activity of granulosa cells. Necrosis, but principally apoptosis, were present during all stages of follicular maturation indicating that growth and maturation of ovarian follicles involves a continuous renewal of granulosa cells, regulated by apoptosis. Mechanisms regulating this equilibrium may participate in the final destiny, whether ovulation or atresia of ovarian follicles.


Assuntos
Atresia Folicular/fisiologia , Líquido Folicular/enzimologia , Células da Granulosa/enzimologia , Lisossomos/enzimologia , Fosfatase Ácida/metabolismo , Animais , Anexina A5/metabolismo , Apoptose , Ciclo Celular , Fragmentação do DNA , Eletroforese em Gel de Ágar , Estradiol/metabolismo , Feminino , Citometria de Fluxo , Hexosaminidases/metabolismo , Necrose , Nucleossomos/genética , Progesterona/metabolismo , Ovinos
10.
Arch Med Res ; 30(4): 298-302, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10573631

RESUMO

BACKGROUND: Several factors inhibit cellular immune response by deactivating macrophages, but very few, such as those described here, prevent macrophage activation. METHODS: Ascites liquid from 12-day-old BALB/c mice bearing 5178Y lymphoma tumors was collected, and cell-free ascites liquid (CFAL) was separated from lymphoblasts. The supernatant (S1) was obtained from the homogenized and centrifuged lymphoblasts. Then, macrophage cultures containing 0.2 x 10(6) cells from lymphoma-bearing or healthy mice were added to 10 microL of CFAL or S1, plus 5 micrograms of lipopolysaccharides (LPS)/mL, 40 U interferon-gamma or a blend of both. Macrophages were incubated with CFAL or S1 prior to or after adding the activators to investigate whether any of the previously mentioned lymphoma fractions inhibited macrophage activation or whether they deactivated them. The effect of CFAL or S1 was estimated as the diminution of the amount of nitric oxide released by the experimental macrophage cultures with respect to controls (activated macrophages treated with none of the lymphoma fractions). RESULTS: LPS, IFN-gamma, and the LPS/gamma blend activated macrophages from both lymphoma-bearing and healthy mice. None of the lymphoma fractions deactivated macrophages. CFAL, but not S1, inhibited the macrophage activation, i.e., the percentage of inhibition of nitric oxide releasing 76.7% and 78.1% in macrophages from healthy and lymphoma-bearing mice, respectively. In addition, CFAL was unable to inhibit the macrophage-activation effect of IFN-gamma or the LPS/IFN-gamma blend. CONCLUSIONS: Mouse L5178Y lymphoma releases a factor that in vitro inhibits the macrophage activation induced by LPS, but not by IFN-gamma controls.


Assuntos
Linfoma/imunologia , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Animais , Células Cultivadas , Interferon-alfa/farmacologia , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos DBA , Mitógenos/farmacologia , Óxido Nítrico/biossíntese
11.
Immunol Lett ; 67(3): 167-77, 1999 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10369123

RESUMO

In this work we eluted peptides from purified class I MHC molecules, isolated from a novel human cervical carcinoma cell line (INBL), generated in our laboratory and positive for HPV-18 infection. A fraction of these peptides was capable of stimulating T lymphocytes obtained from a donor matched for HLA-Cw4 and who was also HPV-18+. Direct N-terminal Edman degradation of these peptides, revealed the sequence (XQFPIFLQF) that matched 85% with the sequence NVFPIFLQM localized in between the 54 and 62 residues of the HPV-18 L1 protein. After stimulation with the synthetic peptide NVFPIFLQM, T lymphocytes from the donor were capable to lyse INBL cells. Our results provide evidence of the existence of naturally occurring viral epitopes presented on cervical cancer cells by the HLA-Cw4 allele, that could be useful for immunotherapy on this type of patient.


Assuntos
Antígenos de Histocompatibilidade Classe I/imunologia , Papillomaviridae/imunologia , Peptídeos/imunologia , Neoplasias do Colo do Útero/virologia , Proteínas Virais/imunologia , Sequência de Aminoácidos , Antígenos Virais/química , Antígenos Virais/imunologia , Citotoxicidade Imunológica , Epitopos/imunologia , Feminino , Antígenos de Histocompatibilidade Classe I/química , Humanos , Ativação Linfocitária , Espectrometria de Massas , Dados de Sequência Molecular , Infecções por Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Peptídeos/química , Peptídeos/isolamento & purificação , Linfócitos T/imunologia , Células Tumorais Cultivadas , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/virologia , Neoplasias do Colo do Útero/imunologia , Proteínas Virais/química , Proteínas Virais/isolamento & purificação
12.
Vaccine ; 16(9-10): 1043-52, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9682357

RESUMO

Attenuated Salmonella typhi are attractive for use as live vector vaccines to express protozoal antigens and deliver them to the human immune system. The gene encoding the mature form of Leishmania mexicana mexicana gp63 under control of tac promoter was integrated into the delta aroC locus of the chromosome of attenuated delta aroC, delta aroD S. typhi strain CVD 908. After oral immunization of BALB/c mice with two 1 x 10(9) colony forming unit doses given 21 days apart, CVD 908 omega (delta aroC::Ptac-gp63) elicited a broad T cell-mediated immune response against L. m. mexicana gp63 as demonstrated by: (1) lymphoproliferative response to fixed whole L. m. mexicana promastigotes; (2) activation of IL-2 (but not IL-4)-producing lymphocytes; (3) appearance of cytotoxic T cells against mouse mastocytoma cells expressing gp63. This T-cell mediated immune response was associated with significant protection in F1 (BALB/cXC57Bl/6) mice challenged in their footpads with a wild type strain of L. m. mexicana.


Assuntos
Antígenos de Protozoários/genética , Leishmania mexicana/genética , Leishmania mexicana/imunologia , Metaloendopeptidases/genética , Metaloendopeptidases/imunologia , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Vacinas Protozoárias/genética , Vacinas Protozoárias/imunologia , Salmonella typhi/genética , Salmonella typhi/imunologia , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Administração Oral , Animais , Sequência de Bases , Citotoxicidade Imunológica , Primers do DNA/genética , Genes de Protozoários , Vetores Genéticos , Humanos , Técnicas In Vitro , Interleucina-2/biossíntese , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/prevenção & controle , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Vacinas Protozoárias/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Linfócitos T/imunologia , Vacinas Sintéticas/administração & dosagem
13.
FEMS Microbiol Lett ; 141(1): 31-6, 1996 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-8764508

RESUMO

Mice were immunized with resin-bound peptides whose sequences have been proposed to be part of exposed loops in Salmonella typhi outer membrane protein OmpC. To screen hybridomas for monoclonal antibodies against those epitopes, we designed fusion proteins where the candidate peptide sequence was attached to the amino end of cholera toxin B-subunit (CTB). The constructed fusion proteins allowed the efficient selection of positive clones by GM1-ELISA. Selected antibodies recognized purified OmpC and whole Salmonella bacteria. This suggests a native structure of our genetically attached peptides in agreement with immunological properties reported for previous CTB recombinant fusion proteins. In a more general context, CTB hybrids could be used to screen for antibodies towards immunogenic epitopes in other systems. This might turn out to be particularly useful when producing antibodies against peptide sequences in microorganisms whose handling is difficult or that pose inherent health risks.


Assuntos
Anticorpos Antibacterianos , Anticorpos Monoclonais , Proteínas da Membrana Bacteriana Externa/imunologia , Toxina da Cólera/imunologia , Salmonella typhi/imunologia , Sequência de Aminoácidos , Animais , Proteínas da Membrana Bacteriana Externa/análise , Proteínas da Membrana Bacteriana Externa/genética , Sequência de Bases , Toxina da Cólera/genética , Epitopos/análise , Hibridomas , Camundongos , Camundongos Endogâmicos C3H , Dados de Sequência Molecular , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Salmonella typhi/genética
14.
Epidemiol Infect ; 115(3): 535-43, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8557086

RESUMO

The prevalence of antibodies against Entamoeba histolytica was studied in the Mexican population using an immunoenzyme assay in solid phase (ELISA) and semiautomatic equipment. The antigen was a mixture of membrane proteins obtained by Triton X-100 extraction from an axenic culture of Entamoeba histolytica HM1-IMSS. The method was standardized by comparing serum samples from amoebic liver abscess patients with healthy volunteers. From the 60,538 samples supplied by the National Seroepidemiology Survey, antibodies were found in 4.49% (4.32-4.65% at 95% confidence limit). More significant titres occurred in the central region of the country. The ratio female to male was 1.25:1. The population living in metropolitan areas had probably been infected at a younger age than those living in the country. Important differences were found in the seroprevalence obtained by ELISA compared with a study which used indirect haemagglutination (IHA) in the same sample frame.


Assuntos
Anticorpos Antiprotozoários/análise , Entamoeba histolytica/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Abscesso Hepático Amebiano/epidemiologia , Abscesso Hepático Amebiano/imunologia , Adolescente , Adulto , Distribuição por Idade , Idoso , Animais , Antígenos de Protozoários/imunologia , Criança , Pré-Escolar , Feminino , Testes de Hemaglutinação , Humanos , Incidência , Lactente , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos
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