RESUMO
BACKGROUND: Typhoid (Salmonella typhi and paratyphi) carriers and gall bladder cancer (GBC) are endemic in northern India. Results of previous studies about association of typhoid carriers with GBC are inconsistent. We studied antibodies against Salmonella typhi and paratyphi in serum samples of patients with GBC. METHODS: We performed modified Widal test for antibodies against Salmonella typhi (Vi and O) and Salmonella paratyphi (AO and BO) antigens in patients with GBC (n=100), xanthogranulomatous cholecystitis (XGC, n=24), chronic cholecystitis (CC, n=200) and healthy controls (HC, n=200). RESULTS: Serum antibodies against Salmonella were more frequently positive in GBC (22%) and XGC (29%), particularly in males in age ≥50 years (GBC: 47% and XGC: 50%) vs. HC (0) (p <0.01). Vi antibody was more common in GBC (13%, OR:9.8) and XGC (8%, OR:5.9) than HC (2%). O antibody was more common in GBC (8%, OR: 8.6) and XGC (8%, OR: 9.0) than HC (1%). O antibody was also more common in males with GBC (12%) than CC (1%) and HC (1%) (P=0.02 and p <0.001, respectively). AO (6%) and BO (4%) antibodies were detected in GBC, particularly in males, than HC (0), (p <0.01). Salmonella antibodies were more frequent in GBC with GS than those without GS (50% vs. 20%, OR=3.94, P=0.01). CONCLUSIONS: Salmonella carrier state was more common in GBC and XGC, particularly in elderly males than HC. The Vi antibody was more common in GBC and XGC than HC. Salmonella infection was more common in GBC with GS than those without GS.
Assuntos
Anticorpos Antibacterianos/sangue , Colecistite/microbiologia , Neoplasias da Vesícula Biliar/microbiologia , Infecções por Salmonella/epidemiologia , Salmonella paratyphi A/imunologia , Salmonella typhi/imunologia , Xantomatose/microbiologia , Adulto , Idoso , Estudos de Casos e Controles , Colecistite/sangue , Colecistite/complicações , Doença Crônica , Feminino , Neoplasias da Vesícula Biliar/sangue , Neoplasias da Vesícula Biliar/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Salmonella/diagnóstico , Xantomatose/sangue , Xantomatose/complicaçõesRESUMO
Salmonella Paratyphi A (SPtA) remains one of the leading causes of enteric (typhoid) fever. Yet, despite the recent increased rate of isolation from patients in Asia, our understanding of its pathogenesis is incomplete. Here we investigated inflammasome activation in human macrophages infected with SPtA. We found that SPtA induces GSDMD-mediated pyroptosis via activation of caspase-1, caspase-4 and caspase-8. Although we observed no cell death in the absence of a functional Salmonella pathogenicity island-1 (SPI-1) injectisome, HilA-mediated overexpression of the SPI-1 regulon enhances pyroptosis. SPtA expresses FepE, an LPS O-antigen length regulator, which induces the production of very long O-antigen chains. Using a ΔfepE mutant we established that the very long O-antigen chains interfere with bacterial interactions with epithelial cells and impair inflammasome-mediated macrophage cell death. Salmonella Typhimurium (STm) serovar has a lower FepE expression than SPtA, and triggers higher pyroptosis, conversely, increasing FepE expression in STm reduced pyroptosis. These results suggest that differential expression of FepE results in serovar-specific inflammasome modulation, which mirrors the pro- and anti-inflammatory strategies employed by STm and SPtA, respectively. Our studies point towards distinct mechanisms of virulence of SPtA, whereby it attenuates inflammasome-mediated detection through the elaboration of very long LPS O-polysaccharides.
Assuntos
Inflamassomos/metabolismo , Macrófagos/microbiologia , Macrófagos/fisiologia , Antígenos O/fisiologia , Febre Paratifoide/microbiologia , Piroptose , Salmonella paratyphi A/patogenicidade , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Caspases/metabolismo , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Macrófagos/imunologia , Antígenos O/química , Proteínas de Ligação a Fosfato/metabolismo , Salmonella paratyphi A/imunologia , Células THP-1 , Sistemas de Secreção Tipo III/metabolismo , Virulência , Fatores de Virulência/metabolismoRESUMO
Enteric fevers, caused by the Salmonella enterica serovars Typhi (ST), Paratyphi A (PA) and Paratyphi B (PB), are life-threatening illnesses exhibiting very similar clinical symptoms but with distinct epidemiologies, geographical distributions and susceptibilities to antimicrobial treatment. Nevertheless, the mechanisms by which the host recognizes pathogens with high levels of homology, such as these bacterial serovars, remain poorly understood. Using a three-dimensional organotypic model of the human intestinal mucosa and PA, PB, and ST, we observed significant differences in the secretion patterns of pro-inflammatory cytokines and chemokines elicited by these serovars. These cytokines/chemokines were likely to be co-regulated and influenced the function of epithelial cells, such as the production of IL-8. We also found differing levels of polymorphonuclear leukocyte (PMN) migration among various infection conditions that either included or excluded lymphocytes and macrophages (MÏ), strongly suggesting feedback mechanisms among these cells. Blocking experiments showed that IL-1ß, IL-6, IL-8, TNF-α and CCL3 cytokines were involved in the differential regulation of migration patterns. We conclude that the crosstalk among the lymphocytes, MÏ, PMN and epithelial cells is cytokine/chemokine-dependent and bacterial-serotype specific, and plays a pivotal role in orchestrating the functional efficiency of the innate cells and migratory characteristics of the leukocytes.
Assuntos
Comunicação Celular , Leucócitos/imunologia , Salmonella paratyphi A/imunologia , Salmonella paratyphi B/imunologia , Salmonella typhi/imunologia , Febre Tifoide/imunologia , Movimento Celular , Citocinas/análise , Células Epiteliais/imunologia , Humanos , Mucosa Intestinal/imunologia , Linfócitos/imunologia , Macrófagos/imunologia , Modelos Teóricos , Técnicas de Cultura de ÓrgãosRESUMO
To tackle the complexity of cross-reactive and pathogen-specific T cell responses against related Salmonella serovars, we used mass cytometry, unbiased single-cell cloning, live fluorescence barcoding, and T cell-receptor sequencing to reconstruct the Salmonella-specific repertoire of circulating effector CD4+ T cells, isolated from volunteers challenged with Salmonella enterica serovar Typhi (S. Typhi) or Salmonella Paratyphi A (S. Paratyphi). We describe the expansion of cross-reactive responses against distantly related Salmonella serovars and of clonotypes recognizing immunodominant antigens uniquely expressed by S. Typhi or S. Paratyphi A. In addition, single-amino acid variations in two immunodominant proteins, CdtB and PhoN, lead to the accumulation of T cells that do not cross-react against the different serovars, thus demonstrating how minor sequence variations in a complex microorganism shape the pathogen-specific T cell repertoire. Our results identify immune-dominant, serovar-specific, and cross-reactive T cell antigens, which should aid in the design of T cell-vaccination strategies against Salmonella.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Salmonella paratyphi A/imunologia , Salmonella typhi/imunologia , ADP-Ribosil Ciclase 1/análise , Adulto , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Linfócitos T CD4-Positivos/química , Células Clonais , Humanos , Fenótipo , Receptores CCR7/análise , Febre Tifoide/imunologiaRESUMO
Mucosal-associated invariant T (MAIT) cells are innate-like T cells that can detect bacteria-derived metabolites presented on MR1. Here we show, using a controlled infection of humans with live Salmonella enterica serovar Paratyphi A, that MAIT cells are activated during infection, an effect maintained even after antibiotic treatment. At the peak of infection MAIT cell T-cell receptor (TCR)ß clonotypes that are over-represented prior to infection transiently contract. Select MAIT cell TCRß clonotypes that expand after infection have stronger TCR-dependent activation than do contracted clonotypes. Our results demonstrate that host exposure to antigen may drive clonal expansion of MAIT cells with increased functional avidity, suggesting a role for specific vaccination strategies to increase the frequency and potency of MAIT cells to optimize effector function.
Assuntos
Proliferação de Células , Células T Invariantes Associadas à Mucosa/imunologia , Febre Paratifoide/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Salmonella paratyphi A/imunologia , Adolescente , Adulto , Linhagem Celular Tumoral , Células Clonais/imunologia , Células Clonais/metabolismo , Células Clonais/microbiologia , Voluntários Saudáveis , Interações Hospedeiro-Patógeno/imunologia , Humanos , Células Jurkat , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/microbiologia , Pessoa de Meia-Idade , Células T Invariantes Associadas à Mucosa/metabolismo , Células T Invariantes Associadas à Mucosa/microbiologia , Febre Paratifoide/metabolismo , Febre Paratifoide/microbiologia , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Salmonella paratyphi A/fisiologia , Adulto JovemRESUMO
Previously we have extensively characterized Salmonella enterica serovar Typhi (S. Typhi)-specific cell-mediated immune (CMI) responses in volunteers orally immunized with the licensed Ty21a typhoid vaccine. In this study we measured Salmonella-specific multifunctional (MF) CD8+ T-cell responses to further investigate whether Ty21a elicits crossreactive CMI against S. Paratyphi A and S. Paratyphi B that also cause enteric fever. Ty21a-elicited crossreactive CMI responses against all three Salmonella serotypes were predominantly observed in CD8+ T effector/memory (T(EM)) and, to a lesser extent, in CD8+CD45RA+ T(EM) (T(EMRA)) subsets. These CD8+ T-cell responses were largely mediated by MF cells coproducing interferon-γ and macrophage inflammatory protein-1ß and expressing CD107a with or without tumor necrosis factor-α. Significant proportions of Salmonella-specific MF cells expressed the gut-homing molecule integrin α4ß7. In most subjects, similar MF responses were observed to S. Typhi and S. Paratyphi B, but not to S. Paratyphi A. These results suggest that Ty21a elicits MF CMI responses against Salmonella that could be critical in clearing the infection. Moreover, because S. Paratyphi A is a major public concern and Ty21a was shown in field studies not to afford cross-protection to S. Paratyphi A, these results will be important in developing a S. Typhi/S. Paratyphi A bivalent vaccine against enteric fevers.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Febre Paratifoide/prevenção & controle , Polissacarídeos Bacterianos/imunologia , Febre Tifoide/prevenção & controle , Vacinas Tíficas-Paratíficas/imunologia , Adulto , Reações Cruzadas/imunologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Febre Paratifoide/imunologia , Salmonella paratyphi A/imunologia , Salmonella paratyphi B/imunologia , Salmonella typhi/imunologia , Febre Tifoide/imunologia , Adulto JovemRESUMO
Live oral Salmonella enterica serovar Typhi vaccine Ty21a induces specific antibodies that cross-react against Salmonella enterica serovar Paratyphi A and Salmonella enterica serovar Paratyphi B, although their functional role in clearance remains unknown. We utilized an in vitro assay with THP-1 macrophages to compare the phagocytosis and survival of Salmonella opsonized with heat-inactivated human sera obtained before and after vaccination with Ty21a or a live oral S. Typhi vaccine, CVD 909. Opsonization with postvaccination sera predominantly increased the phagocytosis of S. Typhi relative to the corresponding prevaccination sera, and increases were also observed with S. Paratyphi A and S. Paratyphi B, albeit of lower magnitudes. Relative to prevaccination sera, opsonization with the postvaccination sera reduced the survival inside macrophages of S. Typhi but not of S. Paratyphi A or S. Paratyphi B. Higher anti-S. Typhi O antigen (lipopolysaccharide [LPS]) IgG, but not IgA, antibody titers correlated significantly with postvaccination increases in opsonophagocytosis. No differences were observed between immunization with four doses of Ty21a or one dose of CVD 909. Ty21a and CVD 909 induced cross-reactive functional antibodies, predominantly against S. Typhi. IgG anti-LPS antibodies may be important in phagocytic clearance of these organisms. Therefore, measurement of functional antibodies might be important in assessing the immunogenicity of a new generation of typhoid and paratyphoid A vaccines. (The CVD 909 study has been registered at ClinicalTrials.gov under registration no. NCT00326443.).
Assuntos
Anticorpos Antibacterianos/sangue , Reações Cruzadas , Proteínas Opsonizantes/sangue , Salmonella paratyphi A/imunologia , Salmonella paratyphi B/imunologia , Salmonella typhi/imunologia , Vacinas Tíficas-Paratíficas/imunologia , Administração Oral , Adulto , Anticorpos Antibacterianos/imunologia , Linhagem Celular , Sobrevivência Celular , Feminino , Humanos , Macrófagos/imunologia , Masculino , Proteínas Opsonizantes/imunologia , Fagocitose , Vacinas Tíficas-Paratíficas/administração & dosagem , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/imunologia , Adulto JovemRESUMO
BaeR is the response regulator of the two-component system, BaeSR, found in Escherichia coli (E. coli) and Salmonella. Several biological functions of BaeR, related to multidrug efflux and bacterial virulence, have been described. Herein, we report a putative function of BaeR during inflammatory response of the host by using BaeR protein of Salmonella enterica Paratyphi A (S. Paratyphi A) origin overexpressed in E. coli, and RAW 264.7 and THP-1 cells as in vitro models. BaeR (3 µg/ml) upregulated iNOS mRNA expression in both cell lines, and induced significant production of NO. Greater than ten-fold (TNF-α), 24-fold (IL-1ß) and 156-fold (IL-6) increases in mRNA expression levels were observed in THP-1 cells treated with BaeR, compared to untreated controls. Furthermore, an eight-fold (IL-1ß), 12-fold (IL-6) and 41-fold (TNF-α) higher protein concentrations were observed in RAW 264.7 cells stimulated with BaeR, compared to control cells. Immunoblot analysis showed BaeR-induced phosphorylation of the MAPKs (ERK 1/2, JNK and p38 MAPK) in RAW 264.7 cells. Pharmacological inhibition of the three MAPKs using specific inhibitors resulted in significant reduction of BaeR-induced NO production and iNOS mRNA expression by inhibitors of JNK and p38 MAPK. Also, all inhibitors of the MAPKs significantly attenuated BaeR-induced IL-1ß, IL-6 and TNF-α at both transcript and protein levels with different degrees of inhibition. Taken together, our data suggest that BaeR is a putative inducer of inflammatory response and the MAPKs are involved in the process.
Assuntos
Interações Hospedeiro-Patógeno , Proteínas Associadas à Resistência a Múltiplos Medicamentos/imunologia , Salmonella paratyphi A/imunologia , Transdução de Sinais , Estresse Fisiológico , Transativadores/imunologia , Animais , Linhagem Celular , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Macrófagos/imunologia , Macrófagos/microbiologia , Camundongos , Óxido Nítrico Sintase Tipo II/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Salmonella enterica serotype Paratyphi A is a human-restricted pathogen and the cause of paratyphoid A fever. Using a high-throughput immunoscreening technique, in vivo-induced antigen technology (IVIAT), we identified 20 immunogenic bacterial proteins expressed in humans who were bacteremic with S. Paratyphi A but not those expressed in S. Paratyphi A grown under standard laboratory conditions. The majority of these proteins have known or potential roles in the pathogenesis of S. enterica. These include proteins implicated in cell adhesion, fimbrial structure, adaptation to atypical conditions, oxidoreductase activity, proteolysis, antimicrobial resistance, and ion transport. Of particular interest among these in vivo-expressed proteins were S. Paratyphi A (SPA)2397, SPA2612, and SPA1604. SPA2397 and SPA2612 are prophage related, and SPA1604 is in Salmonella pathogenicity island 11 (SPI-11). Using real-time quantitative PCR (RT-qPCR), we confirmed increased levels of mRNA expressed by genes identified by IVIAT in a comparison of mRNA levels in organisms in the blood of bacteremic patients to those in in vitro cultures. Comparing convalescent- to acute-phase samples, we also detected a significant increase in the reaction of convalescent-phase antibodies with two proteins identified by IVIAT: SPA2397 and SPA0489. SPA2397 is a phage-related lysozyme, Gp19, and SPA0489 encodes a protein containing NlpC/P60 and cysteine, histidine-dependent amidohydrolase/peptidase (CHAP) domains. In a previous study utilizing a different approach, we found that transcripts for 11 and 7 of the genes identified by IVIAT were detectable in organisms in the blood of humans in Bangladesh who were bacteremic with S. Paratyphi A and Salmonella enterica serovar Typhi, respectively. S. Paratyphi A antigens identified by IVIAT warrant further evaluation for their contributions to pathogenesis and might have diagnostic, therapeutic, or preventive relevance.
Assuntos
Antígenos de Bactérias/sangue , Bacteriemia/microbiologia , Proteínas de Bactérias/sangue , Proteínas de Bactérias/imunologia , Febre Paratifoide/microbiologia , Salmonella paratyphi A/imunologia , Antígenos de Bactérias/biossíntese , Antígenos de Bactérias/imunologia , Bacteriemia/imunologia , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/isolamento & purificação , Humanos , Febre Paratifoide/diagnóstico , Febre Paratifoide/imunologia , Prófagos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Salmonella paratyphi A/genética , Salmonella paratyphi A/virologiaRESUMO
Enteric fever is an invasive life-threatening systemic disease caused by the Salmonella enterica human-adapted serovars Typhi and Paratyphi. Increasing incidence of infections with Salmonella enterica serovar Paratyphi A and the spreading of its antibiotic-resistant derivates pose a significant health concern in some areas of the world. Herein, we describe a molecular and phenotypic characterization of an S. Paratyphi A strain accounted for a recent paratyphoid outbreak in Nepal that affected at least 37 travelers. Pulsed-field gel electrophoresis analysis of the outbreak isolates revealed one genetic clone (pulsotype), confirming a single infecting source. Genetic profiling of the outbreak strain demonstrated the contribution of specific bacteriophages as a prime source of genetic diversity among clinical isolates of S. Paratyphi A. Phenotypic characterization in comparison with the S. Paratyphi A ATCC 9150 reference sequenced strain showed differences in flagellar morphology and increased abilities of the outbreak strain with respect to its motility, invasion into nonphagocytic cells, intracellular multiplication, survival within macrophages, and higher induction of interleukin-8 (IL-8) secreted by host cells. Collectively, these differences suggest an enhanced virulence potential of this strain and demonstrate an interesting phenotypic variation among S. Paratyphi A isolates. In vivo profiling of 16 inflammatory cytokines in patients infected with the outbreak strain revealed a common profile of a remarkable gamma interferon (IFN-γ) induction together with elevated concentrations of tumor necrosis factor alpha (TNF-α), IL-6, IL-8, IL-10, and IL-15, but not IL-12, which was previously demonstrated as elevated in nontyphoidal Salmonella infections. This apparent profile implies a distinct immune response to paratyphoid infections.
Assuntos
Febre Paratifoide/imunologia , Febre Paratifoide/microbiologia , Salmonella paratyphi A/genética , Salmonella paratyphi A/imunologia , Adulto , Idoso , Animais , Bacteriófagos/genética , Células CACO-2 , Citocinas/análise , DNA Bacteriano/genética , Farmacorresistência Bacteriana , Feminino , Variação Genética , Genótipo , Células HeLa , Humanos , Interleucina-8/metabolismo , Israel , Macrófagos/microbiologia , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Nepal/epidemiologia , Febre Paratifoide/epidemiologia , Fenótipo , Salmonella paratyphi A/efeitos dos fármacos , Salmonella paratyphi A/isolamento & purificação , Análise de Sequência de DNA , Adulto JovemAssuntos
Humanos , Febre Tifoide/prevenção & controle , Vacinas Tíficas-Paratíficas/imunologia , Formação de Anticorpos , Salmonella paratyphi A/imunologia , Salmonella typhi/imunologia , Resultado do Tratamento , Vacinas Tíficas-Paratíficas/administração & dosagem , Vacinas Tíficas-Paratíficas , Vacinas Tíficas-Paratíficas/farmacologiaRESUMO
Obtaining antibodies to individual components of Salmonella antigenic complex is highly important for investigations aimed at the study of the antigenic structure of bacteria, their serological identification and the development of diagnostic preparations. The method of obtaining antibodies by the oxidation of Salmonella antigens with sodium periodate and creating immunosorbents based on these antibodies with subsequent affinity chromatography has been developed. Monospecific antibodies thus obtained (O2, O4, O9) have been studied and used as monospecific preparations in the agglutination test, the immunofluorescence test and the immunosorbent assay. The development of methods for stabilizing these preparations, thus ensuring their wide practical use, may be of interest.
Assuntos
Anticorpos Antibacterianos/isolamento & purificação , Anticorpos Monoclonais/isolamento & purificação , Especificidade de Anticorpos , Cromatografia de Afinidade/métodos , Salmonella/imunologia , Testes de Aglutinação , Animais , Anticorpos Antibacterianos/análise , Anticorpos Monoclonais/análise , Antígenos de Bactérias/imunologia , Imunofluorescência , Técnicas Imunoenzimáticas , Antígenos O , Coelhos , Salmonella paratyphi A/imunologiaRESUMO
Altogether 181 patients with typhoid and paratyphoid fever (54 with typhoid fever, 50 with paratyphoid fever type A, and 77 with paratyphoid fever type B) were investigated. Of them 108 (59.7%) patients were examined during the 1st week of disease. Serum specific O-antigens of typhoid and paratyphoid fever agents were determined by enzyme immunoassay (EIA), radioimmunoassay (RIA), and O-aggregate hemagglutination reaction (O-AHA), serum specific O-antibodies were determined by RDHA, EIA, RIA or O-AHA used during the 1st week of disease were twice as effective as RDHA. Combined use of EIA and O-AHA for the detection of serum specific O-antigens made it possible to diagnose typhoid fever in 90.91%, paratyphoid fever type A in 96.15%, and paratyphoid fever type B in 95.55% of cases.
Assuntos
Antígenos de Bactérias/análise , Febre Paratifoide/diagnóstico , Salmonella paratyphi A/imunologia , Salmonella paratyphi B/imunologia , Salmonella typhi/imunologia , Salmonella/imunologia , Febre Tifoide/diagnóstico , Epitopos/análise , Estudos de Avaliação como Assunto , Testes de Inibição da Hemaglutinação , Testes de Hemaglutinação , Humanos , Técnicas Imunoenzimáticas , Antígenos O , Radioimunoensaio , Fatores de TempoRESUMO
Some regularities of distribution and binding of streptomycin in the blood, organs and tissues of immunized rabbits werer studied. The leveles of the bound and free antibiotic in ther were determined. It was found that the immunobiological state of the rabbits had a definite effect on the distribution character and binding of streptomycin with proteins and cells in the animal organs and tissues. These changes were most pronounced in the organs and tissues of lymphoid and hematopoietic systems, the cells of which are indirect active participants of the immunity formation. As a result of proliferation of these cells the antibiotic was accumulated in higher amounts and bound more actively especially in the thymus gland and bone marrow, the central organs of the immunological reconstruction of the host. The studies are indicative of the presence of interaction between immunogenesis, distribution and binding of streptomycin in immunized animals.