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1.
Pan Afr Med J ; 33: 90, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31489068

RESUMO

Introduction: Syphilis rapid test results may be influenced by numerous environmental and genetic factors. Methods: The proportion of false positive syphilis non-treponemal (NT) and treponemal (T) test results using immuno-chromatographic dual syphilis rapid test on serum from Cameroonian blacks (n=103) versus French blacks (n=104) or French caucasians (n=51), all HIV-negative and free of clinical syphilis, was examined. Results: Black individuals in Cameroon had a significantly higher frequency of false positive NT or T tests than black individuals in France. black individuals in France had a higher frequency of indeterminate NT tests as compared to caucasians in France. Conclusion: Both racial and environmental factors may affect immuno-chromatographic dual syphilis rapid testing.


Assuntos
Antígenos de Bactérias/imunologia , Sorodiagnóstico da Sífilis/métodos , Sífilis/diagnóstico , Treponema pallidum/imunologia , Grupo com Ancestrais do Continente Africano , Camarões , Grupo com Ancestrais do Continente Europeu , Reações Falso-Positivas , França , Humanos , Estudos Prospectivos , Sífilis/imunologia
2.
Ann Agric Environ Med ; 26(3): 392-395, 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31559791

RESUMO

Existing research for using the protective antigen (PA) of Bacillus anthracis as a vaccine component shows that protection against anthrax may be obtained using fragments of this protein. The aim of the research is to check whether the selected protein fragment of the protective antigen (domain 4) encoded by an appropriate nucleotide sequence of gene pag of B. anthracis, was expressed in the bacterial system of E. coli. In order to examine the selected sequence of the pag gene, a PCR reaction and a highly effective TOPO cloning strategy were used, followed by purification of the recombinant proteins and their detection by a western-blot method. In the planning of the PA4 antigen expression a higher level of effectiveness in production of small protein - domain 4 - was anticipated. As a result, the 139 amino acids protein fragment of B. anthracis PA (domain 4) was isolated. The research may have found the basis for in vivo research aimed at finding potential anthrax vaccine components.


Assuntos
Vacinas contra Antraz/imunologia , Antraz/microbiologia , Antígenos de Bactérias/imunologia , Bacillus anthracis/imunologia , Toxinas Bacterianas/imunologia , Animais , Antraz/imunologia , Antraz/prevenção & controle , Vacinas contra Antraz/administração & dosagem , Vacinas contra Antraz/genética , Vacinas contra Antraz/isolamento & purificação , Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/genética , Antígenos de Bactérias/isolamento & purificação , Bacillus anthracis/química , Bacillus anthracis/genética , Toxinas Bacterianas/administração & dosagem , Toxinas Bacterianas/genética , Toxinas Bacterianas/isolamento & purificação , Western Blotting , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Humanos , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Domínios Proteicos
3.
Braz J Infect Dis ; 23(4): 246-253, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31421107

RESUMO

Accurate and rapid diagnostic tools are important aspects of managing tuberculosis (TB) cases appropriately. However, the sensitivity and specificity of diagnostic kits based on immune response such as the tuberculin skin test (TST) and interferon gamma release assay (IGRA) are still debated. Thus, the exploration and assessment of specific biomarker-targeted antibodies are needed for the development of an accurate and rapid diagnostic tool. The present study was conducted in patients with a respiratory problem suspected to be TB at Dr. Soetomo Hospital, Surabaya, Indonesia. Among 102 patients tested by GeneXpert and AFB, 59 serum samples were from cases retrospectively determined to have active TB. A total of 102 serum of healthy controls (HC) was also collected. The PPD antigen and the recombinant CFP-10 and ESAT-6 proteins were prepared. Antibody responses against these proteins were evaluated by ELISA. All samples were also screened for the possibility of Mycobacterium avium-intracellulare complex (MAC) infection using Capilla MaC kit. The results showed that TB patients had a significantly higher concentration of IgG antibody in response to PPD than the HC. In addition, the receiver operating characteristic (ROC) curve analysis showed that PPD was acceptable for diagnostic purposes with an AUC value of 0.835 (95% CI 0.770-0.900, p < 0.0001). However, ESAT-6 and CFP-10 had low AUCs, and 32 samples from both groups showed a low concentration of IgA antibody against all antigens. The MAC detection results also showed that the concentration of IgA in the HC group was the highest. The current results indicate that PPD is a better antigen for antibody-based detection of TB than ESAT-6 and CFP-10. Based on the MAC detection assay, 53 people in the HC group were probably infected with rapidly growing nontuberculous mycobacteria (NTM), although antibody response to PPD was low.


Assuntos
Formação de Anticorpos/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculina/imunologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/microbiologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Indonésia , Masculino , Pessoa de Meia-Idade , Valores de Referência , Estudos Retrospectivos , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Teste Tuberculínico , Tuberculose Pulmonar/sangue , Adulto Jovem
4.
Pol J Microbiol ; 68(2): 173-183, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31257790

RESUMO

In this research, Salmonella species were isolated from the animal, insect and human enteric sources in Faisalabad, Punjab, Pakistan. These species were characterized by different microbiological and molecular techniques including polymerase chain reaction (PCR) by amplification of the 16S rRNA gene. Furthermore, sequencing of the amplicons confirmed all ten isolates as Salmonella strains. The antigenic cross-reactivity was found maximum between the HB1 (strain isolated from honeybee) antiserum and its antigen with an antibody titer of 1:128, while the HB1 antiserum showed a cross-reactive titer range of 1:8 to 1:64. On the basis of the highest geometric mean titer (GMT) shown by the antiserum of the HB1 antigen, it was selected as the best candidate for a cross-reactive live Salmonella oral antigen. Moreover, the HB1 antigen was used a live oral antigen (1 × 1010 CFU/ml) in a safety test in rabbits and proved to be avirulent. During the animal trial, three different oral doses of the HB1 live oral antigen were evaluated in four different rabbits' groups (R1, R2, R3, and R4). The dose number 2 of 0.5 ml (two drops orally and repeated after one week) gave the best GMT measured by indirect hemagglutination (IHA) as compared to the other two doses, while R4 group was kept as control. Results of the challenge protection test also validated the efficacy of the double dose of the HB1 live vaccine, which gave the highest survival percentage. Results of this study lay the foundation for a potential cross-reactive live oral Salmonella vaccine that has proved to be immunogenic in rabbits.In this research, Salmonella species were isolated from the animal, insect and human enteric sources in Faisalabad, Punjab, Pakistan. These species were characterized by different microbiological and molecular techniques including polymerase chain reaction (PCR) by amplification of the 16S rRNA gene. Furthermore, sequencing of the amplicons confirmed all ten isolates as Salmonella strains. The antigenic cross-reactivity was found maximum between the HB1 (strain isolated from honeybee) antiserum and its antigen with an antibody titer of 1:128, while the HB1 antiserum showed a cross-reactive titer range of 1:8 to 1:64. On the basis of the highest geometric mean titer (GMT) shown by the antiserum of the HB1 antigen, it was selected as the best candidate for a cross-reactive live Salmonella oral antigen. Moreover, the HB1 antigen was used a live oral antigen (1 × 1010 CFU/ml) in a safety test in rabbits and proved to be avirulent. During the animal trial, three different oral doses of the HB1 live oral antigen were evaluated in four different rabbits' groups (R1, R2, R3, and R4). The dose number 2 of 0.5 ml (two drops orally and repeated after one week) gave the best GMT measured by indirect hemagglutination (IHA) as compared to the other two doses, while R4 group was kept as control. Results of the challenge protection test also validated the efficacy of the double dose of the HB1 live vaccine, which gave the highest survival percentage. Results of this study lay the foundation for a potential cross-reactive live oral Salmonella vaccine that has proved to be immunogenic in rabbits.


Assuntos
Antígenos de Bactérias/imunologia , Abelhas/microbiologia , Salmonelose Animal/prevenção & controle , Salmonella typhimurium/imunologia , Salmonella typhimurium/isolamento & purificação , Vacinas Tíficas-Paratíficas/imunologia , Animais , Antígenos de Bactérias/administração & dosagem , DNA Bacteriano/genética , Fezes/microbiologia , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genética , Coelhos , Salmonelose Animal/microbiologia , Salmonella typhimurium/classificação
5.
Braz J Infect Dis ; 23(3): 151-159, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31271732

RESUMO

BACKGROUND: HIV infection harms adaptive cellular immunity mechanisms. Long-term virological control by combined antiretroviral therapy (cART) reduces the risk of mycobacterial infections. Thus, we aimed to study cellular responses to mycobacterial antigens in 20 HIV-infected adolescents with at least one year of virological control (HIV-RNA <40 copies/mL) and 20 healthy adolescents. METHODS: We evaluated CD8 and γδ T-cell degranulation by measurement of CD107a membrane expression after stimulation with lysates from BCG (10 µg/mL) and H37RA Mycobacterium tuberculosis (Mtb, 10 µg/mL). Immune activation and antigen-presenting ability were also assessed by determination of HLA-DR, CD80, and CD86 markers. RESULTS: TCR γδ T-cell CD107a expression was similar between groups in response to mycobacterial antigens, and lower in the HIV-infected group in response to mitogen. Higher baseline HLA-DR expression and lower mycobacterial-stimulated expression was found within the HIV-infected group. CONCLUSIONS: Similar degranulation in stimulated CD8+ and TCR γδ T-cells from HIV-infected adolescents, when compared to healthy controls suggests long-term immunological preservation with immune reconstitution under successful cART. However, differences in HLA-DR expression may represent ongoing inflammation and lower specific responses in HIV-infected youth. These features may be relevant in the context of the precocity and severity of vertically acquired HIV infection.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/imunologia , Fármacos Anti-HIV/uso terapêutico , Antígenos de Bactérias/imunologia , Linfócitos T CD8-Positivos/imunologia , Mycobacterium tuberculosis/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Tuberculose/imunologia , Apresentação do Antígeno/imunologia , Antígenos de Bactérias/efeitos dos fármacos , Biomarcadores/sangue , Estudos Transversais , Feminino , Humanos , Imunofenotipagem , Transmissão Vertical de Doença Infecciosa , Masculino , Estudos Prospectivos , Adulto Jovem
6.
World J Microbiol Biotechnol ; 35(8): 120, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31332578

RESUMO

Mycobacterium avium subsp. paratuberculosis (MAP) is responsible for Johne's disease (JD) or paratuberculosis. Diagnosis of MAP infection by measuring host cell-mediated and humoral immune responses has been a major focus in MAP research. For this purpose, several MAP antigens such as secreted protein, cell envelope protein, cell-mediated immune and lipoprotein antigens have been identified and tested to measure their diagnostic utility with varying degree of success. Identifying the optimal antigen or antigen combinations for diagnosis of infected animals is hindered by the complex nature of the disease, prolonged subclinical infection, the differential expression of antigens and scarcity of well characterized MAP-specific epitopes making selection of a single MAP antigen very difficult. Thus, multiplexing of antigens with larger scale and longitudinal studies may lead to development of cost-effective next generation serodiagnostics. This mini review focuses on the role of different MAP antigens in the diagnosis of JD.


Assuntos
Doenças dos Bovinos/diagnóstico , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/diagnóstico , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/isolamento & purificação , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/imunologia
7.
Biomed Environ Sci ; 32(6): 427-437, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31262388

RESUMO

OBJECTIVE: This study aimed to characterize the diagnostic and vaccine potential of a novel Mycobacterium tuberculosis antigen Rv0674. METHODS: To evaluate the diagnostic potential and antigenicity of Rv0674, IgG was evaluated using ELISA and interferon (IFN)-γ was done by using ELISpot assay among TB patients and healthy donors. For immunogenicity evaluation, BALB/c mice were immunized with Rv0674. Cytokine production was determined by cytokine release assay using an ELISA kit, and the antibodies were tested using ELISA. RESULTS: The results of serum Elisa tests showed that Rv0674 specific immunoglobulin G (IgG) response was higher in TB patients than negative controls. And Rv0674 had good performance in serological test with sensitivity and specificity of 77.1% and 81.1%, respectively. While it shows poor sensitivity and specificity of 26.23% and 79.69% for IFN-γ tests. In BALB/c mice, Rv0674 adjuvant by DDA/Poly I:C could also induce a high level of IFN-γ, interleukin-2 and interleukin-6 as well as a high IgG titer in both high- and low-dose groups indicating that Rv0674 is essential in humoral and cellular immunity. Moreover, the cytokine profile and IgG isotype characterized Rv0674 as a Th1/Th2-mixed-type protective immunity with the predominance of Th1 cytokines. CONCLUSION: Rv0674 may be a good potential candidate for the development of TB serological diagnosis and a new TB vaccine.


Assuntos
Antígenos de Bactérias/imunologia , Tuberculose/imunologia , Adulto , Idoso , Animais , Feminino , Humanos , Imunidade Celular , Imunidade Humoral , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Tuberculose/diagnóstico , Adulto Jovem
8.
J Med Microbiol ; 68(9): 1314-1319, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31274404

RESUMO

Introduction. Current intradermal tuberculin skin tests for latent tuberculosis infection (LTBI) based on purified protein derivative (PPD) have poor specificity.Aims. Developing a better skin test antigen as well as a simple skin patch test may improve and facilitate diagnostic performance.Methodology. Defined recombinant antigens that were unique to Mycobacterium tuberculosis (MTB), including two potential latency-associated antigens (ESAT-6 and Rv2653c) and five DosR-encoded latency proteins (Rv1996, Rv2031c, Rv2032, DevR and Rv3716c), were used as diagnostic skin test reagents in comparison with a standard PPD. The performance of the skin tests based on the detection of delayed-type hypersensitivity (DTH) reaction in guinea pigs sensitized to MTB and M. bovis bacille Calmette-Guérin (BCG) vaccine was evaluated.Results. The latency antigens Rv1996, Rv2031c, Rv2032 and Rv2653c and the ESAT-6 protein elicited less reactive DTH skin responses in MTB-sensitized guinea pigs than those resulting from PPD, but elicited no response in BCG-vaccinated guinea pigs. The remaining two latency antigens (DevR and Rv3716c) elicited DTH responses in both groups of animals, as did PPD. The reactivity of PPD in BCG-vaccinated guinea pigs was greater than that of any of the selected skin test reagents. Using stronger concentrations of selected skin test reagents in the patch test led to increased DTH responses that were comparable to those elicited by PPD in guinea pigs sensitized with MTB.Conclusion. Transdermal application of defined purified antigens might be a promising method for LTBI screening.


Assuntos
Hipersensibilidade Tardia/imunologia , Tuberculose Latente/diagnóstico , Mycobacterium tuberculosis/imunologia , Testes Cutâneos/métodos , Adesivo Transdérmico , Animais , Antígenos de Bactérias/imunologia , Vacina BCG/imunologia , Feminino , Cobaias , Indicadores e Reagentes , Mycobacterium tuberculosis/isolamento & purificação , Testes Cutâneos/normas , Tuberculina/imunologia
9.
BMC Vet Res ; 15(1): 234, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31286936

RESUMO

BACKGROUND: Enterotoxigenic Escherichia coli K88 (E. coli K88) are considered as a major cause of diarrhea and death in newly weaned piglets. Oral passive immunization with chicken egg yolk immunoglobulins (IgY) have attracted considerable attention for treatment of gastrointestinal infection due to its high specificity. In this study it was estimated the protective effect of anti-K88 fimbriae IgY against E. coli K88 adhesion to piglet intestinal mucus in vitro and to investigate the potential use of IgY for controlling E. coli-induced diarrhea in weaned piglets in vivo. RESULTS: E. coli K88 was incubated with IgY for 24 h, and the bacterial growth profiles showed that specific IgY with a concentration higher than 5 mg/mL was observed to significantly inhibit the growth of E. coli K88 compared to nonspecific yolk powder in a liquid medium. Moreover, pretreatment with 50 mg/mL of IgY was found to significantly decrease the adhesion ability of E. coli K88 to porcine jejunal and ileal mucus, further supported by the observations from our immunofluorescence microscopic analysis. In vivo, administration of IgY successfully protected piglets from diarrhea caused by E. coli K88 challenge. Additionally, IgY treatment efficiently alleviated E. coli-induced intestinal inflammation in piglets as the gene expression levels of inflammatory cytokines TNF-α, IL-22, IL-6 and IL-1ß in IgY-treated piglets remained unchanged after E. coli K88 infection. Furthermore, IgY significantly prevented E. coli K88 adhering to the jejunal and ileal mucosa of piglets with E. coli infection and significantly decreased E. coli and enterotoxin expression in colonic contents. CONCLUSION: Outcome of the study demonstrated that IgY against the fimbrial antigen K88 was able to significantly inhibit the growth of E. coli K88, block the binding of E. coli to small intestinal mucus, and protect piglets from E. coli-induced diarrhea. These results indicate that passive immunization with IgY may be useful to prevent bacterial colonization and to control enteric diseases due to E. coli infection. The study has great clinical implication to provide alternative therapy to antibiotics in E coli induced diarrhea.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Diarreia/etiologia , Diarreia/prevenção & controle , Escherichia coli Enterotoxigênica/efeitos dos fármacos , Infecções por Escherichia coli/complicações , Imunoglobulinas/farmacologia , Animais , Antígenos de Bactérias/imunologia , Citocinas/genética , Diarreia/microbiologia , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/prevenção & controle , Proteínas de Escherichia coli/imunologia , Proteínas de Fímbrias/imunologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Imunização Passiva , Imunoglobulinas/uso terapêutico , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Ligação Proteica/efeitos dos fármacos , Suínos
10.
Nat Commun ; 10(1): 2727, 2019 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-31227708

RESUMO

A fundamental challenge in medical microbiology is to characterize the dynamic protein-protein interaction networks formed at the host-pathogen interface. Here, we generate a quantitative interaction map between the significant human pathogen, Streptococcus pyogenes, and proteins from human saliva and plasma obtained via complementary affinity-purification and bacterial-surface centered enrichment strategies and quantitative mass spectrometry. Perturbation of the network using immunoglobulin protease cleavage, mixtures of different concentrations of saliva and plasma, and different S. pyogenes serotypes and their isogenic mutants, reveals how changing microenvironments alter the interconnectivity of the interaction map. The importance of host immunoglobulins for the interaction with human complement proteins is demonstrated and potential protective epitopes of importance for phagocytosis of S. pyogenes cells are localized. The interaction map confirms several previously described protein-protein interactions; however, it also reveals a multitude of additional interactions, with possible implications for host-pathogen interactions involving other bacterial species.


Assuntos
Anticorpos Antibacterianos/metabolismo , Proteínas de Bactérias/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus pyogenes/imunologia , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/imunologia , Cromatografia de Afinidade , Proteínas do Sistema Complemento/imunologia , Proteínas do Sistema Complemento/metabolismo , Mapeamento de Epitopos , Voluntários Saudáveis , Humanos , Espectrometria de Massas , Proteínas Opsonizantes/imunologia , Proteínas Opsonizantes/metabolismo , Ligação Proteica , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas/imunologia , Infecções Estreptocócicas/sangue , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/metabolismo
11.
Pol J Microbiol ; 68(2): 233-246, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31250594

RESUMO

The aim of this study was to identify the potential vaccine antigens in Corynebacterium diphtheriae strains by in silico analysis of the amino acid variation in the 67-72p surface protein that is involved in the colonization and induction of epithelial cell apoptosis in the early stages of infection. The analysis of pili structural proteins involved in bacterial adherence to host cells and related to various types of infections was also performed. A polymerase chain reaction (PCR) was carried out to amplify the genes encoding the 67-72p protein and three pili structural proteins (SpaC, SpaI, SapD) and the products obtained were sequenced. The nucleotide sequences of the particular genes were translated into amino acid sequences, which were then matched among all the tested strains using bioinformatics tools. In the last step, the affinity of the tested proteins to major histocompatibility complex (MHC) classes I and II, and linear B-cell epitopes was analyzed. The variations in the nucleotide sequence of the 67-72p protein and pili structural proteins among C. diphtheriae strains isolated from various infections were noted. A transposition of the insertion sequence within the gene encoding the SpaC pili structural proteins was also detected. In addition, the bioinformatics analyses enabled the identification of epitopes for B-cells and T-cells in the conserved regions of the proteins, thus, demonstrating that these proteins could be used as antigens in the potential vaccine development. The results identified the most conserved regions in all tested proteins that are exposed on the surface of C. diphtheriae cells.The aim of this study was to identify the potential vaccine antigens in Corynebacterium diphtheriae strains by in silico analysis of the amino acid variation in the 67­72p surface protein that is involved in the colonization and induction of epithelial cell apoptosis in the early stages of infection. The analysis of pili structural proteins involved in bacterial adherence to host cells and related to various types of infections was also performed. A polymerase chain reaction (PCR) was carried out to amplify the genes encoding the 67­72p protein and three pili structural proteins (SpaC, SpaI, SapD) and the products obtained were sequenced. The nucleotide sequences of the particular genes were translated into amino acid sequences, which were then matched among all the tested strains using bioinformatics tools. In the last step, the affinity of the tested proteins to major histocompatibility complex (MHC) classes I and II, and linear B-cell epitopes was analyzed. The variations in the nucleotide sequence of the 67­72p protein and pili structural proteins among C. diphtheriae strains isolated from various infections were noted. A transposition of the insertion sequence within the gene encoding the SpaC pili structural proteins was also detected. In addition, the bioinformatics analyses enabled the identification of epitopes for B-cells and T-cells in the conserved regions of the proteins, thus, demonstrating that these proteins could be used as antigens in the potential vaccine development. The results identified the most conserved regions in all tested proteins that are exposed on the surface of C. diphtheriae cells.


Assuntos
Adesinas Bacterianas/genética , Antígenos de Bactérias/genética , Corynebacterium diphtheriae/genética , Toxoide Diftérico/genética , Difteria/prevenção & controle , Variação Genética , Proteínas de Membrana/genética , Adesinas Bacterianas/imunologia , Antígenos de Bactérias/imunologia , Biologia Computacional , Sequência Conservada , Corynebacterium diphtheriae/imunologia , Toxoide Diftérico/imunologia , Epitopos de Linfócito B/genética , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Proteínas de Membrana/imunologia , Reação em Cadeia da Polimerase , Ligação Proteica , Análise de Sequência de DNA
12.
Vet Immunol Immunopathol ; 212: 1-8, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31213246

RESUMO

Bovine mastitis caused by Staphylococcus aureus is a serious problem in dairy production and effective immunoprophylaxis is an unmet goal so far. The objective of this work was to assess the humoral immune response of heifer calves against two recombinant S. aureus antigens: Clumping factor A (ClfA) and Fibronectin Binding Protein A (FnBPA), formulated with a novel adjuvant based on cationic liposomes (Lip) and CpG oligodeoxynucleotides (CpG-ODN). Six groups of 6-8 months old heifer calves received three doses biweekly of antigens, formulated with Al(OH)3, liposomes, CpG-ODN or Lip + CpG-ODN. Animals also received a fourth dose after a year (day 410) and a booster before calving. The administration of Al(OH)3+FnBPA/ClfA and Lip + FnBPA/ClfA + CpG-ODN induced the highest specific IgG levels, after the first 3 doses and induced a fast increase of antibodies after the fourth dose. All the formulations stimulated the production of specific IgG1, after the third and fourth dose. Specific IgG2 for both proteins was only stimulated after the fourth dose by Lip + FnBPA/ClfA + CpG-ODN. Pre-calving immunisation with Lip + FnBPA/ClfA + CpG-ODN led to the highest IgG levels during the calving period and to the production of the IgG2 subclass. The formulation was also able to stimulate the highest antibody levels in milk, 30 and 45 days after pre-calving booster. The combination of liposomes and CpG-ODN as adjuvant for a subunit vaccine, together with the immunisation schedule described, induced a strong humoral immune response with production of specific IgG2. The formulation demonstrated to induce immune memory allowing the application of a single pre-calving booster to maintain high antibody levels throughout the period of increased susceptibility to intramammary infections.


Assuntos
Antígenos de Bactérias/imunologia , Imunidade Humoral , Mastite Bovina/prevenção & controle , Oligodesoxirribonucleotídeos/farmacologia , Adjuvantes Imunológicos/administração & dosagem , Fatores Etários , Animais , Anticorpos Antibacterianos/sangue , Bovinos , Imunoglobulina G/sangue , Memória Imunológica , Lipossomos/farmacologia , Mastite Bovina/imunologia , Mastite Bovina/microbiologia , Staphylococcus aureus , Vacinação , Soro do Leite/imunologia
14.
Indian J Ophthalmol ; 67(7): 1207-1209, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31238468

RESUMO

The tuberculids are a group of distinct clinicopathological form of skin lesions representing hypersensitivity reaction to hematogenous dissemination of Mycobacterium tuberculosis or its antigen from an underlying active or a silent focus of tuberculosis elsewhere in the body in an individual with a strong antituberculous cell-mediated immunity and by definition do not show bacilli on special stains and are culture-negative. Ocular involvement can occur in tuberculosis, both due to direct invasion by the bacilli as well as an immune-mediated reaction; however, immune-mediated tuberculous uveitis occurring as a hypersensitivity response in association with PNT has hardly been reported in the literature. Here we report one such rare case.


Assuntos
Antígenos de Bactérias/imunologia , Infecções Oculares Bacterianas/imunologia , Mycobacterium tuberculosis/imunologia , Pele/patologia , Tuberculose Cutânea/complicações , Tuberculose Ocular/imunologia , Uveíte/imunologia , Adulto , Biópsia , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/etiologia , Humanos , Masculino , Mycobacterium tuberculosis/isolamento & purificação , Necrose , Pele/microbiologia , Tuberculose Cutânea/diagnóstico , Tuberculose Ocular/diagnóstico , Tuberculose Ocular/etiologia , Uveíte/diagnóstico , Uveíte/etiologia
15.
Microbiol Immunol ; 63(8): 316-327, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31254409

RESUMO

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) and remains a major cause of morbidity and mortality worldwide. In the host's immune response system, T cells play a critical role in mediating protection against Mtb infection, but the role of CD8+ T cells is still controversial. We evaluated the phenotypical characterization and cytotoxic ability of CD8+ T cells by flow cytometry-based assay. Cytokine levels in serum were measured by multiplex cytokine assay. Our data show that cells from TB patients have an increased percentage of peripheral blood CD8+ αß+ T (p = 0.02) and CD56+ CD8+ T (p = 0.02) and a decreased frequency of NKG2D+ CD8+ T (p = 0.02) compared with healthy donors. Unlike CD8+ T cells from healthy donors, CD8+ T cells from TB patients exhibit greater cytotoxicity, mediated by HLA class I molecules, on autologous monocytes in the presence of mycobacterial antigens (p = 0.005). Finally, TB patients have a proinflammatory profile characterized by serum high level of TNF-α (p = 0.02) and IL-8 (p = 0.0001), but, interestingly, IL-4 (p = 0.002) was also increased compared with healthy donors. Our data show evidence regarding the highly cytotoxic status of CD8+ T cells in Mtb infection. These cytotoxic cells restricted to HLA-A, B, and C could be used to optimize strategies for designing new TB vaccines or for identifying markers of disease progression.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Citotoxinas/toxicidade , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Adolescente , Adulto , Antígenos de Bactérias/imunologia , Citocinas/sangue , Feminino , Citometria de Fluxo , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Antígenos HLA-C/imunologia , Humanos , Interleucina-4/sangue , Interleucina-8/sangue , Masculino , Pessoa de Meia-Idade , Vacinas contra a Tuberculose/imunologia , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
16.
J Vet Sci ; 20(3): e24, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31161742

RESUMO

Porcine proliferative enteropathy (PPE) caused by Lawsonia intracellularis (LI) is a global cause for substantial economic losses in the swine industry. Here, we constructed live attenuated Salmonella typhimurium (ST) mutant strains expressing and secreting 4 selected immunogenic LI antigens, namely, optA, optB, Lawsonia flagellin (LfliC), and Lawsonia hemolysin (Lhly); the resultant recombinant strains were designated Sal-optA, Sal-optB, Sal-LfliC, or Sal-Lhly, respectively. Using the BALB/c mouse model, we demonstrate that mice vaccinated once orally, either with a mixture of all 4 recombinant strains or with an individual recombinant strain, show significant (p < 0.05) production of LI-specific systemic immunoglobulin (Ig) G and mucosal IgA responses compared to the Salmonella alone group. Upon restimulation of vaccinated splenocytes with the LI-specific antigens, significant (p < 0.05) and comparable production of interferon-γ responses are found in all vaccinated groups, except the Sal-Lhly group, which shows non-significant levels. Challenge studies were performed in C57BL/6 vaccinated mice. On challenge with the LI (106.9 50% tissue culture infectious dose) 14 days post-vaccination, 20% (1/5) of mice in all vaccinated groups, except Sal-Lhly group, show the presence of the LI-specific genomic DNA (gDNA) in stool samples. In contrast, 40% (2/5) and 60% (3/5) of mice vaccinated with the Sal-Lhly strain and the attenuated Salmonella alone, respectively, were found positive for the LI-specific gDNA. Furthermore, 0% mortality was observed in mice vaccinated against the ST challenge compared to the 30% mortality observed in the unvaccinated control group. In conclusion, we demonstrate that the Salmonella-based LI-vaccines induce LI-specific humoral and cell-mediated immunities, and encompass the potential to offer dual protection against PPE and salmonellosis.


Assuntos
Antígenos de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Infecções por Desulfovibrionaceae/prevenção & controle , Lawsonia (Bactéria)/imunologia , Infecções por Salmonella/prevenção & controle , Vacinas contra Salmonella/imunologia , Animais , Anticorpos Antibacterianos/sangue , Vacinas Bacterianas/administração & dosagem , Células Cultivadas , DNA Bacteriano/análise , Infecções por Desulfovibrionaceae/imunologia , Infecções por Desulfovibrionaceae/mortalidade , Modelos Animais de Doenças , Fezes/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Infecções por Salmonella/mortalidade , Vacinas contra Salmonella/administração & dosagem , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/mortalidade , Doenças dos Suínos/prevenção & controle , Vacinas Atenuadas/imunologia
17.
Int Arch Allergy Immunol ; 180(1): 1-9, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31242493

RESUMO

BACKGROUND: An inverse relation between Helicobacter pylori infection and asthma has been shown in epidemiological studies. Infection with H. pylori, or application of an extract of it before or after sensitization, inhibits allergic airway disease in mice. OBJECTIVES: The aim of this study was to investigate the effect of an extract of H. pylori on allergic airway disease induced by repeated allergen exposure in mice that were sensitized and challenged prior to extract application. METHOD: C57BL/6 mice were intranasally (i.n.) sensitized and challenged with house dust mite (HDM). After a minimum of 4 weeks, mice received the H. pylori extract intraperitoneally and were rechallenged i.n. with HDM. Allergen-specific antibodies were measured by ELISA. Cells present in the bronchoalveolar lavage fluid and dendritic cell (DC) subsets in the lung tissue were analyzed by flow cytometry. Tissue inflammation and goblet cell hyperplasia were assessed by histology. Cells of the mediastinal lymph node (mLN) were isolated and in vitro restimulated with HDM or H. pylori extract. RESULTS: Treatment with H. pylori extract before rechallenge reduced allergen-specific IgE, the DC numbers in the tissue, and goblet cell hyperplasia. Cells isolated from mLN of mice treated with the extract produced significantly more IL-10 and IL-17 after in vitro restimulation with HDM. mLN cells of H. pylori-treated mice that were re-exposed to the H. pylori extract produced significantly more interferon gamma. CONCLUSIONS: An extract of H. pylori is effective in reducing mucus production and various features of inflammation in HDM rechallenged mice.


Assuntos
Alérgenos/imunologia , Antígenos de Bactérias/imunologia , Células Caliciformes/patologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/patologia , Animais , Biomarcadores , Biópsia , Citocinas/metabolismo , Exposição Ambiental , Feminino , Infecções por Helicobacter/microbiologia , Hiperplasia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Imunofenotipagem , Camundongos , Pyroglyphidae/imunologia
18.
Nat Med ; 25(6): 977-987, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31110348

RESUMO

Exposure to Mycobacterium tuberculosis (Mtb) results in heterogeneous clinical outcomes including primary progressive tuberculosis and latent Mtb infection (LTBI). Mtb infection is identified using the tuberculin skin test and interferon-γ (IFN-γ) release assay IGRA, and a positive result may prompt chemoprophylaxis to prevent progression to tuberculosis. In the present study, we report on a cohort of Ugandan individuals who were household contacts of patients with TB. These individuals were highly exposed to Mtb but tested negative disease by IFN-γ release assay and tuberculin skin test, 'resisting' development of classic LTBI. We show that 'resisters' possess IgM, class-switched IgG antibody responses and non-IFN-γ T cell responses to the Mtb-specific proteins ESAT6 and CFP10, immunologic evidence of exposure to Mtb. Compared to subjects with classic LTBI, 'resisters' display enhanced antibody avidity and distinct Mtb-specific IgG Fc profiles. These data reveal a distinctive adaptive immune profile among Mtb-exposed subjects, supporting an expanded definition of the host response to Mtb exposure, with implications for public health and the design of clinical trials.


Assuntos
Tuberculose Latente/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose/imunologia , Adulto , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/imunologia , Criança , Estudos de Coortes , Feminino , Humanos , Interferon gama/imunologia , Testes de Liberação de Interferon-gama , Masculino , Teste Tuberculínico , Uganda , Adulto Jovem
19.
Nat Genet ; 51(6): 1035-1043, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31133745

RESUMO

Group A Streptococcus (GAS; Streptococcus pyogenes) is a bacterial pathogen for which a commercial vaccine for humans is not available. Employing the advantages of high-throughput DNA sequencing technology to vaccine design, we have analyzed 2,083 globally sampled GAS genomes. The global GAS population structure reveals extensive genomic heterogeneity driven by homologous recombination and overlaid with high levels of accessory gene plasticity. We identified the existence of more than 290 clinically associated genomic phylogroups across 22 countries, highlighting challenges in designing vaccines of global utility. To determine vaccine candidate coverage, we investigated all of the previously described GAS candidate antigens for gene carriage and gene sequence heterogeneity. Only 15 of 28 vaccine antigen candidates were found to have both low naturally occurring sequence variation and high (>99%) coverage across this diverse GAS population. This technological platform for vaccine coverage determination is equally applicable to prospective GAS vaccine antigens identified in future studies.


Assuntos
Genômica , Vacinas Estreptocócicas/genética , Vacinas Estreptocócicas/imunologia , Streptococcus pyogenes/genética , Streptococcus pyogenes/imunologia , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Genoma Bacteriano , Estudo de Associação Genômica Ampla , Genômica/métodos , Humanos , Filogenia , Recombinação Genética , Infecções Estreptocócicas/prevenção & controle , Streptococcus pyogenes/classificação
20.
Microbiol Immunol ; 63(7): 280-284, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31087695

RESUMO

In 2018, a patient was diagnosed with Shimokoshi type scrub typhus in Yamagata Prefecture, Japan. The causative pathogen was likely a variant type because 43 (8.3%) of 521 deduced amino acid sequences of the 56-kDa type-specific antigen (TSA) were different from those of the Shimokoshi prototype strain. The patient's paired sera showed low antibody titers against the Shimokoshi prototype strain. Two cases of scrub typhus reported in the Tohoku region during 2011-2012 also involved the same 56-kDa TSA gene sequence. These findings suggest the presence of diversity in Shimokoshi type Orientia tsutsugamushi, which may impede the laboratory diagnosis of scrub typhus.


Assuntos
Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Proteínas de Membrana/genética , Orientia tsutsugamushi/genética , Orientia tsutsugamushi/patogenicidade , Tifo por Ácaros/imunologia , Tifo por Ácaros/microbiologia , Sequência de Aminoácidos , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Sequência de Bases , Genes Bacterianos/genética , Humanos , Japão , Proteínas de Membrana/imunologia , Peso Molecular , Tifo por Ácaros/diagnóstico
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