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1.
J Immunol ; 207(4): 1138-1149, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34341168

RESUMO

Group A streptococcal infections are a significant cause of global morbidity and mortality. A leading vaccine candidate is the surface M protein, a major virulence determinant and protective Ag. One obstacle to the development of M protein-based vaccines is the >200 different M types defined by the N-terminal sequences that contain protective epitopes. Despite sequence variability, M proteins share coiled-coil structural motifs that bind host proteins required for virulence. In this study, we exploit this potential Achilles heel of conserved structure to predict cross-reactive M peptides that could serve as broadly protective vaccine Ags. Combining sequences with structural predictions, six heterologous M peptides in a sequence-related cluster were predicted to elicit cross-reactive Abs with the remaining five nonvaccine M types in the cluster. The six-valent vaccine elicited Abs in rabbits that reacted with all 11 M peptides in the cluster and functional opsonic Abs against vaccine and nonvaccine M types in the cluster. We next immunized mice with four sequence-unrelated M peptides predicted to contain different coiled-coil propensities and tested the antisera for cross-reactivity against 41 heterologous M peptides. Based on these results, we developed an improved algorithm to select cross-reactive peptide pairs using additional parameters of coiled-coil length and propensity. The revised algorithm accurately predicted cross-reactive Ab binding, improving the Matthews correlation coefficient from 0.42 to 0.74. These results form the basis for selecting the minimum number of N-terminal M peptides to include in potentially broadly efficacious multivalent vaccines that could impact the overall global burden of group A streptococcal diseases.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Bactérias/imunologia , Proteínas de Transporte/imunologia , Reações Cruzadas/imunologia , Vacinas Estreptocócicas/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Epitopos/imunologia , Feminino , Humanos , Masculino , Camundongos , Peptídeos/imunologia , Vacinas Sintéticas/imunologia
2.
Int J Mol Sci ; 22(15)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34360926

RESUMO

The microbiota regulates immunological development during early human life, with long-term effects on health and disease. Microbial products include short-chain fatty acids (SCFAs), formyl peptides (FPs), polysaccharide A (PSA), polyamines (PAs), sphingolipids (SLPs) and aryl hydrocarbon receptor (AhR) ligands. Anti-inflammatory SCFAs are produced by Actinobacteria, Bacteroidetes, Firmicutes, Spirochaetes and Verrucomicrobia by undigested-carbohydrate fermentation. Thus, fiber amount and type determine their occurrence. FPs bind receptors from the pattern recognition family, those from commensal bacteria induce a different response than those from pathogens. PSA is a capsular polysaccharide from B. fragilis stimulating immunoregulatory protein expression, promoting IL-2, STAT1 and STAT4 gene expression, affecting cytokine production and response modulation. PAs interact with neonatal immunity, contribute to gut maturation, modulate the gut-brain axis and regulate host immunity. SLPs are composed of a sphingoid attached to a fatty acid. Prokaryotic SLPs are mostly found in anaerobes. SLPs are involved in proliferation, apoptosis and immune regulation as signaling molecules. The AhR is a transcription factor regulating development, reproduction and metabolism. AhR binds many ligands due to its promiscuous binding site. It participates in immune tolerance, involving lymphocytes and antigen-presenting cells during early development in exposed humans.


Assuntos
Antígenos de Bactérias/imunologia , Microbioma Gastrointestinal/imunologia , Bactérias Gram-Negativas , Recém-Nascido/imunologia , Animais , Bactérias Gram-Negativas/imunologia , Bactérias Gram-Negativas/metabolismo , Humanos
3.
Biomed Environ Sci ; 34(7): 528-539, 2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34353416

RESUMO

Objectives: To evaluate the immunogenicity of Mycobacterium intracellulare proteins and determine the cross-reactive proteins between M. intracellulare and M. tuberculosis. Methods: Protein extracts from M. intracellulare were used to immunize BALB/c mice. The antigens were evaluated using cellular and humoral immunoassays. The common genes between M. intracellular and M. tuberculosis were identified using genome-wide comparative analysis, and cross-reactive proteins were screened using immunoproteome microarrays. Results: Immunization with M. intracellulare proteins induced significantly higher levels of the cytokines interferon-γ (IFN-γ), interleukin-2 (IL-2), interleukin-12 (IL-12), interleukin-6 (IL-6) and immunoglobulins IgG, IgG1, IgM, and IgG2a in mouse serum. Bone marrow-derived macrophages isolated from mice immunized with M. intracellulare antigens displayed significantly lower bacillary loads than those isolated from mice immunized with adjuvants. Whole-genome sequence analysis revealed 396 common genes between M. intracellulare and M. tuberculosis. Microchip hybridization with M. tuberculosis proteins revealed the presence of 478 proteins in the serum of mice immunized with M. intracellulare protein extracts. Sixty common antigens were found using both microchip and genomic comparative analyses. Conclusion: This is the advanced study to investigate the immunogenicity of M. intracellulare proteins and the cross-reactive proteins between M. intracellulare and M. tuberculosis. The results revealed the presence of a number of cross-reactive proteins between M. intracellulare and M. tuberculosis. Therefore, this study provides a new way of identifying immunogenic proteins for use in tuberculosis vaccines against both M. intracellulare and M. tuberculosis in future.


Assuntos
Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Complexo Mycobacterium avium/imunologia , Mycobacterium tuberculosis/imunologia , Animais , Reações Cruzadas , Citocinas/imunologia , Feminino , Genoma Bacteriano , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Macrófagos/imunologia , Camundongos Endogâmicos BALB C , Complexo Mycobacterium avium/genética , Mycobacterium tuberculosis/genética , Vacinas contra a Tuberculose/administração & dosagem , Sequenciamento Completo do Genoma
4.
Vet J ; 273: 105676, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34148599

RESUMO

Lyme disease (LD), the most common tick-borne disease of canines and humans in N. America, is caused by the spirochete Borreliella burgdorferi. Subunit and bacterin vaccines are available for the prevention of LD in dogs. LD bacterin vaccines, which are comprised of cell lysates of two strains of B. burgdorferi, contain over 1000 different proteins and cellular constituents. In contrast, subunit vaccines are defined in composition and consist of either outer surface protein (Osp)A or OspA and an OspC chimeritope. In this study, we comparatively assessed antibody responses to OspA and OspC induced by vaccination with all canine bacterin and subunit LD vaccines that are commercially available in North America. Dogs were administered a two-dose series of the vaccine to which they were assigned (3 weeks apart): Subunit-AC, Subunit-A, Bacterin-1, and Bacterin-2. Antibody titers to OspA and OspC were determined by ELISA and the ability of each vaccine to elicit antibodies that recognize diverse OspC proteins (referred to as OspC types) assessed by immunoblot. While all of the vaccines elicited similar OspA antibody responses, only Subunit-AC triggered a robust and broadly cross-reactive antibody response to divergent OspC proteins. The data presented within provide new information regarding vaccination-induced antibody responses to key tick and mammalian phase antigens by both subunit and bacterin LD canine vaccine formulations.


Assuntos
Antígenos de Bactérias/imunologia , Antígenos de Superfície/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Lipoproteínas/imunologia , Vacinas contra Doença de Lyme/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Formação de Anticorpos , Borrelia burgdorferi/imunologia , Doenças do Cão/imunologia , Doenças do Cão/prevenção & controle , Cães , Feminino , Doença de Lyme/prevenção & controle , Doença de Lyme/veterinária , Masculino , Vacinação/veterinária
5.
Infect Immun ; 89(8): e0012121, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34097470

RESUMO

Salmonella enterica Typhimurium is a rod-shaped Gram-negative bacterium that mostly enters the human body through contaminated food. It causes a gastrointestinal disorder called salmonellosis in humans and typhoid-like systemic disease in mice. OmpV, an outer membrane protein of S. Typhimurium, helps in adhesion and invasion of bacteria to intestinal epithelial cells and thus plays a vital role in the pathogenesis of S. Typhimurium. In this study, we have shown that intraperitoneal immunization with OmpV is able to induce high IgG production and protection against systemic disease. Further, oral immunization with OmpV-incorporated proteoliposome (OmpV-proteoliposome [PL]) induces production of high IgA antibody levels and protection against gastrointestinal infection. Furthermore, we have shown that OmpV induces Th1 bias in systemic immunization with purified OmpV, but both Th1 and Th2 polarization in oral immunization with OmpV-proteoliposome (PL). Additionally, we have shown that OmpV activates innate immune cells, such as monocytes, macrophages, and intestinal epithelial cells, in a Toll-like receptor 2 (TLR2)-dependent manner. Interestingly, OmpV is recognized by the TLR1/2 heterodimer in monocytes, but by both TLR1/2 and TLR2/6 heterodimers in macrophages and intestinal epithelial cells. Further, downstream signaling involves MyD88, interleukin-1 receptor-associated kinase (IRAK)-1, mitogen-activated protein kinase (MAPK) (both p38 and Jun N-terminal protein kinase (JNK)), and transcription factors NF-κB and AP-1. Due to its ability to efficiently activate both the innate and adaptive immune systems and protective efficacy, OmpV can be a potential vaccine candidate against S. Typhimurium infection. Further, the fact that OmpV can be recognized by both TLR1/2 and TLR2/6 heterodimers increases its potential to act as good adjuvant in other vaccine formulations.


Assuntos
Adesinas Bacterianas/imunologia , Antígenos de Bactérias/imunologia , Gastroenterite/imunologia , Gastroenterite/microbiologia , Imunidade , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/imunologia , Animais , Biomarcadores , Modelos Animais de Doenças , Suscetibilidade a Doenças , Interações Hospedeiro-Patógeno/imunologia , Camundongos , Transdução de Sinais
6.
Methods Mol Biol ; 2344: 151-161, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34115358

RESUMO

Infectious diseases represent a major cause of morbidity and mortality worldwide. Early detection of infections is capital for managing life-threatening cases. So far, traditional diagnostic methods such as microbiological cultures are slow and, sometimes, inaccurate. In the molecular era, high-throughput techniques are essential for providing tools that are able to diagnose in a fast and reliable way, as well as they can be used for monitoring the humoral response of groups of people in a program of epidemiological surveillance when an outbreak occurs, or when a vaccine is being evaluated. Antigen-based protein microarrays are an ideal means for these purposes, as they can carry up to thousands of protein antigens from pathogenic sources and be probed with sera from different human groups (acute or chronic infected people, convalescent, controls). For the diagnosis of bacterial infections, the best antigens are in principle the surface proteins, as they have the highest chances to raise an effective immune response. Here we describe a general protocol for fabricating a glass slide-based protein microarray using recombinant bacterial surface antigens, according to our own expertise in the study of pneumococcal disease. The probing with human sera aims to evaluate differences between diseased and healthy people, in order to discover discriminating antigens that can be used, after appropriate validation, in further easy-to-use formats such as immunostrips.


Assuntos
Antígenos de Bactérias/imunologia , Infecções Bacterianas/imunologia , Análise Serial de Proteínas , Testes Sorológicos , Anticorpos Antibacterianos/imunologia , Infecções Bacterianas/diagnóstico , Vidro/química , Humanos
7.
Res Vet Sci ; 138: 100-108, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126448

RESUMO

Strangles, which is caused by Streptococcus equi subspecies equi, is one of the most prevalent equine infectious diseases and poses heavy economic losses worldwide. Although various vaccines have been used for decades, they seemed to be sub-optimal to demonstrate effective protection, and the antigen component of vaccines against S. equi remains to be optimized. In the present study, three target antigens (M-like protein, α2-macroglobulin and IgG-binding protein, and glyceraldehyde-3-phosphate dehydrogenase) were selected and expressed. Mice were immunized and challenged, and their immune response and efficacy were evaluated. The results revealed that this optimized multi-antigen treatment elicited a high expression level of T-cell receptor, major histocompatibility complex I, toll-like receptor TLR-4, and increased specific antibody. In addition, the challenge experiment showed an evidently improved protection efficacy. The present work demonstrated that these three proteins might be used as a promising multicomponent subunit vaccine candidate against S. equi infection.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/administração & dosagem , Infecções Estreptocócicas/prevenção & controle , Streptococcus/imunologia , Animais , Feminino , Gliceraldeído-3-Fosfato Desidrogenases/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Streptococcus/enzimologia
8.
Epidemiol Infect ; 149: e136, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34032200

RESUMO

Brucellosis is one of the most serious and widespread zoonotic diseases, which seriously threatens human health and the national economy. This study was based on the T/B dominant epitopes of Brucella outer membrane protein 22 (Omp22), outer membrane protein 19 (Omp19) and outer membrane protein 28 (Omp28), with bioinformatics methods to design a safe and effective multi-epitope vaccine. The amino acid sequences of the proteins were found in the National Center for Biotechnology Information (NCBI) database, and the signal peptides were predicted by the SignaIP-5.0 server. The surface accessibility and hydrophilic regions of proteins were analysed with the ProtScale software and the tertiary structure model of the proteins predicted by I-TASSER software and labelled with the UCSF Chimera software. The software COBEpro, SVMTriP and BepiPred were used to predict B cell epitopes of the proteins. SYFPEITHI, RANKpep and IEDB were employed to predict T cell epitopes of the proteins. The T/B dominant epitopes of three proteins were combined with HEYGAALEREAG and GGGS linkers, and carriers sequences linked to the N- and C-terminus of the vaccine construct with the help of EAAAK linkers. Finally, the tertiary structure and physical and chemical properties of the multi-epitope vaccine construct were analysed. The allergenicity, antigenicity and solubility of the multi-epitope vaccine construct were 7.37-11.30, 0.788 and 0.866, respectively. The Ramachandran diagram of the mock vaccine construct showed 96.0% residues within the favoured and allowed range. Collectively, our results showed that this multi-epitope vaccine construct has a high-quality structure and suitable characteristics, which may provide a theoretical basis for future laboratory experiments.


Assuntos
Vacina contra Brucelose/química , Brucella/imunologia , Epitopos de Linfócito B/química , Epitopos de Linfócito T/química , Sequência de Aminoácidos , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/imunologia , Vacina contra Brucelose/imunologia , Brucelose/prevenção & controle , Biologia Computacional , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Humanos , Imunogenicidade da Vacina , Modelos Moleculares , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Solubilidade , Vacinas de Subunidades/química , Vacinas de Subunidades/imunologia
9.
Infect Immun ; 89(8): e0026521, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34031132

RESUMO

Primary infection of C57BL/6 mice with the bacterial pathogen Yersinia pseudotuberculosis elicits an unusually large H-2Kb-restricted CD8+ T cell response to the endogenous and protective bacterial epitope YopE69-77. To better understand the basis for this large response, the model OVA257-264 epitope was inserted into YopE in Y. pseudotuberculosis and antigen-specific CD8+ T cells in mice were characterized after foodborne infection with the resulting strain. The epitope YopE69-77 elicited significantly larger CD8+ T cell populations in the small intestine, mesenteric lymph nodes (MLNs), spleen, and liver between 7 and 30 days postinfection, despite residing in the same protein and having an affinity for H-2Kb similar to that of OVA257-264. YopE-specific CD8+ T cell precursors were ∼4.6 times as abundant as OVA-specific precursors in the MLNs, spleens, and other lymph nodes of naive mice, explaining the dominance of YopE69-77 over OVA257-264 at early infection times. However, other factors contributed to this dominance, as the ratio of YopE-specific to OVA-specific CD8+ T cells increased between 7 and 30 days postinfection. We also compared the YopE-specific and OVA-specific CD8+ T cells generated during infection for effector and memory phenotypes. Significantly higher percentages of YopE-specific cells were characterized as short-lived effectors, while higher percentages of OVA-specific cells were memory precursor effectors at day 30 postinfection in spleen and liver. Our results suggest that a large precursor number contributes to the dominance and effector and memory functions of CD8+ T cells generated in response to the protective YopE69-77 epitope during Y. pseudotuberculosis infection of C57BL/6 mice.


Assuntos
Antígenos de Bactérias/imunologia , Linfócitos T CD8-Positivos/imunologia , Interações Hospedeiro-Patógeno/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T , Infecções por Yersinia pseudotuberculosis/imunologia , Infecções por Yersinia pseudotuberculosis/microbiologia , Yersinia pseudotuberculosis/imunologia , Animais , Linfócitos T CD8-Positivos/metabolismo , Modelos Animais de Doenças , Epitopos de Linfócito T/imunologia , Memória Imunológica , Camundongos , Camundongos Endogâmicos C57BL , Infecções por Yersinia pseudotuberculosis/transmissão
10.
Biochem Biophys Res Commun ; 560: 126-131, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-33989903

RESUMO

Brucellosis has placed a heavy economic burden on numerous countries and has consumed considerable medical resources worldwide. To improve the specificity and sensitivity of serological methods for diagnosing brucellosis, it is important to develop new diagnostic antigens. Brucella outer membrane proteins(omps) possess good immunogenicity, but there is a scarcity of comparative studies of these proteins in the clinical diagnosis of brucellosis. In this study, six recombinant Brucella outer membrane proteins, omp10, omp16, omp19, omp25, omp31 and BP26, were expressed in prokaryotic cells and utilized as diagnostic antigens. The clinical sera of humans, bovines and goats with brucellosis were analyzed by indirect ELISA using these proteins, lipopolysaccharide(LPS) and Rose Bengale Ag, served as positive-control antigens. In diagnosing human and goat serum, BP26 exhibited the highest diagnostic accuracy of 96.45% and 95.00%, respectively, while omp31 exhibited the strongest ability to detect Brucella in bovine serum with an accuracy of 84.03%. Cross-reaction experiments also confirmed that the diagnostic specificities of omp31 and BP26 were higher than those of the LPS and Rose Bengale Ag antigens. The results of this study indicate that omp31 and BP26 are candidate antigens with high potential application value in the clinical diagnosis of brucellosis.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Brucella/imunologia , Brucelose Bovina/diagnóstico , Brucelose/diagnóstico , Brucelose/veterinária , Doenças das Cabras/diagnóstico por imagem , Animais , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Bovinos , Reações Cruzadas , Doenças das Cabras/diagnóstico , Cabras , Humanos , Proteínas Recombinantes/análise , Proteínas Recombinantes/imunologia
11.
Front Immunol ; 12: 632304, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33953709

RESUMO

Cross-reactive vaccines recognize common molecular patterns in pathogens and are able to confer broad spectrum protection against different infections. Antigens common to pathogenic bacteria that induce broad immune responses, such as the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of the genera Listeria, Mycobacterium, or Streptococcus, whose sequences present more than 95% homology at the N-terminal GAPDH1-22 peptide, are putative candidates for universal vaccines. Here, we explore vaccine formulations based on dendritic cells (DC) loaded with two molecular forms of Listeria monocytogenes GAPDH (LM-GAPDH), such as mRNA carriers or recombinant proteins, and compare them with the same molecular forms of three other antigens used in experimental vaccines, listeriolysin O of Listeria monocytogeness, Ag85A of Mycobacterium marinum, and pneumolysin of Streptococcus pneumoniae. DC loaded with LM-GAPDH recombinant proteins proved to be the safest and most immunogenic vaccine vectors, followed by mRNA encoding LM-GAPDH conjugated to lipid carriers. In addition, macrophages lacked sufficient safety as vaccines for all LM-GAPDH molecular forms. The ability of DC loaded with LM-GAPDH recombinant proteins to induce non-specific DC activation explains their adjuvant potency and their capacity to trigger strong CD4+ and CD8+ T cell responses explains their high immunogenicity. Moreover, their capacity to confer protection in vaccinated mice against challenges with L. monocytogenes, M. marinum, or S. pneumoniae validated their efficiency as cross-reactive vaccines. Cross-protection appears to involve the induction of high percentages of GAPDH1-22 specific CD4+ and CD8+ T cells stained for intracellular IFN-γ, and significant levels of peptide-specific antibodies in vaccinated mice. We concluded that DC vaccines loaded with L. monocytogenes GAPDH recombinant proteins are cross-reactive vaccines that seem to be valuable tools in adult vaccination against Listeria, Mycobacterium, and Streptococcus taxonomic groups.


Assuntos
Vacinas Bacterianas/imunologia , Gliceraldeído-3-Fosfato Desidrogenases/imunologia , Lipídeos/imunologia , Listeria/imunologia , Mycobacterium/imunologia , RNA Mensageiro/imunologia , Streptococcus/imunologia , Adjuvantes Imunológicos , Animais , Anticorpos Antibacterianos/sangue , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Infecções Bacterianas/prevenção & controle , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/genética , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Proteção Cruzada , Reações Cruzadas , Células Dendríticas/imunologia , Gliceraldeído-3-Fosfato Desidrogenases/genética , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Interferon gama/imunologia , Lipídeos/química , Listeria/enzimologia , Listeria/genética , Camundongos , RNA Mensageiro/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia
12.
Life Sci ; 279: 119644, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34048813

RESUMO

Bacterial-derived extracellular vesicles could play a major role in attenuating and treating diseases. They play a major anti-infection role by modulating immune responses against pathogens and preventing infection by inhibiting pathogen localization and proliferation. In this study, outer membrane vesicles (ExHp-CD) released by Helicobacter pylori SS1 (H. pylori) and total antigens isolated from H. pylori SS1 (AgHp) were evaluated for their immunogenic potential and their effect on macrophage RAW 264.7 cells. Results demonstrated that both ExHp-CD and AgHp induced T helper 2 (Th2) immune response, which was reported to be important in immune protection against H. pylori infections. Both ExHp-CD and AgHp produced high levels of IL-10 and IL-4, while no significant levels of IL-12 p70 or IFN-γ were detected. However, ExHp-CD showed a better effect on macrophage RAW 264.7 cells compared to AgHp. Macrophage RAW 264.7 cells stimulated with 5, and 10 µg/mL of ExHp-CD showed an increased ratio of CD206 (M2 phenotype marker) and a decreased ratio of CD86 (M1 phenotype marker). Moreover, results suggested that the immunogenic effect that ExHp-CD possesses was attributed to their cargo of Epimerase_2 domain-containing protein (Epi_2D), Probable malate:quinone oxidoreductase (Pro_mqo), and Probable cytosol aminopeptidase (Pro_ca). Results demonstrated that ExHp-CD possesses an immunological activity to induce Th2 immune response against H. pylori infection with results comparable to AgHp. However, ExHp-CD showed higher efficacy regarding safety, biocompatibility, lack of toxicity, and hemocompatibility. Thus, it could serve as an immunogenic candidate with more desired characteristics.


Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Vesículas Extracelulares/imunologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/imunologia , Imunidade Celular/imunologia , Macrófagos/imunologia , Animais , Infecções por Helicobacter/imunologia , Interações Hospedeiro-Patógeno , Camundongos , Células RAW 264.7
13.
BMC Infect Dis ; 21(1): 498, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34049506

RESUMO

BACKGROUND: The purpose of this study was to examine the value of Xpert MTB/RIF assay and detection of additional Mycobacterium tuberculosis complex (MTBC) species antigens from intestinal tissue samples in differentiating intestinal tuberculosis (ITB) from Crohn's disease (CD). METHODS: Several clinical specimens of intestinal tissue obtained by either endoscopic biopsy or surgical excision were used for mycobacteriologic solid cultures,Xpert MTB/RIF assays, immunohistochemistry, and histological examinations. Four antigens (38KDa, ESAT-6, MPT64, and Ag85 complex) of MTBC in the intestinal tissue were detected by immunohistochemical analysis. RESULTS: The study included 42 patients with ITB and 46 with CD. Perianal lesions and longitudinal ulcers were more common in patients with CD, while caseating granuloma and annular ulcers were more common in patients with ITB. The positive rate of MTBC detected by Xpert MTB/RIF in intestinal tissues of patients with ITB was 33.33%, which was significantly higher than that in patients with CD and that detected using acid-fast staining smears. It was also higher than that detected by tissue MTBC culture, but the difference was not statistically significant. The positive MPT64 expression rate in patients with ITB was 40.48%, which was significantly higher than that observed in patients with CD. The sensitivity of parallelly combined detection of tuberculosis protein MPT64 and Xpert MTB/RIF in diagnosing ITB was 50.0%. CONCLUSIONS: The detection of Xpert MTB/RIF in intestinal tissue is a rapid and useful method for establishing an early diagnosis of ITB. The detection of MTBC using Xpert MTB/RIF and MPT64 antigen in intestinal tissues has a definitive value in the differential diagnosis ofITB and CD. The combination of these two methods can improve the detection sensitivity.


Assuntos
Antígenos de Bactérias/imunologia , Doença de Crohn/diagnóstico , Tuberculose Gastrointestinal/diagnóstico , Adolescente , Adulto , Bioensaio , Doença de Crohn/microbiologia , DNA Bacteriano , Diagnóstico Diferencial , Testes Diagnósticos de Rotina , Feminino , Técnicas Histológicas , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular , Mycobacterium tuberculosis/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico , Sensibilidade e Especificidade , Coloração e Rotulagem , Tuberculose Gastrointestinal/microbiologia , Adulto Jovem
14.
Int J Mol Sci ; 22(9)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33947066

RESUMO

The pathogenesis of nasal inflammatory diseases is related to various factors such as anatomical structure, heredity, and environment. The nasal microbiota play a key role in coordinating immune system functions. Dysfunction of the microbiota has a significant impact on the occurrence and development of nasal inflammation. This review will introduce the positive and negative roles of microbiota involved in immunity surrounding nasal mucosal diseases such as chronic sinusitis and allergic rhinitis. In addition, we will also introduce recent developments in DNA sequencing, metabolomics, and proteomics combined with computation-based bioinformatics.


Assuntos
Microbiota , Cavidade Nasal/microbiologia , Mucosa Nasal/microbiologia , Rinite/microbiologia , Sinusite/microbiologia , Adulto , Antígenos de Bactérias/imunologia , Criança , Doença Crônica , Disbiose/imunologia , Disbiose/microbiologia , Humanos , Metabolômica/métodos , Cavidade Nasal/imunologia , Mucosa Nasal/imunologia , Proteômica/métodos , Rinite/imunologia , Rinite Alérgica/imunologia , Rinite Alérgica/microbiologia , Análise de Sequência de DNA/métodos , Sinusite/imunologia
15.
Infect Immun ; 89(7): e0010621, 2021 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-33875477

RESUMO

There are no vaccines licensed for enterotoxigenic Escherichia coli (ETEC), a leading cause of diarrhea for children in developing countries and international travelers. Virulence heterogeneity among strains and difficulties identifying safe antigens for protective antibodies against STa, a potent but poorly immunogenic heat-stable toxin which plays a key role in ETEC diarrhea, are challenges in ETEC vaccine development. To overcome these challenges, we applied a toxoid fusion strategy and a novel epitope- and structure-based multiepitope fusion antigen (MEFA) vaccinology platform to construct two chimeric multivalent proteins, toxoid fusion 3xSTaN12S-mnLTR192G/L211A and adhesin CFA/I/II/IV MEFA, and demonstrated that the proteins induced protective antibodies against STa and heat-labile toxin (LT) produced by all ETEC strains or the seven most important ETEC adhesins (CFA/I and CS1 to CS6) expressed by the ETEC strains causing 60 to 70% of diarrheal cases and moderate to severe cases. Combining two proteins, we prepared a protein-based multivalent ETEC vaccine, MecVax. MecVax was broadly immunogenic; mice and pigs intramuscularly immunized with MecVax developed no apparent adverse effects but had robust antibody responses to the target toxins and adhesins. Importantly, MecVax-induced antibodies were broadly protective, demonstrated by significant adherence inhibition against E. coli bacteria producing any of the seven adhesins and neutralization of STa and cholera toxin (CT) enterotoxicity. Moreover, MecVax protected against watery diarrhea and provided over 70% and 90% protection against any diarrhea from an STa-positive or an LT-positive ETEC strain in a pig challenge model. These results indicated that MecVax induces broadly protective antibodies and prevents diarrhea preclinically, signifying that MecVax is potentially an effective injectable vaccine for ETEC. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) bacteria are a top cause of children's diarrhea and travelers' diarrhea and are responsible for over 220 million diarrheal cases and more than 100,000 deaths annually. A safe and effective ETEC vaccine can significantly improve public health, particularly in developing countries. Data from this preclinical study showed that MecVax induces broadly protective antiadhesin and antitoxin antibodies, becoming the first ETEC vaccine candidate to induce protective antibodies inhibiting adherence of the seven most important ETEC adhesins and neutralizing the enterotoxicity of not only LT but also STa toxin. More importantly, MecVax is shown to protect against clinical diarrhea from STa-positive or LT-positive ETEC infection in a pig challenge model, recording protection from antibodies induced by the protein-based, injectable, subunit vaccine MecVax against ETEC diarrhea and perhaps the possibility of intramuscularly administered protein vaccines for protection against intestinal mucosal infection.


Assuntos
Diarreia/microbiologia , Diarreia/prevenção & controle , Escherichia coli Enterotoxigênica/imunologia , Infecções por Escherichia coli/prevenção & controle , Vacinas contra Escherichia coli/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/imunologia , Antígenos de Bactérias/imunologia , Toxinas Bacterianas/imunologia , Diarreia/imunologia , Modelos Animais de Doenças , Epitopos/imunologia , Proteínas de Escherichia coli/imunologia , Vacinas contra Escherichia coli/administração & dosagem , Vacinas contra Escherichia coli/efeitos adversos , Camundongos , Proteínas Recombinantes de Fusão/imunologia , Suínos , Vacinas Combinadas/genética , Vacinas Combinadas/imunologia
16.
mBio ; 12(2)2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33879592

RESUMO

New vaccines are urgently needed against Mycobacterium tuberculosis (Mtb), which kills more than 1.4 million people each year. CD4 T cell differentiation is a key determinant of protective immunity against Mtb, but it is not fully understood how host-pathogen interactions shape individual antigen-specific T cell populations and their protective capacity. Here, we investigated the immunodominant Mtb antigen, MPT70, which is upregulated in response to gamma interferon (IFN-γ) or nutrient/oxygen deprivation of in vitro-infected macrophages. Using a murine aerosol infection model, we compared the in vivo expression kinetics of MPT70 to a constitutively expressed antigen, ESAT-6, and analyzed their corresponding CD4 T cell phenotype and vaccine protection. For wild-type Mtb, we found that in vivo expression of MPT70 was delayed compared to ESAT-6. This delayed expression was associated with induction of less differentiated MPT70-specific CD4 T cells but, compared to ESAT-6, also reduced protection after vaccination. In contrast, infection with an MPT70-overexpressing Mtb strain promoted highly differentiated KLRG1+CX3CR1+ CD4 T cells with limited lung-homing capacity. Importantly, this differentiated phenotype could be prevented by vaccination, and against the overexpressing strain, vaccination with MPT70 conferred protection similar to vaccination with ESAT-6. Together, our data indicate that high in vivo antigen expression drives T cells toward terminal differentiation and that targeted vaccination with adjuvanted protein can counteract this phenomenon by maintaining T cells in a protective less differentiated state. These observations shed new light on host-pathogen interactions and provide guidance on how future Mtb vaccines can be designed to tip the immune balance in favor of the host.IMPORTANCE Tuberculosis, caused by Mtb, constitutes a global health crisis of massive proportions and the impact of the current coronavirus disease 2019 (COVID-19) pandemic is expected to cause a rise in tuberculosis-related deaths. Improved vaccines are therefore needed more than ever, but a lack of knowledge on protective immunity hampers their development. The present study shows that constitutively expressed antigens with high availability drive highly differentiated CD4 T cells with diminished protective capacity, which could be a survival strategy by Mtb to evade T cell immunity against key antigens. We demonstrate that immunization with such antigens can counteract this phenomenon by maintaining antigen-specific T cells in a state of low differentiation. Future vaccine strategies should therefore explore combinations of multiple highly expressed antigens and we suggest that T cell differentiation could be used as a readily measurable parameter to identify these in both preclinical and clinical studies.


Assuntos
Antígenos de Bactérias/imunologia , Linfócitos T CD4-Positivos/imunologia , Mycobacterium tuberculosis/imunologia , Vacinas contra a Tuberculose/farmacologia , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/prevenção & controle , Animais , Antígenos de Bactérias/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/microbiologia , Diferenciação Celular/imunologia , Modelos Animais de Doenças , Epitopos de Linfócito T/genética , Epitopos de Linfócito T/imunologia , Feminino , Expressão Gênica , Genes Bacterianos , Humanos , Epitopos Imunodominantes/genética , Epitopos Imunodominantes/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/genética , Vacinas contra a Tuberculose/genética , Vacinas contra a Tuberculose/imunologia , Tuberculose Pulmonar/microbiologia
17.
Front Immunol ; 12: 629103, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33828549

RESUMO

Many bacteria can interfere with how antibodies bind to their surfaces. This bacterial antibody targeting makes it challenging to predict the immunological function of bacteria-associated antibodies. The M and M-like proteins of group A streptococci (GAS) exhibit IgGFc-binding regions, which they use to reverse IgG binding orientation depending on the host environment. Unraveling the mechanism behind these binding characteristics may identify conditions under which bound IgG can drive an efficient immune response. Here, we have developed a biophysical model for describing these complex protein-antibody interactions. We show how the model can be used as a tool for studying the binding behavior of various IgG samples to M protein by performing in silico simulations and correlating this data with experimental measurements. Besides its use for mechanistic understanding, this model could potentially be used as a tool to aid in the development of antibody treatments. We illustrate this by simulating how IgG binding to GAS in serum is altered as specified amounts of monoclonal or pooled IgG is added. Phagocytosis experiments link this altered antibody binding to a physiological function and demonstrate that it is possible to predict the effect of an IgG treatment with our model. Our study gives a mechanistic understanding of bacterial antibody targeting and provides a tool for predicting the effect of antibody treatments in the presence of bacteria with IgG-modulating surface proteins.


Assuntos
Anticorpos Antibacterianos/metabolismo , Anticorpos Monoclonais/metabolismo , Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Transporte/metabolismo , Imunoglobulina G/metabolismo , Modelos Imunológicos , Streptococcus pyogenes/metabolismo , Especificidade de Anticorpos , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Sítios de Ligação de Anticorpos , Ligação Competitiva , Proteínas de Transporte/imunologia , Epitopos , Humanos , Fagocitose , Ligação Proteica , Streptococcus pyogenes/imunologia , Células THP-1
18.
Front Immunol ; 12: 641563, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33841424

RESUMO

At present, the central role played by arginine in the modulation of the inflammatory cellular responses is well-recognized, and many pro-inflammatory stimuli are known to modulate the expression and activity of its transmembrane transporters. In this regard, we have addressed the effects of bacterial flagellin from Pseudomonas aeruginosa (FLA-PA) on the uptake of the amino acid in human epithelial respiratory cells. Among the arginine transporters, only ATB0,+, y+L, and y+ were operative in bronchial epithelial Calu-3 cells under control conditions; however, only the expression and activity of ATB0,+ were stimulated upon incubation with flagellin, whereas those of systems y+L and y+ were not stimulated. As a result, this induction, in turn, led to an increase in the intracellular content of arginine without making any change to its metabolic pathway. In addition, flagellin upregulated the amount of other amino acids substrates of ATB0,+, in particular, all the essential amino acids, such as valine, isoleucine, and leucine, along with the non-essential glutamine. At the molecular level, these effects were directly referable to the stimulation of a toll-like receptor-5 (TLR5) signaling pathway and to the induction of nuclear factor-κB (NF-κB) transcription factor. An induction of ATB0,+ expression has been observed also in EpiAirway™, a model of primary human normal tracheal-bronchial epithelial cells that mimics the in vitro pseudostratified columnar epithelium of the airways. In this tissue model, the incubation with flagellin is associated with the upregulation of messenger RNAs (mRNAs) for the chemokine IL-8 and for the cytokines IL-6 and interleukin-1ß (IL-1ß); as for the latter, a marked secretion in the extracellular medium was also observed due to the concomitant activation of caspase-1. The overall findings indicate that, in human respiratory epithelium, flagellin promotes cellular responses associating the increase of intracellular amino acids through ATB0,+ with the activation of the inflammasome. Given the role of the ATB0,+ transporter as a delivery system for bronchodilators in human airway epithelial cells, its induction under inflammatory conditions gains particular relevance in the field of respiratory pharmacology.


Assuntos
Sistema ASC de Transporte de Aminoácidos/imunologia , Arginina/metabolismo , Flagelina/imunologia , Antígenos de Histocompatibilidade Menor/imunologia , Mucosa Respiratória/imunologia , Mucosa Respiratória/metabolismo , Sistema ASC de Transporte de Aminoácidos/metabolismo , Aminoácidos Neutros/metabolismo , Antígenos de Bactérias/imunologia , Células Cultivadas , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Antígenos de Histocompatibilidade Menor/metabolismo , Pseudomonas aeruginosa
19.
Int J Mol Sci ; 22(8)2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33917768

RESUMO

The growth in the number of chronic non-communicable diseases in the second half of the past century and in the first two decades of the new century is largely due to the disruption of the relationship between the human body and its symbiotic microbiota, and not pathogens. The interaction of the human immune system with symbionts is not accompanied by inflammation, but is a physiological norm. This is achieved via microbiota control by the immune system through a complex balance of pro-inflammatory and suppressive responses, and only a disturbance of this balance can trigger pathophysiological mechanisms. This review discusses the establishment of homeostatic relationships during immune system development and intestinal bacterial colonization through the interaction of milk glycans, mucins, and secretory immunoglobulins. In particular, the role of fucose and fucosylated glycans in the mechanism of interactions between host epithelial and immune cells is discussed.


Assuntos
Interações Hospedeiro-Patógeno , Imunidade , Microbiota , Polissacarídeos/metabolismo , Fatores Etários , Animais , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Parede Celular/imunologia , Parede Celular/metabolismo , Fucose , Microbioma Gastrointestinal/imunologia , Glicosilação , Interações Hospedeiro-Patógeno/imunologia , Humanos , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Imunoglobulinas , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Microbiota/imunologia
20.
Int J Mol Sci ; 22(8)2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33917862

RESUMO

Pneumonia due to respiratory infection with most prominently bacteria, but also viruses, fungi, or parasites is the leading cause of death worldwide among all infectious disease in both adults and infants. The introduction of modern antibiotic treatment regimens and vaccine strategies has helped to lower the burden of bacterial pneumonia, yet due to the unavailability or refusal of vaccines and antimicrobials in parts of the global population, the rise of multidrug resistant pathogens, and high fatality rates even in patients treated with appropriate antibiotics pneumonia remains a global threat. As such, a better understanding of pathogen virulence on the one, and the development of innovative vaccine strategies on the other hand are once again in dire need in the perennial fight of men against microbes. Recent data show that the secretome of bacteria consists not only of soluble mediators of virulence but also to a significant proportion of extracellular vesicles-lipid bilayer-delimited particles that form integral mediators of intercellular communication. Extracellular vesicles are released from cells of all kinds of organisms, including both Gram-negative and Gram-positive bacteria in which case they are commonly termed outer membrane vesicles (OMVs) and membrane vesicles (MVs), respectively. (O)MVs can trigger inflammatory responses to specific pathogens including S. pneumonia, P. aeruginosa, and L. pneumophila and as such, mediate bacterial virulence in pneumonia by challenging the host respiratory epithelium and cellular and humoral immunity. In parallel, however, (O)MVs have recently emerged as auspicious vaccine candidates due to their natural antigenicity and favorable biochemical properties. First studies highlight the efficacy of such vaccines in animal models exposed to (O)MVs from B. pertussis, S. pneumoniae, A. baumannii, and K. pneumoniae. An advanced and balanced recognition of both the detrimental effects of (O)MVs and their immunogenic potential could pave the way to novel treatment strategies in pneumonia and effective preventive approaches.


Assuntos
Bactérias/metabolismo , Membrana Externa Bacteriana/metabolismo , Vesículas Extracelulares/metabolismo , Pneumonia Bacteriana/microbiologia , Imunidade Adaptativa , Animais , Antígenos de Bactérias/imunologia , Bactérias/imunologia , Membrana Externa Bacteriana/imunologia , Vacinas Bacterianas/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Pneumonia Bacteriana/imunologia , Pneumonia Bacteriana/prevenção & controle , Mucosa Respiratória/imunologia , Mucosa Respiratória/microbiologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/microbiologia , Infecções Respiratórias/prevenção & controle , Virulência
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