RESUMO
Anatomical positioning of memory lymphocytes within barrier tissues accelerates secondary immune responses and is thought to be essential for protection at mucosal surfaces. However, it remains unclear whether resident memory in the female reproductive tract (FRT) is required for Chlamydial immunity. Here, we describe efficient generation of tissue-resident memory CD4 T cells and memory lymphocyte clusters within the FRT after vaginal infection with Chlamydia Despite robust establishment of localized memory lymphocytes within the FRT, naïve mice surgically joined to immune mice, or mice with only circulating immunity following intranasal immunization, were fully capable of resisting Chlamydia infection via the vaginal route. Blocking the rapid mobilization of circulating memory CD4 T cells to the FRT inhibited this protective response. These data demonstrate that secondary protection in the FRT can occur in the complete absence of tissue-resident immune cells. The ability to confer robust protection to barrier tissues via circulating immune memory provides an unexpected opportunity for vaccine development against infections of the FRT.
Assuntos
Anticorpos Antibacterianos/biossíntese , Linfócitos T CD4-Positivos/imunologia , Infecções por Chlamydia/prevenção & controle , Chlamydia muridarum/imunologia , Genitália Feminina/imunologia , Imunização/métodos , Administração Intranasal , Administração Intravaginal , Animais , Antígenos de Bactérias/administração & dosagem , Vacinas Bacterianas/administração & dosagem , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/microbiologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/imunologia , Infecções por Chlamydia/imunologia , Infecções por Chlamydia/microbiologia , Chlamydia muridarum/efeitos dos fármacos , Chlamydia muridarum/crescimento & desenvolvimento , Chlamydia muridarum/patogenicidade , Feminino , Genitália Feminina/efeitos dos fármacos , Genitália Feminina/microbiologia , Imunidade nas Mucosas/efeitos dos fármacos , Memória Imunológica/efeitos dos fármacos , Camundongos , Parabiose/métodosRESUMO
Leprosy is still a considerable health threat in pockets of several low and middle income countries worldwide where intense transmission is witnessed, and often results in irreversible disabilities and deformities due to delayed- or misdiagnosis. Early detection of leprosy represents a substantial hurdle in present-day leprosy health care. The dearth of timely diagnosis has, however, particularly severe consequences in the case of inflammatory episodes, designated leprosy reactions, which represent the major cause of leprosy-associated irreversible neuropathy. There is currently no accurate, routine diagnostic test to reliably detect leprosy reactions, or to predict which patients will develop these immunological exacerbations. Identification of host biomarkers for leprosy reactions, particularly if correlating with early onset prior to development of clinical symptoms, will allow timely interventions that contribute to decreased morbidity. Development of a point-of-care (POC) test based on such correlates would be a definite game changer in leprosy health care. In this review, proteomic-, transcriptomic and metabolomic research strategies aiming at identification of host biomarker-based correlates of leprosy reactions are discussed, next to external factors associated with occurrence of these episodes. The vast diversity in research strategies combined with the variability in patient- and control cohorts argues for harmonisation of biomarker discovery studies with geographically overarching study sites. This will improve identification of specific correlates associated with risk of these damaging inflammatory episodes in leprosy and subsequent application to rapid field tests.
Assuntos
Anticorpos Antibacterianos/análise , Determinação de Ponto Final/métodos , Hanseníase/diagnóstico , Mycobacterium leprae/imunologia , Transcriptoma/imunologia , Anticorpos Antibacterianos/biossíntese , Biomarcadores/metabolismo , Ligante CD30/genética , Ligante CD30/imunologia , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/imunologia , Diagnóstico Tardio , Progressão da Doença , Humanos , Hanseníase/imunologia , Hanseníase/microbiologia , Hanseníase/patologia , Metaboloma/imunologia , Mycobacterium leprae/isolamento & purificação , Mycobacterium leprae/patogenicidade , Testes Imediatos , Biologia de Sistemas/métodos , Receptores Toll-Like/genética , Receptores Toll-Like/imunologiaRESUMO
The obligate intracellular bacterium Chlamydia trachomatis causes the most prevalent bacterial sexually transmitted infection worldwide. CD4 T cells play a central role in the protective immunity against Chlamydia female reproductive tract (FRT) infection, while B cells are thought to be dispensable for resolution of primary Chlamydia infection in mouse models. We recently reported an unexpected requirement of B cells in local Chlamydia-specific CD4 T-cell priming and bacterial containment within the FRT. Here, we sought to tackle the precise effector function of B cells during Chlamydia primary infection. Using mixed bone marrow chimeras that lack B-cell-dependent Ag presentation (MHCIIB-/- ) or devoid of circulating antibodies (AID-/- × µS-/- ), we show that Chlamydia-specific CD4 T-cell expansion does not rely on Ag presentation by B cells. Importantly, we demonstrate that antibody, but not B-cell-dependent Ag presentation, is required for preventing systemic bacterial dissemination following Chlamydia FRT infection.
Assuntos
Anticorpos Antibacterianos/biossíntese , Linfócitos B/imunologia , Bacteriemia/imunologia , Células da Medula Óssea/imunologia , Linfócitos T CD4-Positivos/imunologia , Infecções por Chlamydia/imunologia , Chlamydia trachomatis/imunologia , Animais , Apresentação de Antígeno , Linfócitos B/microbiologia , Bacteriemia/microbiologia , Bacteriemia/patologia , Células da Medula Óssea/microbiologia , Linfócitos T CD4-Positivos/microbiologia , Infecções por Chlamydia/microbiologia , Infecções por Chlamydia/patologia , Chlamydia trachomatis/crescimento & desenvolvimento , Chlamydia trachomatis/patogenicidade , Modelos Animais de Doenças , Feminino , Imunidade Humoral , Isotipos de Imunoglobulinas , Camundongos , Quimeras de Transplante , Vagina/imunologia , Vagina/microbiologia , Irradiação Corporal TotalRESUMO
Heat shock proteins are molecular chaperones that are immunogens as well as potent inducers of an antigen-specific immunological response. In this study, we aimed to evaluate if co-immunization of Brucella rOmp22 and rDnaK proteins had boosted immunogenic activity as compared to rOmp22 immunization alone in mice. For this, gene-encoding DnaK of B. abortus was cloned, expressed in E. coli and purified using Ni-NTA agarose. Immuno-modulatory effect of rDnaK protein was evaluated in mice when co-immunized with Brucella rOmp22. Four groups of mice (n = 6 per group) were used in the study. The control group was immunized with rOmp22 alone, while rOmp22 emulsified with conventional adjuvants (Freund's complete and incomplete adjuvants) and rOmp22 mixed with rDnaK were injected to group I and group II in mice, respectively. Group III mice were immunized with rDnaK alone. IgG class switching (IgG1 and IgG2a) response to immunization was assessed by enzyme-linked immunosorbent assay and expression of IL-4 and IL-12 mRNA was assessed by real-time PCR to evaluate the immune response in mice. The ratio of IgG1-IgG2a was less than 1 in mice co-immunized with rOmp22 and rDnaK, indicating that the immune response was directed towards CMI arm in this group of mice. Moreover, IL-12 mRNA expression was also up-regulated to a greater extent in mice co-immunized with rOmp22 and rDnaK as compared to those immunized with rOmp22 along with the conventional adjuvants, or rOmp22 alone. Our data suggest that rDnaK could be responsible for modulating the immune response, specifically the CMI response.
Assuntos
Anticorpos Antibacterianos/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Brucella abortus/imunologia , Proteínas de Choque Térmico HSP70/imunologia , Switching de Imunoglobulina/imunologia , Animais , Anticorpos Antibacterianos/biossíntese , Brucella abortus/genética , Ensaio de Imunoadsorção Enzimática , Escherichia coli/genética , Imunização , Imunoglobulina G/imunologia , Subunidade p35 da Interleucina-12/genética , Interleucina-4/genética , Masculino , Camundongos , Proteínas Recombinantes/genéticaRESUMO
Bacillus anthracis is the causative agent of anthrax disease, presents with high mortality, and has been at the center of bioweapon efforts. The only currently U.S. FDA-approved vaccine to prevent anthrax in humans is anthrax vaccine adsorbed (AVA), which is protective in several animal models and induces neutralizing antibodies against protective antigen (PA), the cell-binding component of anthrax toxin. However, AVA requires a five-course regimen to induce immunity, along with an annual booster, and is composed of undefined culture supernatants from a PA-secreting strain. In addition, it appears to be ineffective against strains that lack anthrax toxin. Here, we investigated a vaccine formulation consisting of recombinant proteins from a surface-localized heme transport system containing near-iron transporter (NEAT) domains and its efficacy as a vaccine for anthrax disease. The cocktail of five NEAT domains was protective against a lethal challenge of inhaled bacillus spores at 3 and 28 weeks after vaccination. The reduction of the formulation to three NEATs (IsdX1, IsdX2, and Bslk) was as effective as a five-NEAT domain cocktail. The adjuvant alum, approved for use in humans, was as protective as Freund's Adjuvant, and protective vaccination correlated with increased anti-NEAT antibody reactivity and reduced bacterial levels in organs. Finally, the passive transfer of anti-NEAT antisera reduced mortality and disease severity, suggesting the protective component is comprised of antibodies. Collectively, these results provide evidence that a vaccine based upon recombinant NEAT proteins should be considered in the development of a next-generation anthrax vaccine.
Assuntos
Vacinas contra Antraz/imunologia , Antraz/prevenção & controle , Anticorpos Antibacterianos/biossíntese , Anticorpos Neutralizantes/biossíntese , Antígenos de Bactérias/imunologia , Bacillus anthracis/efeitos dos fármacos , Administração por Inalação , Compostos de Alúmen/administração & dosagem , Animais , Antraz/imunologia , Antraz/microbiologia , Antraz/mortalidade , Vacinas contra Antraz/administração & dosagem , Vacinas contra Antraz/genética , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/genética , Bacillus anthracis/imunologia , Bacillus anthracis/patogenicidade , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Proteínas de Transporte/administração & dosagem , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Complemento C5/deficiência , Feminino , Adjuvante de Freund/administração & dosagem , Humanos , Imunogenicidade da Vacina , Camundongos Knockout , Análise de Sobrevida , Vacinação/métodosRESUMO
The most promising means of controlling anthrax, a lethal zoonotic disease during the early infection stages, entail restricting the resilient infectious form, i.e., the spores from proliferating to replicating bacilli in the host. The extractible antigen (EA1), a major S-layer protein present on the vegetative cells and spores of Bacillus anthracis, is highly immunogenic and protects mice against lethal challenge upon immunization. In the present study, mice were immunized with r-EA1C, the C terminal crystallization domain of EA1, to generate a neutralizing monoclonal antibody EA752-862, that was evaluated for its anti-spore and anti-bacterial properties. The monoclonal antibody EA752-862 had a minimum inhibitory concentration of 0.08 mg/ml, was bactericidal at a concentration of 0.1 mg/ml and resulted in 100% survival of mice against challenge with B. anthracis vegetative cells. Bacterial cell lysis as observed by scanning electron microscopy and nucleic acid leakage assay could be attributed as a possible mechanism for the bactericidal property. The association of mAb EA752-862 with spores inhibits their subsequent germination to vegetative cells in vitro, enhances phagocytosis of the spores and killing of the vegetative cells within the macrophage, and subsequently resulted in 90% survival of mice upon B. anthracis Ames spore challenge. Therefore, owing to its anti-spore and bactericidal properties, the present study demonstrates mAb EA752-862 as an efficient neutralizing antibody that hinders the establishment of early infection before massive multiplication and toxin release takes place.
Assuntos
Antraz/prevenção & controle , Antibacterianos/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Bacillus anthracis/imunologia , Esporos Bacterianos/imunologia , Animais , Antraz/imunologia , Antibacterianos/biossíntese , Antibacterianos/química , Antibacterianos/farmacologia , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/química , Anticorpos Antibacterianos/isolamento & purificação , Anticorpos Antibacterianos/farmacologia , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/química , Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/biossíntese , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Neutralizantes/farmacologia , Antígenos de Bactérias/imunologia , Bacillus anthracis/efeitos dos fármacos , Sítios de Ligação , Feminino , Imunização , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Fagocitose/efeitos dos fármacos , Fagocitose/imunologia , Esporos Bacterianos/efeitos dos fármacosRESUMO
Immunogenic and protective activity of recombinant pneumolysin was studied in experiments on male BALB/c mice. The mice were immunized intraperitoneally with recombinant pneumolysin sorbed on Al(OH)3 (200 µg per mouse). In 2 weeks after immunization, the isotypes of antibodies to recombinant pneumolysin in the serum of immunized mice were determined by ELISA. The animals were infected with Streptococcus pneumoniae serotype 3. Immunization with recombinant pneumolysin induced the production of anti-pneumolysin antibodies, mainly of IgG1 subisotype. On day 21 after intraperitoneal infection with S. pneumoniae serotype 3 in a dose of 106 microbial cells, the survival rate of animals immunized with recombinant pneumolysin in a dose of 25 µg/mouse was 67% vs. 0% in the control (p<0.001). Recombinant pneumolysin could be considered as a promising protective antigen for inclusion in the serotype-independent vaccine against S. pneumoniae.
Assuntos
Anticorpos Antibacterianos/biossíntese , Imunoglobulina G/biossíntese , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Streptococcus pneumoniae/imunologia , Estreptolisinas/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Compostos de Alúmen/administração & dosagem , Animais , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/biossíntese , Imunização/métodos , Imunogenicidade da Vacina , Injeções Intraperitoneais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/mortalidade , Infecções Pneumocócicas/patologia , Vacinas Pneumocócicas/biossíntese , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/biossíntese , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/patogenicidade , Estreptolisinas/biossíntese , Análise de SobrevidaRESUMO
The biosurfactant monoacyltrehalose fraction isolated from Rhodococcus ruber IEGM 231 actinobacterium suppresses antibody production, bactericidal potential, and production of IL-1ß by mouse peritoneal cells after intraperitoneal and intramuscular injection and stimulates the production of IL-10 after intraperitoneal injection. The data of in vitro experiments attest to an important role of bacterial glycolipids in the regulation of the functions of splenocytes and peritoneal macrophages.
Assuntos
Fatores Imunológicos/farmacologia , Linfócitos/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Rhodococcus/química , Tensoativos/farmacologia , Trealose/farmacologia , Imunidade Adaptativa/efeitos dos fármacos , Animais , Anticorpos Antibacterianos/biossíntese , Expressão Gênica , Imunidade Inata/efeitos dos fármacos , Fatores Imunológicos/química , Fatores Imunológicos/isolamento & purificação , Injeções Intraperitoneais , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Linfócitos/citologia , Linfócitos/imunologia , Macrófagos Peritoneais/citologia , Macrófagos Peritoneais/imunologia , Masculino , Camundongos , Cultura Primária de Células , Baço/citologia , Baço/efeitos dos fármacos , Baço/imunologia , Tensoativos/química , Tensoativos/isolamento & purificação , Trealose/análogos & derivados , Trealose/isolamento & purificaçãoRESUMO
Infection with Coxiella burnetii, the causative agent of Q fever, can result in life-threatening persistent infection. Reactogenicity hinders worldwide implementation of the only licensed human Q fever vaccine. We previously demonstrated long-lived immunoreactivity in individuals with past symptomatic and asymptomatic Coxiella infection (convalescents) to promiscuous HLA class II C. burnetii epitopes, providing the basis for a novel T-cell targeted subunit vaccine. In this study, we investigated in a cohort of 22 individuals treated for persistent infection (chronic Q fever) whether they recognize the same set of epitopes or distinct epitopes that could be candidates for a therapeutic vaccine or aid in the diagnosis of persistent infection. In cultured enzyme-linked immunosorbent spot (ELISpot) assays, individuals with chronic Q fever showed strong class II epitope-specific responses that were largely overlapping with the peptide repertoire identified previously for convalescents. Five additional peptides were recognized more frequently by chronic subjects, but there was no combination of epitopes uniquely recognized by or nonreactive in subjects with chronic Q fever. Consistent with more recent/prolonged exposure, we found, however, stronger ex vivo responses by direct ELISpot to both whole-cell C. burnetii and individual peptides in chronic patients than in convalescents. In conclusion, we have validated and expanded a previously published set of candidate epitopes for a novel T-cell targeted subunit Q fever vaccine in treated patients with chronic Q fever and demonstrated that they successfully mounted a T-cell response comparable to that of convalescents. Finally, we demonstrated that individuals treated for chronic Q fever mount a broader ex vivo response to class II epitopes than convalescents, which could be explored for diagnostic purposes.
Assuntos
Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias/imunologia , Coxiella burnetii/imunologia , Epitopos de Linfócito T/imunologia , Febre Q/imunologia , Idoso , Antibacterianos/uso terapêutico , Antígenos de Bactérias/química , Antígenos de Bactérias/genética , Vacinas Bacterianas/química , Vacinas Bacterianas/imunologia , Doença Crônica , Convalescença , Coxiella burnetii/patogenicidade , ELISPOT , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Feminino , Expressão Gênica , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Teste de Histocompatibilidade , Humanos , Interferon gama/genética , Interferon gama/imunologia , Masculino , Pessoa de Meia-Idade , Peptídeos/genética , Peptídeos/imunologia , Febre Q/tratamento farmacológico , Febre Q/genética , Febre Q/prevenção & controle , Linfócitos T/imunologia , Linfócitos T/microbiologiaRESUMO
Acute otitis media is one of the most common childhood infections worldwide. Currently licensed vaccines against the common otopathogen Streptococcus pneumoniae target the bacterial capsular polysaccharide and confer no protection against nonencapsulated strains or capsular types outside vaccine coverage. Mucosal infections such as acute otitis media remain prevalent, even those caused by vaccine-covered serotypes. Here, we report that a protein-based vaccine, a fusion construct of epitopes of CbpA to pneumolysin toxoid, confers effective protection against pneumococcal acute otitis media for non-PCV-13 serotypes and enhances protection for PCV-13 serotypes when coadministered with PCV-13. Having cross-reactive epitopes, the fusion protein also induces potent antibody responses against nontypeable Haemophilus influenzae and S. pneumoniae, engendering protection against acute otitis media caused by emerging unencapsulated otopathogens. These data suggest that augmenting capsule-based vaccination with conserved, cross-reactive protein-based vaccines broadens and enhances protection against acute otitis media.
Assuntos
Anticorpos Antibacterianos/biossíntese , Infecções por Haemophilus/prevenção & controle , Haemophilus influenzae/imunologia , Otite Média/prevenção & controle , Vacinas Pneumocócicas/biossíntese , Proteínas Recombinantes de Fusão/biossíntese , Streptococcus pneumoniae/imunologia , Doença Aguda , Animais , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Proteção Cruzada , Reações Cruzadas , Feminino , Expressão Gênica , Infecções por Haemophilus/imunologia , Infecções por Haemophilus/microbiologia , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/patogenicidade , Humanos , Imunogenicidade da Vacina , Camundongos , Camundongos Endogâmicos BALB C , Otite Média/imunologia , Otite Média/microbiologia , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/patogenicidade , Estreptolisinas/biossíntese , Estreptolisinas/genética , Toxoides/biossíntese , Toxoides/genética , Vacinação , Vacinas SintéticasRESUMO
As important players in the host defense system, commensal microbes and the microbiota influence multiple aspects of host physiology. Bordetella pertussis infection is highly contagious among humans. However, the roles of the microbiota in B. pertussis pathogenesis are poorly understood. Here, we show that antibiotic-mediated depletion of the microbiota results in increased susceptibility to B. pertussis infection during the early stage. The increased susceptibility was associated with a marked impairment of the systemic IgG, IgG2a, and IgG1 antibody responses to B. pertussis infection after antibiotic treatment. Furthermore, the microbiota impacted the short-lived plasma cell responses as well as the recall responses of memory B cells to B. pertussis infection. Finally, we found that the dysbiosis caused by antibiotic treatment affects CD4+ T cell generation and PD-1 expression on CD4+ T cells and thereby perturbs plasma cell differentiation. Our results have revealed the importance of commensal microbes in modulating host immune responses to B. pertussis infection and support the possibility of controlling the severity of B. pertussis infection in humans by manipulating the microbiota.
Assuntos
Bordetella pertussis/imunologia , Disbiose/imunologia , Microbioma Gastrointestinal/imunologia , Imunidade Humoral , Simbiose/imunologia , Coqueluche/imunologia , Ampicilina/farmacologia , Animais , Antibacterianos/farmacologia , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/classificação , Bacteroidetes/classificação , Bacteroidetes/efeitos dos fármacos , Bacteroidetes/crescimento & desenvolvimento , Bacteroidetes/imunologia , Bordetella pertussis/crescimento & desenvolvimento , Bordetella pertussis/patogenicidade , Disbiose/microbiologia , Disbiose/fisiopatologia , Feminino , Firmicutes/classificação , Firmicutes/efeitos dos fármacos , Firmicutes/crescimento & desenvolvimento , Firmicutes/imunologia , Microbioma Gastrointestinal/efeitos dos fármacos , Imunidade Inata , Imunoglobulina G/biossíntese , Imunoglobulina G/classificação , Metronidazol/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Neomicina/farmacologia , Proteobactérias/classificação , Proteobactérias/efeitos dos fármacos , Proteobactérias/crescimento & desenvolvimento , Proteobactérias/imunologia , Simbiose/efeitos dos fármacos , Vancomicina/farmacologia , Coqueluche/microbiologia , Coqueluche/fisiopatologiaRESUMO
In this study, a novel recombinant attenuated Yersinia pseudotuberculosis PB1+ strain (χ10069) engineered with ΔyopK ΔyopJ Δasd triple mutations was used to deliver a Y. pestis fusion protein, YopE amino acid 1 to 138-LcrV (YopENt138-LcrV), to Swiss Webster mice as a protective antigen against infections by yersiniae. χ10069 bacteria harboring the pYA5199 plasmid constitutively synthesized the YopENt138-LcrV fusion protein and secreted it via the type 3 secretion system (T3SS) at 37°C under calcium-deprived conditions. The attenuated strain χ10069(pYA5199) was manifested by the establishment of controlled infection in different tissues without developing conspicuous signs of disease in histopathological analysis of microtome sections. A single-dose oral immunization of χ10069(pYA5199) induced strong serum antibody titers (log10 mean value, 4.2), secretory IgA in bronchoalveolar lavage (BAL) fluid from immunized mice, and Yersinia-specific CD4+ and CD8+ T cells producing high levels of tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), and interleukin 2 (IL-2), as well as IL-17, in both lungs and spleens of immunized mice, conferring comprehensive Th1- and Th2-mediated immune responses and protection against bubonic and pneumonic plague challenges, with 80% and 90% survival, respectively. Mice immunized with χ10069(pYA5199) also exhibited complete protection against lethal oral infections by Yersinia enterocolitica WA and Y. pseudotuberculosis PB1+. These findings indicated that χ10069(pYA5199) as an oral vaccine induces protective immunity to prevent bubonic and pneumonic plague, as well as yersiniosis, in mice and would be a promising oral vaccine candidate for protection against plague and yersiniosis for human and veterinary applications.
Assuntos
Anticorpos Antibacterianos/biossíntese , Imunoglobulina A/biossíntese , Vacina contra a Peste/administração & dosagem , Peste/prevenção & controle , Proteínas Recombinantes de Fusão/administração & dosagem , Yersinia pestis/efeitos dos fármacos , Infecções por Yersinia pseudotuberculosis/prevenção & controle , Yersinia pseudotuberculosis/efeitos dos fármacos , Administração Oral , Animais , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/microbiologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/microbiologia , Proteção Cruzada , Feminino , Expressão Gênica , Humanos , Imunização , Interferon gama/genética , Interferon gama/imunologia , Interleucina-2/genética , Interleucina-2/imunologia , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/microbiologia , Masculino , Camundongos , Peste/imunologia , Peste/microbiologia , Peste/mortalidade , Vacina contra a Peste/biossíntese , Vacina contra a Peste/genética , Vacina contra a Peste/imunologia , Plasmídeos/química , Plasmídeos/metabolismo , Proteínas Citotóxicas Formadoras de Poros/genética , Proteínas Citotóxicas Formadoras de Poros/imunologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Análise de Sobrevida , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia , Vacinas Sintéticas , Yersinia pestis/imunologia , Yersinia pestis/patogenicidade , Yersinia pseudotuberculosis/imunologia , Yersinia pseudotuberculosis/patogenicidade , Infecções por Yersinia pseudotuberculosis/imunologia , Infecções por Yersinia pseudotuberculosis/microbiologia , Infecções por Yersinia pseudotuberculosis/mortalidadeRESUMO
OBJECTIVES: We aimed to assess the safety and immunogenicity of a diphtheria/tetanus vaccine booster dose in three different patient groups with rheumatic diseases on a variety of immunosuppressive/immunomodulatory medications compared with healthy controls (HCs). METHODS: We conducted a multi-centre prospective cohort study in Switzerland. We enrolled patients with RA, axial SpA/PsA, vasculitis (Behçet's disease, ANCA-associated vasculitis) and HCs. Diphtheria/tetanus vaccination was administered according to the Swiss vaccination recommendations. Blood samples were drawn before vaccination, and 1 month and 3 months afterwards. Antibody concentrations against vaccine antigens were measured by ELISA. Immunogenicity was compared between patient and medication groups. A mixed model was applied for multivariate analysis. Missing data were dealt with using multiple imputation. RESULTS: Between January 2014 and December 2015, we enrolled 284 patients with rheumatic diseases (131 RA, 114 SpA/PsA, 39 vasculitis) and 253 HCs. Of the patients, 89% were on immunosuppressive/immunomodulatory medication. Three months post-vaccination 100% of HCs vs 98% of patients were protected against tetanus and 84% vs 73% against diphtheria. HCs and SpA/PsA patients had significantly higher responses than RA and vasculitis patients. Assessing underlying diseases and medications in a multivariate model, rituximab was the only factor negatively influencing tetanus immunogenicity, whereas only MTX treatment had a negative influence on diphtheria antibody responses. No vaccine-related serious adverse events were recorded. CONCLUSION: Diphtheria/tetanus booster vaccination was safe. Tetanus vaccination was immunogenic; the diphtheria component was less immunogenic. Vaccine responses were blunted by rituximab and MTX. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov, Identifier: NCT01947465.
Assuntos
Anticorpos Antibacterianos/biossíntese , Vacina contra Difteria e Tétano/efeitos adversos , Imunogenicidade da Vacina/efeitos dos fármacos , Doenças Reumáticas/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Clostridium tetani/imunologia , Corynebacterium diphtheriae/imunologia , Difteria/prevenção & controle , Vacina contra Difteria e Tétano/imunologia , Feminino , Humanos , Imunização Secundária , Imunogenicidade da Vacina/imunologia , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Doenças Reumáticas/tratamento farmacológico , Tétano/prevenção & controle , Vacinação , Adulto JovemRESUMO
Enterococcus faecium (E. faecium) has emerged as one of today's leading causes of health care-associated infections that is difficult to treat with the available antibiotics. These pathogens produce capsular polysaccharides on the cell surface which play a significant role in adhesion, virulence and evasion. Therefore, we aimed at the identification and characterization of bacterial polysaccharide antigens which are central for the development of vaccine-based prophylactic approaches. The crude cell wall-associated polysaccharides from E. faecium, its mutant and complemented strains were purified and analyzed by a primary antibody raised against lipoteichoic acid (LTA) and diheteroglycan (DHG). The resistant E. faecium strains presumably possess novel capsular polysaccharides that allow them to avoid the evasion from opsonic killing. The E. faecium U0317 strain was very well opsonized by anti-U0317 (~95%), an antibody against the whole bacterial cell. The deletion mutant showed a significantly increased susceptibility to opsonophagocytic killing (90-95%) against the penicillin binding protein (anti-PBP-5). By comparison, in a mouse urinary tract and rat endocarditis infection model, respectively, there were no significant differences in virulence. In this study we explored the biological role of the capsule of E. faecium. Our findings showed that the U0317 strain is not only sensitive to anti-LTA but also to antibodies against other enterococcal surface proteins. Our findings demonstrate that polysaccharides capsule mediated-resistance to opsonophagocytosis. We also found that the capsular polysaccharides do not play an important role in bacterial virulence in urinary tract and infective endocarditis in vivo models.
Assuntos
Anticorpos Antibacterianos/farmacologia , Antígenos de Bactérias/isolamento & purificação , Parede Celular/química , Enterococcus faecium/química , Lipopolissacarídeos/isolamento & purificação , Polissacarídeos Bacterianos/isolamento & purificação , Ácidos Teicoicos/isolamento & purificação , Animais , Antibacterianos/farmacologia , Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias/química , Antígenos de Bactérias/imunologia , Cápsulas Bacterianas/química , Cápsulas Bacterianas/imunologia , Parede Celular/imunologia , Modelos Animais de Doenças , Farmacorresistência Bacteriana , Endocardite Bacteriana/tratamento farmacológico , Endocardite Bacteriana/microbiologia , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/imunologia , Enterococcus faecium/patogenicidade , Feminino , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Lipopolissacarídeos/química , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Opsonizantes/farmacologia , Proteínas de Ligação às Penicilinas/química , Proteínas de Ligação às Penicilinas/imunologia , Proteínas de Ligação às Penicilinas/isolamento & purificação , Proteínas de Ligação às Penicilinas/farmacologia , Fagocitose/efeitos dos fármacos , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/imunologia , Cultura Primária de Células , Ratos , Ratos Wistar , Ácidos Teicoicos/química , Ácidos Teicoicos/imunologia , Ácidos Teicoicos/farmacologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologiaRESUMO
Immune mechanisms responsible for pathogen clearance from the female reproductive tract (FRT) are incompletely defined; in particular, the contribution of lymphocyte trafficking to this process is unclear. CCR7-deficient mice have profoundly altered lymphocyte recirculation and display ectopic formation of lymphocyte aggregates within mucosal nonlymphoid tissues, including the FRT. In this study, we investigated how altered lymphocyte distribution in CCR7-deficient mice would affect host responses to Chlamydia muridarum within the reproductive tract. As expected, CCR7-deficient mice exhibited reduced lymphocyte trafficking to lymph nodes and a corresponding increase in T cell populations within the FRT. After intravaginal infection with Chlamydia, CCR7-deficient mice displayed markedly reduced Ag-specific CD4 T cell responses within the local draining iliac lymph nodes, yet robust Th1 and Th17 responses were prominent in the FRT. In addition, Chlamydia-specific Ab responses were dysregulated in CCR7-deficient mice, displaying an unexpected increase in the systemic IgA responses. Importantly, prominent mucosal immune responses in CCR7-deficient mice increased the efficiency of bacteria clearance from the FRT while reducing tissue-associated inflammation and pathology. Thus, increased numbers of lymphocytes within the FRT result in pathogen clearance with reduced immune-mediated pathology.
Assuntos
Infecções por Chlamydia/imunologia , Infecções por Chlamydia/microbiologia , Chlamydia muridarum/imunologia , Receptores CCR7/imunologia , Infecções do Sistema Genital/imunologia , Infecções do Sistema Genital/microbiologia , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/sangue , Linfócitos T CD4-Positivos/imunologia , Movimento Celular , Chlamydia muridarum/isolamento & purificação , Feminino , Imunoglobulina A/sangue , Inflamação/microbiologia , Linfonodos/imunologia , Camundongos , Camundongos Knockout , Receptores CCR7/deficiência , Receptores CCR7/genética , Células Th1/imunologia , Células Th17/imunologiaRESUMO
Immunization strategies against commensal bacterial pathogens have long focused on eradicating asymptomatic carriage as well as disease, resulting in changes in the colonizing microflora with unknown future consequences. Additionally, current vaccines are not easily adaptable to sequence diversity and immune evasion. Here, we present a "smart" vaccine that leverages our current understanding of disease transition from bacterial carriage to infection with the pneumococcus serving as a model organism. Using conserved surface proteins highly expressed during virulent transition, the vaccine mounts an immune response specifically against disease-causing bacterial populations without affecting carriage. Aided by a delivery technology capable of multivalent surface display, which can be adapted easily to a changing clinical picture, results include complete protection against the development of pneumonia and sepsis during animal challenge experiments with multiple, highly variable, and clinically relevant pneumococcal isolates. The approach thus offers a unique and dynamic treatment option readily adaptable to other commensal pathogens.
Assuntos
Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/administração & dosagem , Animais , Anticorpos Antibacterianos/biossíntese , Biofilmes , Humanos , Camundongos , Infecções Pneumocócicas/imunologia , Vacinas Pneumocócicas/imunologiaRESUMO
A hallmark of Staphylococcus aureus disease in humans is persistent infections without development of protective immune responses. Infected patients generate VH3 plasmablast expansions and increased VH3 idiotype Ig; however, the mechanisms for staphylococcal modification of immune responses are not known. We report here that S. aureus-infected mice generate VH3 antibody expansions via a mechanism requiring MHC-restricted antigen presentation to CD4(+) T cells and staphylococcal protein A (SpA), a cell wall-anchored surface molecule that binds Fcγ and VH3 variant heavy chains of Ig. VH3 expansion occurred with peptidoglycan-linked SpA from the bacterial envelope but not with recombinant SpA, and optimally required five tandem repeats of its Ig-binding domains. Signaling via receptor-interacting serine/threonine protein kinase 2 (RIPK2) was essential for implementing peptidoglycan-linked SpA superantigen activity. VH3 clan IgG from S. aureus-infected or SpA-treated animals was not pathogen-specific, suggesting that SpA cross-linking of VH3 idiotype B-cell receptors and activation via attached peptidoglycan are the determinants of staphylococcal escape from adaptive immune responses.
Assuntos
Anticorpos Antibacterianos/biossíntese , Infecções Estafilocócicas/imunologia , Proteína Estafilocócica A/imunologia , Staphylococcus aureus/imunologia , Linfócitos T/metabolismo , Animais , Anticorpos Antibacterianos/sangue , Formação de Anticorpos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Peptidoglicano/imunologia , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/microbiologia , Linfócitos T/imunologia , Linfócitos T/microbiologiaRESUMO
The bacterial type 6 secretion system (T6SS) is a dynamic apparatus that translocates proteins between cells by a mechanism analogous to phage tail contraction. T6SS sheaths are cytoplasmic tubular structures composed of stable VipA-VipB (named for ClpV-interacting protein A and B) heterodimers. Here, the structure of the VipA/B sheath was exploited to generate immunogenic multivalent particles for vaccine delivery. Sheaths composed of VipB and VipA fused to an antigen of interest were purified from Vibrio cholerae or Escherichia coli and used for immunization. Sheaths displaying heterologous antigens generated better immune responses against the antigen and different IgG subclasses compared with soluble antigen alone. Moreover, antigen-specific antibodies raised against sheaths presenting Neisseria meningitidis factor H binding protein (fHbp) antigen were functional in a serum bactericidal assay. Our results demonstrate that multivalent nanoparticles based on the T6SS sheath represent a versatile scaffold for vaccine applications.
Assuntos
Antígenos/administração & dosagem , Nanopartículas/química , Sistemas de Secreção Tipo VI/ultraestrutura , Vacinas/administração & dosagem , Acinetobacter/química , Acinetobacter/genética , Aminoaciltransferases/metabolismo , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/imunologia , Antígenos/imunologia , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/química , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/imunologia , Linhagem Celular , Cisteína Endopeptidases/metabolismo , Dimerização , Sistemas de Liberação de Medicamentos , Escherichia coli/química , Feminino , Genes Reporter , Imunoglobulina G/biossíntese , Imunoglobulina G/genética , Macrófagos/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica , Nanopartículas/administração & dosagem , Nanopartículas/ultraestrutura , Pseudomonas aeruginosa/química , Pseudomonas aeruginosa/genética , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/imunologia , Sistemas de Secreção Tipo VI/química , Vacinação , Vacinas/imunologia , Vibrio cholerae/químicaRESUMO
It is widely accepted that live vaccines elicit higher immune protection than inactivated vaccines. However, the mechanisms are largely unknown. Here, an array with 64 recombinant outer membrane proteins of Vibrio parahemolyticus was developed to explore antibody responses of live and inactivated V. parahemolyticus post immunization of the 8th, 12th, 16th and 20th day. Among the 64 outer membrane proteins, 28 elicited antibody generation. They were all detected in live vaccine-induced immunity but only 15 antibodies were found in inactivated vaccine-induced immunity. Passive immunization showed that higher percent survival was detected in live than inactivated vaccine-induced immunities. Active immunization indicated that out of 19 randomly selected outer membrane proteins, 5 stimulated immune protection against V. parahemolyticus infection. Among them, antibodies to VP2309 and VPA0526 were shared in mice immunized by live or inactivated vaccines, whereas antibodies to VPA0548, VPA1745, and VP1667 were only found in mice immunized by live vaccine. In addition, live V. parahemolyticus stimulated earlier antibody response than inactivated bacteria. These results indicate that not all of the outer membrane proteins elicited antibody responses when they work together in the form of live or inactivated bacteria; live vaccine elicits more protective antibodies, which contribute to higher immune protection in live vaccine than inactivated vaccine. Notably, the recombinant proteins might be different from those separated from live bacteria, and they might be different in their immunogenic potencies.
Assuntos
Anticorpos Antibacterianos/biossíntese , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Imunidade Humoral/efeitos dos fármacos , Vibrioses/prevenção & controle , Animais , Proteínas da Membrana Bacteriana Externa/administração & dosagem , Proteínas da Membrana Bacteriana Externa/genética , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/genética , Temperatura Alta , Soros Imunes/administração & dosagem , Imunização Passiva/métodos , Imunogenicidade da Vacina , Camundongos , Análise Serial de Proteínas , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Análise de Sobrevida , Vacinas de Produtos Inativados , Vibrioses/imunologia , Vibrioses/microbiologia , Vibrioses/mortalidade , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio parahaemolyticus/crescimento & desenvolvimento , Vibrio parahaemolyticus/imunologia , Peixe-ZebraRESUMO
The recommended management of inhalational anthrax, a high-priority bioterrorist threat, includes antibiotics and antitoxins. Obiltoxaximab, a chimeric monoclonal antibody against anthrax protective antigen (PA), is licensed under the U.S. Food and Drug Administration's (FDA's) Animal Rule for the treatment of inhalational anthrax. Because of spore latency, disease reemergence after treatment cessation is a concern, and there is a need to understand the development of endogenous protective immune responses following antitoxin-containing anthrax treatment regimens. Here, acquired protective immunity was examined in New Zealand White (NZW) rabbits challenged with a targeted lethal dose of Bacillus anthracis spores and treated with antibiotics, obiltoxaximab, or a combination of both. Survivors of the primary challenge were rechallenged 9 months later and monitored for survival. Survival rates after primary and rechallenge for controls and animals treated with obiltoxaximab, levofloxacin, or a combination of both were 0, 65, 100, and 95%, and 0, 100, 95, and 89%, respectively. All surviving immune animals had circulating antibodies to PA and serum toxin-neutralizing titers prior to rechallenge. Following rechallenge, systemic bacteremia and toxemia were not detected in most animals, and the levels of circulating anti-PA IgG titers increased starting at 5 days postrechallenge. We conclude that treatment with obiltoxaximab, alone or combined with antibiotics, significantly improves the survival of rabbits that received a lethal inhalation B. anthracis spore challenge dose and does not interfere with the development of immunity. Survivors of primary challenge are protected against reexposure, have rare incidents of systemic bacteremia and toxemia, and have evidence of an anamnestic response.