RESUMO
Probiotic microorganisms can stimulate an immune response and increase the efficiency of vaccines. For example, Bacillus toyonensis is a nonpathogenic, Gram-positive bacterium that has been used as a probiotic in animal supplementation. It induces immunomodulatory effects and increases the vaccine response in several species. This study aimed to evaluate the effect of B. toyonensis supplementation on the modulation of the immune response in horses vaccinated with recombinant Clostridium tetani toxin. Twenty horses were vaccinated twice, with an interval of 21 days between doses, and equally divided into two groups: the first group was supplemented orally for 42 days with feed containing viable spores of B. toyonensis (1 × 108) mixed with molasses (40 ml), starting 7 days before the first vaccination; the second (control) group received only feed mixed with molasses, starting 7 days before the first vaccination. Serum samples were collected to evaluate the humoral immune response using an in-house indirect enzyme-linked immunosorbent assay (ELISA), and peripheral blood mononuclear cells (PBMCs) were collected to evaluate cytokine transcription (qPCR). For the specific IgG-anti-rTENT titer, the supplemented group had ELISA values that were four times higher than those of the control group (p < 0.05). The supplemented group also showed higher ELISA values for the IgGa and IgGT sub-isotypes compared to the control group. In PBMCs stimulated with B. toyonensis, relative cytokine transcription of the supplemented group showed 15-, 8-, 7-, and 6-fold increases for IL1, TNFα, IL10 and IL4, respectively. When stimulated with a vaccine antigen, the supplemented group showed 1.6-, 1.8-, and 0.5-fold increases in IL1, TNFα, and IL4, respectively, compared to the control group. Horses supplemented with B. toyonensis had a significantly improved vaccine immune response compared to those in the control group, which suggests a promising approach for improving vaccine efficacy with probiotics.
Assuntos
Bacillus , Doenças dos Cavalos , Probióticos , Animais , Cavalos/imunologia , Bacillus/imunologia , Probióticos/administração & dosagem , Probióticos/farmacologia , Doenças dos Cavalos/prevenção & controle , Doenças dos Cavalos/imunologia , Doenças dos Cavalos/microbiologia , Tétano/prevenção & controle , Tétano/imunologia , Toxoide Tetânico/imunologia , Toxoide Tetânico/administração & dosagem , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/administração & dosagem , Masculino , Ração Animal , Feminino , Dieta/veterinária , Citocinas/metabolismoRESUMO
For several years, we have been committed to exploring the potential of Bordetella pertussis-derived outer membrane vesicles (OMVBp) as a promising third-generation vaccine against the reemerging pertussis disease. The results of our preclinical trials not only confirm its protective capacity against B. pertussis infection but also set the stage for forthcoming human clinical trials. This study delves into the examination of OMVBp as an adjuvant. To accomplish this objective, we implemented a two-dose murine schedule to evaluate the specific immune response induced by formulations containing OMVBp combined with 3 heterologous immunogens: Tetanus toxoid (T), Diphtheria toxoid (D), and the SARS-CoV-2 Spike protein (S). The specific levels of IgG, IgG1, and IgG2a triggered by the different tested formulations were evaluated using ELISA in dose-response assays for OMVBp and the immunogens at varying levels. These assays demonstrated that OMVBp exhibits adjuvant properties even at the low concentration employed (1.5 µg of protein per dose). As this effect was notably enhanced at medium (3 µg) and high concentrations (6 µg), we chose the medium concentration to determine the minimum immunogen dose at which the OMV adjuvant properties are significantly evident. These assays demonstrated that OMVBp exhibits adjuvant properties even at the lowest concentration tested for each immunogen. In the presence of OMVBp, specific IgG levels detected for the lowest amount of antigen tested increased by 2.5 to 10 fold compared to those found in animals immunized with formulations containing adjuvant-free antigens (p<0.0001). When assessing the adjuvant properties of OMVBp compared to the widely recognized adjuvant alum, we detected similar levels of specific IgG against D, T and S for both adjuvants. Experiments with OMVs derived from E. coli (OMVE.coli) reaffirmed that the adjuvant properties of OMVs extend across different bacterial species. Nonetheless, it's crucial to highlight that OMVBp notably skewed the immune response towards a Th1 profile (p<0.05). These collective findings emphasize the dual role of OMVBp as both an adjuvant and modulator of the immune response, positioning it favorably for incorporation into combined vaccine formulations.
Assuntos
Adjuvantes Imunológicos , Bordetella pertussis , Imunoglobulina G , Células Th1 , Coqueluche , Bordetella pertussis/imunologia , Animais , Adjuvantes Imunológicos/administração & dosagem , Camundongos , Células Th1/imunologia , Coqueluche/imunologia , Coqueluche/prevenção & controle , Feminino , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Vacina contra Coqueluche/imunologia , Vacina contra Coqueluche/administração & dosagem , Anticorpos Antibacterianos/imunologia , Anticorpos Antibacterianos/sangue , Glicoproteína da Espícula de Coronavírus/imunologia , Camundongos Endogâmicos BALB C , SARS-CoV-2/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Humanos , COVID-19/imunologia , COVID-19/prevenção & controle , Toxoide Tetânico/imunologiaRESUMO
Recent changes in the epidemiology of meningococcal have been reported and meningococcal group W (MenW) has become the third most prevalent group isolated in Brazil in the last 10 years. In this study we have developed a conjugate vaccine for MenW using a modified reductive amination conjugation method through a covalent linkage between periodate-oxidized MenW non-O-acetylated polysaccharide and hydrazide-activated monomeric tetanus toxoid. Process control of bulks was done by physicochemical analysis including polysaccharide and protein quantification, high performance liquid chromatography - size exclusion chromatography, capillary electrophoresis, and hydrogen nuclear magnetic resonance. Conjugate bulks were best produced with concentration of polysaccharide twice as high as protein, at room temperature, and pH approximately 6.0. A scaled-up bulk (100 mg scale) was formulated and inoculated intramuscularly in mice in a dose-response study (0.1, 0.5, 1.0 and 10.0 µg of polysaccharide/dose). The immunogenicity of conjugate bulks was determined by serum bactericidal assay and ELISA assays of serum from immunized mice. ELISA and SBA titers revealed high titers of IgG and demonstrated the functionality of the antibodies produced in all doses studied 15 days after the third dose. However, significant differences were observed among them by ELISA. In conclusion, this study established the best conditions to produce MenW conjugate bulks and showed the efficacy of the obtained conjugate bulk in induce a good immune response in mice. Further experiments will need to be done to scale up the conjugation reaction and then allow the use of this conjugate in clinical trials.
Assuntos
Infecções Meningocócicas/epidemiologia , Infecções Meningocócicas/prevenção & controle , Vacinas Meningocócicas/imunologia , Neisseria meningitidis/classificação , Animais , Anticorpos Antibacterianos , Atividade Bactericida do Sangue , Brasil/epidemiologia , Feminino , Glicoconjugados , Humanos , Masculino , Camundongos , Projetos Piloto , Toxoide Tetânico/imunologia , Vacinas Conjugadas/imunologiaRESUMO
BACKGROUND: The protective effect of breastfeeding on celiac disease (CD) onset is controversial. We studied a wide range of milk components in milk produced by celiac mothers following long-term gluten-free diet (GFD) in comparison to milk produced by healthy mothers. METHODS: Breast-milk samples from celiac (n = 33) and healthy (n = 41) mothers were obtained during the first year of lactation. A panel of bioactive components was analyzed by enzyme-linked immunosorbent assay in the aqueous fraction. We studied molecules involved in defenses, immunoregulation, and strengthening of the gut-epithelial barrier. RESULTS: During late lactation (from 6 to 12 months after delivery), the content of total immunoglobulin A (IgA) and IgM was significantly lower in the milk produced by celiac patients. Nevertheless, gliadin (GFD)-specific IgA relative contribution was higher in this group, in contrast to tetanus toxoid-specific antibodies. The balance between pro-inflammatory and anti-inflammatory molecules was different. While interleukin-6, tumor necrosis factor-α, and monocyte chemoattractant protein-1 were most frequently found in samples from celiac mothers, soluble Toll-like receptor-2 prevalence was lower. CONCLUSIONS: We describe differences between the innate and adaptive immune profile of milk produced by celiac and healthy mothers. These results might explain previous controversial reports about breastfeeding and CD protection. IMPACT: In spite of a long-term adherence to GFD, the milk produced by mothers with CD exhibit a different immune profile, in relation with some immunoregulatory factors and antibody content. This work shows a more comprehensive characterization of milk from celiac mothers, including macronutrients, lysozymes, growth factors, and immunoregulatory components that had not been studied before. The present study widens the available data regarding the characteristics of human milk of celiac mothers following GFD. Further follow-up studies of the health of children who were breastfed by celiac mothers will be necessary in order to also estimate the impact of the present results therein.
Assuntos
Doença Celíaca/imunologia , Leite Humano/imunologia , Adulto , Anticorpos Antibacterianos/análise , Autoanticorpos , Aleitamento Materno , Doença Celíaca/dietoterapia , Doença Celíaca/metabolismo , Citocinas/análise , Dieta Livre de Glúten , Feminino , Gliadina/imunologia , Humanos , Imunoglobulina A/análise , Imunoglobulina M/análise , Leite Humano/química , Muramidase/análise , Toxoide Tetânico/imunologia , Receptor 2 Toll-Like/análiseRESUMO
BACKGROUND: Invasive meningococcal disease is a major cause of meningitis in children. An investigational meningococcal (serogroups A, C, Y, and W) tetanus toxoid conjugate vaccine (MenACYW-TT) could offer protection against invasive meningococcal disease in this population. This phase III study assessed the immunogenicity and safety of MenACYW-TT in children compared with a licensed quadrivalent meningococcal vaccine conjugated with diphtheria protein CRM197 (MenACWY-CRM). METHODS: Healthy children 2-9 years of age in the United States, including Puerto Rico, were randomized (1:1) to receive MenACYW-TT (n = 499) or MenACWY-CRM (n = 501) (NCT03077438). Meningococcal antibody titers to the 4 vaccine serogroups were measured using a serum bactericidal antibody assay with human complement (hSBA) before and at day 30 after vaccination. Noninferiority between the vaccine groups was assessed by comparing seroresponse rates (postvaccination titers ≥1:16 when prevaccination titers were <1:8, or ≥4-fold increase if prevaccination titers were ≥1:8) to the 4 serogroups at day 30. Safety was monitored. RESULTS: The proportion of participants achieving seroresponse at day 30 in the MenACYW-TT group was noninferior to the MenACWY-CRM group (A: 55.4% vs. 47.8%; C: 95.2% vs. 47.8%; W: 78.8% vs. 64.1%; Y: 91.5% vs. 79.3%, respectively). Geometric mean titers for serogroups C, W, and Y were higher with MenACYW-TT than for MenACWY-CRM. Both vaccines were well-tolerated and had similar safety profiles. CONCLUSIONS: MenACYW-TT was well-tolerated in children and achieved noninferior immune responses to MenACWY-CRM against each of the 4 vaccine serogroups.
Assuntos
Imunogenicidade da Vacina , Infecções Meningocócicas/prevenção & controle , Vacinas Meningocócicas/imunologia , Vacinas Combinadas/imunologia , Anticorpos Antibacterianos/sangue , Criança , Pré-Escolar , Método Duplo-Cego , Drogas em Investigação/administração & dosagem , Humanos , Infecções Meningocócicas/imunologia , Vacinas Meningocócicas/administração & dosagem , Neisseria meningitidis/imunologia , Porto Rico , Toxoide Tetânico/administração & dosagem , Toxoide Tetânico/imunologia , Estados Unidos , Vacinação , Vacinas Combinadas/administração & dosagem , Vacinas Conjugadas/administração & dosagem , Vacinas Conjugadas/imunologiaRESUMO
PROBLEM: Pregnancy appears to favor maternal antibody production. In contrast, by damaging follicular helper T cells (TFH ), HIV-1 infection compromises protective humoural immune response. Therefore, we aimed to investigate the frequency of different TFH -like cells in HIV-infected pregnant women (PW) before and after antiretroviral (ARV) therapy. METHOD OF STUDY: Peripheral blood mononuclear cells, CD4+ T and B cells, were obtained from asymptomatic HIV-1-infected non-PW and PW just before and after ARV therapy. In some experiments, healthy HIV-1-negative PW were also tested. The frequency of different TFH -like cell subsets was determined by flow cytometry. The plasma titers of IgG anti-tetanus toxoid (TT), anti-HBsAg, and anti-gp41 were determined by ELISA. The in vitro production of total IgG, IL-21, and hormones (estrogen and progesterone) was quantified also by ELISA. RESULTS: Our results demonstrate that antiretroviral (ARV) therapy was more efficient in elevating the percentage of circulating IL-21-secreting TFH cells in HIV-1-infected pregnant women (PW) than in non-pregnant patients (nPW). Moreover, in co-culture systems, CD4+ T cells from ART-treated PW were more efficient in assisting B cells to produce IgG production. The in vivo anti-HBsAg IgG titers after ARV therapy were also significantly higher in PW, and their levels were directly associated with both IL-21+ TFH frequency and plasma concentration of estrogen. CONCLUSION: In summary, our results suggest that pregnancy favors the recovery of TFH -like cells after ARV therapy in HIV-1-infected women, which could help these mothers to protect their newborns from infectious diseases by transferring IgG across the placenta.
Assuntos
Fármacos Anti-HIV/farmacologia , Infecções por HIV/imunologia , HIV-1 , Interleucinas/metabolismo , Complicações Infecciosas na Gravidez/imunologia , Células T Auxiliares Foliculares/metabolismo , Adulto , Fármacos Anti-HIV/uso terapêutico , Anticorpos Antibacterianos/sangue , Formação de Anticorpos/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Contagem de Linfócito CD4 , Células Cultivadas , Técnicas de Cocultura , Estrogênios/sangue , Feminino , Anticorpos Anti-HIV/sangue , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , HIV-1/imunologia , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Humanos , Imunoglobulina G/sangue , Gravidez , Complicações Infecciosas na Gravidez/sangue , Progesterona/sangue , Toxoide Tetânico/imunologia , Adulto JovemRESUMO
Submicroscopic Plasmodium infections in pregnancy are common in endemic areas, and it is important to understand the impact of these low-level infections. Asymptomatic, chronic infections are advantageous for parasite persistence, particularly in areas where the optimal eco-epidemiological conditions for parasite transmission fluctuate. In chronic infections, the persistence of the antigenic stimulus changes the expression of immune mediators and promotes constant immune regulation, including increases in regulatory T cell populations. These alterations of the immune system could compromise the response to routine vaccination. This study aimed to evaluate the effect of submicroscopic plasmodial infection with P. falciparum and P. vivax during pregnancy on the immune response to the tetanus toxoid vaccine in Colombian women. Expression of different cytokines and mediators of immune regulation and levels of anti-tetanus toxoid (TT) immunoglobulin (Ig)G were quantified in pregnant women with and without submicroscopic plasmodial infection. The anti-TT IgG levels were significantly lower in the infected group compared with the uninfected group. The expression of interferon (IFN)-γ, tumour necrosis factor (TNF) and forkhead box protein 3 (FoxP3) was significantly higher in the infected group, while the expression of cytotoxic T lymphocyte antigen 4 (CTLA-4) and transforming growth factor (TGF)-ß was lower in the group of infected. In conclusion, submicroscopic Plasmodium infection altered the development of the immune response to the TT vaccine in Colombian pregnant women. The impact of Plasmodium infections on the immune regulatory pathways warrants further exploration.
Assuntos
Anticorpos Antibacterianos/sangue , Malária/imunologia , Plasmodium falciparum/fisiologia , Plasmodium vivax/fisiologia , Complicações Infecciosas na Gravidez/imunologia , Linfócitos T Reguladores/imunologia , Toxoide Tetânico/imunologia , Adolescente , Adulto , Doença Crônica , Colômbia , Citocinas/metabolismo , Feminino , Humanos , Imunidade Heteróloga , Gravidez , Vacinação , Adulto JovemRESUMO
BACKGROUND: Pertussis cases have increased worldwide and knowledge on immune response and cytokine profile after Tdap vaccine in immunodeficient adolescents is scarce. OBJECTIVE: To evaluate the immune response after Tdap in HIV-infected (HIV) and in healthy adolescents (CONTROL). METHODOLOGY: Thirty HIV adolescents with CD4 cell countsâ¯>200 and 30 CONTROLs were immunized with Tdap, after a prior whole-cell DTP vaccine primary scheme. Blood samples were collected immediately before and after vaccine. Lymphocyte immunophenotyping was performed by flow cytometry; tetanus, diphtheria and pertussis toxin antibodies were assessed by ELISA; whole blood was stimulated with tetanus toxoid and Bordetella pertussis and supernatants were assessed for cytokines by xMAP. RESULTS: Mean age of HIV and CONTROL groups were 17.9 e 17.1â¯years, respectively. Pain at injection site was more intense in CONTROL group. HIV group had similar increase in tetanus antibodies at 28â¯days (geometric mean concentration, GMC, 15.6; 95% CI, 7.52-32.4) than CONTROL group (GMC, 23.1; 95% CI, 15.0-35.5), but lower diphtheria antibodies at 28â¯days (GMC, 2.3; 95% CI, 0.88-6.19) than CONTROL group (GMC, 16.4; 95% CI, 10.3-26.2); for pertussis, the percentage of individuals who seroconverted was lower in HIV than CONTROL group (HIV, 62.1% versus CONTROL, 100%; pâ¯=â¯.002). Both groups built a cellular immune response to tetanus, with a Th2 (IL-4, IL-5 and IL-13) and Th1 (IFN-γ) response, with lower cytokine levels in HIV than in CONTROL group. Especially for pertussis, cellular and humoral responses were less intense in HIV adolescents, with a lower Th1 and Th17 profile and higher IL-10 levels. HIV-infected adolescents on viral suppression showed an enhanced immune response to all the three vaccine antigens, although still at lower levels if compared to CONTROL group. CONCLUSIONS: Both groups tolerated well and built an immune response after Tdap. However, HIV-infected adolescents would probably benefit from more frequent booster doses.
Assuntos
Anticorpos Antibacterianos/sangue , Vacina contra Difteria e Tétano/uso terapêutico , Vacinas contra Difteria, Tétano e Coqueluche Acelular/uso terapêutico , Infecções por HIV/imunologia , Imunização Secundária , Adolescente , Antígenos de Bactérias/imunologia , Criança , Citocinas/imunologia , Difteria/prevenção & controle , Feminino , Humanos , Imunidade Celular , Imunidade Humoral , Transmissão Vertical de Doenças Infecciosas , Masculino , Linfócitos T Auxiliares-Indutores/imunologia , Tétano/prevenção & controle , Toxoide Tetânico/imunologia , Coqueluche/prevenção & controle , Adulto JovemRESUMO
Ultraviolet radiation (UVr) promotes several well-known molecular changes, which may ultimately impact on health. Some of these effects are detrimental, like inflammation, carcinogenesis and immunosuppression. On the other hand, UVr also promotes vitamin D synthesis and other beneficial effects. We recently demonstrated that exposure to very low doses of UVr on four consecutive days [repetitive low UVd (rlUVd)] does not promote an inflammatory state, nor the recruitment of neutrophils or lymphocytes, as the exposure to a single high UV dose (shUVd) does. Moreover, rlUVd reinforce the epithelium by increasing antimicrobial peptides transcription and epidermal thickness. The aim of this study was to evaluate the adaptive immune response after shUVd and rlUVd, determining T-cell and B-cell responses. Finally, we challenged animals exposed to both irradiation procedures with Staphylococcus aureus to study the overall effects of both innate and adaptive immunity during a cutaneous infection. We observed, as expected, a marked suppression of T-cell and B-cell responses after exposure to an shUVd but a novel and significant increase in both specific responses after exposure to rlUVd. However, the control of the cutaneous S. aureus infection was defective in this last group, suggesting that responses against pathogens cannot be ruled out from isolated stimuli.
Assuntos
Imunidade Adaptativa/efeitos da radiação , Exposição à Radiação , Raios Ultravioleta , Animais , Formação de Anticorpos/imunologia , Formação de Anticorpos/efeitos da radiação , Linfócitos B/imunologia , Linfócitos B/metabolismo , Linfócitos B/efeitos da radiação , Biomarcadores , Citocinas/metabolismo , Dermatite/imunologia , Dermatite/metabolismo , Dermatite/microbiologia , Dermatite/prevenção & controle , Modelos Animais de Doenças , Imunização , Imunofenotipagem , Masculino , Camundongos , Doses de Radiação , Infecções Cutâneas Estafilocócicas/imunologia , Infecções Cutâneas Estafilocócicas/microbiologia , Infecções Cutâneas Estafilocócicas/prevenção & controle , Staphylococcus aureus/imunologia , Staphylococcus aureus/efeitos da radiação , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/efeitos da radiação , Toxoide Tetânico/administração & dosagem , Toxoide Tetânico/imunologiaRESUMO
This study investigated phenotypic and functional characteristics of lymphocytes in children with common variable immunodeficiency (CVID) and unclassified hypogammaglobulinemia (UH), as well as B-cell subsets in non-consanguineous parents. Blood samples of 30 children, CVID (n = 9), UH (n = 9), healthy donors HD (n = 12), and 19 adults (parents and controls) were labeled by a combination of surface markers to identify CD4, CD8 T-cell and B-cell subpopulations. T-cell cytokine production in children was analyzed in vitro after stimulation with phytohemagglutinin (PHA) and tetanus toxoid. We observed low percentages of switched memory B cells in children with CVID, increase in total CD4+ T-cell counts, and high percentages of transitional B cells only in UH group. Analysis of T-cell immunity showed that CVID children had decreased percentages of CD8+ IFN-γ-producing cells after stimulation with PHA and tetanus toxoid. Parent of children with CVID had low percentages of naive B cell and increased percentages of memory B cells in comparison with controls. These results suggest that (i) early combined immune defect in children with CVID and (ii) a possible familial B-cell disturbance in pediatric CVID.