Isolation of a foodborne Bacillus cereus strain and its effect on intestinal mucosal immunity-associated factors and gut microbial community in mice / 生物工程学报

Bacillus cereus is a common foodborne pathogen. Accidently eating food contaminated by B. cereus will cause vomiting or diarrhea, and even death in severe cases. In the present study, a B. cereus strain was isolated from spoiled rice by streak culture. The pathogenicity and drug resistance of the isolated strain were analyzed by drug sensitivity test and PCR amplification of virulence-associated gene respectively. Cultures of the purified strain were injected intraperitoneally into mice to examine their effects on intestinal immunity-associated factors and gut microbial communities, to provide references for the pathogenic mechanism and medication guidance of these spoilage microorganisms. The results showed that the isolated B. cereus strain was sensitive to norfloxacin, nitrofurantoin, tetracycline, minocycline, ciprofloxacin, spectinomycin, clindamycin, erythrocin, clarithromycin, chloramphenicol, levofloxacin, and vancomycin, but resistant to bactrim, oxacillin and penicillin G. The strain carries seven virulence-associated genes including hblA, hblC, hblD, nheA, nheB, nheC and entFM, which are involved in diarrhea-causing toxins production. After infecting mice, the isolated B. cereus strain was found to cause diarrhea in mice, and the expression levels of immunoglobulins and inflammatory factors in the intestinal mucosae of the challenged mice were significantly up-regulated. Gut microbiome analysis showed that the composition of gut microbial community in mice changed after infection with B. cereus. The abundance of the uncultured_bacterium_f_Muribaculaceae in Bacteroidetes, which is a marker of body health, was significantly decreased. On the other hand, the abundance of uncultured_bacterium_f_Enterobacteriaceae, which is an opportunistic pathogen in Proteobacteria and a marker of dysbacteriosis, was significantly increased and was significantly positively correlated with the concentrations of IgM and IgG. These results showed that the pathogenic B. cereus carrying diarrhea type virulence-associated gene can activate the immune system by altering the composition of gut microbiota upon infection.

Mucosal-associated invariant T cells and oral microbiome in persistent apical periodontitis / 国际口腔科学杂志·英文版

Opportunistic bacteria in apical periodontitis (AP) may pose a risk for systemic dissemination. Mucosal-associated invariant T (MAIT) cells are innate-like T cells with a broad and potent antimicrobial activity important for gut mucosal integrity. It was recently shown that MAIT cells are present in the oral mucosal tissue, but the involvement of MAIT cells in AP is unknown. Here, comparison of surgically resected AP and gingival tissues demonstrated that AP tissues express significantly higher levels of Vα7.2-Jα33, Vα7.2-Jα20, Vα7.2-Jα12, Cα and tumour necrosis factor (TNF), interferon (IFN)-γ and interleukin (IL)-17A transcripts, resembling a MAIT cell signature. Moreover, in AP tissues the MR1-restricted MAIT cells positive for MR1-5-OP-RU tetramer staining appeared to be of similar levels as in peripheral blood but consisted mainly of CD4 subset. Unlike gingival tissues, the AP microbiome was quantitatively impacted by factors like fistula and high patient age and had a prominent riboflavin-expressing bacterial feature. When merged in an integrated view, the examined immune and microbiome data in the sparse partial least squares discriminant analysis could identify bacterial relative abundances that negatively correlated with Vα7.2-Jα33, Cα, and IL-17A transcript expressions in AP, implying that MAIT cells could play a role in the local defence at the oral tissue barrier. In conclusion, we describe the presence of MAIT cells at the oral site where translocation of oral microbiota could take place. These findings have implications for understanding the immune sensing of polymicrobial-related oral diseases.

Microfold cells-targeting antigen delivery: a promising strategy to enhance the efficacy of mucosal vaccines / 生物工程学报

The mucosae represent the first line of defense against the invasion of most pathogens, and the mucosal immune system plays a crucial role in the control of infection. Mucosal vaccination can trigger both humoral and cell-mediated immune responses mucosally as well as systemically. Hence, protective immune responses can be elicited effectively by mucosal vaccination. Microfold (M) cells being unique to the mucosal immune system can take up luminal antigens and initiating antigen-specific immune responses. The number of antigen uptake by M cells is directly related to the immune efficacy of mucosal vaccines. Utilizing M cell ligands, M cells-targeting antigen delivery can achieve highly effective mucosal immune responses. The strategy of targeted delivery of antigens to M cells and its applications can be used for the improvement of mucosal immune responses and the development of mucosal vaccines. Despite these efforts, successful development of safe and effective mucosal vaccines remains a big challenge and needs a long way to go, and provably still resort to further researches on cellular properties and functions as well as mucosal immune mechanisms.

Age distribution characteristics of intestinal segmented filamentous bacteria and their relationship with intestinal mucosal immunity in children / 中国当代儿科杂志

OBJECTIVE@#To investigate the age distribution characteristics of intestinal segmented filamentous bacteria (SFB) in children and their relationship with intestinal mucosal immunity.@*METHODS@#The fresh feces of 177 children and the ileocecal fluid of 47 children during colonoscopy were collected. The SFB was determined by real-time PCR. The concentration of secretory immunoglobulin A (sIgA) was determined by enzyme-linked immunosorbent assay. The numbers of interleukin 17A (IL-17A) cells and intraepithelial lymphocytes in the terminal ileum mucosa and the expression of transcription factors associated with the differentiation of T helper (Th) cells, T-box transcription factor (T-bet), forkhead box P3 (FOXP3), and retinoid-related orphan receptor gamma t (ROR-γt), were determined by immunohistochemistry.@*RESULTS@#The positive rate of intestinal SFB in these children was 19.2% (34/177). Trend analysis showed that the positive rate of SFB was correlated with age: the rates for children aged 0-, 1-, 2-, 3-, 4-, 5-, 6-, and 7-15 years were 40%, 47%, 32%, 15%, 12%, 13%, 15% and 4% respectively (P<0.001). The concentration of sIgA in intestinal fluid was significantly higher in SFB-positive children (n=24) than in SFB-negative children (n=23) (P<0.01). The number of intraepithelial lymphocytes in the terminal ileum mucosa and the expression of T-bet, FOXP3, and ROR-γt were not significantly different between the SFB-positive group (n=12) and the SFB-negative group (n=11), but the number of IL-17A cells in the terminal ileum mucosa was significantly lower in the SFB-positive group than in the SFB-negative group (P<0.05).@*CONCLUSIONS@#Intestinal SFB colonization in children is age-related, and the colonization rate is relatively high in children under 3 years old. In SFB-positive children, the secretion of intestinal sIgA is increased, while the number of IL-17A cells in the terminal ileum is reduced.

Expressão diferencial de biomarcadores imunológicos de infecção subclínica em casos multibacilares de hanseníase e seus contatos domiciliares / Differential expression of immunological biomarkers of subclinical infection in multibacillary leprosy cases and their home contacts

A hanseníase é uma doença infectocontagiosa, causada pelo bacilo Mycobacterium leprae, com sintomatologia dermatoneurológica. Várias estratégias têm sido adotadas para o controle da hanseníase, porém o diagnóstico da hanseníase é essencialmente clínico. O desafio atual é identificar biomarcadores que possibilitem a identificação de parâmetros imunológicos de infecção subclínica e, em última análise, o diagnóstico precoce da hanseníase em indivíduos infectados e assintomáticos, para realização de imunoprofilaxia de forma oportuna quebrando, assim, a cadeia de transmissão do bacilo. Aprofundar nas diferenças entre casos índice multibacilares e seus contatos domiciliares foi a estratégia deste estudo, através da avaliação conjunta de parâmetros imunológicos gerais e específicos. Objetivo: o objetivo deste trabalho foi avaliar o perfil da resposta imune inata e adaptativa de casos multibacilares de hanseníase e seus contatos domiciliares para a identificação de parâmetros imunológicos de infecção subclínica. Metodologia: Para mensurar a expressão de moléculas de superfície foi realizada imunofenotipagem por citometria de fluxo. Para dosar os níveis de citocinas e quimiocinas séricas as foi utilizada a técnica de Cytometric Bead Array (CBA). Os níveis de IgM anti PGL-1 de foram mensurados pela técnica de ELISA. Resultados: Os níveis de IgM/IgG anti PGL-1, de linfócitos ativados T CD4+ e CD8+ e a frequência de monócitos circulantes estavam mais elevados em casos índice em relação aos seus contatos. A frequência de linfócitos T estava menor em casos índice MB. A distância imunológica entre casos e contatos domiciliares não foi significativa quando se avaliou em conjunto todos os parâmetros imunológicos. Conclusão: Nós inferimos, a partir dos parâmetros diferencialmente expressos em casos índice MB e contatos domiciliares, que a elevação da resposta humoral específica, o maior nível de ativação de linfócitos (com provável proliferação e diferenciação em células T efetoras e/ou de memória), a maior frequência de monócitos em trânsito no sangue periférico, podem ser opções de biomarcadores preditores de infecção subclínica em contatos domiciliares.(AU)

Leprosy is an infectious disease caused by the bacillus Mycobacterium leprae, with dermatoneurological symptoms. Several strategies have been adopted for leprosy control, but the diagnosis of leprosy is essentially clinical. The current challenge is to identify biomarkers that enable the identification of immunological parameters of subclinical infection and, ultimately, the early diagnosis of leprosy in infected and asymptomatic individuals, to perform immunoprophylaxis in a timely manner, thus breaking the bacillus transmission chain. Deepening the differences between multibacillary index cases and their household contacts was the strategy of this study, through the joint evaluation of general and specific immunological parameters. Objective: The aim of this study was to evaluate the profile of the innate and adaptive immune response of multibacillary leprosy cases and their household contacts for the identification of immunological parameters of subclinical infection. Methodology: To measure the expression of surface molecules, immunophenotyping was performed by flow cytometry. To measure serum cytokine and chemokine levels, the Cytometric Bead Array (CBA) technique was used. Anti-PGL-1 IgM/IgG levels were measured by ELISA. Results: Anti-PGL-1 IgM/IgG levels, CD4 + and CD8 + activated T lymphocytes and the frequency of circulating monocytes were higher in index cases compared to their contacts. The frequency of T lymphocytes was lower in MB index cases. The immunological distance between cases and home contacts was not significant when all immunological parameters were evaluated together. Conclusion: We infer from the differentially expressed parameters in MB index cases and household contacts that the elevation of specific humoral response, the highest level of lymphocyte activation (with probable proliferation and differentiation in effector and / or memory T cells), the higher frequency of peripheral blood transit monocytes, may be predictive biomarker options for subclinical infection in household contacts.

Etiopatogenia de la hemorragia digestiva alta no variceal, respuesta inflamatoria y Helicobacterpylori / Etiopathogeny of the non-variceal high digestive hemorrhage, inflammatory answer and Helicobacter pylori

RESUMEN La infección por la bacteria Helicobacter pylori ocurre a nivel mundial, aunque es más frecuente en países en vías de desarrollo y en comunidades en condiciones socioeconómicas pobres, donde existe hacinamiento o migración de regiones de prevalencia alta. La infección ocurre principalmente durante la infancia y se incrementa con la edad. Se realizó una revisión exhaustiva donde se explican de manera explícita los mecanismos que desencadenan la respuesta inflamatoria una vez que la bacteria coloniza el estómago, que incluye dos etapas: la primera caracterizada por la llegada y penetración del microorganismo al moco gástrico, donde se asienta y se multiplica y la segunda etapa caracterizada por una amplificación de esta respuesta inflamatoria. El conocimiento de estos mecanismos etiopatogénicos no sólo ayuda a la erradicación de la bacteria, sino que contribuye a la regulación del sistema neuroinmune antes, durante y después del daño tisular, para lograr una regeneración tisular adecuada, mejorar la capacidad funcional del órgano sangrante e impedir la evolución tórpida de la enfermedad (AU).

ABSTRACT The infection by Helicobacter pylori occurs worldwide, although it is more frequent in developing countries and in communities with poor socioeconomic conditions, where there is overcrowding or migration from regions of high prevalence. The infection occurs mainly during the childhood and increases with age. An exhaustive review was carried out where the mechanisms unchaining the inflammatory answer after the bacteria colonizes the stomach are explained in an explicit way. It has two stages: the first one is characterized by the microorganism arrival and penetration to the gastric mucus, where it settles and multiplies, and the second stage characterized by an amplification of the inflammatory answer. The knowledge of these etiopathogenic mechanisms does not only help the eradication of the bacteria but also contributes to the regulation of the neuroimmune system before, during and after tissue damage, for reaching an adequate tissue regeneration, improving the functional capacity of the bleeding organ, and preventing the disease torpid evolution (AU).

Salivary levels of SIgA and perceived stress among dental students / Imunoglobulina A salivar e fatores de estresse em estudantes de odontologia

Background: Academic stress may impair mucosal immunity and expose dental students to an increased risk of infections. Objective: to assess stress scores in dental students and their relationship with variation in SIgA levels. Methods: All students (n = 289) were invited to take part of the study, and 207 (71.63%) effectively participated, being 152 (73.4%) females. At the day of data collection, the students answered The Dental Environmental Stress Questionnaire (DES) and unstimulated saliva samples were collected for determination of salivary flow rate and SIgA concentration and secretion rate. Results: Mean DES scores were higher in females (78.97 ± 16.42), but no correlations between the sum of DES scores and salivary parameters were observed (P=0.08). A moderate inverse relationship was observed between SIgA secretion rates and the subscales Academic Performance (P=0.01), Interpersonal relationships (P=0.02) and Difficulties and Insecurities about Professional Future (P=0.05). A weak correlation was found between SIgA concentration and the items Amount of assigned classwork (P=0.02), Lack of confidence in self to be a successful dentist (P=0.01), Lack of time for relaxation (P=0.01), Financial responsibilities (P=0.02) and Personal physical health (P=0.005). Weak correlations between SIgA secretion rates and DES items were also found for Lack of cooperation by patient in their home care (P=0.003), Patients being late or not showing up for their appointments (P=0.02), Lack of self confidence to be a successful dentist (P=0.008), Personal physical health (P=0.019), and others. Conclusion: Different sources of stress were observed among first to fifth year students and some of these stressors may negatively impact on salivary SIgA secretion. (AU)

Introdução: o estresse acadêmico pode prejudicar a imunidade das mucosas e expor os estudantes de odontologia a um maior risco de infecções. Este estudo teve como objetivo avaliar os fatores de estresse em estudantes de odontologia e sua relação com a variação nos níveis de SIgA. Metodologia: Todos os alunos (n = 289) foram convidados a fazer parte do estudo, dos quais 207 (71,63%) participaram efetivamente, sendo 152 (73,4%) do sexo feminino. No dia da coleta de dados, os alunos responderam ao Questionário de Estresse no Ambiente Odontológico (DES) e foram coletadas amostras de saliva não estimuladas para determinação da taxa de fluxo salivar, da concentração de SIgA e da taxa de secreção. Resultados: os escores do DES foram maiores no gênero feminino (78,97 ± 16,42), mas não foram observadas correlações entre a soma dos escores DES e os parâmetros salivares (P = 0,08). Observou-se uma relação inversa moderada entre as taxas de secreção de SIgA e as subescalas Desempenho Acadêmico (P = 0,01), Relações Interpessoais (P = 0,02) e Insegurança em relação ao futuro profissional (P = 0,05). Uma correlação fraca foi encontrada entre a concentração de SIgA e os itens quantidade de trabalho exigido em sala de aula (P = 0,02), falta de autoconfiança para ser um dentista de sucesso (P = 0,01), falta de tempo para relaxar ou para lazer (P = 0,01), responsabilidades financeiras (P = 0,02) e saúde física pessoal (P = 0,005). Também foram encontradas correlações fracas entre as taxas de secreção de SIgA e os itens DES para falta de cooperação por parte do paciente em seus cuidados (P = 0,003), Atraso ou falta de pacientes nas consultas (P = 0,02), falta de autoconfiança para ser um dentista bem sucedido (P = 0,008), saúde física pessoal (P = 0,019) e outros. Conclusão: diferentes fontes de estresse foram observadas entre os estudantes do primeiro ao quinto ano e alguns desses fatores podem afetar negativamente a secreção de SIgA. (AU)

Gut microbiota and its implications in small bowel transplantation / 医学前沿

The gut microbiota is mainly composed of a diverse population of commensal bacterial species and plays a pivotal role in the maintenance of intestinal homeostasis, immune modulation and metabolism. The influence of the gut microbiota on solid organ transplantation has recently been recognized. In fact, several studies indicated that acute and chronic allograft rejection in small bowel transplantation (SBT) is closely associated with the alterations in microbial patterns in the gut. In this review, we focused on the recent findings regarding alterations in the microbiota following SBTand the potential roles of these alterations in the development of acute and chronic allograft rejection. We also reviewed important advances with respect to the interplays between the microbiota and host immune systems in SBT. Furthermore, we explored the potential of the gut microbiota as a microbial marker and/or therapeutic target for the predication and intervention of allograft rejection and chronic dysfunction. Given that current research on the gut microbiota has become increasingly sophisticated and comprehensive, large cohort studies employing metagenomic analysis and multivariate linkage should be designed for the characterization of host-microbe interaction and causality between microbiota alterations and clinical outcomes in SBT. The findings are expected to provide valuable insights into the role of gut microbiota in the development of allograft rejection and other transplant-related complications and introduce novel therapeutic targets and treatment approaches in clinical practice.

Mucosal Immunity Related to FOXP3⁺ Regulatory T Cells, Th17 Cells and Cytokines in Pediatric Inflammatory Bowel Disease

BACKGROUND: We aimed to investigate mucosal immunity related to forkhead box P3 (FOXP3+) regulatory T (Treg) cells, T helper 17 (Th17) cells and cytokines in pediatric inflammatory bowel disease (IBD). METHODS: Mucosal tissues from terminal ileum and colon and serum samples were collected from twelve children with IBD and seven control children. Immunohistochemical staining was done using anti-human FOXP3 and anti-RORγt antibodies. Serum levels of cytokines were analyzed using a multiplex assay covering interleukin (IL)-1β, IL-4, IL-6, IL-10, IL-17A/F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, interferon (IFN)-γ, soluble CD40L, and tumor necrosis factor-α. RESULTS: FOXP3+ Treg cells in the lamina propria (LP) of terminal ileum of patients with Crohn's disease were significantly (P < 0.05) higher than those in the healthy controls. RORγt+ T cells of terminal ileum tended to be higher in Crohn's disease than those in the control. In the multiplex assay, serum concentrations (pg/mL) of IL-4 (9.6 ± 1.5 vs. 12.7 ± 3.0), IL-21 (14.9 ± 1.5 vs. 26.4 ± 9.1), IL-33 (14.3 ± 0.9 vs. 19.1 ± 5.3), and IFN-γ (15.2 ± 5.9 vs. 50.2 ± 42.4) were significantly lower in Crohn's disease than those in the control group. However, serum concentration of IL-6 (119.1 ± 79.6 vs. 52.9 ± 39.1) was higher in Crohn's disease than that in the control. Serum concentrations of IL-17A (64.2 ± 17.2 vs. 28.3 ± 10.0) and IL-22 (37.5 ± 8.8 vs. 27.2 ± 3.7) were significantly higher in ulcerative colitis than those in Crohn's disease. CONCLUSION: Mucosal immunity analysis showed increased FOXP3+ T reg cells in the LP with Crohn's disease while Th17 cell polarizing and signature cytokines were decreased in the serum samples of Crohn's disease but increased in ulcerative colitis.

N-terminal Domain of the Spike Protein of Porcine Epidemic Diarrhea Virus as a New Candidate Molecule for a Mucosal Vaccine

Porcine epidemic diarrhea virus (PEDV) is a contagious coronavirus infecting pigs that leads to significant economic losses in the swine industry. Given that PEDV infection occurs in gut epithelial cells mainly via the fecal-oral route, induction of PEDV-specific immune responses in the mucosal compartment is required for protective immunity against viral infection. However, an effective mucosal vaccine against the currently prevalent PEDV strain is not available. In this study, we demonstrated that the N-terminal domain (NTD) of the spike (S) protein of PEDV represents a new vaccine candidate molecule to be applied via the mucosal route. We first established an Escherichia coli expression system producing the partial NTD (NTD231–501) of the PEDV S protein. Orally administered NTD231–501 protein specifically interacted with the apical area of M cells in the follicle-associated epithelium of Peyer's patch. Additionally, the NTD protein induced antigen-specific immune responses in both the systemic and mucosal immune compartments when administered orally. Collectively, we propose the NTD of the PEDV S protein to be a candidate mucosal vaccine molecule.

Porphyromonas gingivalis, patógeno de relevancia en la enfermedad periodontal / Porphyromonas gingivalis, pathogen of interest in periodontal disease

Porphyromonas gingivalis (P.Gingivalis) es un microorganismo comprometido en el inicio y progresión de la enfermedad periodontal crónica y agresiva, y es considerado su principal agente etiológico. Esta bacteria cuenta con una serie de factores de virulencia que le permiten, iniciar el proceso infeccioso, perpetuar la infección y también transformar la placa dental benigna en una comunidad microbiana patógena. Estudiar sus factores de virulencia y su capacidad de modular la respuesta inmunológica del huésped es muy importante para comprender el papel de este patógeno en el desarrollo y establecimiento de la enfermedad. Esta revisión proporciona una visiónactual sobre los factores de virulencia y su impacto sobre la respuesta inmunológica en relación con la patogénesis de la enfermedad periodontal.

Serosal Cavities Contain Two Populations of Innate-like integrin α4highCD4+ T Cells, Integrin α4β1+α6β1+α4β7− and α4β1+α6β1−α4β7+ Cells

We previously reported peritoneal innate-like integrin α4 (CD49d)highCD4+ T cells that provided help for B-1a cells. Here we analyzed the expression of various integrin chains on the peritoneal and pleural integrin α4highCD4+ T cells and investigated the functional heterogeneity of the subpopulations based on the integrin expression. Pleural cavity contained a lower ratio of integrin α4highCD4+ T cells to integrin α4lowCD4+ T cells than peritoneal cavity, but the pleural integrin α4highCD4+ T cells have the same characteristics of the peritoneal integrin α4highCD4+ T cells. Most of integrin α4highCD4+ T cells were integrin β1highβ7−, but a minor population of integrin α4highCD4+ T cells was integrin β1+β7+. Interestingly, the integrin α4highβ1highβ7− CD4+ T cells expressed high levels of integrin α4β1 and α6β1, whereas integrin α4highβ1+β7+ CD4+ T cells expressed high levels of integrin α4β1 and α4β7, suggesting an alternative expression of integrin α6β1 or α4β7 in combination with α4β1 in respective major and minor populations of integrin α4highCD4+ T cells. The minor population, integrin α4highβ1+β7+ CD4+ T cells, were different from the integrin α4highβ1highβ7− CD4+ T cells in that they secreted a smaller amount of Th1 cytokines upon stimulation and expressed lower levels of Th1-related chemokine receptors CCR5 and CXCR3 than the integrin α4highβ1 highβ7− CD4+ T cells. In summary, the innate-like integrin α4highCD4+ T cells could be divided into 2 populations, integrin α4β1+α6β1+α4β7− and α4β1+α6β1−α4β7+ cells. The functional significance of serosal integrin α4β7+ CD4+ T cells needed to be investigated especially in view of mucosal immunity.

The development of mucosal vaccines for both mucosal and systemic immune induction and the roles played by adjuvants

Vaccination is the most successful immunological practice that improves the quality of human life and health. Vaccine materials include antigens of pathogens and adjuvants potentiating the effectiveness of vaccination. Vaccines are categorized using various criteria, including the vaccination material used and the method of administration. Traditionally, vaccines have been injected via needles. However, given that most pathogens first infect mucosal surfaces, there is increasing interest in the establishment of protective mucosal immunity, achieved by vaccination via mucosal routes. This review summarizes recent developments in mucosal vaccines and their associated adjuvants.

Narrow-band imaging with magnifying endoscopy for Peyer's patches is useful in predicting the recurrence of remissive patients with ulcerative colitis

BACKGROUND/AIMS: Peyer's patches (PPs) are aggregates of lymphoid follicles that are mainly located in the distal ileum; they play a major role in mucosal immunity. We recently reported that patients with ulcerative colitis (UC) have alterations in PPs that can be detected using narrow-band imaging with magnifying endoscopy (NBI-ME). However, the usefulness of NBI-ME in UC treatment as a whole is still unknown. METHODS: We collected NBI-ME images of PPs from 67 UC patients who had undergone ileocolonoscopy. We evaluated changes in the villi using the "villi index," which is based on three categories: irregular formation, hyperemia, and altered vascular network pattern. The patients were divided into two groups on the basis of villi index: low (L)- and high (H)-types. We then determined the correlation between morphological alteration of the PPs and various clinical characteristics. In 52 patients who were in clinical remission, we also analyzed the correlation between NBI-ME findings of PPs and clinical recurrence. RESULTS: The time to clinical recurrence was significantly shorter in remissive UC patients with H-type PPs than in those with L-type PPs (P<0.01). Moreover, PP alterations were not correlated with age, sex, disease duration, clinical activity, endoscopic score, or extent of disease involvement. Multivariate analysis revealed that the existence of H-type PPs was an independent risk factor for clinical recurrence (hazard ratio, 3.3; P<0.01). CONCLUSIONS: UC patients with morphological alterations in PPs were at high risk of clinical relapse. Therefore, to predict the clinical course of UC, it may be useful to evaluate NBI-ME images of PPs.

Narrow-band imaging with magnifying endoscopy for Peyer's patches is useful in predicting the recurrence of remissive patients with ulcerative colitis

BACKGROUND/AIMS: Peyer's patches (PPs) are aggregates of lymphoid follicles that are mainly located in the distal ileum; they play a major role in mucosal immunity. We recently reported that patients with ulcerative colitis (UC) have alterations in PPs that can be detected using narrow-band imaging with magnifying endoscopy (NBI-ME). However, the usefulness of NBI-ME in UC treatment as a whole is still unknown. METHODS: We collected NBI-ME images of PPs from 67 UC patients who had undergone ileocolonoscopy. We evaluated changes in the villi using the "villi index," which is based on three categories: irregular formation, hyperemia, and altered vascular network pattern. The patients were divided into two groups on the basis of villi index: low (L)- and high (H)-types. We then determined the correlation between morphological alteration of the PPs and various clinical characteristics. In 52 patients who were in clinical remission, we also analyzed the correlation between NBI-ME findings of PPs and clinical recurrence. RESULTS: The time to clinical recurrence was significantly shorter in remissive UC patients with H-type PPs than in those with L-type PPs (P<0.01). Moreover, PP alterations were not correlated with age, sex, disease duration, clinical activity, endoscopic score, or extent of disease involvement. Multivariate analysis revealed that the existence of H-type PPs was an independent risk factor for clinical recurrence (hazard ratio, 3.3; P<0.01). CONCLUSIONS: UC patients with morphological alterations in PPs were at high risk of clinical relapse. Therefore, to predict the clinical course of UC, it may be useful to evaluate NBI-ME images of PPs.

Effect of visfatin on the structure and immune levels in the small intestine of LPS-induced rats / Efecto de la visfatina sobre la estructura y los niveles de inmunidad en el intestino delgado de ratas inducidas por lipopolisacáridos

This study investigated the effects of visfatin on the structure and the immunity levels in the small intestine of LPS-induced rats. Forty Wistar male and female SPF rats were randomly and equally divided into four groups: the saline (control), vistfatin, lipopolysaccharide (LPS), and visfatin+LPS co-stimulated. The functions of visfatin in the intestinal mucosal immunity were investigated by examining the variation of tissue structure, inflammation and immunity-related proteins in the intestine of immunologically stressed rats using HE staining, ELISA, immunohistochemistry and Western Blot. The results showed that, when compared with the control group, the visfatin-treated group showed a decrease in the intestinal villus height and width, and a significant increase in the levels of IL-6 and TNF-ð as well as Immunoglobulin A (IgA) positive cells. Additionally, when compared with the LPS-treated group, the visfatin+LPS co-stimulated group showed a decrease in the villus height and width as well as the levels of IL-6 and TNF-ð, and an increase in IgA levels, implying a shrinking response to LPS injection. All the results suggest that, under normal physiological conditions, visfatin disturbs the body's homeostasis and causes intestinal villus atrophy by increasing IgA expression. While under immune response conditions, LPS acts as an exogenous antigen to promote visfatin against LPS-induced inflammation by decreasing the expression of IgA. Under immune stress conditions, visfatin as an exogenous stimulus promotes the immune response by regulating the protein levels of IL-6, TNF-ð and IgA.

Este estudio investigó los efectos de la visfatina sobre la estructura y los niveles de inmunidad en el intestino delgado de ratas inducidas por lipopolisacáridos (LPS). Cuarenta ratas Wistar se dividieron aleatoriamente e igualmente en cuatro grupos: solución salina (control), vistafin, LPS y visfatina + LPS co-estimuladas. Las funciones de la visfatina en la inmunidad de la mucosa intestinal se investigaron mediante el examen de variación de la estructura del tejido, la inflamación y las proteínas relacionadas con la inmunidad en el intestino de ratas estresadas inmunológicamente; usando tinción HE, ELISA, inmunohistoquímica y Western Blot. Los resultados mostraron que, en comparación con el grupo control, el grupo tratado con visfatina presentó una disminución en la altura y ancho de las vellosidades intestinales, y un aumento significativo en los niveles de IL-6 y TNF-ð, así como inmunoglobulina A (IgA células positivas). Además, al comparar este grupo con el grupo tratado con LPS- el grupo visfatina + LPS co-estimulado mostró una disminución en la altura y ancho de las vellosidades, así como en los niveles de IL-6 y TNF-ð, y un aumento en los niveles de IgA, lo que implica reducción de una respuesta a la inyección LPS. Todos los resultados sugieren que, en condiciones fisiológicas normales, la visfatina perturba la homeostasis del cuerpo y provoca la atrofia de las vellosidades intestinales mediante el aumento de la expresión de IgA. Mientras que bajo condiciones de la respuesta inmune, LPS actúa como un antígeno exógeno para promover visfatina contra la inflamación inducida por LPS por la disminución de la expresión de IgA. En condiciones de estrés inmunológico, la visfatina como estímulo exógeno promueve la respuesta inmune mediante la regulación de los niveles de proteína de IL-6, TNF-ð e IgA.

Avaliação da resposta imunológica da mucosa intestinal de frangos de corte desafiados com diferentes sorovares de Salmonella / Evaluation of immune response of the intestinal mucosa in broilers challenged with different Salmonella serovars

Objetivou-se com o presente estudo comparar o efeito de diferentes sorovares de Salmonella na resposta imune local da mucosa do intestino de frangos de corte. Aos sete dias de idade, as aves foram desafiadas com os sorovares S. Enteritidis, S. Typhimurium, S. Senftenberg, S. Mbandaka e S. Minnesota. Foi observado que todos os sorovares testados foram capazes de colonizar o intestino das aves sendo possível o isolamento de Salmonella em suabes de cloaca, 48 h após inoculação. De maneira geral, as aves do grupo controle negativo, que não foram desafiados apresentaram quantidade significativamente menor de células imunológicas na mucosa intestinal do que as aves desafiadas. Porém, verificou-se que os sorovares de Salmonella, utilizados neste estudo, apresentaram diferentes efeitos sobre a dinâmica celular da mucosa do íleo e ceco e afetaram de modo diferente o ganho de peso e ganho médio diário das aves demonstrando distintos graus de patogenicidade. Os sorovares Enteritidis e Typhimurium apresentaram um efeito mais intenso tanto no desempenho quanto na mobilização de células imunológicas na mucosa intestinal de frangos de corte.

The study was designed to compare the effect of different Salmonella serovars in immune response across the count of CD8+ cells, CD4+ cells, goblet cells and macrophages in the gut mucosa of broilers. During the experimental inoculation at 7 day-old were used Salmonella enterica subspecies enterica sorovars Enteritidis, Typhimurium, Senftenberg, Mbandaka and Minnesota. It was observed that all serovars tested were capable of contaminating the poultry being possible counts of Salmonella in cloacal swabs, 48 h after inoculation and into the crop and cecum, at 14 and 20 day-old. Serovars tested had different effects on broiler performance assessed at 20 days. In the mucosa of the ileum and cecum of broilers, it was observed that some of the serotypes increased CD8 + cells, CD4 + cells, goblet cells and macrophages compared to the negative control group both at 14 and at 20 day-old. S. Enteritidis and S. Typhimurium are the serovars that showed the more intense effect in live performance and in the immune system of birds showing pathogenic characteristic; generally the broilers of the negative control showed significantly less immune cells on the intestinal mucosa than broilers inoculated experimentally. However, it was found that the Salmonella serovars used in this study had different effects on the cellular dynamics of the mucosa of the ileum and cecum and differently affect weight gain and average daily gain of poultry showing different levels of pathogenicity.

Innate endogenous adjuvants prime to desirable immune responses via mucosal routes

Vaccination is an effective strategy to prevent infectious or immune related diseases, which has made remarkable contribution in human history. Recently increasing attentions have been paid to mucosal vaccination due to its multiple advantages over conventional ways. Subunit or peptide antigens are more reasonable immunogens for mucosal vaccination than live or attenuated pathogens, however adjuvants are required to augment the immune responses. Many mucosal adjuvants have been developed to prime desirable immune responses to different etiologies. Compared with pathogen derived adjuvants, innate endogenous molecules incorporated into mucosal vaccines demonstrate prominent adjuvanticity and safety. Nowadays, cytokines are broadly used as mucosal adjuvants for participation of signal transduction of immune responses, activation of innate immunity and polarization of adaptive immunity. Desired immune responses are promptly and efficaciously primed on basis of specific interactions between cytokines and corresponding receptors. In addition, some other innate molecules are also identified as potent mucosal adjuvants. This review focuses on innate endogenous mucosal adjuvants, hoping to shed light on the development of mucosal vaccines.

Envolvimento do receptor TLR-9 na resposta imune do hospedeiro durante o curso da infecção pelo Mycobacterium leprae / Involvement of the TLR9 receptor in host immune responses during infection by Mycobacterium leprae

Mycobacterium leprae, agente etiológico da hanseníase, expressa em abundância uma proteína catiônica semelhante às histonas, denominada Hlp, presente tanto no envelope como no nucleóide bacteriano. O reconhecimento do DNA bacteriano, rico em motivos CpG não metilados, pelo receptor TLR-9 representa uma importante via para a ativação da resposta imune inata, a qual pode levar à eliminação do agente infeccioso ou mediar manifestações patológicas. Foi mostrado ainda que complexos DNA-histona são mais potentes agonistas de TLR-9 que DNA sozinho. Assim, o presente trabalho teve como objetivo investigar o envolvimento do receptor TLR-9 na ativação da resposta imune do hospedeiro durante o curso da infecção pelo M. leprae.Inicialmente foi analisada a participação do TLR-9 na ativação da resposta imune inata em células epiteliais alveolares da linhagem A549 após estímulo com M. leprae. M. leprae foi capaz de induzir aumento das quimiocinas IL-8 eMCP-1 e a transcrição gênica do peptídeo antimicrobiano HbetaD-2 nas células epiteliais. O aumento da expressão de CD80 na superfície celular também foi observada após estímulo com o bacilo. O complexo CpG-Hlp micobacteriano solúvel também induziu aumento na produção de IL-8 nas células A549. Foi observado que o aumento de IL-8 induzido pelo M. leprae ocorre de forma dependente da translocação nuclear do NF-capaB e que o antagonista sintético deTLR-9 afetou a secreção de IL-8 induzida pelo M. leprae. A adição de CpG aoM. smegmatis selvagem, mas não mutante para o gene hlp, aumentou a produção de IL-8 pelas células epiteliais. Em conjunto, esses dados sugerem que as células epiteliais respiratórias podem reconhecer M. leprae via TLR-9 e,assim, participar da resposta imune inata no sítio inicial da infecção. Uma vez que o aparecimento do eritema nodoso hansênico (ENH) está associado a liberação massiva de antígenos micobacterianos, foi investigado o envolvimento do TLR-9 na patogênese do ENH...

Mycobacterium leprae, etiological agent of leprosy, expresses in abundance acationic protein similar to histones, called histone-like protein (Hlp), present inthe envelope as well as in bacterial nucleoid.The recognition of bacterial DNArich in unmethylated CpG motifs by TLR-9 is an important pathway for activationof the innate immune response, which can lead to the elimination of theinfectious agent or mediate pathological manifestations. Moreover, studiesshowed that DNA-histone complexes are more potent agonists of TLR-9 thanDNA alone. This study aimed to investigate the involvement of TLR-9 in theactivation of the host immune response during the course of M. leprae infection.Initially, we analyzed the participation of TLR-9 activation on the innate immuneresponse in A549 alveolar epithelial cells after stimulation with M. leprae. It wasshown that M. leprae was able to induce the chemokines IL-8 and MCP-1, andgene transcription of antimicrobial peptide HbetaD-2 in epithelial cells. Theincrease of CD80 expression on the cell surface was also observed afterstimulation with bacillus. Soluble mycobacterial CpG-Hlp complex also inducedan increase in IL-8 in A549 cells. It was observed that the increase of IL-8,induced by M. leprae, occurs dependently nuclear translocation of NF-capaB andsynthetic TLR-9 antagonist affected IL-8 secretion induced by M. leprae. Theaddition of CpG to wild type M. smegmatis, but not to the mutant gene hlp,increased IL-8 production by epithelial cells. As a whole, these results suggestthat respiratory epithelial cells can recognize M. leprae via TLR-9 and thusparticipate in the innate immune response in the initial infection site. Since theappearance of erythema nodosum leprosum (ENL) is associated with themassive release of mycobacterial antigens, it was investigated the involvementof TLR-9 in the pathogenesis of ENL...

A Molecular Mucosal Adjuvant To Enhance Immunity Against Pneumococcal Infection In The Elderly

Streptococcus pneumoniae (the pneumococcus) causes a major upper respiratory tract infection often leading to severe illness and death in the elderly. Thus, it is important to induce safe and effective mucosal immunity against this pathogen in order to prevent pnuemocaccal infection. However, this is a very difficult task to elicit protective mucosal IgA antibody responses in older individuals. A combind nasal adjuvant consisting of a plasmid encoding the Flt3 ligand cDNA (pFL) and CpG oligonucleotide (CpG ODN) successfully enhanced S. pneumoniae-specific mucosal immunity in aged mice. In particular, a pneumococcal surface protein A-based nasal vaccine given with pFL and CpG ODN induced complete protection from S. pneumoniae infection. These results show that nasal delivery of a combined DNA adjuvant offers an attractive potential for protection against the pneumococcus in the elderly.