Augmentation of anti-influenza virus hemagglutinin antibody production by Peyer's patch cells with Bifidobacterium breve YIT4064

Immunomodulatory effects of probiotic Lactobacillus casei on GM-CSF-adjuvanted influenza DNA vaccine

Aim: This study investigates the protective efficacy of influenza DNA vaccine combined with a granulocyte macrophage-colony stimulating factor (GM-CSF) adjuvant, and probiotic Lactobacillus casei, an oral immunomodulator, in a BALB/c mice. Materials & methods: The mice were immunized with HA1 DNA vaccine along with GM-CSF and probiotic twice within a one-week interval. Results: The results showed that both adjuvants exert a synergistic effect in enhancing the humoral and cellular immune responses of the DNA vaccine. This combination also deceased IL-6 and IL-17A levels in the lung homogenates. The protection patterns were closely associated with influenza virus-specific splenocyte proliferative and serum IgG antibody (Ab) responses. Conclusion: The Findings demonstrate L. casei modulate balanced Th1/Th2 immune responses toward HA1 DNA vaccine adjuvanted by GM-CSF.

Can probiotics enhance vaccine-specific immunity in children and adults?

The growing use of probiotics by the general public has heightened the interest in understanding the role of probiotics in promoting health and preventing disease. General practitioners and specialists often receive inquiries from their patients regarding probiotic products and their use to ward off systemic infection or intestinal maladies. Enhanced immune function is among the touted health benefits conferred by probiotics but has not yet been fully established. Results from recent clinical trials in adults suggest a potential role for probiotics in enhancing vaccine-specific immunity. Although almost all vaccinations are given during infancy and childhood, the numbers of and results from studies using probiotics in pediatric subjects are limited. This review evaluates recent clinical trials of probiotics used to enhance vaccine-specific immune responses in adults and infants. We highlight meaningful results and the implications of these findings for designing translational and clinical studies that will evaluate the potential clinical role for probiotics. We conclude that the touted health claims of probiotics for use in children to augment immunity warrant further investigation. In order to achieve this goal, a consensus should be reached on common study designs that apply similar treatment timelines, compare well-characterised probiotic strains and monitor effective responses against different classes of vaccines.

Modulation of Respiratory TLR3-Anti-Viral Response by Probiotic Microorganisms: Lessons Learned from Lactobacillus rhamnosus CRL1505

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract illness in infants and young children. Host immune response is implicated in both protective and immunopathological mechanisms during RSV infection. Activation of Toll-like receptor (TLR)-3 in innate immune cells by RSV can induce airway inflammation, protective immune response, and pulmonary immunopathology. A clear understanding of RSV–host interaction is important for the development of novel and effective therapeutic strategies. Several studies have centered on whether probiotic microorganisms with the capacity to stimulate the immune system (immunobiotics) might sufficiently stimulate the common mucosal immune system to improve defenses in the respiratory tract. In this regard, it was demonstrated that some orally administered immunobiotics do have the ability to stimulate respiratory immunity and increase resistance to viral infections. Moreover, during the last decade scientists have significantly advanced in the knowledge of the cellular and molecular mechanisms involved in the protective effect of immunobiotics in the respiratory tract. This review examines the most recent advances dealing with the use of immunobiotic bacteria to improve resistance against viral respiratory infections. More specifically, the article discuss the mechanisms involved in the capacity of the immunobiotic strain Lactobacillus rhamnosus CRL1505 to modulate the TLR3-mediated immune response in the respiratory tract and to increase the resistance to RSV infection. In addition, we review the role of interferon (IFN)-γ and interleukin (IL)-10 in the immunoregulatory effect of the CRL1505 strain that has been successfully used for reducing incidence and morbidity of viral airways infections in children.

Oral immunization of mice using Bifidobacterium longum expressing VP1 protein from enterovirus 71

Bifidobacterium longum is an attractive candidate for delivering biologically active proteins by the mucosal route due to its non-pathogenic and colonizing properties. Enterovirus 71 (EV71) has aroused widespread attention recently due to several epidemics, and great attention should be paid to the fact that there are currently no effective antiviral drugs or vaccines against EV71 infection. In this report, we described a recombinant B. longum that could be used to develop an oral vaccine against EV71 infection. A VP1 expression vector (pBBADs-VP1) was constructed by amplifying the EV71 VP1 gene and inserting it into the E. coli-Bifidobacterium shuttle expression vector pBBAD/Xs. Then, the expression of VP1 protein in pBBADs-VP1-transformed bacteria was demonstrated by western blot. In vivo studies indicated that oral immunization of BALB/c mice with pBBADs-VP1-transformed bacteria induced potent immune responses against EV71 infection, including virus-neutralising titers, anti-EV71-VP1 antibody and the induction of Th1 immune responses in the spleen and Peyer's patches. Importantly, immunization of mother mice with this recombinant VP1-expressing B. longum conferred protection to neonatal mice. These results demonstrate that the novel oral vaccine utilizing B. longum expressing the VP1 protein might successfully elicit a specific immune response against EV71 infection.

Swine-origin influenza-virus-induced acute lung injury: Novel or classical pathogenesis?

Influenza viruses are common respiratory pathogens in humans and can cause serious infection that leads to the development of pneumonia. Due to their host-range diversity, genetic and antigenic diversity, and potential to reassort genetically in vivo, influenza A viruses are continual sources of novel influenza strains that lead to the emergence of periodic epidemics and outbreaks in humans. Thus, newly emerging viral diseases are always major threats to public health. In March 2009, a novel influenza virus suddenly emerged and caused a worldwide pandemic. The novel pandemic influenza virus was genetically and antigenically distinct from previous seasonal human influenza A/H1N1 viruses; it was identified to have originated from pigs, and further genetic analysis revealed it as a subtype of A/H1N1, thus later called a swine-origin influenza virus A/H1N1. Since the novel virus emerged, epidemiological surveys and research on experimental animal models have been conducted, and characteristics of the novel influenza virus have been determined but the exact mechanisms of pulmonary pathogenesis remain to be elucidated. In this editorial, we summarize and discuss the recent pandemic caused by the novel swine-origin influenza virus A/H1N1 with a focus on the mechanism of pathogenesis to obtain an insight into potential therapeutic strategies.

Pediococcus pentosaceus Sn26 inhibits IgE production and the occurrence of ovalbumin-induced allergic diarrhea in mice

We investigated the anti-allergic effect of a new strain (Pediococcus pentosaceus Sn26, the Sn26 strain) among 59 strains isolated from Japanese fermented vegetable pickles, the Sunki pickle. The Sn26 strain increased Th1 type cytokine (IL-12 and IFN-gamma) production of Peyer's patch (PP) cells in BALB/c mice, improved the Th1/Th2 balance, and inhibited IgE production of splenocytes of ovalbumin (OVA)-induced allergic diarrheic mice. Next we demonstrated, by neutralizing IL-12 and IFN-gamma, that the Sn26 strain first induced IL-12, that IL-12 induced IFN-gamma, and that decreases in IL-4 and IgE production followed. Furthermore, oral administration of the Sn26 strain decreased serum OVA-specific IgE levels and ameliorated the appearance of diarrhea in OVA-induced allergic diarrheic mice. Based on these results, it was assumed that oral administration of the Sn26 strain ameliorated type-1 allergies through improvement of the Th1/Th2 balance and decreases in IgE production.

Oral administration of heat-killed Lactobacillus plantarum L-137 enhances protection against influenza virus infection by stimulation of type I interferon production in mice

We have previously reported that heat-killed Lactobacillus plantarum L-137 (HK-LP) stimulates macrophage/dendritic cells to produce T helper (Th) 1-related cytokines in vitro and in vivo in mice. We here examined the effect of oral administration of HK-LP on protection against influenza virus infection in mice. C57BL/6 mice were orally given HK-LP from day -7 to 7 and intranasally infected with influenza virus A/FM/1/47 (H1N1, a mouse-adapted strain) at 100 pfu on day 0. The survival time was significantly prolonged in mice treated with HK-LP than that in mice treated with PBS as controls. The viral titers in the lung were significantly lower in mice treated with HK-LP than controls at the early stage after influenza virus infection. An appreciable level of interferon (IFN)-beta was detected in the serum of mice treated with HK-LP, while no IFN-beta was detected in controls after influenza infection. Our results suggest that HK-LP, a potent IFN-beta inducer, is useful for prevention against influenza infection.

Anti-inflammatory activity of probiotic Bifidobacterium: Enhancement of IL-10 production in peripheral blood mononuclear cells from ulcerative colitis patients and inhibition of IL-8 secretion in HT-29 cells

AIM: To determine the anti-inflammatory activity of probiotic Bifidobacteria in Bifidobacteria-fermented milk (BFM) which is effective against active ulcerative colitis (UC) and exacerbations of UC, and to explore the immunoregulatory mechanisms.

METHODS: Peripheral blood mononuclear cells (PBMNC) from UC patients or HT-29 cells were co-cultured with heat-killed probiotic bacteria or culture supernatant of Bifidobacterium breve strain Yakult (BbrY) or Bifidobacterium bifidum strain Yakult (BbiY) to estimate the amount of IL-10 or IL-8 secreted.

RESULTS: Both strains of probiotic Bifidobacteria contained in the BFM induced IL-10 production in PBMNC from UC patients, though BbrY was more effective than BbiY. Conditioned medium (CM) and DNA of both strains inhibited IL-8 secretion in HT-29 cells stimulated with TNF-α, whereas no such effect was observed with heat-killed bacteria. The inhibitory effect of CM derived from BbiY was greater than that of CM derived from BbrY. DNAs of the two strains had a comparable inhibitory activity against the secretion of IL-8. CM of BbiY induced a repression of IL-8 gene expression with a higher expression of IκB-ζ mRNA 4 h after culture of HT-29 cells compared to that in the absence of CM.

CONCLUSION: Probiotic Bifidobacterium strains in BFM enhance IL-10 production in PBMNC and inhibit IL-8 secretion in intestinal epithelial cells, suggesting that BFM has anti-inflammatory effects against ulcerative colitis.

Synbiotics reduce postoperative infectious complications: a randomized controlled trial in biliary cancer patients undergoing hepatectomy

BACKGROUND AND AIMS

The clinical value of synbiotics in surgical patients remains unclear. The aim of this study was to investigate the effect of synbiotics on intestinal integrity and microflora, as well as on surgical outcome, in patients undergoing high-risk hepatectomy.

METHODS

Fifty-four patients with biliary cancer were randomly allocated to two groups before hepatectomy. One group received postoperative enteral feeding that included synbiotics; the other received enteral feeding only. Lactulose/mannitol (L/M) ratio, serum diamine oxidase (DAO) activity, and fecal microflora and organic acid concentrations were determined. Postoperative infectious complications were recorded.

RESULTS

Of the 54 patients, 44 completed the trial (21 receiving synbiotics and 23 others as controls). Postoperative changes in L/M ratios and serum DAO activities were identical between the two groups. Numbers of beneficial bacteria increased in the synbiotics group after surgery but decreased in controls. Numbers of harmful microorganisms decreased in the synbiotics group but increased in controls. Total organic acid concentrations increased in the synbiotics group but decreased in controls. Incidence of infectious complications was 19% (4/21) in the synbiotics group and 52% (12/23) in controls (P<0.05). All study patients tolerated surgery (mortality 0%).

CONCLUSIONS

Synbiotics, combined with early enteral nutrition, can reduce postoperative infections. This beneficial effect presumably involves correction of an intestinal microbial imbalance induced by surgical stress.

Increased poliovirus-specific intestinal antibody response coincides with promotion of Bifidobacterium longum-infantis and Bifidobacterium breve in infants: a randomized, double-blind, placebo-controlled trial

To determine whether the size of the intestinal bifidobacterial population can influence the immune response to poliovirus vaccination in infants, we set up a randomized, placebo-controlled trial. From birth to 4 mo, infants were given a fermented infant formula (FIF) or a standard formula (placebo). Bifidobacteria were quantified monthly in infant stools. Antipoliovirus IgA response to Pentacoq was assessed before and 1 mo after the second vaccine injection. Thirty infants were randomized, and 20 completed the study (nine in the placebo group and 11 in the FIF group). Fecal bifidobacterial level was significantly higher with the FIF group at 4 mo of age (p=0.0498). Furthermore, B. longum/B. infantis carriage was higher at 4 mo in the FIF group (p=0.0399). Antipoliovirus IgA titers increased after Pentacoq challenge (p <0.001), and the rise was significantly higher in the FIF group (p <0.02). Antibody titers correlated with bifidobacteria, especially with B. longum/B. infantis and B. breve levels (p <0.002). Infants who harbored B. longum/B. infantis also exhibited higher levels of antipoliovirus IgAs (p <0.002). In conclusion, the present results indicate that antipoliovirus response can be triggered with a fermented formula that is able to favor intestinal bifidobacteria. Whether this effect on the immune system is achieved through the bifidogenic effect of the formula (mainly through B. longum/B. infantis and B. breve stimulation) or directly linked to compounds (i.e. peptides) produced by milk fermentation remains to be investigated.

Human studies with probiotics and prebiotics: clinical implications

Probiotic agents have been shown to have significant clinical beneficial effects in the prevention and management of gastrointestinal and non-gastrointestinal conditions. These observations have led to work demonstrating that an important mechanism of these agents is their close interaction with the gut associated lymphoid tissue (GALT) and suggested immunomodulatory effects on systemic immune response. Studies on the possibility that prebiotic agents might directly or indirectly induce similar immunomodulation have only recently begun. The preliminary findings of several recent human clinical trials reviewed in this article indicate that prebiotics may indeed prove to be a clinically beneficial dietary supplement, in the context of novel nutritional strategies for the management of gastrointestinal and systemic conditions.

Enhancement of Chicken Resistance Against Escherichia coli Infection by Oral Administration of Bifidobacterium thermophilum Preparations

Three types of Bifidobacterium thermophilum extract were prepared and fed to 2-wk-old chickens to evaluate their usefulness in enhancing the defense activity of the chickens against pathogenic Escherichia coli. All three preparations resulted in significant reduction (P < 0.05) of E. coli numbers in the lungs of the treated chicken groups compared with the control nontreated group. Besides, improvement in the survival rate was observed in the treated chicken groups, especially the one administered the enzyme-digested B. thermophilum extract sample. Concanavalin A-stimulated lymphocytes from the latter group demonstrated significantly higher proliferation activity compared with those from the control group. These results suggest that oral administration of B. thermophilum preparations may be used to enhance the resistance of chickens against E. coli infection.

Influenza Aviária: Uma Revisão dos Últimos Dez Anos

A influenza aviária é doença exótica no Brasil. O sistema de vigilância implementado pelo Programa Nacional de Sanidade Avícola (PNSA) mantém monitoração permanente das aves das principais espécies domésticas, tanto do material genético importado para a indústria avícola, por exemplo, da espécie das galinhas (Gallus gallus formadomestica), perus (Meleagris gallopavo formadomestica), codornas (Coturnix coturnix japonica), patos (Anas), primários (elite), bisavós e avós para postura ou corte, como aves de espécies de exploração mais recente, exóticas, por exemplo avestruzes (Struthio camelus) ou nativas, por exemplo emas (Rhea americana). Os plantéis de reprodutores em produção são também acompanhados por amostragens periódicas, conforme previsto no PNSA, além da monitoração das respostas aos programas de vacinação, por exemplo, contra bronquite infecciosa e doença infecciosa bursal. O PNSA estabelece as normas de atuação para o controle e erradicação da doença de Newcastle (ND) e Influenza Aviária (AI) (Projeto de Vigilância, 2001), a saber: I - Notificação de focos da doença (e confirmação laboratorial no LARA-Campinas); II - Assistência a focos; III - Medidas de desinfecção; IV - Sacrifício sanitário; V - Vazio sanitário; VI - Vacinação dos plantéis ou esquemas emergenciais; VII - Controle e fiscalização dos animais susceptíveis; VIII - Outras medidas sanitárias; A vigilância e atenção ao foco exige o diagnóstico laboratorial e diferencial de AI e ND, que segue as normas do PNSA, conforme o sumário abaixo: 1- Interdição e coleta de materiais para exame laboratorial oficial; 2- Registro das aves: espécie(s), categoria(s), número(s), manutenção de aves; utensílios e produtos no local; proibição de trânsito de e para a(s) propriedade(s) em um raio de 10 km; controle de todos os animais e materiais possíveis fontes de propagação; desinfecção de vias de entradas e saídas à(s) propriedade(s); inquérito epidemiológico. 3- Confirmação laboratorial: isolamento de agente letal hemaglutinante em ovos embrionados de galinhas SPF, não inibido (inibição da hemaglutinação) ou não neutralizado (soroneutralização) por soro específico para o vírus da doença de Newcastle; caracterização do agente como vírus da influenza aviária (AIV) por detecção de antígenos da nucleoproteína e/ou matriciais de AIV e de seu subtipo por ensaios específicos para a caracterização da hemaglutinina e neuraminidase (imunodifusão, imunoenzimáticos ou moleculares). 4- Abate e destruição imediata (cremação) de todas as aves, resíduos, carnes e ovos da(s) propriedade(s) atingida(s) e vizinhas (raio de 3 km); limpeza e desinfecção das instalações; vazio sanitário (mínimo 21 dias); 5- Permitir o transporte para o abate ou incubação dentro da zona de vigilância (raio de 10 km). 6- Proibir feiras, exposições, mercados na zona de vigilância (10 km). 7- Aplicar estas medidas por mínimo de 21 dias após a destruição das fontes de propagação e desinfecção das instalações, proibir a retirada de aves e produtos na zona de proteção (3 km) por 21 dias e 15 dias na zona de vigilância (10 km). A certificação de área livre segue as normas da OIE e PNSA, considerando AI exótica no Brasil (país livre), e exige: 1- AI de alta patogenicidade não diagnosticada pelo sistema de vigilância pelos últimos 3 anos; 2- Um período de 6 meses após o abate, destruição das aves e resíduos e desinfecção após surto; O sistema de criação da avicultura predominante no Brasil (galinhas e perus) emprega a mais atual tecnologia e conhecimento científico na produção, no qual os plantéis são gerenciados com biossegurança, avaliação permanente dos pontos críticos, sistema de qualidade total e programas de vacinações que garantem a prevenção de inúmeros problemas sanitários. A prevenção de influenza aviária é especialmente favorecida por essas características. O sistema e tipo de construção (galpões) para o alojamento dos plantéis dessas espécies dificultam também o desafio eventualmente imposto pelas aves de vida livre. A localização geográfica da avicultura nacional, localizada fora das rotas migratórias das aves-reservatório, pode também exercer papel importante na ausência de focos de influenza no Brasil. Além disso, o baixo índice de replicação dos AIV nas aves migratórias durante a estada na região subtropical também influi para a menor ocorrência. As espécies de aves domésticas de importância comercial mais sensíveis à infecção e potencialmente envolvidas no papel de fonte de infecção, conforme citadas na literatura internacional, perus e patos, são mantidas em galpões industriais com sistema de biossegurança e de distribuição geográfica bastante restrita, em contraste com as criações dos países com relatos permanentes de surtos, em que se associam as condições de desafio naturais geográficas ditadas pelas rotas migratórias, mais alta replicação na ave na estação (países temperados) e a criação em campo aberto.

Bifidobacterium bifidum exhibits a lipopolysaccharide-like mitogenic activity for murine B lymphocytes

To determine the role of bifidobacteria in the systemic and mucosal antibody response, we examined the direct modulatory effect of bifidobacteria on the synthesis of antibodies by murine spleen B cells. Whole spleen B cells were cultured with Bifidobacterium bifidum or Clostridium perfringens (Welch's bacilli, negative control), and antibody synthesis was measured by ELISA and enzyme-linked immunospot assay. The B. bifidum, but not C. perfringens, substantially increased total secretion of major immunoglobulin (Ig) isotypes and the number of IgA-secreting cells. In addition, B. bifidum increased proliferation of spleen cells by threefold, and C. perfringens had little to diminishing effect on the cells. These results indicate that B. bifidum increased Ig synthesis through its mitogenic influence on B cells. Further, B. bifidum induced spleen B cells to be reactive to transforming growth factor-beta 1 and interleukin-5 and resulted in increased surface IgA expression (approximately threefold) and total IgA production (> 20-fold) but not increased production of IgM and IgG2a isotypes. Together, these studies indicate that B. bifidum can act as a lipopolysaccharide-like polyclonal activator for B cells. Furthermore, that bifidobacteria enable B cells to respond to transforming growth factor-beta 1 and interleukin-5 for the IgA production has important implications for the primary defense against pathogens in the gastrointestinal tract.

Modulation of nonspecific mechanisms of defense by lactic acid bacteria: effective dose

The purpose of this study was to determine the effect of a fermented milk product containing Lactobacillus johnsonii La1 (formerly known as Lactobacillus acidophilus La1) on the phagocytic activity of peripheral blood leukocytes in healthy adult volunteers. Furthermore, we sought to define the effective doses of the bacteria, examine the effect on respiratory burst activity, and, finally, examine the contribution made by the starter culture to the biological effects. Volunteers were randomly distributed among three groups; each subject received one pot (150 ml) of fermented milk each day for 3 wk. The first two groups received a freshly prepared product fermented by Streptococcus thermophilus (group A) alone or S. thermophilus and 10(7) cfu/ml L. johnsonii La1 (group B). Group C received a product stored for a period of 21 to 28 d and that contained S. thermophilus and 10(6) cfu/ml of L. johnsonii La1. Ingestion of L. johnsonii La1 did not significantly increase fecal lactobacilli counts. However, L. johnsonii La1 was able to survive intestinal transit and was only recovered from the feces of the volunteers of groups B and C. The fermented base alone showed a weak effect on respiratory burst but not on phagocytic activity. However, the product containing 10(7) cfu/ml L. johnsonii La1 significantly enhanced both functions. The product containing 10(6) cfu/ml of L. johnsonii La1 had no significant effect on either function. These results suggest that fecal persistence may not necessarily reflect in vivo colonization and may not be a prerequisite for all forms of immune reactivity.

Protection against influenza virus infection of mice fed Bifidobacterium breve YIT4064

Mice fed Bifidobacterium breve YIT4064 and immunized orally with influenza virus were more strongly protected against influenza virus infection of the lower respiratory tract than ones immunized with influenza virus only. The number of mice with enhanced anti-influenza virus immunoglobulin G (IgG) in serum upon oral administration of B. breve YIT4064 and oral immunization with influenza virus was significantly greater than that upon oral immunization with influenza virus only. These findings demonstrated that the oral administration of B. breve YIT4064 increased anti-influenza virus IgG antibodies in serum and protected against influenza virus infection. The oral administration of B. breve YIT4064 may enhance antigen-specific IgG against various pathogenic antigens taken orally and induce protection against various virus infections.