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Results for “mucosal immunization”

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PubMed2006

Olaquindox and cyadox stimulate growth and decrease intestinal mucosal immunity of piglets orally inoculated with Escherichia coli.

One hundred and fifty piglets were randomly allotted to one of six treatments to determine the effects of olaquindox and cyadox on growth and intestinal immune response including the number of intraepithelial lymphocytes and immunoglobulin A secreting cells (ASCs) during the three-week period. A 2 x 3 factorial arrangement of treatments was employed with the following factors: (1) Escherichia coli (O(139):K(88), 10(10) CFU) inoculation or control and (2) no antimicrobials, 100 mg/kg olaquindox and 100 mg/kg cyadox in the basal diet respectively. The antimicrobial supplementations improved (p < 0.01) average daily gain and feed conversion ratio (FCR) during the experiment. Average daily gain and FCR in the cyadox-supplemented pigs were higher (p < 0.05) than those in the olaquindox-supplemented pigs. Intraepithelial lymphocytes and ASCs decreased (p < 0.05) when the diets were supplemented. Jejunal ASCs in the cyadox-supplemented pigs were lower (p < 0.05) than those in the olaquindox-supplemented pigs. Olaquindox and cyadox suppressed E. coli-induced intestinal immune activation, which may be involved in the observed growth promotion.

Animal Feed↗
PubMed2006

Mucosal immunization with a urease B DNA vaccine induces innate and cellular immune responses against Helicobacter pylori.

BACKGROUND: Helicobacter pylori is recognized as a major risk factor for recurrent gastroduodenal inflammatory diseases and gastric adenocarcinoma. The high prevalence of H. pylori infection worldwide, the risks of side-effects from antibiotic therapy, and increasing resistance to antibiotics are the main primers for the development of improved H. pylori vaccines. The antigenic potential of its urease enzyme, a critical virulence factor required for colonization of the gastric mucosa, has been demonstrated in animal and human studies. An important but controversial issue in H. pylori vaccine studies is the type of immune response required to control infection. A new approach in H. pylori vaccinology is the administration of DNA vaccines, which has included heat-shock protein and catalase DNA vaccines. MATERIALS AND METHODS: The H. pylori urease subunit B construct or vector alone was administered to mice via the intranasal route. Spleens and stomachs were examined on day 0 and weeks 3, 6, and 12 after immunization. Proliferation of spleen cells was assessed using the carboxyfluorescein diacetate succinimidyl ester-based flow cytometry assay and cytokine secretion from cultured spleen cells was detected by ELISA, after stimulation with the urease subunit B recombinant antigen. Total RNA was isolated from stomach and spleen tissue and the expression of beta-defensin and cytokine genes was monitored by reverse transcription followed by polymerase chain reaction (RT-PCR). Immunized mice were challenged with H. pylori and bacterial DNA quantified by TaqMan PCR. RESULTS: The urease B subunit DNA vaccine increased INF-gamma secretion and splenocyte proliferation without inducing adverse effects in the spleen. Increase in gastric beta-defensin 1 and marked induction in local IL-10 : IFN-gamma ratio up to 12 weeks post-immunization suggest a potential role for local innate immune responses in protection at the site of infection. Although significant bacterial reduction in the stomachs of urease B subunit DNA-immunized mice was observed, intermediate reduction was also noted in the vector group. Increased defensin expression and adjuvant effects of the cytosine preceding guanosine motifs may contribute to this phenomenon. Our data confirm that cytosine preceding guanosine motifs, even without coadministration with antigen, can reduce extracellular bacterial load. CONCLUSIONS: In this study, a DNA construct encoding the urease B subunit was assessed for its immune profile and its ability to reduce bacterial colonization in the murine stomach. Our studies suggest that local innate immune responses may play a greater role than previously supposed in limiting H. pylori colonization in the gastric mucosa.

Animals↗
PubMedDate not supplied

Mucosal immunization with a live, virulence-attenuated simian immunodeficiency virus (SIV) vaccine elicits antiviral cytotoxic T lymphocytes and antibodies in rhesus macaques.

An effective AIDS vaccine must protect against sexual transmission of human immunodeficiency virus (HIV). Therefore, vaccine regimens which stimulate antiviral immunity in the genital tract as well as in peripheral blood and systemic lymphoid tissues are needed. Here, we describe a method of immunization by direct inoculation of the vaginal submucosa with a live attenuated SIV, SIVmac1A11. Immunization by this route generated low levels of SIV-specific IgG and IgA antibodies in serum and vaginal secretions and viral specific cytotoxic T lymphocyte (CTL) activity in peripheral blood.

AIDS Vaccines↗
PubMed1993

Glutamine in parenteral solutions enhances intestinal mucosal immune function in rats.

Biliary secretory immunoglobulin A (sIgA) and proportions of IgA+ plasma cells, helper T cells, and suppressor/cytotoxic T cells in intestinal tissue were lower in rats receiving a standard total parenteral nutrition (TPN) solution than in those receiving TPN enriched with glutamine. Parenteral solutions supplemented with glutamine may preserve the ability of intestinal immune tissue to produce sIgA-synthesizing plasma cells following antigenic stimulation.

Animals↗
PubMed1993

Defective mucosal immunity and normal systemic immunity of Mongolian gerbils, Meriones unguiculatus, to reinfection with Strongyloides venezuelensis.

The systemic and local protective activity of Mongolian gerbils was examined after re-infection with Strongyloides venezuelensis. Mongolian gerbils were unable to expel S. venezuelensis adult worms from the intestine for over ten weeks after a primary infection. Therefore, immune animals were prepared by treating with mebendazole four weeks after a primary infection and then they were challenged by different maturation stages of the parasite; subcutaneous inoculation with the infective larvae (L3) obtained by faecal culture, oral administration of L3 obtained from the lungs of rats three days after a primary infection, or oral implantation of adult worms obtained from the intestines of rats seven days after a primary infection. The results show that, although immune animals were highly resistant against challenge infection by subcutaneous inoculation with cultured L3, they were unable to expel orally administered lung-recovered L3 nor orally implanted adult worms. Although potentiated mastocytosis was induced by challenge infections with lung-recovered L3 and adult worms, all mast cells were formalin-resistant, heparin-containing cells and never seen in the epithelial layer. In spite of the defective protective capacity at the intestinal mucosa, circulating antibody production specific to S. venezuelensis adult as well as L3 antigen was positive. Therefore, the inability of Mongolian gerbils to expel S. venezuelensis adult worms from the intestine seems to be due to the defects of effector/regulator cells, presumably mast cells, but not due to immune unresponsiveness to parasite antigen.

Animals↗
PubMed2001

Cryptosporidium parvum-specific mucosal immune response in C57BL/6 neonatal and gamma interferon-deficient mice: role of tumor necrosis factor alpha in protection.

Both neonatal and C57BL/6 gamma interferon (IFN-gamma) knockout (C57BL/6-GKO) mice are susceptible to Cryptosporidium parvum, but the course of infection is different. Neonatal mice are able to clear the parasite within 3 weeks, whereas C57BL/6-GKO mice, depending on age, die rapidly or remain chronically infected. The mechanism by which IFN-gamma leads to a protective immunity is yet poorly understood. In order to investigate the effect of IFN-gamma on other cytokines expressed in the intestinal mucosa during C. parvum infection, we studied cytokine mRNA expression in the neonates and GKO (neonatal and adult) mice by quantitative reverse transcription-PCR (RT-PCR) at 4 and 9 days after infection. IFN-gamma mRNA levels were quickly and strongly up-regulated in the mucosa of neonatal mice. In GKO mice, the Th1-type response was dramatically altered during the infection, whereas the mRNA expression levels of the Th2-type cytokines interleukin 4 (IL-4) and IL-10 were increased in both mouse models. In the absence of IFN-gamma, the adult knockout mice up-regulated the mRNA levels of inflammatory cytokines, such as IL-1beta, IL-6, and granulocyte-macrophage colony-stimulating factor, in the mucosa, but not tumor necrosis factor alpha (TNF-alpha), whereas all these cytokines were up-regulated in the infected neonatal mice. Further experiments indicated that injections of TNF-alpha into GKO adult mice significantly reduced oocyst shedding. The results of the present study indicate that the resolution of infection is dependent on the expression of Th1-type cytokines in the mucosa of C57BL/6 mice and that TNF-alpha may participate in the control of parasite development.

Animals↗
PubMed1992

Mucosal immune defence mechanisms in enterocolitis complicating Hirschsprung's disease.

Enterocolitis remains an important cause of morbidity and mortality in Hirschsprung's disease. The aetiology of enterocolitis is uncertain-ischaemic and bacterial causes and recently, rotavirus infections, have been suggested. Bowel tissue from 12 patients with Hirschsprung's disease who underwent Swenson's operation (five of whom had clinical evidence of enterocolitis) and colon from six controls subjects were examined to investigate possible immunopathological mechanisms associated with the disease. IgA, IgM, and J chain (but not IgG) containing plasma cells were significantly increased in the lamina propria along the entire length of resected bowel in enterocolitis patients, compared with non-enterocolitis patients and controls (p less than 0.01). Luminal secretory component staining of the anganglionic segment of colon from enterocolitis patients was considerably reduced. Lamina propria CD68 positive monocyte/macrophages and CD45RO positive leukocytes were increased in enterocolitis patients compared with non-enterocolitis patients (p less than 0.01). CD57 positive natural killer (NK) cells showed a unique distribution pattern compared with other cell types. Patients with enterocolitis showed a significant increase in CD57 positive NK cells in the lamina propria of ganglionic bowel only (p less than 0.05). NK cell values in ganglionic bowel of non-enterocolitis patients and in aganglionic bowel in all patients were similar to controls. The diversity of altered local immune response seen in this study may reflect a multifactorial microbial aetiology in enterocolitis associated with Hirschsprung's disease.

Antigens, CD↗