interleukin-8 and Salmonella-Infections--Animal

The study aimed to determine the effects of orally supplemental zinc on body weight, Salmonella invasion, serum IgA, intestinal histomorphology, and immune response of Salmonella enterica serovar Typhimurium (S. typhimurium)-challenged young pigeons. A total of 72 healthy White King pigeons (25 days old) with similar weight were randomly assigned to 3 treatments with six replicate cages. The 3 treatments were unchallenged, S. typhimurium-challenged, and S. typhimurium-challenged orally supplemented with 1 mg zinc per bird. Salmonella infection decreased (P < 0.05) the body weight, the bursa index, the serum IgA content, and the villus height/crypt depth ratio in the ileum, but increased the neutrophil proportion (P < 0.001) and the mRNA expressions of IL-1β and IL-8 in the jejunum (P < 0.05). Orally supplemental zinc reduced (P = 0.007) the bacterial load in the liver and improved (P < 0.05) the body weight, the bursa index, the serum IgA content, the villus height/crypt depth ratio, and the NOD-like receptor family pyrin domain containing 3 (NLRP3) protein expression, as well as tended to increase (P = 0.064) the protein abundance of caspase-1 of the jejunum, but did not alleviate the high level of neutrophil proportion and IL-1β mRNA expression of the jejunum (P > 0.05). The results indicated that oral zinc supplementation improved the intestinal mucosal morphology and enhanced the immune response, as well as activated caspase-1-dependent cell pyroptosis pathways in the jejunal epithelium, thereby restricting Salmonella invasion of the challenged young pigeons.

Topics: Animals; Body Weight; Caspases; Columbidae; Immunity; Immunoglobulin A; Interleukin-8; NLR Family, Pyrin Domain-Containing 3 Protein; RNA, Messenger; Salmonella Infections, Animal; Salmonella typhimurium; Serogroup; Zinc

The expanding knowledge on the systemic influence of the human microbiome suggests that fecal samples are underexploited sources of new beneficial strains for extra-intestinal health. We have recently shown that acetate, a main circulating microbiota-derived molecule, reduces the deleterious effects of pulmonary

Topics: Animals; Clostridiales; Disease Models, Animal; Humans; Influenza, Human; Interleukin-8; Mice; Orthomyxoviridae Infections; Pneumococcal Infections; Salmonella Infections, Animal; Salmonella typhimurium; Streptococcus pneumoniae

Salmonella enterica (SE) is a major foodborne bacterial pathogen in the United States, commonly found as the normal flora of various animals that is attributed to causing at least 1.2 million infections annually. Poultry plays a major role in disseminating SE through direct contact with live animals and consumption of contaminated products. Vaccinating poultry against SE is a sustainable approach that can reduce SE in the host, preventing future infections in humans. An intracellular autolytic SE serovar Typhimurium vaccine (STLT2

Topics: Animals; Chickens; Humans; Interleukin-12; Interleukin-6; Interleukin-8; Poultry Diseases; RNA, Ribosomal, 16S; Salmonella enterica; Salmonella Infections, Animal; Salmonella typhimurium; Salmonella Vaccines

Avian salmonellosis caused by

Topics: Animals; Bacterial Proteins; Beclin-1; Caco-2 Cells; Chickens; Cytokines; HeLa Cells; Host-Pathogen Interactions; Humans; Interleukin-8; MAP Kinase Signaling System; NF-kappa B; Poultry Diseases; Salmonella enterica; Salmonella enteritidis; Salmonella Infections, Animal; Serogroup; Transfection; Tumor Necrosis Factor-alpha

Vaccination has been widely used to reduce the Salmonella burden in poultry and subsequently the transmission to humans. Concerning turkey, there is little knowledge on the immune response to colonization and invasion by Salmonella species or about efficacy of vaccination and involved immune mechanisms. In the present study, turkeys were vaccinated at the day of hatch and infected with Salmonella Typhimurium (ST) or Enteritidis (SE) field strains three weeks later. A control group was kept uninfected. After challenge infection, bacterial counts in the cecal content, liver and spleen were determined 7 and 14days post infection. They were often statistically significantly lower in vaccinated poults than in non-vaccinated ones. Production of iNOS, and the cytokines IL-8, IL-10 and IFN-γ were reduced in vaccinated birds. However, neither the influx of CD4+, CD8α+ and CD28+ cells into cecal mucosa after infection nor the antibody response were statistically significantly altered in vaccinated birds.

Topics: Animals; Cecum; Cytokines; Interleukin-10; Interleukin-8; Liver; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Salmonella typhimurium; Salmonella Vaccines; Spleen; Turkeys; Vaccination

The majority of Salmonella serovars cause no clinical disease in cattle, while some are associated with severe disease. The objective of the current study was to determine the innate immune responses of bovine peripheral blood leukocytes exposed to Salmonella enterica serovar Dublin (bovine-specific), Salmonella typhimurium (murine adapted, but zoonotic), and Salmonella enteritidis (poultry host-adapted) in 3-week-old calves. All Salmonella exposures increased cell surface CD14 and CD18 regardless of serovar. The greatest CD14 marker mean fluorescence was in monocytes and the greatest mean fluorescent of the marker mean was in neutrophils. Phagocytosis increased with all serovars, but was not different among them. Neutrophils had the greatest marker mean fluorescence for phagocytosis, with all serovars being equal. Oxidative burst increased in all serovars compared to control cells, but were not different among the serovars. Neutrophils and monocytes were similar in the oxidative burst, with limited oxidative burst detected in the primarily lymphocyte population. mRNA expression of TNF-α, IL-8, and IL-12, increased above the control cells whereas none of these serovars affected mRNA expression of TLR4. TNF-α was greatest in S. enterica and S. typhimurium, compared to Salmonella dublin. In contrast, IL-8 was expressed more in S. dublin than S. typhiurium, with S. Enteriditus intermediary. These results show while cell surface markers, phagocytosis, and oxidative burst were largely unaffected by serovar, cytokine and chemokine expression differed among the Salmonella serovars. It appears that internal responses of the cells differ, rather than cell recognition, creating pathogenicity differences among of the serovars, even in the neonate with developing immunity.

Topics: Animals; Animals, Newborn; Cattle; Cattle Diseases; CD18 Antigens; Female; Immunity, Innate; Interleukin-12; Interleukin-8; Leukocytes; Lipopolysaccharide Receptors; Phagocytosis; Respiratory Burst; Salmonella enterica; Salmonella enteritidis; Salmonella Infections, Animal; Salmonella typhimurium; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) that are vital to activation of the innate immune system in response to invading pathogens through their recognition of pathogen-associated molecular patterns (PAMPs). TLR5 is responsible for the recognition of bacterial flagellin in vertebrates. In this study, we cloned the goose TLR5 gene using rapid amplification of cDNA ends (RACE). The open reading frame (ORF) of goose TLR5 cDNA is 2583 bp in length and encodes an 860 amino acid protein. The entire coding region of the TLR5 gene was successfully amplified from genomic DNA and contained a single exon. The putative amino acid sequence of goose TLR5 consisted of a signal peptide sequence, 11 leucine-rich repeat (LRR) domains, a leucine-rich repeat C-terminal (LRR-CT) domain, a transmembrane domain and an intracellular Toll-interleukin-1 receptor (TIR) domain. The amino acid sequence of goose TLR5 shared 50.5% identity with human (Homo sapiens), 49.8% with mouse (Mus musculus) and 82.7% with chicken (Gallus gallus). The goose TLR5 gene was highly expressed in the spleen, liver and brain; moderately expressed in PBMCs, kidney, lung, heart, bone marrow, small intestine and large intestine; and minimally expressed in the cecum. HEK293 cells transfected with goose TLR5 and NF-κB-luciferase containing plasmids significantly responded to flagellin from Salmonella typhimurium indicating that it is a functional TLR5 homologue. In response to infection with S. enterica serovar Enteritidis (SE), the level of TLR5 mRNA significantly increased over the control in PBMCs at 1 d post infection (p.i.) and was slightly elevated in the spleen at 1 d or 3 d p.i. IL-6 was expressed below control levels in PBMCs but was upregulated in the spleen. In contrast to IL-6, an evident decrease in the expression level of IL-8 was observed in both PBMCs and spleens at 1 d or 3 d p.i. SE challenge also resulted in an increase in the mRNA expression of IL-18 and IFN-γ in PBMCs and the spleen. These results imply that the expression of goose TLR5 is differentially regulated in various tissues and may participate in the immune response against bacterial pathogens.

Topics: Amino Acid Sequence; Animals; Bird Diseases; Cell Line; Cloning, Molecular; Flagellin; Geese; Gene Expression Regulation; HEK293 Cells; Humans; Interferon-gamma; Interleukin-18; Interleukin-6; Interleukin-8; Molecular Sequence Data; NF-kappa B; Open Reading Frames; RNA, Messenger; Salmonella enteritidis; Salmonella Infections, Animal; Salmonella typhimurium; Sequence Alignment; Spleen; Toll-Like Receptor 5

Genetic line and diet affect chicken heterophil activity and gene expression, and the combination of these factors can enhance disease resistance. This study evaluated the effects of immune modulating diets on heterophil/lymphocyte (H/L) ratio and heterophil chemokine expression in distinct genetic lines. Fayoumi and Leghorn chickens were fed a basal diet or immune modulating diets enhanced with β-glucans, ascorbic acid, or corticosterone. H/L ratios and heterophil gene expression in response to in vitro stimulation with Salmonella enteritidis (SE) were evaluated on days 1, 3, 7, and 21 of diet treatment. The stress-mimicking corticosterone diet influenced H/L ratio in the Leghorn line, but not the Fayoumi line, suggesting resistance to stress-induced immunosuppression in the Fayoumi line. Leghorn line H/L ratios were increased on days 1 and 3 of corticosterone diet treatment, but not days 7 or 21. Expression of CXCLi2 by SE stimulated heterophils was higher in the Leghorn line, suggesting that Leghorns rely more heavily on inflammatory response than do Fayoumis. Corticosterone diet was associated with reduced CXCLi2 expression in heterophils from both lines. Dietary β-glucan or ascorbic acid did not affect H/L ratio or CXCLi2 expression, suggesting that benefits of these immunomodulators may not be evident in healthy birds.

Topics: Animals; Ascorbic Acid; Avian Proteins; beta-Glucans; Chickens; Corticosterone; Diet; Gene Expression; Granulocytes; Immunologic Factors; Interleukin-8; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Species Specificity

In commercial poultry production, there is a lack of natural flora providers since chickens are hatched in the clean environment of a hatchery. Events occurring soon after hatching are therefore of particular importance, and that is why we were interested in the development of the gut microbial community, the immune response to natural microbial colonization, and the response to Salmonella enterica serovar Enteritidis infection as a function of chicken age. The complexity of chicken gut microbiota gradually increased from day 1 to day 19 of life and consisted of Proteobacteria and Firmicutes. For the first 3 days of life, chicken cecum was protected by increased expression of chicken β-defensins (i.e., gallinacins 1, 2, 4, and 6), expression of which dropped from day 4 of life. On the other hand, a transient increase in interleukin-8 (IL-8) and IL-17 expression could be observed in chicken cecum on day 4 of life, indicating physiological inflammation and maturation of the gut immune system. In agreement, the response of chickens infected with S. Enteritidis on days 1, 4, and 16 of life shifted from Th1 (characterized mainly by induction of gamma interferon [IFN-γ] and inducible nitric oxide synthase [iNOS]), observed in younger chickens, to Th17, observed in 16-day-old chickens (characterized mainly by IL-17 induction). Active modification of chicken gut microbiota in the future may accelerate or potentiate the maturation of the gut immune system and increase its resistance to infection with different pathogens.

Topics: Aging; Animals; beta-Defensins; Cecum; Chickens; Cytokines; Enteritis; Enzyme-Linked Immunosorbent Assay; Gastrointestinal Tract; Immunity, Innate; Interleukin-17; Interleukin-8; Polymerase Chain Reaction; Poultry Diseases; Proteobacteria; RNA, Ribosomal, 16S; Salmonella enteritidis; Salmonella Infections, Animal; Th1 Cells; Th17 Cells

Salmonella enterica Serovar Typhimurium (S. Typhimurium) causes enterocolitis with diarrhea and polymorphonuclear cell (PMN) influx into the intestinal mucosa in humans and calves. The Salmonella Type III Secretion System (T3SS) encoded at Pathogenicity Island I translocates Salmonella effector proteins SipA, SopA, SopB, SopD, and SopE2 into epithelial cells and is required for induction of diarrhea. These effector proteins act together to induce intestinal fluid secretion and transcription of C-X-C chemokines, recruiting PMNs to the infection site. While individual molecular interactions of the effectors with cultured host cells have been characterized, their combined role in intestinal fluid secretion and inflammation is less understood. We hypothesized that comparison of the bovine intestinal mucosal response to wild type Salmonella and a SipA, SopABDE2 effector mutant relative to uninfected bovine ileum would reveal heretofore unidentified diarrhea-associated host cellular pathways. To determine the coordinated effects of these virulence factors, a bovine ligated ileal loop model was used to measure responses to wild type S. Typhimurium (WT) and a ΔsipA, sopABDE2 mutant (MUT) across 12 hours of infection using a bovine microarray. Data were analyzed using standard microarray analysis and a dynamic bayesian network modeling approach (DBN). Both analytical methods confirmed increased expression of immune response genes to Salmonella infection and novel gene expression. Gene expression changes mapped to 219 molecular interaction pathways and 1620 gene ontology groups. Bayesian network modeling identified effects of infection on several interrelated signaling pathways including MAPK, Phosphatidylinositol, mTOR, Calcium, Toll-like Receptor, CCR3, Wnt, TGF-β, and Regulation of Actin Cytoskeleton and Apoptosis that were used to model of host-pathogen interactions. Comparison of WT and MUT demonstrated significantly different patterns of host response at early time points of infection (15 minutes, 30 minutes and one hour) within phosphatidylinositol, CCR3, Wnt, and TGF-β signaling pathways and the regulation of actin cytoskeleton pathway.

Topics: Animals; Bacterial Proteins; Bayes Theorem; Cattle; Chemokine CCL2; Chemokine CCL8; Chemokine CXCL6; Guanine Nucleotide Exchange Factors; Interleukin-8; Intestinal Mucosa; Male; Microfilament Proteins; Oligonucleotide Array Sequence Analysis; Peyer's Patches; Real-Time Polymerase Chain Reaction; Salmonella Infections, Animal; Salmonella typhimurium; Signal Transduction; Systems Biology

Cyclic di-GMP (c-di-GMP), a novel secondary signalling molecule present in most bacteria, controls transition between motility and sessility. In Salmonella enterica serovar Typhimurium (S. typhimurium) high c-di-GMP concentrations favour the expression of a biofilm state through expression of the master regulator CsgD. In this work, we investigate the effect of c-di-GMP signalling on virulence phenotypes of S. typhimurium. After saturation of the cell with c-di-GMP by overexpression of a di-guanylate cyclase, we studied invasion and induction of a pro-inflammatory cytokine in epithelial cells, basic phenotypes that are major determinants of S. typhimurium virulence. Elevated c-di-GMP had a profound effect on invasion into and IL-8 production by the gastrointestinal epithelial cell line HT-29. Invasion was mainly inhibited through CsgD and the extracellular matrix component cellulose, while inhibition of the pro-inflammatory response occurred through CsgD, which inhibited the secretion of monomeric flagellin. Our results suggest that transition between biofilm formation and virulence in S. typhimurium at the epithelial cell lining is mediated by c-di-GMP signalling through CsgD and cellulose expression.

Topics: Animals; Bacterial Adhesion; Bacterial Proteins; Biofilms; Cell Line; Cyclic GMP; Epithelial Cells; Female; Flagellin; Gene Deletion; Gene Expression Regulation, Bacterial; Humans; Interleukin-8; Mice; Mice, Inbred BALB C; Salmonella Infections, Animal; Salmonella typhimurium; Signal Transduction; Virulence

The role of neutrophils in the pathogenesis of Salmonella enterica Typhimurium-induced ruminant and human enteritis and diarrhea has yet to be characterized with in vivo models. To address this question, the in vivo bovine ligated ileal loop model of nontyphoidal salmonellosis was used in calves with the naturally occurring bovine leukocyte adhesion deficiency (BLAD) mutation whose neutrophils are unable to extravasate and infiltrate the extravascular matrix. Data obtained from 4 BLAD Holstein calves homozygous for BLAD (CD18-), 1 to 5 weeks of age, were compared with 4 controls, age-matched Holstein calves negative for BLAD (CD18+). Morphologic studies revealed that infection of CD18- calves with S Typhimurium resulted in no significant tissue infiltration by neutrophils, less tissue damage, reduced luminal fluid accumulation, and increased bacterial invasion, when compared with CD18+ calves. Ultrastructurally, lesions in enterocytes induced by S Typhimurium infection in CD18- calves--including attachment and disruption of the brush border, apical membrane ruffling formation, and cellular degeneration--were similar to the ones reported in the literature for CD18- calves. Study of cytokine gene expression by quantitative real-time polymerase chain reaction revealed that early stages of acute infection (4-8 hours postinfection) were associated with increased interleukin 8 gene expression in the absence of tissue influx of neutrophils in CD18- calves, whereas later stages of infection (12 hours postinfection) were associated with increased expression of growth-related oncogene alpha in the presence of neutrophil influx in CD18+ calves. In contrast, the proinflammatory cytokines interleukin 1beta and tumor necrosis factor alpha were poorly correlated with the presence or absence of tissue neutrophils.

Topics: Animals; Animals, Suckling; Cattle; Cattle Diseases; CD18 Antigens; Chemokine CXCL1; Female; Histocytochemistry; In Vitro Techniques; Interleukin-1beta; Interleukin-8; Leukocyte-Adhesion Deficiency Syndrome; Male; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Peyer's Patches; Reverse Transcriptase Polymerase Chain Reaction; RNA; Salmonella Infections, Animal; Salmonella typhimurium; Tumor Necrosis Factor-alpha

Two serovars of Salmonella enterica, namely serovar Typhimurium (ST) and serovar Choleraesuis (SC) account for the vast majority of clinical cases of swine salmonellosis worldwide. These serovars are thought to be transmitted among pigs in production settings mainly through fecal-oral routes. Yet, few studies have evaluated effects of these serovars on expression of innate immune targets when presented to pigs via repeated oral dosing in an attempt to model transmission in production settings. Thus, a primary objective of the current experiments was to evaluate expression of Toll-like receptors (TLR) and selected chemoattractive mediators (interleukin 8, IL8; macrophage migration inhibitory factor, MIF; osteopontin, OPN) in tissues from pigs exposed to ST or SC that had been transformed with kanamycin resistance and green (STG) or red (SCR) fluorescent protein to facilitate isolation from pen fecal samples. In vitro studies confirmed that STG and SCR largely (though not completely) retained their ability to upregulate IL8 and CC chemokine ligand 20 (CCL20) in cultured swine jejunal epithelial cells. Transformed bacteria were then fed to pigs in an in vivo study to determine tissue specific effects on mRNA relative expression. Pigs were fed cookie dough inoculated with bacteria on days 0, 3, 7, and 10 with 10(8)CFU STG (n=8) or SCR (n=8), while control (CTL) pigs (n=8) received dough without bacteria. Animals were sacrificed 14 days from the initial bacterial challenge and samples of tonsil, jejunum, ileum, colon, mesenteric lymph node (MLN), spleen, and liver were removed for subsequent RNA isolation. Expression of mRNA in tissues was determined using real-time quantitative PCR and expressed relative to 18S rRNA. Within CTL pigs, when expressed relative to the content in liver, mRNA for all targets demonstrated substantial tissue effects (P<0.001 for all TLR; MIF, and OPN; P<0.05 for IL8). Feeding STG and SCR resulted in significant (P

Topics: Animals; Chemokines, CC; Interleukin-8; Intestinal Diseases; Luminescent Proteins; Macrophage Migration-Inhibitory Factors; Osteopontin; Random Allocation; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Salmonella arizonae; Salmonella Infections, Animal; Salmonella typhimurium; Swine; Swine Diseases; Toll-Like Receptors; Transformation, Genetic

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular bacterium which can infect and colonize pigs. After contact with enterocytes and macrophages, S. Typhimurium induces production of cytokines thus triggering the innate immune response. In this study we evaluated the cytokine response of two porcine cell lines, IPI-2I and 3D4/31, of epithelial or macrophage origins, respectively, to the wild-type S. Typhimurium and its hilA and ssrA mutants. We observed that the 3D4/31 cell line essentially did not respond to S. Typhimurium infection when a medium with foetal calf serum was used. However when the 3D4 cell line was incubated overnight in the presence of porcine serum, it efficiently responded to the wild-type strain and the ssrA mutant but not to the noninvasive hilA mutant as measured by mRNA quantification of TNF-alpha, IL-8 and GM-CSF by the real-time RT-PCR. In IPI-2I, all the cytokines were also induced by the wild-type S. Typhimurium and the ssrA mutant although the induction of TNF-alpha was lower than that induced by the wild-type strain. The hilA mutant was unable to induce any of the cytokines tested. The ssrA mutant can therefore be considered as more suitable for further vaccine development as the stimulation of innate immune response is important for animal protection against a challenge with virulent strains.

Topics: Animals; Bacterial Adhesion; Bacterial Proteins; Cells, Cultured; Cytokines; Epithelial Cells; Granulocyte-Macrophage Colony-Stimulating Factor; Interleukin-8; Macrophages; Mutation; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Salmonella enterica; Salmonella Infections, Animal; Swine; Swine Diseases; Trans-Activators; Tumor Necrosis Factor-alpha; Virulence

Salmonella enterica serovar Choleraesuis is an enteric pathogen of swine, producing septicemia, enterocolitis, pneumonia, and hepatitis. The initial molecular events at the site of Salmonella infection are hypothesized to be critical in the initiation of innate and adaptive immune responses; however, the acute immune response elicited by porcine intestinal tissues is not well understood. To address this need, we employed explants of jejunal Peyer's patch (JPP) mucosa from pigs to examine Salmonella-induced immune responses under controlled conditions as well as to overcome limitations of whole animal approaches. JPP explants mounted in Ussing chambers maintained normal histological structure for 2 h and stable short-circuit current and electrical conductance for 2.5 h. After ex vivo luminal exposure to Salmonella serovar Choleraesuis, JPP responded with an increase in mRNA expression of IL-1beta and IL-8, but not TNFalpha. Increased IL-1beta and IL-8 expression were dependent on efficient Salmonella adhesion and internalization, whereas mutant Salmonella did not induce inflammatory cytokine expression. Commensal enteric bacteria, present in some experiments, also did not induce inflammatory cytokine expression. These findings indicate that Salmonella uptake by Peyer's patch is important in the induction of an innate response involving expression of IL-1beta and IL-8, and that ex vivo intestinal immune tissue explants provide an intact tissue model that will facilitate investigation of mucosal immunity in swine.

Topics: Animals; Female; Histocytochemistry; In Vitro Techniques; Interleukin-1; Interleukin-8; Intestinal Mucosa; Jejunal Diseases; Male; Patch-Clamp Techniques; Peyer's Patches; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Salmonella enterica; Salmonella Infections, Animal; Swine; Swine Diseases; Tumor Necrosis Factor-alpha

Salmonella Pathogenicity Island 1 (SPI-1) genes are indispensable for virulence of Salmonella Typhimurium in mice after oral challenge. These genes mediate invasion in intestinal epithelial cells and induce cell death in murine macrophages. The role of SPI-1 in the pathogenesis of Salmonella Typhimurium infections in food producing animals is not known. It was the aim of the present study to characterize the interactions of a porcine Salmonella Typhimurium field strain and its isogenic mutants in the SPI-1 genes hilA, sipA and sipB with porcine macrophages. SPI-1 was found to be important in the invasion of porcine pulmonary alveolar macrophages (PAM) and the induction of the formation of spacious phagosomes. Both early and delayed cytotoxicity were seen in PAM, but only the early cytotoxicity was SPI-1 dependent. Exposure of PAM to Salmonella Typhimurium induced the production of reactive oxygen species (ROS) and interleukin-8, but no differences were noticed between the induction mediated by the wild type strain and its SPI-1 mutant strains. In conclusion, invasion of porcine macrophages and the induction of early, but not delayed, cytotoxicity by Salmonella Typhimurium is SPI-1 dependent. SPI-1 dependent invasion, however, is not a prerequisite to induce a pro-inflammatory response.

Topics: Animals; Bacterial Proteins; Cytotoxicity Tests, Immunologic; DNA Primers; Interleukin-8; Macrophages, Alveolar; Membrane Proteins; Microfilament Proteins; Mutation; Phagosomes; Reactive Oxygen Species; Salmonella Infections, Animal; Salmonella typhimurium; Swine; Time Factors; Trans-Activators

The innate immune response is critical to enteric disease resistance and the induction of mucosal adaptive immunity. In mucosae of the small intestine, Peyer's patches play a central role in immune surveillance and sampling of bacteria by specialized M cells. The innate immune response to Salmonella enterica serovar Choleraesuis, an enteric pathogen of swine, involves IL-1beta and IL-8 mRNA induction but not that of IL-6 and TNFalpha, in contrast to Salmonella serovar Typhimurium infection of murine small intestine. We investigated in vivo responses to Salmonella and potential effects of animal variation since the gut environment is highly dynamic and constantly changing physiologically. Salmonella serovar Choleraesuis induced an early proinflammatory cytokine response at 6h after infection, which was characterized by a 4-fold increase in production of CXCL2 mRNA by jejunal Peyer's patches (JPP), and a 12-fold increase in IL-1beta and 4-fold increase in IL-8 (CXCL8) mRNAs by distal ileal Peyer's patches (IPP). Levels of IL-1beta and IL-8 mRNA were positively correlated with numbers of mucosal neutrophils in the distal IPP. Salmonella DNA was also detected in ileal tissues, including Peyer's patches, absorptive epithelium and mesenteric lymph nodes, in 33-83% of infected animals, compared to the jejunal tissues, which were positive in 0-33% of infected pigs. Notwithstanding substantial animal-to-animal variation, IL-1beta was increased in both proximal and distal IPP, IL-8 was increased in the distal IPP, and calprotectin was associated with both by cluster analysis. These data indicate that IL-1beta and IL-8 expression in the IPP plays a key role early in the interaction between Salmonella serovar Choleraesuis and the small intestine.

Topics: Animals; DNA, Bacterial; Gastric Mucosa; Gene Expression Regulation; Immunity, Innate; Immunity, Mucosal; Interleukin-1; Interleukin-8; Leukocyte L1 Antigen Complex; Lymphoid Tissue; Neutrophils; Peyer's Patches; RNA, Messenger; Salmonella enterica; Salmonella Infections, Animal; Swine

Intestinal epithelial cells represent the first line of defence against pathogenic bacteria in the lumen of the gut. Besides acting as a physical barrier, epithelial cells orchestrate the immune response through the production of several innate immune mediator molecules including beta-defensins. Here, we establish the porcine intestinal cell line IPI-2I as a new model system to test the regulation of porcine beta-defensins 1 and 2. Gene expression of both defensins was highly upregulated by foetal calf serum components in normal growth medium. In serum-free medium, baseline expression remained low, but pBD-2 gene expression was increased 10-fold upon infection with Salmonella Typhimurium. Arcobacter cryaerophilus and Salmonella Enteritidis, pathogenic bacteria with comparable adhesion and invasion characteristics, failed to increase pBD-2 mRNA levels. Heat killed or colistin-treated Salmonella Typhimurium had no effect, showing that the upregulation of pBD-2 was dependent on the viability of the Salmonella Typhimurium. Gene expression of pBD-1 was regulated differently since an increase in pBD-1 mRNA was observed by Salmonella Enteritidis infection. We conclude that the IPI-2I cells can serve as a new model to study porcine beta-defensin regulation and that pBD-1 and pBD-2 are differentially regulated in this cell line.

Topics: Animals; Bacterial Adhesion; beta-Defensins; Cell Line; Enzyme-Linked Immunosorbent Assay; Epithelial Cells; Gene Expression Regulation; Interleukin-8; Intestinal Diseases; Microscopy, Electron, Scanning; Reverse Transcriptase Polymerase Chain Reaction; RNA; Salmonella Infections, Animal; Salmonella typhimurium; Statistics, Nonparametric; Swine; Swine Diseases

We recently showed that increased in vitro heterophil functional efficiency translates to increased in vivo resistance to a systemic Salmonella enteritidis (SE) infection utilizing a parental pair of broiler chickens (lines A and B) and the F1 reciprocal crosses (C and D). Heterophils produce cytokines and modulate acute protection against Salmonella in young poultry. Therefore, we hypothesize that heterophils from SE-resistant chickens (A and D) have the ability to produce an up-regulated pro-inflammatory cytokine response compared to that of heterophils from SE-susceptible chickens (B and C). In this study, heterophils were isolated from day-old chickens and treated with either RPMI-1640 (as the control), or phagocytic agonists (SE, or SE opsonized with either normal chicken serum or immune serum against SE) and cytokine mRNA expression assessed using real-time quantitative reverse transcription-polymerase chain reaction. Heterophils from SE-resistant chickens (A and D) had significantly higher levels of pro-inflammatory cytokine (interleukin (IL)-6, IL-8, and IL-18) mRNA expression upon treatment with all agonists compared to heterophils from SE-susceptible lines (B and C). Further, heterophils from SE-resistant chickens had significantly decreased mRNA expression levels of transforming growth factor-beta4, an anti-inflammatory cytokine, when compared to heterophils from SE-susceptible chickens. These data indicate cytokine gene expression in heterophils may be a useful parameter in determining resistance to Salmonella, as indicated by our previous in vivo SE studies. Therefore, heterophil functional efficiency and cytokine production may be useful biomarkers for poultry breeders to consider when developing new immunocompetent lines of birds.

Topics: Animals; Chickens; Cytokines; Disease Susceptibility; Gene Expression; Immunocompetence; Interleukin-18; Interleukin-6; Interleukin-8; Neutrophils; Poultry Diseases; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Salmonella Infections, Animal; Transforming Growth Factor beta

The expression of mRNA encoding tumour necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), IL-6 and IL-8 was studied, by in situ hybridization with a non-radioactive digoxigenin-labelled probe, in formalin-fixed, paraffin wax-embedded colonic tissue from pigs naturally infected with Salmonella typhimurium and S. choleraesuis. By in situ hybridization, a distinct positive signal for TNF-alpha, IL-1, IL-6 and IL-8 was detected in colon from all 12 infected pigs. Hybridization signals for all four inflammatory cytokines were detected primarily inflammatory cells infiltrating the lamina propria and submucosa. In comparison, expression of all four inflammatory cytokines was minimal in non-lesional colon of infected pigs and in normal colon from control pigs. The results suggest that these cytokines play an important role in the pathophysiological processes in porcine salmonellosis.

Topics: Animals; Colon; Cytokines; DNA Primers; Interleukin-1; Interleukin-6; Interleukin-8; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Salmonella; Salmonella Infections, Animal; Salmonella typhimurium; Swine; Tumor Necrosis Factor-alpha

Increased resistance to Salmonella enteritidis (SE) organ infectivity in chickens can be conferred by the prophylactic administration of SE-immune lymphokines (ILK). Resistance is associated with an enhanced heterophilic accumulation within 4 h of ILK injection. In these studies, the role of IL-8 in ILK-mediated heterophil recruitment during SE infections in young chickens was investigated. Heterophil accumulation was enhanced 2-4 h after the i.p. injection of both ILK and SE (ILK/SE) when compared to the control chicks. An i.p. injection of a rabbit polyclonal anti-human IL-8 antibody significantly (P < 0.01) reduced the accumulation of heterophils in the peritoneum after the injection of ILK/SE. Injections of preimmune rabbit IgG had no effect on peritoneal heterophil numbers. Within 2 h of injection of ILK/SE, a ten-fold increase in heterophil chemotactic activity was found in the peritoneal lavage fluid from these chicks compared to the saline control chicks. Pretreatment, with the anti-IL-8 antibody, of the peritoneal lavage fluids collected from the ILK/SE-treated chicks dramatically reduced this heterophil chemotactic activity. Treatment of the lavage fluids from all groups with preimmune IgG had no effect on heterophil chemotaxis. Additionally, pretreatment of ILK with the anti-human IL-8 antibody had no effect on heterophil chemotaxis. The results from these experiments suggest that IL-8 is produced locally by the host in response to both the SE infection and the ILK. With these studies, it was established that IL-8 is a major chemotactic factor produced by the host, which aids in mediating the ILK/SE-induced recruitment of heterophils to the site of SE invasion.

Topics: Animals; Chemotaxis, Leukocyte; Chickens; Granulocytes; Inflammation; Interleukin-8; Lymphokines; Neutrophils; Peritoneal Lavage; Peritoneum; Poultry Diseases; Salmonella enteritidis; Salmonella Infections, Animal; Spleen; T-Lymphocytes; Time Factors