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Michael H. Kogut - One of the best experts on this subject based on the ideXlab platform.
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effect of induced molting on Heterophil function in
2016Co-Authors: Michael H. Kogut, Kenneth J Genovese, Larry H StankeraAbstract:SUMMARY. This study was undertaken to determine the effects of induced molt on basal functional activities of Heterophils from aging hens. For this purpose, Heterophils from both molted and unmolted hens were examined by in vitro bioassays for functional responsiveness and efficiency. We evaluated the ability of the Heterophils to migrate to chemotactic stimuli, phagocytize opsonized and nonopsonized Salmonella enteritidis (SE), and generate an oxidative burst in response to inflammatory agonists. A significant (P < 0.001) Heterophilia was found in the molted hens within 2 days after feed withdrawal and remained throughout the length of the experimental feed withdrawal period. No significant differences were found in the random migration of Heterophils from either group. The chemotactic movement of Heterophils from molted hens was not affected until 8 days after feed withdrawal when compared with Heterophil chemotaxis from unmolted hens. A significant decrease in chemotaxis by the Heterophils from molted hens was observed days 8-12 after feed withdrawal (P < 0.05). Significantly (P < 0.05) fewer Heterophils from molted hens were able to phagocytize opsonized (59% vs. 38%) and nonopsonized (26% vs. 15%) SE within 2 days after feed withdrawal. Likewise, significantly (P < 0.05) fewer bacteria were phagocytized per Heterophil from the molted hens when compared with the number of bacteria per Heterophil from the unmolted hens. The oxidative burst of Heterophils stimulated by either opsonized zymosan A or phorbol myristate acetate of Heterophils from molted hens was significantly (P < 0.05) reduced when compared with that generated by Heterophils from the unmolted hens. These results indicate that feed withdrawal to induce molt alters the number and function of peripheral blood Heterophils. This decreased efficiency of Heterophil functional activity appears to play a role in the increased susceptibility of molting hens to SE infections.
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The avian Heterophil.
Developmental and comparative immunology, 2013Co-Authors: Kenneth J Genovese, Christina L Swaggerty, Michael H. KogutAbstract:Heterophils play an indispensable role in the immune defense of the avian host. To accomplish this defense, Heterophils use sophisticated mechanisms to both detect and destroy pathogenic microbes. Detection of pathogens through the toll-like receptors (TLR), FC and complement receptors, and other pathogen recognition receptors has been recently described for the avian Heterophil. Upon detection of pathogens, the avian Heterophil, through a network of intracellular signaling pathways and the release and response to cytokines and chemokines, responds using a repertoire of microbial killing mechanisms including production of an oxidative burst, cellular degranulation, and production of extracellular matrices of DNA and histones (HETs). In this review, the authors describe the recent advances in our understanding of the avian Heterophil, its functions, receptors and signaling, identified antimicrobial products, cytokine and chemokine production, and some of the effects of genetic selection on Heterophils and their functional characteristics.
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gene expression analysis of toll like receptor pathways in Heterophils from genetic chicken lines that differ in their susceptibility to salmonella enteritidis
Frontiers in Genetics, 2012Co-Authors: Michael H. Kogut, Christina L Swaggerty, Hsini Chiang, Igal Y Pevzner, Huaijun ZhouAbstract:Previously conducted studies using two chicken lines (A and B) show that line A birds have increased resistance to a number of bacterial and protozoan challenges and that het- erophils isolated from line A birds are functionally more responsive. Furthermore, when stimulated withToll-like receptor (TLR) agonists, Heterophils from line A expressed a totally different cytokine and chemokine mRNA expression pattern than Heterophils from line B. A large-scale gene expression profile using an Agilent 44K microarray on Heterophils isolated from line A and line B also revealed significantly differential expression in many immune-related genes following Salmonella enteritidis (SE) stimulation, which included genes involved in the TLR pathway. Therefore, we hypothesize the differences between the lines result from distinctive TLR pathway signaling cascades that mediate Heterophil function and, thus, innate immune responsiveness to SE. Using quantitative RT-PCR on mRNA from Heterophils isolated from control and SE-stimulated Heterophils of each line, we profiled the expression of all chicken homologous genes identified in a reference TLR pathway. Several differentially expressed genes found were involved in the TLR-induced My88-dependent pathway, showing higher gene expression in line A than line B Heterophils following SE stimulation. These genes included the TLR genes TLR4, TLR15, TLR21, MD-2, the adaptor proteins Toll-interleukin 1 receptor domain-containing adaptor protein (TIRAP ), Tumor necrosis factor-receptor associated factor 3 (TRAF3), the IkB kinases transforming growth factor-b-activating kinase 1 (TAK1), IKK+ and IKKa, the transcription factors NFkB2 and interferon regulatory factor 7, phosphatidylinositol-3 kinase (PI-3K ), and the mitogen- activated protein kinase p38. These results indicate that higher expression of TLR signaling activation of both MyD88-dependent and TRIF-dependent pathways are more beneficial to avian Heterophil-mediated innate immunity and a complicated regulation of downstream adaptors is involved in stronger induction of a TLR-mediated innate response in the resis- tant line A.These findings identify new targets for genetic selection of chickens to increase resistance to bacterial infections.
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bt cationic peptides small peptides that modulate innate immune responses of chicken Heterophils and monocytes
Veterinary Immunology and Immunopathology, 2012Co-Authors: Michael H. Kogut, Kenneth J Genovese, Christina L Swaggerty, Yi Wei JiangAbstract:Abstract Neonatal poultry exhibit a transient susceptibility to infectious diseases during the first week of life that stems from inefficient host defense mechanisms. Yet, the initial host immune response to pathogens is a critical determinant of disease resistance and susceptibility. With this context in mind, novel ways to stimulate or modulate the hosts’ natural immune response is emerging as an important area of interest for food animal producers including the poultry industry. Specifically, we have been investigating new modulation strategies tailored around the selective stimulation of the host's immune system, and particularly rapid acting innate immunity, as an alternative to direct targeting of microbial pathogens. One such approach that we have been investigating is the use of a group of cationic peptides produced by a Gram-positive soil bacterium, Brevibacillus texasporus (BT peptides). We have previously shown that, provided as a feed additive, BT peptides significantly induced a concentration-dependent protection against cecal colonization and extraintestinal colonization by Salmonella enterica serovar Enteritidis (SE). This protection is not the result of direct antibacterial activity of the BT peptides on the SE since the concentrations used were below the minimum inhibitory concentration for SE. We also found that BT are not absorbed in the intestine, but still induce a significant up-regulation in the functional efficiency of peripheral blood Heterophils and monocytes. The mechanisms of this immune modulation are unknown. Here, using in vitro models for measuring: (1) leukocyte oxidative burst, (2) changes in leukocyte cytokine and chemokines gene expression profiles, and (3) phosphorylation of the mitogen activated protein kinases (MAPKs) in leukocytes, we evaluated the role of BT peptides as priming mediators for Heterophil and monocyte responses at the level of cell function, gene transcription/expression, and cell phosphorylation following stimulation with inflammatory agonists. BT peptides primed both Heterophils and monocytes for an increased oxidative burst and up-regulation in transcription of the pro-inflammatory cytokines IL-1β and IL-6 and inflammatory chemokines CXCLi1 and CXCLi2 induced by inflammatory agonists. In addition, BT peptides induced a rapid (10 min) phosphorylation and activation of the extracellular signal-regulated kinase (ERK1/2) and p38 kinase pathways in primary chicken Heterophils. Taken together, we conclude that BT peptides, acting through MAPK pathways, enhance leukocyte functional and pro-inflammatory cytokine and chemokine gene transcription activities. These small cationic peptides may prove useful as immune modulators in neonatal poultry.
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bacterial toll like receptor agonists induce sequential nf κb mediated leukotriene b4 and prostaglandin e2 production in chicken Heterophils
Veterinary Immunology and Immunopathology, 2012Co-Authors: Michael H. Kogut, Kenneth J GenoveseAbstract:Studies of the response of the primary avian polymorphonuclear leukocyte, the Heterophil, to microbe associated molecular patterns (MAMPs) through toll-like receptors (TLR) has concentrated on the activation of the respiratory burst, release of intracellular granules, and the induction of cytokine and chemokine expression. Virtually no studies have been described on the role of lipid mediators, leukotrienes and prostaglandins, as effectors of the avian inflammatory response. We have previously shown that flagellin (FLG), the bacterial lipoprotein mimic palmitoly-3-cysteine-serine-lysine-4 (PAM), and unmethylated CpG motifs of bacteria DNA (CpG) are all potent activators of the avian innate immune system. In the present studies, we hypothesized that FLG, PAM, and CpG are also capable of eliciting the production of these lipid mediators of inflammation by avian Heterophils. Compared to non-stimulated control Heterophils, all three TLR agonists were potent inducers (3-5-fold increase) of a rapid production (30 min) of leukotriene B(4) (LTB(4)) followed by a later release (60-120 min) of prostaglandin (PGE(2)) by the Heterophils. LTB(4) and PGE(2) production were derived from lipoxygenase-5 (5-LO) and cyclooxygenase-2 (COX-2) enzymatic activities, respectively, as the selective 5-LO (caffeic acid) and COX-2 (NS-398) inhibitors eliminated LTB(4) and PGE(2) production from the MAMP-stimulated Heterophils. These results demonstrate that both the lipoxygenase and cycloxygenase pathways are operational in avian Heterophils in response to bacterial MAMPs. Treatment of Heterophils with either FLG, PAM, or CpG also induced a significant increase in DNA binding by NF-κB family members' p50, c-Rel, and RelB. Additionally, the production of LTB(4) and PGE(2) were inhibited following treatment of Heterophils with the specific pharmacologic inhibitor of NF-κB (Bay 11-7086), thus suggesting that TLR pathway activation of NF-κB controls LTB(4) and PGE(2) production. This the first report of the production of lipid mediators of inflammation by avian Heterophils in response to PAMPs. Since FLG, lipoproteins, and bacterial CpG DNA are abundant during bacterial infections, these data support their role in the inflammatory response mediated by avian Heterophils.
Virginia K Lowry - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Heterophil functions of modern commercial and wild-type Rio Grande turkeys.
Avian pathology : journal of the W.V.P.A, 2006Co-Authors: Kenneth J Genovese, Virginia K Lowry, Christina L Swaggerty, Michael H. KogutAbstract:The purpose of the present study was to measure any functional differences in peripheral blood Heterophils isolated from a commercial turkey line to wild-type Rio Grande turkeys. The phagocytosis of Salmonella enteritidis, oxidative burst (OXB) and degranulation (DGR) were used as parameters of Heterophil functional efficiency in these studies. Blood was collected and Heterophils isolated from each line of turkeys at days 4, 7, and 14 post-hatch. On days 4 and 7 post-hatch, Heterophils from Rio Grande turkeys responded to phorbol A-myristate-13-acetate with significantly greater OXB activity than commercial line A. Results from the DGR assay also revealed a greater level of activity in Rio Grande Heterophils when compared with Heterophils from Line A turkeys. On day 14 post-hatch, Heterophils from the commercial line A responded at similar or greater levels than Rio Grande turkey Heterophils in the OXB and DGR assays. No differences in the phagocytosis of S. enteritidis were observed between the lines. Th...
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CpG-oligodeoxynucleotide-stimulated chicken Heterophil degranulation is serum cofactor and cell surface receptor dependent.
Developmental and comparative immunology, 2005Co-Authors: Virginia K Lowry, Pamela J. Ferro, Michael H. KogutAbstract:Synthetic oligodeoxynucleotide containing unmethylated CpG motif (CpG-ODN) is immune stimulatory to chicken Heterophils. Recognition of CpG-ODN by chicken Heterophils leads to the mobilization and release of granules. This CpG-ODN-induced Heterophil degranulation was chicken serum (CS)-dependent. Heat-denaturation and membrane filtration of CS revealed that the active serum cofactor(s) was likely a protein in nature with a molecule mass within 50,000 to 100,000. This serum cofactor(s) was heat-resistant at 56 °C for 1 h. The involvement of a cell surface receptor in recognition of CpG-ODN was also demonstrated by (1) trypsin treatment of the Heterophils abrogated the degranulation response and (2) CpG-ODN-induced Heterophil degranulation was sensitive to the inhibition of Clathrin-dependent endocytosis. In addition, among various microbial agonists, including CpG-ODN, lipopolysaccharide, lipoteichoic acid, phorbol myristate acetate, and formalin-killed Salmonella enteritidis, CpG-ODN was the only agonist that displayed serum-dependent induction of degranulation in chicken Heterophils. This is the first report that shows serum-dependent activation of leukocytes by CpG-ODN.
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the use of selective pharmacological inhibitors to delineate signal transduction pathways activated during complement receptor mediated degranulation in chicken Heterophils
International Immunopharmacology, 2003Co-Authors: Michael H. Kogut, Virginia K Lowry, M B FarnellAbstract:Abstract Complement receptors (CRs), along with Fc receptors, play a primary role in the removal of bacterial pathogens in poultry. The binding of serum-opsonized bacteria to CR results in the secretion of both toxic oxygen metabolites and antibacterial granules. We have previously shown that the stimulation of chicken Heterophils with serum-opsonized Salmonella enteritidis induced tyrosine kinase-dependent phosphorylation regulated degranulation. In the present studies, we used selective pharmacological inhibitors to investigate the roles of protein tyrosine kinases, phospholipases C and D (PLC and PLD), phosphatidylinositol 3′-kinase (PI3-K), and the super family of mitogen-activated protein kinases (MAPKs) on CR-mediated Heterophil degranulation. Inhibitors of receptor-linked tyrosine kinases (the tryphostins AG1478 and AG1296) had no attenuating effects on CR-mediated degranulation. However, PP2, a selective inhibitor of the src family of protein tyrosine kinases, and piceatannol, an inhibitor of Syk tyrosine kinases, both significantly attenuated the CR-mediated degranulation. Additionally, the specific inhibitors of PLC, U73122, and PI3-K, LY294002, significantly decreased CR-mediated Heterophil degranulation. Two inhibitors of PLD-mediated signaling, 2,3-diphosphoglycerate (2,3-DPG) and 1-butanol, hindered degranulation. Addition of purified PLD restored control levels of degranulation in Heterophils in which PLD was inhibited. Lastly, SP600125, a selective inhibitor of c-Jun N-terminal kinase (JNK), inhibited degranulation; whereas neither PD98059, the inhibitor of p38 MAPK, nor SB203580, the inhibitor of extracellular signal-regulated kinase, had any effect on CR-mediated Heterophil degranulation. These studies demonstrate that CRs on chicken Heterophils lack intrinsic tyrosine kinase activity, but that binding of serum-opsonized bacteria activates both proximal tyrosine kinases ( src and Syk kinases), but differentially activates downstream tyrosine kinases (JNK, but not p38 nor ERK). Activation of src and Syk kinases plays a significant role in signal transduction of Heterophil degranulation probably by stimulating downstream phosphorylation of PLC, PLD, and PI3-K. PI3-K has also been recently shown to be an upstream mediator of JNK activation, suggesting that this enzyme can induce signaling as both a lipid kinase and protein kinase. Engaging CRs on chicken Heterophils activates a proximal tyrosine kinase ( src and Syk kinases)→PLC (PLD)→PI3-K→JNK signal transduction pathway that induces degranulation.
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functional comparison of Heterophils isolated from commercial broiler chickens
Avian Pathology, 2003Co-Authors: Christina L Swaggerty, Virginia K Lowry, I Y Pevzner, M B Farnell, Michael H. KogutAbstract:Heterophils from two pure lines (A and B) of commercial broiler chickens were isolated on days 1, 4, and 7 post-hatch to evaluate their ability to (1) phagocytose Salmonella enteritidis (SE) (2) degranulate when exposed to immune-IgG opsonized SE, and (3) produce an oxidative burst. On days 1 and 4, Heterophils from line A were functionally more efficient compared to Heterophils from line B (p<0.05). By 7 days post hatch, Heterophil functions for both lines were comparable. To further study the inheritance of Heterophil functional efficiency, F1 reciprocal crosses (line C=male B×female A; line D=male A×female B) were evaluated for functional activity and compared with the immunologically efficient (A) and non-efficient (B) parent lines. Heterophils from line D had a more efficient Heterophil function (p<0.05) when compared to Heterophils from C. These results suggest that Heterophil function and efficiency can be genetically transferred to progeny. Moreover they indicate that Heterophil function is sex...
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selective pharmacological inhibitors reveal the role of syk tyrosine kinase phospholipase c phosphatidylinositol 3 kinase and p38 mitogen activated protein kinase in fc receptor mediated signaling of chicken Heterophil degranulation
International Immunopharmacology, 2002Co-Authors: Michael H. Kogut, Virginia K Lowry, M B FarnellAbstract:Abstract Fc receptors of avian Heterophils play a primary role in the elimination of bacterial pathogens in poultry. The cross-linking of Fc receptors with IgG-bacteria complexes results in the secretion of toxic oxygen metabolites and anti-bacterial granules. We have been investigating the upstream signaling events that precede degranulation following crosslinkage of Fc receptors on Heterophils. Previously when using the non-selective pharmacological inhibitors genistein, chelerythrine, verapamil, and pertussis toxin, we found no significant inhibitory effects on Fc-mediated Heterophil degranulation. In the present studies, we used more selective pharmacological inhibitors to investigate the roles of protein tyrosine kinases, phospholipase C (PLC), phosphatidylinositol 3′-kinase, and the family of mitogen-activated protein kinases (MAPK) on Fc-mediated Heterophil degranulation. Inhibitors of the receptor-linked tyrosine kinases (the tryphostins AG 1478 and AG 1296) had no attenuating effects on the Fc receptor-mediated degranulation of chicken Heterophils. Likewise, PP2, a selective inhibitor of the Src family of protein tyrosine kinases, had no inhibitory effects on degranulation. However, piceatannol, a selective inhibitor of Syk tyrosine kinase, significantly attenuated the effect of Fc receptor-mediated degranulation. Additionally, Fc-mediated degranulation was significantly attenuated by SB 203580, an inhibitor of p38 MAPK, but not by PD98059, an inhibitor of the extracellular signal-regulated kinase (ERK). An inhibitor of phospholipase C, U73122 and LY294002, an inhibitor of phosphoinositol-3 kinase significantly decreased Heterophil degranulation. These results suggest that the Fc receptors on chicken Heterophils, like their counterparts on mammalian neutrophils, have no intrinsic tyrosine kinase activity, but probably mediate downstream events through activation of tyrosine-based activation motifs (ITAM). Activation of the Syk tyrosine kinase stimulates downstream phosphorylation of p38 MAPK, phospholipase C, and phosphatidylinositol-3 kinase as signaling pathways that regulate Fc-receptor-mediated degranulation of chicken Heterophils. Engaging Fc receptors on chicken Heterophils activates a Syk →PLC→PI3-K→p38 MAPK signal transduction pathway that induces degranulation.
Peter K Kaiser - One of the best experts on this subject based on the ideXlab platform.
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cytokine and chemokine gene expression profiles in Heterophils from chickens treated with corticosterone
Stress, 2010Co-Authors: Shaniko Shini, Agim Shini, Peter K KaiserAbstract:In chickens, corticosterone is the end-product of stress. However, the nature of the immune response to elevated plasma corticosterone concentrations at the molecular level has not yet been characterised. We recently demonstrated that exposure to corticosterone in drinking water for 1 week significantly upregulates mRNA expression levels for the pro-inflammatory interleukins (IL)-1β, IL-6, IL-18 and the pro-inflammatory chemokine CCLi2 in chicken lymphocytes, particularly 3 h after the treatment started. In the present study, we investigated cytokine and chemokine mRNA expression levels in circulating Heterophils of chickens, and show that at 3 h post initial treatment with corticosterone in drinking water (20 mg/1L) the mRNA expression levels for IL-1β, IL-6, IL-10, IL-12α and IL-18 are upregulated. The mRNA expression levels for IL-6, IL-10 and IL-18 correlate with plasma corticosterone concentration and total Heterophil counts. Corticosterone downregulated the expression levels of all pro-inflammatory cytokines at 24 h and 1 week post-treatments. Repeated treatment with corticosterone upregulated mRNA expression levels of transforming growth factor-β4 and the chemokine CCL16. These data indicate that cytokine and chemokine gene expression signatures in chicken Heterophils can be altered during stress and therefore could be used as an indicator of stress. Copyright © 2010 Informa Plc. All rights reserved.
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flagellin and lipopolysaccharide up regulation of il 6 and cxcli2 gene expression in chicken Heterophils is mediated by erk1 2 dependent activation of ap 1 and nf κb signaling pathways
Innate Immunity, 2008Co-Authors: Michael H. Kogut, Kenneth J Genovese, Peter K KaiserAbstract:The Toll-like receptor agonists, flagellin (FLG) and lipopolysaccharide (LPS), stimulate chicken Heterophils to induce the expression and secretion of pro-inflammatory cytokines by a mechanism involving the triggering of differential MEK-ERK signaling cascades. However, the translocation and activation of transcription factors potentially involved in the control of cytokine gene expression remains unknown. Herein, we examined the effects of FLG and LPS on the activation of the transcription factors NF-κB and AP-1 and their role in regulating Heterophil activation leading to cytokine gene expression. Treatment of Heterophils with either FLG or LPS induced a significant increase in DNA binding by the NF-κB family members p50, c-Rel, and RelB. Likewise, FLG and LPS induced a significant increase in DNA binding by the AP-1 family members c-Jun and JunD. The activation of both NF-κB and AP-1 was inhibited following treatment of Heterophils with specific inhibitors of ERK1/2 (U0126 and PD098059), NF-κB (Bay 11-...
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toll like receptor agonists stimulate differential functional activation and cytokine and chemokine gene expression in Heterophils isolated from chickens with differential innate responses
Microbes and Infection, 2006Co-Authors: Michael H. Kogut, Christina L Swaggerty, I Y Pevzner, Peter K KaiserAbstract:Heterophils isolated from distinct broilers (lines A and B) differ in function and cytokine gene expression profiles. Nothing is known about Toll-like receptor (TLR) expression nor functional activation and cytokine/chemokine gene expression of line A and B Heterophils when stimulated with TLR agonists. We found that line A and B Heterophils express the same range of TLRs. All the bacterial TLR agonists, peptidoglycan, the synthetic lipoprotein Pam3CSK4, ultra-pure lipopolysaccharide, and flagellin all induced significantly greater functional activation of Heterophils from line A compared to B. Only stimulation with the guanosine analog, loxoribine, (LOX) induced a significantly greater functional response in B over A. Additionally, all Heterophils from line A stimulated with the bacterial TLR agonists had dramatic upregulation of pro-inflammatory cytokine and chemokine mRNA expression, whereas Heterophils from line B had little or no upregulation of these genes. However, stimulation of all Heterophils from line B with the bacterial TLR agonists and LOX induced a significant upregulation of IFN-α, with little transcription of this cytokine gene in line A Heterophils. These findings suggest that the difference in Heterophil functional efficiency between these parent lines is due to recognition of pathogens and activation of signaling pathways that induce innate cytokine and chemokine responses.
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Heterophil cytokine mRNA profiles from genetically distinct lines of chickens with differential Heterophil-mediated innate immune responses
Avian pathology : journal of the W.V.P.A, 2006Co-Authors: Christina L Swaggerty, I Y Pevzner, Lisa Rothwell, Peter K Kaiser, Michael H. KogutAbstract:Previously we demonstrated that increased in-vitro Heterophil function translates to increased in-vivo resistance to Salmonella enteritidis infections in broilers (line A > B). Heterophils produce cytokines and modulate acute protection against Salmonella in neonatal poultry. We hypothesized that Heterophils from S. enteritidis-resistant chickens produce an up-regulated pro-inflammatory cytokine/chemokine response compared with S. enteritidis-susceptible chickens. In this study, Heterophils were isolated 1, 14, and 28 days post-hatch, treated with RPMI or phagocytic agonists, and the cytokine/chemokine mRNA expression assessed using quantitative real-time reverse transcriptase-polymerase chain reaction. At all time-points, Heterophils from S. enteritidis-resistant chickens (line A) had higher levels of pro-inflammatory cytokine/chemokine mRNA expression upon stimulation compared with Heterophils from S. enteritidis-susceptible chickens (line B). Furthermore, Heterophils from line A chickens had decreased mRNA expression of transforming growth factor-beta4, an anti-inflammatory cytokine, compared with line B. These data indicate a relationship between cytokine/chemokine mRNA expression by Heterophils and determining overall immune competence. Therefore, Heterophil functional efficiency, accompanied by evaluating cytokine/chemokines produced by Heterophils, may be useful biomarkers for breeders to consider when developing new immunocompetent lines.
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lipopolysaccharide binding protein cd14 tlr4 dependent recognition of salmonella lps induces the functional activation of chicken Heterophils and up regulation of pro inflammatory cytokine and chemokine gene expression in these cells
Animal Biotechnology, 2005Co-Authors: Michael H. Kogut, Peter K KaiserAbstract:Lipopolysaccharide (LPS) is the major pathogen-associated molecular pattern (PAMP) found in the cell wall of gram-negative bacteria and, in mammals, is recognized by the Toll-like receptor 4 (TLR4) in conjunction with the serum protein, lipopolysaccharide-binding protein (LBP), and the CD14 co-receptor. We have found that chicken Heterophils constitutively express multiple TLRs including TLR4. Interestingly, ultrapure LPS from Salmonella minnesota directly induced the functional activation of Heterophils without the presence of LBP. However, the role of LBP and CD14 in the recognition of LPS and the induction of innate immunity, including cell functional activation and the transcription of cytokine and chemokine genes in chicken Heterophils, is not known. As previously seen, in the absence of chicken serum, Heterophil exposure to ultrapure LPS from Salmonella minnesota stimulated an increased degranulation response. However, the presence of 5% chicken serum, presumed to be a source of LBP, increased heter...
Christina L Swaggerty - One of the best experts on this subject based on the ideXlab platform.
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The avian Heterophil.
Developmental and comparative immunology, 2013Co-Authors: Kenneth J Genovese, Christina L Swaggerty, Michael H. KogutAbstract:Heterophils play an indispensable role in the immune defense of the avian host. To accomplish this defense, Heterophils use sophisticated mechanisms to both detect and destroy pathogenic microbes. Detection of pathogens through the toll-like receptors (TLR), FC and complement receptors, and other pathogen recognition receptors has been recently described for the avian Heterophil. Upon detection of pathogens, the avian Heterophil, through a network of intracellular signaling pathways and the release and response to cytokines and chemokines, responds using a repertoire of microbial killing mechanisms including production of an oxidative burst, cellular degranulation, and production of extracellular matrices of DNA and histones (HETs). In this review, the authors describe the recent advances in our understanding of the avian Heterophil, its functions, receptors and signaling, identified antimicrobial products, cytokine and chemokine production, and some of the effects of genetic selection on Heterophils and their functional characteristics.
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gene expression analysis of toll like receptor pathways in Heterophils from genetic chicken lines that differ in their susceptibility to salmonella enteritidis
Frontiers in Genetics, 2012Co-Authors: Michael H. Kogut, Christina L Swaggerty, Hsini Chiang, Igal Y Pevzner, Huaijun ZhouAbstract:Previously conducted studies using two chicken lines (A and B) show that line A birds have increased resistance to a number of bacterial and protozoan challenges and that het- erophils isolated from line A birds are functionally more responsive. Furthermore, when stimulated withToll-like receptor (TLR) agonists, Heterophils from line A expressed a totally different cytokine and chemokine mRNA expression pattern than Heterophils from line B. A large-scale gene expression profile using an Agilent 44K microarray on Heterophils isolated from line A and line B also revealed significantly differential expression in many immune-related genes following Salmonella enteritidis (SE) stimulation, which included genes involved in the TLR pathway. Therefore, we hypothesize the differences between the lines result from distinctive TLR pathway signaling cascades that mediate Heterophil function and, thus, innate immune responsiveness to SE. Using quantitative RT-PCR on mRNA from Heterophils isolated from control and SE-stimulated Heterophils of each line, we profiled the expression of all chicken homologous genes identified in a reference TLR pathway. Several differentially expressed genes found were involved in the TLR-induced My88-dependent pathway, showing higher gene expression in line A than line B Heterophils following SE stimulation. These genes included the TLR genes TLR4, TLR15, TLR21, MD-2, the adaptor proteins Toll-interleukin 1 receptor domain-containing adaptor protein (TIRAP ), Tumor necrosis factor-receptor associated factor 3 (TRAF3), the IkB kinases transforming growth factor-b-activating kinase 1 (TAK1), IKK+ and IKKa, the transcription factors NFkB2 and interferon regulatory factor 7, phosphatidylinositol-3 kinase (PI-3K ), and the mitogen- activated protein kinase p38. These results indicate that higher expression of TLR signaling activation of both MyD88-dependent and TRIF-dependent pathways are more beneficial to avian Heterophil-mediated innate immunity and a complicated regulation of downstream adaptors is involved in stronger induction of a TLR-mediated innate response in the resis- tant line A.These findings identify new targets for genetic selection of chickens to increase resistance to bacterial infections.
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bt cationic peptides small peptides that modulate innate immune responses of chicken Heterophils and monocytes
Veterinary Immunology and Immunopathology, 2012Co-Authors: Michael H. Kogut, Kenneth J Genovese, Christina L Swaggerty, Yi Wei JiangAbstract:Abstract Neonatal poultry exhibit a transient susceptibility to infectious diseases during the first week of life that stems from inefficient host defense mechanisms. Yet, the initial host immune response to pathogens is a critical determinant of disease resistance and susceptibility. With this context in mind, novel ways to stimulate or modulate the hosts’ natural immune response is emerging as an important area of interest for food animal producers including the poultry industry. Specifically, we have been investigating new modulation strategies tailored around the selective stimulation of the host's immune system, and particularly rapid acting innate immunity, as an alternative to direct targeting of microbial pathogens. One such approach that we have been investigating is the use of a group of cationic peptides produced by a Gram-positive soil bacterium, Brevibacillus texasporus (BT peptides). We have previously shown that, provided as a feed additive, BT peptides significantly induced a concentration-dependent protection against cecal colonization and extraintestinal colonization by Salmonella enterica serovar Enteritidis (SE). This protection is not the result of direct antibacterial activity of the BT peptides on the SE since the concentrations used were below the minimum inhibitory concentration for SE. We also found that BT are not absorbed in the intestine, but still induce a significant up-regulation in the functional efficiency of peripheral blood Heterophils and monocytes. The mechanisms of this immune modulation are unknown. Here, using in vitro models for measuring: (1) leukocyte oxidative burst, (2) changes in leukocyte cytokine and chemokines gene expression profiles, and (3) phosphorylation of the mitogen activated protein kinases (MAPKs) in leukocytes, we evaluated the role of BT peptides as priming mediators for Heterophil and monocyte responses at the level of cell function, gene transcription/expression, and cell phosphorylation following stimulation with inflammatory agonists. BT peptides primed both Heterophils and monocytes for an increased oxidative burst and up-regulation in transcription of the pro-inflammatory cytokines IL-1β and IL-6 and inflammatory chemokines CXCLi1 and CXCLi2 induced by inflammatory agonists. In addition, BT peptides induced a rapid (10 min) phosphorylation and activation of the extracellular signal-regulated kinase (ERK1/2) and p38 kinase pathways in primary chicken Heterophils. Taken together, we conclude that BT peptides, acting through MAPK pathways, enhance leukocyte functional and pro-inflammatory cytokine and chemokine gene transcription activities. These small cationic peptides may prove useful as immune modulators in neonatal poultry.
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protein tyrosine kinase and mitogen activated protein kinase signalling pathways contribute to differences in Heterophil mediated innate immune responsiveness between two lines of broilers
Avian Pathology, 2011Co-Authors: Christina L Swaggerty, Kenneth J Genovese, I Y Pevzner, Michael H. KogutAbstract:Protein tyrosine phosphorylation mediates signal transduction of cellular processes with protein tyrosine kinases (PTKs) regulating virtually all signalling events. The mitogen-activated protein kinase (MAPK) super-family consists of three conserved pathways that convert receptor activation into cellular functions: extracellular response kinases (ERK), c-Jun N-terminal kinases (JNK) and p38. Previously conducted studies using two chicken lines (A and B) show line A Heterophils are functionally more responsive and produce a differential cytokine/chemokine profile compared with line B, which also translates to increased resistance to bacterial challenges. Therefore, we hypothesize the differences between the lines result from distinctive signalling cascades that mediate Heterophil function. Heterophils from lines A and B were isolated from 1-day-old chickens and total phosphorylated PTK and p38, JNK, ERK, and transcription factor (activator protein 1 (AP-1) and nuclear factor kappa B (NF-κB)) protein levels...
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in vivo priming Heterophil innate immune functions and increasing resistance to salmonella enteritidis infection in neonatal chickens by immune stimulatory cpg oligodeoxynucleotides
Veterinary Immunology and Immunopathology, 2007Co-Authors: Kenneth J Genovese, Christina L Swaggerty, David J Nisbet, Michael H. KogutAbstract:Oligodeoxynucleotides (ODN) containing CpG dinucleotides (CpG-ODN) mimic bacterial DNA and stimulate the innate immune system of vertebrates. Here, we investigated the effects of intraperitoneal (ip) administered CpG-ODN on the innate immune functions of chicken Heterophils. Our results demonstrated CpG-ODN-dependent priming of chicken Heterophil degranulation and oxidative burst. Heterophils from chickens treated with CpG-ODN exhibited significantly higher (p < 0.05) degranulation activity compared to PBS and control ODN (ODN containing no CpG motif) treated groups when stimulated with opsonized Salmonella enterica serovar enteritidis. Similarly, oxidative burst activity, which generates bactericidal reactive oxygen species, was significantly higher (p < 0.05) in Heterophils from the CpG-ODN treated group than from PBS and control ODN groups when stimulated with formalin-killed S. enteritidis. The priming effects of CpG-ODN on Heterophil immune functions continued at least 4 days post-treatment. In the infection study, newly hatched chickens were treated with CpG-ODN, control ODN or PBS for 24 h then challenged with oral inoculation of S. enteritidis. A significant reduction (p < 0.05) in colonization by S. enteritidis was observed in chickens treated with CpG-ODN. Our study provides evidence that immunostimulatory CpG-ODN potentiates the innate immune responses of Heterophils and enhances resistance to infectious pathogens in neonatal chickens.
Kenneth J Genovese - One of the best experts on this subject based on the ideXlab platform.
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effect of induced molting on Heterophil function in
2016Co-Authors: Michael H. Kogut, Kenneth J Genovese, Larry H StankeraAbstract:SUMMARY. This study was undertaken to determine the effects of induced molt on basal functional activities of Heterophils from aging hens. For this purpose, Heterophils from both molted and unmolted hens were examined by in vitro bioassays for functional responsiveness and efficiency. We evaluated the ability of the Heterophils to migrate to chemotactic stimuli, phagocytize opsonized and nonopsonized Salmonella enteritidis (SE), and generate an oxidative burst in response to inflammatory agonists. A significant (P < 0.001) Heterophilia was found in the molted hens within 2 days after feed withdrawal and remained throughout the length of the experimental feed withdrawal period. No significant differences were found in the random migration of Heterophils from either group. The chemotactic movement of Heterophils from molted hens was not affected until 8 days after feed withdrawal when compared with Heterophil chemotaxis from unmolted hens. A significant decrease in chemotaxis by the Heterophils from molted hens was observed days 8-12 after feed withdrawal (P < 0.05). Significantly (P < 0.05) fewer Heterophils from molted hens were able to phagocytize opsonized (59% vs. 38%) and nonopsonized (26% vs. 15%) SE within 2 days after feed withdrawal. Likewise, significantly (P < 0.05) fewer bacteria were phagocytized per Heterophil from the molted hens when compared with the number of bacteria per Heterophil from the unmolted hens. The oxidative burst of Heterophils stimulated by either opsonized zymosan A or phorbol myristate acetate of Heterophils from molted hens was significantly (P < 0.05) reduced when compared with that generated by Heterophils from the unmolted hens. These results indicate that feed withdrawal to induce molt alters the number and function of peripheral blood Heterophils. This decreased efficiency of Heterophil functional activity appears to play a role in the increased susceptibility of molting hens to SE infections.
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The avian Heterophil.
Developmental and comparative immunology, 2013Co-Authors: Kenneth J Genovese, Christina L Swaggerty, Michael H. KogutAbstract:Heterophils play an indispensable role in the immune defense of the avian host. To accomplish this defense, Heterophils use sophisticated mechanisms to both detect and destroy pathogenic microbes. Detection of pathogens through the toll-like receptors (TLR), FC and complement receptors, and other pathogen recognition receptors has been recently described for the avian Heterophil. Upon detection of pathogens, the avian Heterophil, through a network of intracellular signaling pathways and the release and response to cytokines and chemokines, responds using a repertoire of microbial killing mechanisms including production of an oxidative burst, cellular degranulation, and production of extracellular matrices of DNA and histones (HETs). In this review, the authors describe the recent advances in our understanding of the avian Heterophil, its functions, receptors and signaling, identified antimicrobial products, cytokine and chemokine production, and some of the effects of genetic selection on Heterophils and their functional characteristics.
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bacterial toll like receptor agonists induce sequential nf κb mediated leukotriene b4 and prostaglandin e2 production in chicken Heterophils
Veterinary Immunology and Immunopathology, 2012Co-Authors: Michael H. Kogut, Kenneth J GenoveseAbstract:Studies of the response of the primary avian polymorphonuclear leukocyte, the Heterophil, to microbe associated molecular patterns (MAMPs) through toll-like receptors (TLR) has concentrated on the activation of the respiratory burst, release of intracellular granules, and the induction of cytokine and chemokine expression. Virtually no studies have been described on the role of lipid mediators, leukotrienes and prostaglandins, as effectors of the avian inflammatory response. We have previously shown that flagellin (FLG), the bacterial lipoprotein mimic palmitoly-3-cysteine-serine-lysine-4 (PAM), and unmethylated CpG motifs of bacteria DNA (CpG) are all potent activators of the avian innate immune system. In the present studies, we hypothesized that FLG, PAM, and CpG are also capable of eliciting the production of these lipid mediators of inflammation by avian Heterophils. Compared to non-stimulated control Heterophils, all three TLR agonists were potent inducers (3-5-fold increase) of a rapid production (30 min) of leukotriene B(4) (LTB(4)) followed by a later release (60-120 min) of prostaglandin (PGE(2)) by the Heterophils. LTB(4) and PGE(2) production were derived from lipoxygenase-5 (5-LO) and cyclooxygenase-2 (COX-2) enzymatic activities, respectively, as the selective 5-LO (caffeic acid) and COX-2 (NS-398) inhibitors eliminated LTB(4) and PGE(2) production from the MAMP-stimulated Heterophils. These results demonstrate that both the lipoxygenase and cycloxygenase pathways are operational in avian Heterophils in response to bacterial MAMPs. Treatment of Heterophils with either FLG, PAM, or CpG also induced a significant increase in DNA binding by NF-κB family members' p50, c-Rel, and RelB. Additionally, the production of LTB(4) and PGE(2) were inhibited following treatment of Heterophils with the specific pharmacologic inhibitor of NF-κB (Bay 11-7086), thus suggesting that TLR pathway activation of NF-κB controls LTB(4) and PGE(2) production. This the first report of the production of lipid mediators of inflammation by avian Heterophils in response to PAMPs. Since FLG, lipoproteins, and bacterial CpG DNA are abundant during bacterial infections, these data support their role in the inflammatory response mediated by avian Heterophils.
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bt cationic peptides small peptides that modulate innate immune responses of chicken Heterophils and monocytes
Veterinary Immunology and Immunopathology, 2012Co-Authors: Michael H. Kogut, Kenneth J Genovese, Christina L Swaggerty, Yi Wei JiangAbstract:Abstract Neonatal poultry exhibit a transient susceptibility to infectious diseases during the first week of life that stems from inefficient host defense mechanisms. Yet, the initial host immune response to pathogens is a critical determinant of disease resistance and susceptibility. With this context in mind, novel ways to stimulate or modulate the hosts’ natural immune response is emerging as an important area of interest for food animal producers including the poultry industry. Specifically, we have been investigating new modulation strategies tailored around the selective stimulation of the host's immune system, and particularly rapid acting innate immunity, as an alternative to direct targeting of microbial pathogens. One such approach that we have been investigating is the use of a group of cationic peptides produced by a Gram-positive soil bacterium, Brevibacillus texasporus (BT peptides). We have previously shown that, provided as a feed additive, BT peptides significantly induced a concentration-dependent protection against cecal colonization and extraintestinal colonization by Salmonella enterica serovar Enteritidis (SE). This protection is not the result of direct antibacterial activity of the BT peptides on the SE since the concentrations used were below the minimum inhibitory concentration for SE. We also found that BT are not absorbed in the intestine, but still induce a significant up-regulation in the functional efficiency of peripheral blood Heterophils and monocytes. The mechanisms of this immune modulation are unknown. Here, using in vitro models for measuring: (1) leukocyte oxidative burst, (2) changes in leukocyte cytokine and chemokines gene expression profiles, and (3) phosphorylation of the mitogen activated protein kinases (MAPKs) in leukocytes, we evaluated the role of BT peptides as priming mediators for Heterophil and monocyte responses at the level of cell function, gene transcription/expression, and cell phosphorylation following stimulation with inflammatory agonists. BT peptides primed both Heterophils and monocytes for an increased oxidative burst and up-regulation in transcription of the pro-inflammatory cytokines IL-1β and IL-6 and inflammatory chemokines CXCLi1 and CXCLi2 induced by inflammatory agonists. In addition, BT peptides induced a rapid (10 min) phosphorylation and activation of the extracellular signal-regulated kinase (ERK1/2) and p38 kinase pathways in primary chicken Heterophils. Taken together, we conclude that BT peptides, acting through MAPK pathways, enhance leukocyte functional and pro-inflammatory cytokine and chemokine gene transcription activities. These small cationic peptides may prove useful as immune modulators in neonatal poultry.
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effects of avian triggering receptor expressed on myeloid cells trem a1 activation on Heterophil functional activities
Developmental and Comparative Immunology, 2012Co-Authors: Michael H. Kogut, Kenneth J Genovese, Jessica R NerrenAbstract:A class of innate receptors called the triggering receptors expressed on myeloid cells (TREM) has been discovered and shown to be involved in innate inflammatory responses. The TREM family has been found in the chicken genome and consists of one activating gene (TREM-A1) and two inhibitory genes (TREM-B1 and TREM-B2). However, to date, there have been no reports on the effects of activating the TREM molecules on the functional activity of the primary avian polymorphonuclear cell, the Heterophil. To characterize the activation of avian Heterophils, we evaluated the effect of receptor ligation on Heterophil effector functions. A specific agonistic antibody (Ab) was generated against the peptide sequence of chicken TREM-A1 38-51aa (YNPRQQRWREKSWC). To study TREM-A1 mediated activation, purified peripheral blood Heterophils were incubated with various concentrations of the anti-TREM-A1 Ab or control Ab against an irrelevant antigen. Activation via TREM-A1 induces a significant increase in phagocytosis of Salmonella enteritidis, a rapid degranulation, and a dramatic up-regulation in gene expression of the pro-inflammatory cytokine, IL-6, and the inflammatory chemokine, CXCLi2. However, we found no direct TREM-A1 stimulation of the Heterophil oxidative burst. Like mammalian TREM, avian TREM-A1 ligation synergizes with the activation of Toll-like receptor-4 (TLR4) ligand, LPS. In addition, the synergistic activity of LPS and TREM-A1 resulted in a significantly (p⩽0.05) increased production of an oxidative burst. Taken together, these results suggest, unlike in mammalian neutrophils, TREM-A1 engagement activates a differential functional activation of avian Heterophils, but like mammalian neutrophils, acts in synergy with TLR agonists. These results provide evidence of the function of TREM-A1 in Heterophil biology and avian innate immunity.