Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10145 (IL-8)
23,849 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In contrast to other mastitis pathogens, the host response evoked during Staphylococcus aureus intramammary infection is marked by the absence of the induction of critical cytokines, including IL-8 and TNF-alpha, which have established roles in mediating host innate immunity. The elucidation of changes in the expression of other mediators with the potential to regulate mammary inflammatory responses to S. aureus remains lacking. Transforming growth factor (TGF)-alpha, TGF-beta1, and TGF-beta2 are cytokines that regulate mammary gland development. Because these cytokines also have a demonstrated role in mediating inflammation, the objective of the current study was to determine whether S. aureus intramammary infection influences their expression. Ten cows were challenged with S. aureus and milk samples collected. Increases in milk levels of TGF-alpha were evident within 32h of infection and persisted for 16h. Increases in TGF-beta1 and TGF-beta2 levels were detected within 40h of S. aureus infection and persisted through the end of the study. Thus, in contrast to IL-8 and TNF-alpha, S. aureus elicits host production of TGF-alpha, TGF-beta1, and TGF-beta2. This finding may suggest a role for these cytokines in mediating mammary gland host innate immune responses to S. aureus.
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PMID:Staphylococcus aureus intramammary infection elicits increased production of transforming growth factor-alpha, beta1, and beta2. 1675 Feb 72

We sought to determine whether prolactin (PRL) could influence the neutrophilic inflammation that characterizes chronic mastitis. Most of the genes encoding inflammatory proteins depend on the nuclear factor kappaB (NF-kappaB) for their expression. We addressed the hypothesis that immunomodulatory activities of PRL might arise from an increase in NF-kappaB activity. MAC-T cells, a bovine mammary epithelial cell line, were stimulated with increasing concentrations of bovine PRL (1, 5, 25, 125, and 1,000 ng/mL). Level of NF-kappaB binding activity was measured and mRNA was evaluated for IL-1beta, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor (GMCSF), IFN-gamma, and tumor necrosis factor (TNF)-alpha, cytokines known to require NF-kappaB for their maximal transcription. Prolactin activated NF-kappaB; maximal NF-kappaB activation was weaker with PRL than with TNF-alpha at 30 or 180 min poststimulation. In addition, PRL significantly amplified, in a dose-dependent manner, mRNA expression of IL-1beta, IL-6, IL-8, GMCSF, and TNF-alpha. We measured PRL concentrations in blood and milk from healthy and chronic mastitis-infected cows, and studied the relationship between the PRL concentration and the degree of inflammation in the mammary gland as indirectly assessed by somatic cell counts (SCC). Plasma PRL did not differ significantly between healthy and chronic mastitis-affected cows (63.7 and 67.5 ng/mL, respectively). Milk PRL concentration was significantly increased in chronic mastitis-affected quarters with the highest SCC, and had a positive significant correlation between SCC, as well as between the number of neutrophils present in milk samples. The present findings show that PRL promotes an inflammatory response in bovine mammary epithelial cells via NF-kappaB activation, and suggest a role for PRL in the pathogenesis of chronic mastitis.
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PMID:Prolactin-induced activation of nuclear factor kappaB in bovine mammary epithelial cells: role in chronic mastitis. 1718 84

The expression of the proinflammatory cytokines interleukin-1beta (IL-1beta), IL-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) mRNAs was determined by reverse transcription-PCR (RT-PCR) analysis of biopsies from the mammary glands of sows. The biopsies were collected before and 24h after intramammary inoculation of 12 pregnant sows with Escherichia coli (E. coli). Four of the sows developed clinical signs of mastitis and these animals displayed significantly lower levels of IL-1beta mRNA before inoculation than those that remained clinically healthy. There was a significant increase in IL-1beta, IL-6, IL-8, and TNF-alpha mRNA expression in the inoculated mammary glands of sows that developed clinical signs of mastitis (affected group) 24h postinoculation. This was also true for IL-8 and TNF-alpha mRNA expression in the inoculated mammary glands of sows that did not develop clinical signs of mastitis (non-affected group). No significant differences were found in IL-1beta, IL-6, and TNF-alpha mRNA expression in the inoculated mammary glands between groups (affected versus non-affected) 24h postinoculation. Thus, a local production of proinflammatory cytokines in the mammary gland of sows was indicated by the induced expression of IL-1beta, IL-6, IL-8, and TNF-alpha mRNAs after intramammary inoculation with E. coli.
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PMID:Proinflammatory cytokine mRNA expression in mammary tissue of sows following intramammary inoculation with Escherichia coli. 1721 47

The aim of this study was to identify the presence of SNPs in the chemokine genes CCL2 and IL8 and the chemokine receptor genes IL8RA and CCR2, and assess their potential contribution to variation in estimated breeding values (EBVs) for somatic cell score (SCS) and four other traits in Canadian Holstein bulls. Pools of DNA for bulls with high (H) and low (L) EBVs for SCS were used for identification of 11 SNPs. Two unreported SNPs were found in the CCL2 gene and one SNP was found in the CCR2 gene. Previously reported SNPs (three in the IL8 gene and five in the IL8RA chemokine receptor) were also identified. Two SNPs in CCL2, three in IL8, one in IL8RA and one in CCR2 were genotyped in Canadian Holstein bulls (n = 338) using tetra primer ARMS-PCR. We investigated associations of these seven polymorphisms with three production traits (milk yield, fat yield and protein yield) and one conformation trait related to mastitis (udder depth). The allele substitution effect for the CCL2 rs41255713:T>C SNP was significant at an experimental-wise level for milk yield (247.5 +/- 79.9 kg) and protein yield (7.4 +/- 2.3 kg) EBVs (P <or= 0.05). The associations of the SNPs with SCS EBVs were not significant at an experimental-wise level. However, the allele substitution effect of the CCR2 rs41257559:C>T SNP on SCS was significant at the comparison-wise level (-0.04 +/- 0.02, P = 0.05), which might indicate a possible association in support of other published studies. Lastly, we assigned CCR2 to BTA22q24, where a previously QTL for SCS was identified.
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PMID:Identification of single nucleotide polymorphisms in the bovine CCL2, IL8, CCR2 and IL8RA genes and their association with health and production in Canadian Holsteins. 1743 17

Mastitis is an inflammation of the mammary gland, most of the time caused by invading pathogens. Phagocytosis by neutrophils is a crucial defense of the mammary gland and the prompt recruitment of these phagocytes from blood to milk compartments is essential for the outcome of the infection. ELR+ CXC chemokines, ligands of the two interleukin-8 receptors (IL-8R), CXCR1 and CXCR2, are likely to be involved in the initiation of the inflammatory response and also in the migration of neutrophils. Recently, the polymorphism of bovine CXCR2 has been associated with resistance to mastitis. However, as the bovine IL-8R are not functionally defined, their contribution to the recruitment of neutrophils remains undetermined. In this study, the RNA ligase-mediated (RLM)-RACE method was used to clone a novel bovine interleukin-8 receptor (nIL-8R) of the bovine species. We showed that both bovine IL-8R (nIL-8R and the published CXCR2) are functional since bovine IL-8 induced migration of HEK-293 cells expressing either IL-8R. In addition, comparisons of full-length sequences suggested that the published CXCR2 sequence was improperly annotated and that the sequences of the nIL-8R and the published CXCR2 are homologous to human CXCR2 and CXCR1, respectively. This was confirmed by binding assays with labeled IL-8 and GRO-beta and calcium (Ca) flux responses of transfected cells. Moreover, the C-terminal of both bovine IL-8R showed 100% identity, whereas they differ in most other species, suggesting that the two bovine IL-8R initiate similar signal transduction. These results constitute a basis to improve our understanding of the molecular mechanisms implicated in the recruitment of bovine neutrophils.
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PMID:Identification and characterization of a new interleukin-8 receptor in bovine species. 1772 52

Twelve healthy primiparous sows received intramammary inoculation with Escherichia coli (serotype O127) during the 24-h period preceding parturition. Mammary gland biopsy samples were taken immediately before inoculation (0 h) and from the inoculated and the contralateral non-inoculated glands 24 h after inoculation. The analyses of interleukin-1 beta (IL-1beta), IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) by immunohistochemistry revealed that the production of these proinflammatory cytokines significantly increased in the inoculated mammary glands of sows that developed clinical signs of mastitis (affected group, n=4) 24 h after inoculation. This was also true for IL-8 in the inoculated mammary glands of sows that did not develop clinical signs of mastitis (nonaffected group, n=8). Sows that developed clinical signs of mastitis displayed significantly lower constitutive production of IL-1beta than did sows that remained clinically healthy. The data indicate that the development of clinical symptoms of coliform mastitis in the sow is associated with a locally increased proinflammatory cytokine production in response to intramammary E. coli infection.
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PMID:Morphometric analysis of proinflammatory cytokines in mammary glands of sows suggests an association between clinical mastitis and local production of IL-1beta, IL-6 and TNF-alpha. 1790 20

Staphylococcus aureus, but not E. coli pathogens frequently cause subclinical, chronic infections of the mammary gland. We examined here, if inadequate activation of the bovine TLR2 and TLR4 pathogen receptors by ligands derived from S. aureus pathogens might contribute to molecular mechanisms underpinning the escape strategies from mammary immune defence of this pathogen. We show that infections with live E. coli, but not S. aureus pathogens induce strongly IL-8 and TNFalpha gene expression in the udders. Yet, preparations of heat-killed bacteria from both pathogens activate equally well bovine TLR2 and TLR4 receptors to induce NF-kappaB activation, as shown in the HEK293 reconstitution system of TLR-signal transduction. LTA prepared from the S. aureus strain used to infect the cows activates the bovine TLR2 as strongly as the entire, heat-killed pathogen. Both pathogens induce in primary bovine mammary epithelial cells (pbMEC) IL-8 and TNFalpha gene expression, but S. aureus to less than 5% of the degree caused by E. coli. This impaired proinflammatory activation is paralleled by a complete lack of NF-kappaB activation in pbMEC by S. aureus or LTA. In contrast, E. coli and LPS activate strongly NF-kappaB in these cells. A large proportion of this activation is attributable to TLR-mediated signalling, since a dual transdominant negative DN-MyD88-DN-TRIF factor blocks >80% of the pathogen-related NF-kappaB activation in pbMEC. Our results prove that impaired binding of TLR-ligands from the pathogenic S. aureus strain are not the cause for the inadequate mammary immune response elicited by this pathogen. Rather, the pathogen causing subclinical mastitis impairs NF-kappaB activation in MEC thereby severely weakening the immune response in the udder.
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PMID:Bovine TLR2 and TLR4 properly transduce signals from Staphylococcus aureus and E. coli, but S. aureus fails to both activate NF-kappaB in mammary epithelial cells and to quickly induce TNFalpha and interleukin-8 (CXCL8) expression in the udder. 1793 7

Mastitis, caused by bacterial infection of the mammary gland, is a major disease of dairy cattle. The greatest risks of intramammary infection occur at the end of lactation and at the initiation of the next lactation when the cow calves. Treating serum with zymosan (yeast cell wall preparation) causes the complement to cleave, allowing this serum to serve as a source of complement fragment 5a (C5a), a potent chemoattractant and activator of the immune system. Our hypothesis was that intramammary infusion of zymosan-treated serum (ZTS) would recruit polymorphonuclear neutrophils (PMN) and generate prolonged activity in lymphocytes within the mammary gland. Ultimately this could help prevent bacterial infections in cows at dry-off and at the initiation of lactation. Two ipsilateral quarters of the mammary gland of each cow were infused with ZTS (12.5 mL/quarter), and 2 contralateral quarters were infused with saline in 8 cows shortly after lactation ended. Mammary secretions were collected periodically throughout the dry period and the first 2 wk of the next lactation. Activation status of lymphocytes and PMN in those secretions was assessed based on the intracellular presence or absence of IFN-gamma and IL-8 as determined by flow cytometry. The ZTS infusion greatly increased PMN numbers in mammary secretions for the first week only. The percentage of IFN-gamma positive lymphocytes and PMN, and the percentage of IL-8 positive PMN, exhibited a sustained increase in secretions from ZTS-treated quarters through the first 2 wk of lactation. The ZTS can stimulate PMN and lymphocyte-mediated immune defense mechanisms in the mammary gland, which may provide a useful means of preventing new intramammary infections during the dry period as well as at the initiation of lactation.
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PMID:Activation of immune cells in bovine mammary gland secretions by zymosan-treated bovine serum. 1842 Jun 16

Pathogens invading the mammary gland cause a complex signaling network that activates the early immune defense and leads to an outcome of inflammation symptoms. To examine the importance of mammary epithelial cells in these regulations and interactions resulting in a pathogen-related course of mastitis, we characterized the mRNA expression profile of key molecules of the innate immune system by quantitative real-time PCR. Mammary gland epithelial cells isolated on d 42 of lactation from 28 first-lactation Holstein dairy cows were cultured separately under standardized conditions and treated for 1, 6, and 24 h with heat-inactivated gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. Both pathogens increased mRNA expression patterns of proteins involved in pathogen recognition such as Toll-like receptors and nuclear factor-kappa B, whereas gram-negatives acted as a stronger stimulus. Furthermore, this could be confirmed by the expression profile of the proinflammatory cytokines tumor necrosis factor alpha, IL-1 beta, IL-6, and chemokines such as IL-8 and RANTES (regulated upon activation, normal T-cell expressed and secreted). Remarkably, at a low level of mRNA expression after 1 h of treatment these cytokines and chemokines were expressed at a significantly higher level in Staphyloccocus aureus than in Escherichia coli affected cells. Lactoferrin showed a deviating expression pattern to pathogen stimulation (i.e., at the 1-h measuring point Escherichia coli induced a higher mRNA expression, whereas the highest level was reached after 24 h of stimulation with Staphylococcus aureus). Complement factor 3 was the only measured factor that responded equally to both microorganisms. Our data emphasize the role of mammary epithelial cells in the immune defense of the udder and confirm their contribution to pathogen-related different courses of mastitis.
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PMID:Staphylococcus aureus and Escherichia coli cause deviating expression profiles of cytokines and lactoferrin messenger ribonucleic acid in mammary epithelial cells. 1848 44

Mastitis is one of the most prevalent diseases in cattle and remains among the most costly diseases to the dairy industry. Various surveys have indicated a greater prevalence of and risk for mastitis in Holstein cows than in Jersey cows. The innate immune system comprises the immediate host defense mechanisms that respond to infection, and differences in the magnitude and rapidity of this response are known to influence susceptibility to and clearance of infectious pathogens. The reported differences in the prevalence of mastitis between Holstein and Jersey cows may suggest the occurrence of breed-dependent differences in the innate immune response to intramammary infection. The objective of the current study was to compare the acute phase and cytokine responses of Holstein and Jersey cows following intramammary infection by the bacterial pathogen Escherichia coli, a leading cause of clinical mastitis. All cows in the study were in similar stages of lactation, of the same parity, subjected to the same housing and management conditions, and experimentally infected on the same day with the same inoculum preparation. Before and after infection, the following innate immune parameters were monitored: bacterial clearance; febrile response; induction of the acute phase proteins serum amyloid A and lipopolysaccharide-binding protein; alterations in total and differential white blood cell counts; changes in milk somatic cell counts and mammary vascular permeability; and induction of the cytokines IFN-gamma, IL-1beta, IL-8, IL-12, and tumor necrosis factor-alpha. Overall innate immune responses were similar between the 2 breeds; however, temporal differences in the onset, cessation, and duration of several responses were detected. Despite these differences, intramammary clearance of E. coli was comparable between the breeds. Together, these data demonstrate a highly conserved innate immune response of Holstein and Jersey cows to E. coli intramammary infection.
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PMID:Comparison of Holstein and Jersey innate immune responses to Escherichia coli intramammary infection. 1848 45


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