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1.
The early cytokines interferon-alpha (IFN-alpha), tumour necrosis factor-alpha (TNF-alpha), interleukin-1, -6 and -8 (IL-1, -6, -8) are produced during the most early stage of an infection. The activities of these cytokines have been studied extensively in vitro and in rodents, but in vivo studies on the role of these cytokines in infectious diseases of food animals are few. This review concentrates on in vivo studies of cytokine involvement in infectious respiratory diseases of swine, with an emphasis on viral infections. First evidence for the role of early cytokines in pneumonia in swine came from experimental infections with Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae. The role of TNF-alpha and IL-1 in the symptoms and pathology of porcine pleuropneumonia has recently been proven by use of an adenovirus vector expressing the anti-inflammatory IL-10. In the authors' laboratory, studies were undertaken to investigate the relationship between viral respiratory disease and bioactive lung lavage levels of IFN-alpha, TNF-alpha, IL-1 and IL-6. Out of three respiratory viruses-porcine respiratory coronavirus (PRCV), porcine reproductive and respiratory syndrome virus (PRRSV) and swine influenza virus (SIV)-only SIV induced acute respiratory disease and severe lung damage by itself. Disease and lung pathology were tightly associated with the simultaneous production of IFN-alpha, TNF-alpha, IL-1 and IL-6. In challenge studies of SIV-vaccinated pigs, levels of IFN-alpha, TNF-alpha and IL-6, but not IL-1 were correlated with clinical and virological protection. Multifactorial respiratory disease was reproduced by combined inoculations with PRCV or PRRSV followed by LPS from Escherichia coli. In comparison with the respective single inoculations, which were subclinical, there was a true potentiation of disease and production of TNF-alpha, IL-1 and IL-6. TNF-alpha and IL-6 were best correlated with disease. In further studies, we will use more specific strategies to dissect the role of cytokines during viral infections.  相似文献   

2.
The effect of a bacterial infection on interferon-alpha (IFN-alpha) and interleukin-6 (IL-6) production by porcine cells was studied in specific pathogen-free (SPF) pigs, infected intranasally with Actinobacillus pleuropneumoniae serotype 2. Three experimental groups of five pigs were used: infected non-treated pigs, infected pigs that were treated with enrofloxacin at disease onset, and non-infected, non-treated control pigs. Blood samples were collected from all pigs on the day of infection and on days 1, 4, 7, 13 and 17 post-infection. Sera were analysed for presence of antibodies to A. pleuropneumoniae and for the cytokines IL-6 and IFN-alpha. Ability to produce these cytokines was tested in vitro using whole blood cultures stimulated with inactivated virus (Aujeszky's disease virus infected porcine kidney cells (ADV/PK-15)), inactivated bacteria (A. pleuropneumoniae) or bacterial plasmid (pcDNA3). All cytokine inducers were used neat or pre-incubated with the transfectious agent lipofectin. IL-6 appeared in the serum of all infected non-treated animals but no IFN-alpha was found in the serum of any of the experimental pigs. Accordingly, the bacteria induced a substantial IL-6 but hardly any IFN-alpha production when tested in vitro. However, following incubation with lipofectin, the inactivated bacteria as well as pcDNA3 became efficient inducers of IFN-alpha in whole blood cultures. The increased IFN-alpha production, previously recorded in vitro during the acute phase of infection with A. pleuropneumoniae, was confirmed using lipofected plasmid DNA and it was indicated that leukocytes obtained from infected but apparently cured animals also exhibited an increased production of IFN-alpha. Thus, even mild/sub-clinical bacterial infections may affect cytokine production in pigs.  相似文献   

3.
The aim of the present study was to determine postnatal ontogeny of proinflammatory cytokines IL-1beta, IL-8 and TNF-alpha production by in vitro stimulated porcine blood leukocytes. Four age categories of pigs were chosen. Cytokine production was determined using intracellular flow cytometry. It was found that IL-8 and TNF-alpha production by blood monocytes significantly increased during the postnatal period while production of IL-1beta remained unchanged. In blood neutrophils, the IL-8 production increased only during the postnatal period, while the levels of TNF-alpha and IL-1beta were undetectable during the whole postnatal period. Generally, the most intensive changes in cytokine production occurred before weaning. The production of low levels of cytokines by monocytes and neutrophils from young pigs was not caused by a delayed cytokine response because the cytokine production after 8-h stimulation was lower than that after 4-h stimulation in all age categories. The ontogenetical changes showed the same trends when two different stimulators (LPS, heat-inactivated E. coli) were used, suggesting that the ontogenetical changes are not caused by a simple defect in one signalling pathway, but it is probably a more complex process. No differences in cytokine production between the whole blood and the isolated cells supplemented with newborn or adult serum were found. Thus the ability of newborn monocytes and neutrophils to produce proinflammatory cytokines was not decreased due to the influence of composition of the microenvironment, where the cells were present. In conclusion, the ability of porcine blood leukocytes to produce cytokines develops during postnatal life.  相似文献   

4.
Pathophysiologic correlates of acute porcine pleuropneumonia   总被引：3，自引：0，他引：3  
OBJECTIVE: To develop and evaluate an in vivo model to study early events in the pathogenesis of acute porcine pleuropneumonia. ANIMALS: Thirty-six 6- to 8-week-old pigs. PROCEDURE: Pigs were inoculated intranasally or endotracheally with Actinobacillus pleuropneumoniae; inoculation routes were compared by evaluation of clinical signs, gross and microscopic lung lesions, hematologic changes, serum zinc, iron, and haptoglobin concentrations, and inflammatory cytokines. RESULTS: The 2 inoculation routes resulted in similar findings, although intranasal inoculation caused unilateral gross lung lesions, whereas endotracheal inoculation caused bilateral gross lesions. Clinical signs of disease were observed < 2 hours after endotracheal inoculation and 6 to 8 hours after intranasal inoculation. Total WBC counts did not differ significantly after inoculation by either inoculation route, although band neutrophils increased significantly. The earliest findings associated with A pleuropneumoniae inoculation, irrespective of route, were decreased serum zinc and iron concentrations. Serum haptoglobin concentrations were significantly increased after inoculation. Inoculation induced rapid influx of macrophages into the lung and local induction of proinflammatory cytokines. Northern blot analysis of total RNA from lung tissue indicated that inoculated pigs had increased concentrations of interleukin (IL)-1beta, IL-1alpha, and IL-8; tumor necrosis factor messenger RNA concentration was not increased. CONCLUSIONS: Endotracheal inoculation with A pleuropneumoniae rapidly and consistently induced diffuse bilateral pneumonia; thus, this method may be useful for the study of acute pathophysiologic changes associated with bacterial pneumonia and may provide an experimental model for testing modalities for prevention and treatment of this and other respiratory tract diseases of pigs.  相似文献   

5.
The influence of interferon (IFN)-alpha on the in vitro differentiation of myeloid porcine dendritic cells (DC) was evaluated as the ability of the DC to stimulate to cell proliferation in a mixed leukocyte reaction (MLR), and as their ability to produce cytokines at exposure to bacterial and viral preparations. Porcine monocytes were enriched from purified peripheral blood mononuclear cells (PBMC) by plastic adherence and cultured in the presence of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 or in GM-CSF, IL-4 and IFN-alpha. After 5 days of culture, the cells developed a dendritic morphology and the proportion of cells expressing MHC class II and B7 molecules was increased as determined by flow cytometry. Dendritic cells, differentiated for 5 days in GM-CSF, IL-4 and IFN-alpha, were able to stimulate both allogeneic and syngeneic PBMC to proliferation in an MLR. The DC produced the Th1 associated cytokines IFN-alpha at Sendai virus stimulation, and IL-12 at stimulation with plasmid DNA (pre-incubated in the presence of lipofectin), heat-inactivated Actinobacillus pleuropneumoniae, UV-inactivated Aujeszky's disease virus and live Sendai virus. The heat-inactivated bacteria and Sendai virus also induced production of the Th2 associated cytokines IL-10 and IL-6. The addition of IFN-alpha during differentiation of DC in GM-CSF and IL-4 enhanced their ability to stimulate allogeneic and syngeneic MLR, but did not alter their ability to produce cytokines.  相似文献   

6.
The effects of Actinobacillus (Haemophilus) pleuropneumoniae and its metabolites on the oxygenation activity of porcine pulmonary alveolar macrophages (PAM) were studied, using a chemiluminescence technique. Actinobacillus pleuropneumoniae strains of serotypes 2, 3, and 9 in a dose of 1, 10, and 100 colony-forming units/macrophage first stimulated the oxygen radical production of PAM. After having reached a peak value, oxygenation activity decreased, finally resulting in total suppression of PAM. All these effects were neutralized by homologous convalescent pig sera that had been adsorbed onto inactivated A pleuropneumoniae strains. Moreover, cross-neutralization was shown between serotypes 2 and 3. Inactivated A pleuropneumoniae strains did not influence the oxidative activity of PAM. Undiluted and lower dilutions of sterile A pleuropneumoniae culture supernatants were toxic for PAM, whereas higher dilutions of the supernatants stimulated oxygen radical production of the macrophages. These effects were heat-sensitive and were neutralized by homologous convalescent pig sera. Cross-neutralization was shown between serotypes 2 and 3. These findings indicated that stimulation and inhibition of the oxygenation activity of PAM are attributable to heat-sensitive metabolites produced by A pleuropneumoniae.  相似文献   

7.
OBJECTIVE: To evaluate mRNA expression of several proinflammatory and anti-inflammatory cytokines and chemokines in equine unstimulated and interleukin-1beta (IL-1beta)-stimulated chondrocytes. STUDY DESIGN: In vitro experiment using equine chondrocyte cultures. SAMPLE POPULATION: Whole articular cartilage from metacarpophalangeal joints (n=5 horses; 10 fetlocks). METHODS: Chondrocyte monolayer cultures were established from digested adult equine articular cartilage and stimulated with 5 ng/mL of recombinant human IL-1beta. RNA was extracted from the cells 24 hours after stimulation. IL-1beta, IL-4, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and ubiquitin (house keeping gene) mRNA expression were investigated by real-time RT-PCR. RESULTS: IL-1beta, IL-6, and IL-8 mRNA were expressed in unstimulated chondrocytes from macroscopically normal joints and were significantly up-regulated after stimulation (5/5 horses). IL-4 mRNA was not detected in any samples (0/5 horses). TNF-alpha mRNA, by comparison, was expressed in 2/5 unstimulated samples and in all stimulated samples but a considerable sample variation in response to IL-1beta stimulation was observed. CONCLUSIONS: Equine chondrocytes express mRNA for several proinflammatory cytokines and chemokines and IL-1beta modulates their expression. CLINICAL RELEVANCE: Chondrocytes express proinflammatory cytokines and chemokines capable of modulating a local inflammatory cascade in articular cartilage, which could potentially lead to focal degradation and osteoarthritis.  相似文献   

8.
ABSTRACT: Actinobacillus pleuropneumoniae (A. pleuropneumoniae) causes fibrino-hemorrhagic necrotizing pleuropneumonia in pigs. Production of proinflammatory mediators in the lungs is an important feature of A. pleuropneumoniae infection. However, bacterial components other than lipopolysaccharide involved in this process remain unidentified. The goals of this study were to determine the role of A. pleuropneumoniae exotoxin ApxI in cytokine induction and to delineate the underlying mechanisms. Using real-time quantitative PCR analysis, we found native ApxI stimulated porcine alveolar macrophages (PAMs) to transcribe mRNAs of IL-1β, IL-8 and TNF-α in a concentration- and time-dependent manner. Heat-inactivation or pre-incubation of ApxI with a neutralizing antiserum attenuated ApxI bioactivity to induce cytokine gene expression. The secretion of IL-1β, IL-8 and TNF-α protein from PAMs stimulated with ApxI was also confirmed by quantitative ELISA. In delineating the underlying signaling pathways contributing to cytokine expression, we observed mitogen-activated protein kinases (MAPKs) p38 and cJun NH2-terminal kinase (JNK) were activated upon ApxI stimulation. Administration of an inhibitor specific to p38 or JNK resulted in varying degrees of attenuation on ApxI-induced cytokine expression, suggesting the differential regulatory roles of p38 and JNK in IL-1β, IL-8 and TNF-α production. Further, pre-incubation of PAMs with a CD18-blocking antibody prior to ApxI stimulation significantly reduced the activation of p38 and JNK, and subsequent expression of IL-1β, IL-8 or TNF-α gene, indicating a pivotal role of β2 integrins in the ApxI-mediated effect. Collectively, this study demonstrated ApxI induces gene expression of IL-1β, IL-8 and TNF-α in PAMs that involves β2 integrins and downstream MAPKs.  相似文献   

9.
Proinflammatory cytokines and viral respiratory disease in pigs   总被引：8，自引：0，他引：8  
Swine influenza virus (SIV), porcine respiratory coronavirus (PRCV) and porcine reproductive and respiratory syndrome virus (PRRSV) are enzootic viruses causing pulmonary infections in pigs. The first part of this review concentrates on known clinical and pathogenetic features of these infections. SIV is a primary respiratory pathogen; PRCV and PRRSV, on the contrary, tend to cause subclinical infections if uncomplicated but they appear to be important contributors to multifactorial respiratory diseases. The exact mechanisms whereby these viruses cause symptoms and pathology, however, remain unresolved. Classical studies of pathogenesis have revealed different lung cell tropisms and replication kinetics for each of these viruses and they suggest the involvement of different lung inflammatory responses or mediators. The proinflammatory cytokines interferon-alpha (IFN-alpha), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) have been shown to play key roles in several respiratory disease conditions. The biological effects of these cytokines and their involvement in human viral respiratory disease are discussed in the second part of this review. The third part summarises studies that were recently undertaken in the authors' laboratory to investigate the relationship between respiratory disease in pigs and bioactive lung lavage levels of IFN-alpha, TNF-alpha and IL-1 during single and combined infections with the above viruses. In single SIV infections, typical signs of swine "flu" were tightly correlated with an excessive and coordinate production of the 3 cytokines examined. PRCV or PRRSV infections, in contrast, were subclinical and did not induce production of all 3 cytokines. Combined infections with these 2 subclinical respiratory viruses failed to potentiate disease or cytokine production. After combined inoculation with PRCV followed by bacterial lipopolysaccharide, both clinical respiratory disease and TNF-alpha/IL-1 production were markedly more severe than those associated with the respective single inoculations. Taken together, these data are the first to demonstrate that proinflammatory cytokines can be important mediators of viral respiratory diseases in pigs.  相似文献   

10.
The aim of the present study was to estimate the absorption of 125I-labeled proinflammatory cytokines--interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) from inflamed porcine uterus into the uterine venous blood. Moreover, in order to test the hypothesis that the above cytokines penetrate directly into ovaries and oviduct via local destination transfer in the area of the ovarian vascular pedicle and bypassing the systemic circulation, the concentration of IL-1beta, IL-6 and TNF-alpha in ovarian and oviductal tissues was also studied. These cytokine concentrations were also estimated in the ovarian venous blood. IL-1beta, IL-6 and TNF-alpha from both control and inflamed uteri were absorbed into the uterine venous blood, but it was higher (P < 0.05-0.001) from the pathologically changed uteri. The uterine tissues, particularly the endometrium, of both control and inflamed uteri retained all studied cytokines, but to a higher degree (P < 0.001) in the inflamed uteri. Injections of IL-1beta, IL-6 and TNF-alpha into the control and inflammatory changed uteri produced the presence of these proteins in the ovary and oviduct. However, the concentrations of IL-1beta and IL-6 in the ovarian and oviductal tissues was low after injections of control and inflamed uteri with these cytokines. In turn, administration of TNF-alpha into the inflammatory changed uteri lead to an enhancement in the concentration of this cytokine in the ovarian parenchyma (P < 0.05) and oviduct (P < 0.001). All studied cytokines were found in the ovarian venous blood after their injection into both control and inflamed uteri, which indicated its local destination transfer to the ovary. However, the concentration of cytokines increased (P <0.05-0.001) in the gilts with pathologically changed uteri as compared to controls. The study showed that both control and inflamed porcine uteri absorbed IL-1beta, IL-6 and TNF-alpha into the uterine venous blood, but the values of absorbed cytokines from inflamed uteri were higher. Moreover, the quantity and the manner of the studied cytokineS absorption into the uterine venous blood differed.  相似文献   

11.
An adjuvant effect of invertebrate DNA has been attributed to its relative high frequency of unmethylated CpG dinucleotides. Here we describe the interferon-alpha (IFN-alpha) and interleukin-6 (IL-6) inducing properties of a commonly used eukaryotic expression vector, pcDNA3, in porcine leukocytes. The magnitude of the cytokine response was compared to that induced by the synthetic ds RNA analogue poly(I):poly(C), inactivated preparations of Aujeszky's disease virus (ADV) and the Gram-negative bacteria Actinobacillus pleuropneumoniae. The plasmid, as well as poly(I):poly(C), required lipofectin to induce IFN-alpha production whereas both preparations induced IL-6 irrespective of preincubation with lipofectin. However, the nucleic acid-induced levels of IL-6 were low compared to those induced by A. pleuropneumoniae. The IFN-alpha response elicited by pcDNA3 in the presence of lipofectin was as high as, or higher than that induced by ADV. Interestingly, also A. pleuropneumoniae induced a substantial production of IFN-alpha when preincubated with lipofectin. Plasmid expression was not necessary for induction of IFN-alpha. Furthermore, the IFN-alpha inducing capacity of pcDNA3 was not reduced when the two predicted immunostimulatory sequences 5'AACGTT3' were deleted. Nor did the ability of the plasmid to induce IFN-alpha production decrease when the ampicillin resistance (ampR) gene was replaced with the kanamycin resistance (kanR) gene. However, methylation of all cytidines in CpG dinucleotides of pcDNA3 abolished the IFN-alpha inducing capacity. These in vitro results indicate an immunomodulatory role of bacterial DNA also in the pig. Unmethylated CpG dinucleotides are crucial for induction of IFN-alpha by the plasmid, but other CpG motifs than those within the 5'AACGTT3' sequences of the ampR gene contribute to this induction in porcine cells.  相似文献   

12.
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13.
OBJECTIVE: To measure and compare activities of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and matrix metalloproteinase-3 (MMP-3); as well as sulfated glycosaminoglycan (S-GAG) content in synovial fluid from dogs with cranial cruciate ligament rupture (CCLR) and dogs with clinically normal stifles. To determine whether correlations exist between demographic and disease-related variables and these synovial markers. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs with CCLR (n=23) and Beagles with normal stifle joints (n=21). METHODS: Synovial fluid activities of proinflammatory cytokines (IL-1beta, IL-6, and TNF-alpha) were determined by bioassay. MMP-3 activity was measured using fluorogenic substrate. S-GAG contents were determined by dimethylmethylene blue dye-binding assay. Mann-Whitney U-test was used to compare results from CCLR joints with normal controls. Spearman's rank correlation test was used to evaluate associations between demographic and disease-related markers and synovial markers. RESULTS: Mean values for synovial markers were significantly higher in CCLR joints compared with controls. IL-1beta and MMP-3 were positively correlated with lameness duration. CONCLUSIONS: Activities of proinflammatory cytokines, MMP-3 activity and S-GAG contents were significantly elevated in synovial fluid from canine stifle joints with naturally acquired CCLR. These results indicate that there is joint inflammation and increased release of GAGs into synovial fluid, suggesting that these inflammatory changes are associated with depletion of proteoglycan from articular cartilage. CLINICAL RELEVANCE: Medical and surgical treatments designed to decrease joint inflammation and breakdown of proteoglycans may be of value in the management of CCLR in the dog.  相似文献   

14.
To understand the role of non-secreted components of Actinobacillus pleuropneumoniae in virulence, we investigated in vitro cytotoxicity and in vivo pulmonary changes in pigs due to various A. pleuropneumoniae (serotype 1) fractions. Following 1.5 h incubation, lipopolysaccharide (LPS), 2 crude extracts and bacterial culture supernatant (BCS) at high concentrations were cytotoxic to porcine pulmonary alveolar macrophages (PAM), peripheral blood mononuclear leucocytes, neutrophils and a cultured porcine bone marrow cell line. Heat-killed bacteria were cytotoxic to PAM after 24 h incubation. The 2 crude extracts were prepared by shaking either intact bacteria after removing culture supernatants (crude surface extract, CSE), or whole bacterial culture (crude surface plus culture supernatant extract, CSSE) with glass beads in saline at 60 degrees C. Further experiments showed that proteins from the bacterial membrane were partially involved in cytotoxicities of these 2 extracts. Both BCS and CSSE caused multivocal hemorrhage and neutrophil infiltration when inoculated into porcine lungs, but CSE did not. The lung:whole body weight ratios of the pigs treated with CSSE were significantly higher (P < 0.05) than those of pigs treated with BCS, CSE, or control solution. It is concluded that beside the secreted proteins, bacterial surface components including LPS and non-secreted proteins were cytotoxic in vitro; and secreted and non-secreted components act synergistically to cause lung lesions.  相似文献   

15.
After intramammary infection, polymorphonuclear neutrophil leukocytes (PMN) are the first cells recruited into the mammary gland. Rapid recruitment of and bacterial phagocytosis and killing by PMN are the most effective defenses against establishment of bacterial infection. In addition to their phagocytic and bactericidal properties, PMN may play a key supportive role through secretion of cytokines during the innate immune response. We sought to determine whether bovine PMN produce cytokines in response to stimulation by lipopolysaccharide (LPS). To investigate the effects of LPS on the expression of cytokines secreted by bovine PMN, we measured the expression of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-12, and interferon (IFN)-gamma by ELISA after stimulation with different concentrations of LPS, and secretion of IL-8 after co-stimulation with LPS and either TNF-alpha or IL-1beta. Bovine PMN were shown to secrete TNF-alpha , IL-1beta, IL-12, IL-8 and IFN-gamma in response to LPS. Co-incubation of PMN with LPS and TNF-alpha increased secretion of IL-8 when compared to LPS alone. It was concluded that LPS stimulation up-regulates the secretion of cytokines by bovine PMN, and that co-incubation of LPS with TNF-alpha had an additive effect on the secretion of IL-8. These data show that bovine PMN, in addition to their phagocytic and bactericidal properties, may play a supportive role in the innate immune response to infection by Gram-negative bacteria through their ability to produce immuno-regulating cytokines.  相似文献   

16.
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.  相似文献   

17.
To gain further insight into the pathogenesis of porcine enzootic pneumonia (PEP), cytokine expression in different pulmonary compartments was examined. Mycoplasma hyopneumoniae (Mh) and proinflammatory and immunoregulatory cytokines (IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10 and TNF-alpha) were detected by immunohistochemical methods in porcine lungs experimentally infected with Mh. Ten pigs were inoculated intranasally with Mh and killed in pairs weekly from 1- to 5-week post-inoculation (wpi). Three Mh-free pigs were taken as controls. Mh-antigen was shown in paraffin-wax-embedded tissues by immunohistochemistry in the luminal surface of bronchial and bronchiolar epithelial cells of all Mh-infected pigs. Significant increase in cytokine expression was detected on snap-frozen tissues from the bronchoalveolar exudate of the airways, mononuclear cells of the alveolar septa and macrophages and lymphocytes of the peribronchial and peribronchiolar lymphoid tissue, from 1 wpi onwards, compared to expression in non-pneumonic lungs. The main cytokines in the BALT of Mh-infected animals that showed an increase were IL-2, IL-4, IL-8, IL-10 and TNF-alpha. In the alveolar septa and bronchoalveolar exudate IL-1 (alpha and beta), IL-2, IL-4, IL-8 and IL-10 expression also increased in infected animals.  相似文献   

18.
试验旨在探究S100A12在胸膜肺炎放线杆菌（Actinobacillus pleuropneumoniae，APP）诱导猪肺泡巨噬细胞（porcine alveolar macrophages，PAM）炎性细胞因子表达及吞噬中的作用。PAM细胞接种APP菌株后，用实时荧光定量PCR检测感染后不同时间点炎性细胞因子和S100A12的mRNA表达水平；构建S100A12重组蛋白表达载体并进行重组蛋白的表达纯化，用MTT法检测其对PAM的细胞毒性，实时荧光定量PCR检测不同浓度（0、5、50和500 ng/mL） S100A12重组蛋白对PAM炎性细胞因子mRNA表达水平的影响；构建S100A12干扰质粒，用Western blotting、实时荧光定量PCR及流式细胞术检测其干扰效率及其对APP感染PAM后炎性细胞因子mRNA表达水平和细胞凋亡的影响；用平板计数法检测S100A12表达对APP的黏附侵袭及其在PAM细胞内存活的影响。结果表明，APP感染促进PAM中IL-6、IL-8、IL-18、IL-1β和TNF-α等炎性细胞因子表达的同时也促进S100A12的表达，且该表达随APP感染剂量增大及时间的延长均显著或极显著增加（P<0.05；P<0.01）。5、50和500 ng/mL重组蛋白S100A12对PAM均没有毒性。5和50 ng/mL的重组蛋白S100A12均可显著促进PAM中IL-6、IL-8、TNF-α、IL-1β、IL-21和IL-5等炎性细胞因子的表达（P<0.05），而高浓度的S100A12重组蛋白则对上述炎性细胞因子表达无影响（P>0.05）。干扰质粒可成功阻断S100A12蛋白的表达，与转染shNC的对照组相比，在APP诱导下转染shS100A12干扰质粒的PAM中细胞因子IL-6、IL-8、IL-1β和IL-5的转录水平显著或极显著降低，且细胞凋亡率也显著或极显著增加（P<0.05；P<0.01）。进一步研究发现，干扰PAM中S100A12蛋白的表达可显著增强APP对PAM的黏附侵袭能力及其在PAM内的存活能力（P<0.05），相反，体外添加S100A12重组蛋白则显著抑制APP对PAM细胞的黏附侵袭及其在PAM内的存活（P<0.05）。以上研究表明，S100A12具有增强APP感染后PAM炎性细胞因子的表达、抑制APP诱导的PAM凋亡和降低APP对PAM的黏附侵袭及其在PAM内存活的作用，为进一步揭示APP感染过程中S100A12对PAM调控作用及机制奠定了基础。  相似文献   

19.
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20.
This paper reviews in vivo studies on the interaction between porcine reproductive and respiratory syndrome virus (PRRSV) and LPS performed in the authors' laboratory. The main aim was to develop a reproducible model to study the pathogenesis of PRRSV-induced multifactorial respiratory disease. The central hypothesis was that respiratory disease results from an overproduction of proinflammatory cytokines in the lungs. In a first series of studies, PRRSV was shown to be a poor inducer of TNF-alpha and IFN-alpha in the lungs, whereas IL-1 and the anti-inflammatory cytokine IL-10 were produced consistently during infection. We then set up a dual inoculation model in which pigs were inoculated intratracheally with PRRSV and 3-14 days later with LPS. PRRSV-infected pigs developed acute respiratory signs for 12-24h upon intratracheal LPS inoculation, in contrast to pigs inoculated with PRRSV or LPS only. Moreover, peak TNF-alpha, IL-1 and IL-6 titers were 10-100 times higher in PRRSV-LPS inoculated pigs than in the singly inoculated pigs and the cytokine overproduction was associated with disease. To further prove the role of proinflammatory cytokines, we studied the effect of pentoxifylline, a known inhibitor of TNF-alpha and IL-1, on PRRSV-LPS induced cytokine production and disease. The clinical effects of two non-steroidal anti-inflammatory drugs (NSAIDs), meloxicam and flunixin meglumine, were also examined. Pentoxifylline, but not the NSAIDs, significantly reduced fever and respiratory signs from 2 to 6h after LPS. The levels of TNF-alpha and IL-1 in the lungs of pentoxifylline-treated pigs were moderately reduced, but were still 26 and 3.5-fold higher than in pigs inoculated with PRRSV or LPS only. This indicates that pathways other than inhibition of cytokine production contributed to the clinical improvement. Finally, we studied a mechanism by which PRRSV may sensitize the lungs for LPS. We hypothesized that PRRSV would increase the amount of LPS receptor complex in the lungs leading to LPS sensitisation. Both CD14 and LPS-binding protein, two components of this complex, increased significantly during infection and the amount of CD14 in particular was correlated with LPS sensitisation. The increase of CD14 was mainly due to infiltration of strongly CD14-positive monocytes in the lungs. The PRRSV-LPS combination proved to be a simple and reproducible experimental model for multifactorial respiratory disease in pigs. To what extent the interaction between PRRSV and LPS contributes to the development of complex respiratory disease is still a matter of debate.  相似文献   

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