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1.
We have established experimental models of bovine leukemia virus (BLV) infection followed by progression to persistent lymphocytosis (PL) positive (BLV+PL+) or PL negative (BLV+PL-) stages of infection. Two out of six BLV infected animals developed PL+ 4 weeks after BLV infection. One other animal became PL+ late in the course of infection and three infected animals stayed PL-. These animals (PL-) exhibited transient lymphocytosis 3-4 weeks after infection and sustained PL- lymphocyte counts up to 24 weeks after infection. Competitive RT-PCR analysis of IFN-gamma mRNA expression revealed that peripheral blood mononuclear cells (PBMC) of animals with PL+ status developed by 4 weeks after infection had augmented IFN-gamma mRNA expression 3-4 weeks after BLV infection. However PBMC of animals that sustained a long-termed PL- lymphocyte count had elevated IFN-gamma mRNA expression 1-24 weeks after infection. Competitive RT-PCR analysis of IL-2 mRNA expression showed an increase in the levels of IL-2 mRNA in PL animals. Interleukin-10 (IL-10) mRNAs expression were elevated both in PL+ and PL- animals from 3 and 12 weeks after infection respectively. We suggest that early and extended expression of cellular response cytokines may delay the progression to PL+ in enzootic bovine leukemia.  相似文献   

2.
We report the effects of supplemental chromium (Cr) on interferon-gamma (IFN-gamma) expression in response to Newcastle disease virus (NDV) vaccine in broiler chicken. Two hundred and eighty day old straight run broiler chicks were randomly selected and allocated at random to one of the seven treatment groups replicated four times having 10 chicks in each replication. Treatment 1 (C) was a standard control diet in which no Cr was offered to birds either through feed or drinking water. In treatments 2-4 (F500, F1000 and F1500), Cr in the form of chromium picolinate (CrPic) was added at rates of 500, 1000 and 1500 ppb in diets, respectively. In treatments 5-7 (W250, W500 and W750), Cr as added to the drinking water at rates of 250, 500 and 750 ppb, respectively. The feeding was continued from 1 to 49 d of age. On 49 d, three birds from each replicate, i.e. 12 birds/treatment were inoculated intramuscularly with R(2)B strain of NDV. Twelve unvaccinated birds along with 12 vaccinated birds from each treatment (four birds each day) were then sacrificed on 1, 3 and 7 days post-immunization to study the IFN-gamma expression using quantitative real time PCR. Following the immunization, the IFN-gamma mRNA expression in spleen was significantly (P<0.01) either up-regulated or down-regulated at day 1 and day 3 post-stimulation. Whereas, IFN-gamma mRNA expression reached basal level in all the vaccinated groups at day 7 post-stimulation. IFN-gamma mRNA expression on day 1 was approximately two and four times higher than the control (C) levels in F500 and W500 groups, respectively. On 3 day post-immunization, IFN-gamma mRNA expression in spleen was about 40 and 27 times higher than controls (C) in F500 and W500 groups, respectively. Other groups (F1000, F1500, W250 and W750) showed down-regulation of IFN-gamma mRNA expression. The results suggested that the dosage of chromium modulates the expression of IFN-gamma and route has effect on the onset and duration of the response. Thus, the supplementation of chromium at appropriate dose might be helpful to enhance the IFN-gamma mRNA expression in response to NDV.  相似文献   

3.
Colibacillosis results from infection with avian pathogenic Escherichia coli bacteria. Healthy broilers are resistant to inhaled E. coli, but previous infection with vaccine or virulent strains of Infectious Bronchitis Virus (IBV) predisposes birds for severe colibacillosis. We investigated whether IBV affects recruitment and function of phagocytic cells and examined NO production, phagocytic and bactericidal activity, and kinetics of peripheral blood mononuclear cells (PBMC) and splenocytes. Moreover, we measured cytokine mRNA expression in lung and spleen samples. Broilers were inoculated with IBV H120 vaccine or virulent M41 and challenged 5 days later with E. coli 506. A PBS control and E. coli group without previous virus inoculation were also included. Birds were sacrificed at various time points after inoculation (h/dpi). Inoculation with IBV induced extended and more severe colibacillosis than with E. coli alone. At 4dpi, the number of KUL-01(+) PBMC in all E. coli-inoculated groups was significantly higher than in PBS-inoculated birds, which correlated with lesion scores. From 1 to 4dpi, NO production by PBMC from all E. coli-inoculated animals was elevated compared to PBS birds. Bactericidal activity of PBMC in IBV-inoculated animals at 7dpi was lower than in PBS- and E. coli-inoculated birds, but phagocytic capacity and recruitment were not severely impaired. In spleen samples of IBV-infected animals reduced expression of IL-1beta, IL-6, IL-8, IL-10, IL-18 and IFN-gamma mRNA was found 1dpi. Our results suggest that enhanced colibacillosis after IBV infection or vaccination is caused at least by altered innate immunity and less by impairment of phagocytic cell function.  相似文献   

4.
The immune protective response developed by swine against Trichinella spiralis is not yet fully understood, particularly at the mucosal level. This study aimed to characterise intestinal immunity to T. spiralis by comparison with the systemic response in specifically pathogen-free pigs. For this purpose, the kinetics of cytokine and antibody production were assessed in the intestinal mucosa and serum of swine infected with T. spiralis for up to 60 days post-infection (dpi). An ex vivo model of jejunum mucosa culture was used to collect the supernatant as a source of antibodies (Abs). Mucosal antibodies were observed by Western blot from 15 dpi, while serum antibodies were expressed from 20 dpi. Both sources of antibodies initially recognized a 110 kDa protein, followed by the identification of 35, 43/46 and 55/59 kDa proteins. IgG1 and IgA antibodies were strongly expressed within the mucosa. The expression levels of Type 1 (IFN-gamma, IL-12), Type 2 (IL-4, IL-6), pro-inflammatory (TNF-alpha) and regulatory (IL-10, TGF-beta) cytokines were assessed by RT-PCR in the intestinal mucosa and spleen. Both IL-10 and IFN-gamma mRNA levels were increased in mucosa, whereas IL-6 and IL-12 mRNA were expressed in spleen. Taken together, these results demonstrated a mixed Type 1/Type 2 profile, the Type 2 profile being dominant in the mucosa.  相似文献   

5.
In Chinese Meishan/German Landrace cross-bred swine F2 generation interferon gamma (IFN-gamma) production by peripheral blood mononuclear cells (PBMC) was determined directly ex vivo at different time points after survival of a virulent pseudorabies virus (PRV) infection. This reactivity was compared with the reactivity of na?ve PBMC. Significant IFN-gamma production was determined in ELISA and ELISPOT only after in vitro PBMC re-stimulation with PRV and not with the closely related bovine herpesvirus BHV-1. The PRV-specific IFN-gamma secretion from re-stimulated PBMC showed high levels 6 days after infection, before the presence of serum antibodies, and it persisted at a high level over a 3 months period. The response of a group of eight piglets infected intranasally with PRV varied. Only two animals showed the expected typical fever response. PRV specific IFN-gamma production by PBMC clearly indicated that infection had occurred. Early significant IFN-gamma production by primed PBMC turned out to be a reliable and specific ex vivo marker for cellular response against productive PRV infection in swine before antibody formation.  相似文献   

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8.
Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) expression in crossbred (Bos taurusxBos indicus) bovine calves during primary infection with Fasciola gigantica was measured. Ten crossbred calves of 1-year age were divided into two groups of five calves each, group I uninfected control and group II calves orally infected with a dose of 1000 metacercariae of F. gigantica. The two cytokines were measured 10, 30 and 75 days post-infection (PI) by real-time polymerase chain reaction (RT-PCR) with the double stranded DNA-binding dye SYBR Green. IL-4 was present in detectable levels in peripheral blood mononuclear cells (PBMCs) of infected animals at 10, 30 and 75 days PI but no IFN-gamma was detected in PBMCs of infected animals at 10 and 30 days PI. However, at 75 days PI, IFN-gamma in two infected animals was present in detectable level. Eosinophil count increased from 2nd fortnight after infection and the increased level persisted till the termination of experiment. Present study indicated that T-cell response during F. gigantica infection was Th2-type during earlier phase of infection, which may be polarized in chronic infection to that of a Th0-type.  相似文献   

9.
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10.
Most of the studies regarding the immunopathogenesis of avian Metapneumovirus (aMPV) have been done with subtype C of aMPV. Not much is known about the immunopathogenesis of aMPV subtypes A and B in turkeys. Specifically, local immune reactions have not been investigated yet. We conducted two experiments in commercial turkeys. We investigated local and systemic humoral and cell mediated immune reactions following infection with an attenuated vaccine strain of aMPV subtype B (Experiment I) and virulent strains of aMPV subtypes A and B (Experiment II). Turkeys infected with virulent aMPV strains developed mild respiratory signs while birds inoculated with the attenuated aMPV did not show any clinical signs. Virus neutralizing antibodies were detected locally in tracheal washes and systemically in serum as soon as 5-7 days post aMPV infection (PI) independent of the strain used. Virus neutralizing antibody titres peaked at 7 days PI and then antibody levels declined. The peak of serum ELISA antibody production varied between infected groups and ranged from 14 and 28 days PI. All aMPV strains induced an increase in the percentage of CD4+ T cell populations in spleen and Harderian gland at days 7 or 14 PI. Furthermore, as shown in Experiment I, infection with the attenuated aMPV-B strain stimulated spleen leukocytes to release significantly higher levels of interferons (IFNs), interleukin-6 and nitric oxide in ex vivo culture in comparison to virus-free controls up to 7 days PI (P<0.05). As detected by quantitative real time RT-PCR in Experiment II, infection with virulent aMPV induced an increased IFNgamma expression in the Harderian gland in comparison to virus-free controls. IFNgamma expression in the spleen varied between aMPV strains and days PI. Overall, our study demonstrates that aMPV subtypes A and B infection induced humoral and cell mediated immune reactions comparable to subtype C infections. We observed only temporary stimulation of serum virus neutralizing antibodies and of most of the local immune reactions independent of the aMPV strain used. The temporary character of immune reactions may explain the short duration of protection against challenge following aMPV vaccination in the field.  相似文献   

11.
Porcine reproductive and respiratory syndrome virus (PRRSV) induces a persistent viral infection associated with an inefficient humoral immune response. A study of lymphoid B cells and specific humoral immune response was performed in blood and several lymphoid organs collected from PRRSV experimentally-infected pigs. Groups of specific pathogen-free (SPF) pigs were infected with the LHVA-93-3 isolate of PRRSV, and blood, tonsils, spleen and mediastinal lymph nodes (MLN) were collected at various times postinfection (p.i.) (3-60 days). Lymphoid cells were isolated, immunolabeled for cytofluorometric determination of B cell percentages, used for counting specific anti-PRRSV antibody secreting B cells by an ELISPOT assay, or cultured for metabolic activity. The presence of anti-PRRSV antibodies in the serum of infected pigs was determined using a commercial ELISA assay. Virus detection was performed in all tissues, including lungs, by virus isolation and RT-PCR. The results show that percentages of B cells increased in tonsils as soon as 3 days until 17 days p.i. in PRRSV-infected pigs while they increased in spleen at 3 days p.i. only, due to an increase of larger Ig(high)-producing B cells. Metabolic activity of lymphoid cells from blood and spleen increased at 3 days p.i. only while lymphoid cells from tonsils and MLN transiently decreased at that time and increased thereafter up to 60 days p.i. Anti-PRRSV antibody-secreting B cells occurred in tonsils after 10 days p.i. and strongly increased up to 60 days p.i. However, specific anti-PRRSV-secreting B cells were detected in blood and spleen after 17 days p.i and in MLN only after 45 days p.i. Specific antibodies were detectable in serum at 10 days p.i., reached the maximum level at 45 days and remained high up to 60 days p.i. Infectious virus was detected in lungs and MLN as soon as 3 days p.i., and remained detectable up to 45 days p.i. in tonsils of one pig while viral RNA was detected in most organs up to 60 days p.i. In vitro experiments revealed that inactivated virus induced a stimulation of lymphoid cells isolated from PRRSV-infected pigs while it was cytotoxic for lymphoid cells from control pigs. Taken together, these results indicate that viral infection induced simultaneously a polyclonal activation of B cells, mainly in tonsils, and an exaggerated and prolonged specific humoral immune response due to persistent viral infection in lymphoid organs.  相似文献   

12.
Previously, we have reported that the injection of an expression vector containing Herpes simplex virus (HSV) Glycoprotein D-1 (gD-1) generated a significant antibody response in mice and protected them against HSV lethal challenge. We tested its potential to induce antibody and cell mediated immune responses in latently infected mice. Positive control group (KOS) and HSV gD-1 vaccinated mice demonstrated protection against a lethal ocularly challenge of 10(5.5) plaque-forming units (pfu)/eye of wild HSV-1 versus negative control groups. For neutralizing antibody titers, delayed-type hypersensitivity (DTH), lymphocyte proliferation responses, clinical evaluation and survival following lethal challenge, no considerable difference was observed between mice vaccinated with DNA plasmid and those vaccinated with KOS. KOS-vaccinated mice demonstrated the ability to completely prevent latency whereas DNA vaccinated group showed some degree of protection and displayed less latency than negative control groups and had considerably high levels of IFN-gamma and strong CTL responses versus negative control groups. It can be concluded that although immunization with the DNA vaccine is more effective in both protecting mice and induction of immune response, however it could not completely block the latent infection in sensory nerves.  相似文献   

13.
A DNA vaccination trial was performed on sheep to determine whether vaccination with bovine leukemia virus (BLV) transactivator Tax DNA is effective against BLV infection. Immunization was carried out with cationic liposomes containing the Tax-expressing plasmid DNA and subsequently all sheep were challenged with BLV. BLV titers in peripheral blood mononuclear cell (PBMC) determined by syncytium formation assay and BLV provirus load detected by genomic PCR analysis showed higher levels of virus titers in control sheep than those in Tax-vaccinated sheep. Higher levels of IFN-gamma mRNA expression have been demonstrated in vaccinated sheep after the challenge. These results suggested that Th1 type immune response induced by Tax DNA vaccine inhibited BLV propagation in vaccinated sheep at the early phase of infection.  相似文献   

14.
PRRSV SC-1株在人工感染仔猪体内的分布   总被引：2，自引：0，他引：2  
为研究猪繁殖与呼吸综合征病毒(PRRSV)在感染猪体内各器官组织的分布,用PRRSV SC-1株人工感染健康断奶仔猪,接毒后23 d,无菌采集试验猪器官组织,用RT-PCR检测其中病毒核酸分布情况。结果显示,心脏、脾脏、肺脏、肾脏、支气管淋巴结、肠系膜淋巴结、腹股沟淋巴结、髂内淋巴结内有病毒核酸,在所有试验猪的肺脏、腹股沟淋巴结都检测到了病毒核酸。本研究结果为PRRS诊断及病毒分离鉴定提供了一定参考依据。  相似文献   

15.
This test was designed to study the expression of POTs (PepT1, PepT2, PHT1 and PHT2) mRNA in calves'tissues.Tissue-specific expression of the mRNA corresponding to peptide transporter protein in four 3-month-old Chinese Holstein calves was examined by relative quantitative RT-PCR analysis.The results showed that the expression of PepT1 mRNA in the rumen was extremely significantly higher than that in the heart and muscle (P<0.01);The expression of PepT2 mRNA in the liver and kidney was extremely significantly higher than that in the heart, spleen, thymus, muscle, rumen, reticulum, omasum and abomasum (P<0.01);The expression of PHT1 mRNA in the lung and spleen was extremely significantly higher than that in the heart and muscle (P<0.01);The expression of PHT2 mRNA in the lung and thymus was significantly higher than that in the heart, liver, kidney, spleen, muscle, rumen, reticulum, omasum and abomasum (P<0.05).The results indicated that PepT1, PepT2, PHT1 and PHT2 mRNA were respectively abundantly expressed in rumen, kidney and liver, spleen and lung, lung and thymus.  相似文献   

16.
为研究犊牛部分组织中小肽转运体(proton-dependent oligopeptide transporters,POTs) (PepT1、PepT2、PHT1、PHT2) mRNA的表达,试验选用4头3月龄的中国荷斯坦犊牛进行屠宰,采用实时荧光定量PCR方法来定量组织中小肽转运蛋白表达水平。结果表明,犊牛PepT1 mRNA在瘤胃中表达丰度极显著高于心脏和肌肉(P<0.01);犊牛PepT2 mRNA在肝脏和肾脏中表达丰度极显著高于心脏、脾脏、胸腺、肌肉、瘤胃、网胃、瓣胃、皱胃(P<0.01);犊牛PHT1 mRNA在肺脏和脾脏中表达丰度极显著高于心脏和肌肉(P<0.01);犊牛PHT2 mRNA在肺脏和胸腺中表达丰度显著高于心脏、肝脏、肾脏、脾脏、肌肉、瘤胃、网胃、瓣胃、皱胃(P<0.05)。综上所述,PepT1、PepT2、PHT1、PHT2 mRNA分别在犊牛瘤胃、肾脏和肝脏、脾脏和肺脏、肺脏和胸腺中表达量最高。  相似文献   

17.
Interleukin 4 (IL-4) is expected to play a dominant role in the development of T helper (Th) 2 cells. Th2 immune responses with expression of relatively large amounts of interleukin 4 (IL-4) but little interferon gamma (IFN-gamma) are characteristic for chronic helminth infections. But no information is available about IL4 expression during early Fasciola hepatica (F. hepatica) infections in cattle. Therefore, we investigated F. hepatica specific IL-4 and IFN-gamma mRNA expression in peripheral blood mononuclear cells (PBMCs) from calves experimentally infected with F. hepatica. Cells were collected prior to infection and on post-inoculation days (PIDs) 10, 28 and 70. Interestingly, PBMCs responded to stimulation with F. hepatica secretory-excretory products (FhSEP) already on PID 10 and expressed high amounts of IL-4 but not of IFN-gamma mRNA suggesting that F. hepatica induced a Th2 biased early immune response which was not restricted to the site of infection. Later in infection IL-4 mRNA expression decreased whereas IFN-gamma mRNA expression increased slightly. Isolated lymph node cells (LNCs) stimulated with FhSEP and, even more importantly, non-stimulated LN tissue samples indicated highly polarized Th2 type immune responses in the draining (hepatic) lymph node, but not in the retropharyngeal lymph node. During preliminary experiments, two splice variants of bovine IL-4 mRNA, boIL-4delta2 and boIL-4delta3, were detected. Since a human IL-4delta2 was assumed to act as competitive inhibitor of IL-4, it was important to know whether expression of these splice variants of bovine IL-4 have a regulatory function during an immune response to infection with F. hepatica. Indeed, IL-4 splice variants could be detected in a number of samples, but quantitative analysis did not yield any clue to their function. Therefore, the significance of bovine IL-4 splice variants remains to be determined.  相似文献   

18.
In order to study the effect of different weaning age on related-growth gene expressions of spleen in piglets,24 similar body weight and healthy piglets were selected (Duroc×Landrace×Yorkshine).All piglets were randomly divided into 4 groups (14,21,28 and 35 days of age weaning groups),and each group had 6 replications including 1 piglet separately.They were slaughtered at 24 days of age and spleen samples were acquired.The relative expression of growth hormone receptor (GHR),insulin like growth factor-1 (IGF-1),insulin like growth factor-1 receptor (IGF-1R) mRNA in spleen were measured by RT-PCR.The results showed that the relative expression of GHR mRNA in 14 and 21 days of age weaning groups was significantly higher than that in 35 days of age weaning group (P<0.05);The relative expression of IGF-1 mRNA in spleen at different weaning age groups was no significant difference (P>0.05);The relative expression of IGF-1R mRNA in 35 days of age weaning group was significantly higher than that in 28 days of age weaning group (P<0.05).The results indicated that the patterns of weaning age on related growth gene expressions of spleen are different;The expressions of spleen IGF-1R mRNA in different weaning age groups were possibly effected by the spleen self regulation of IGF-1.  相似文献   

19.
不同断奶日龄对仔猪脾脏生长相关基因表达的影响   总被引：1，自引：0，他引：1  
为研究不同断奶日龄对仔猪脾脏中生长激素受体(growth hormone receptor,GHR)、胰岛素样生长因子-1(insulin like growth factor-1,IGF-1)和胰岛素样生长因子-1受体(insulin like growth factor-1 receptor,IGF-1R)基因表达的影响,试验选取体重相近、健康的杜×长×大仔猪24头,随机分为4组(14、21、28和35日龄断奶组),每个试验组6个重复,每个重复1头仔猪,至42日龄时全部宰杀取样,用RT-PCR方法检测脾脏中上述基因的相对表达水平.结果表明,14和21日龄断奶组仔猪脾脏GHR mRNA的相对表达量显著高于35日龄断奶组(P<0.05);不同断奶日龄组仔猪脾脏中的IGF-1 mRNA的相对表达量均无显著性变化(P>0.05);35日龄断奶组仔猪脾脏中IGF-1R mRNA的相对表达量显著高于28日龄断奶组(P<0.05).结果提示,不同断奶日龄对仔猪脾脏相关生长基因表达影响的模式不同;不同断奶日龄脾脏IGF-1R mRNA的表达可能受脾脏自身局部IGF-1的调控.  相似文献   

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