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1.
Oligodeoxynucleotides containing the cytosine-phosphate-guanine (CpG) motif (CpG-ODNs) have been shown to induce T(H)1 immune responses in animals. Since the sequences of CpG-ODNs that induce T(H)1 responses are considered to vary among animal species, it is necessary to identify effective CpG-ODNs in each animal. In order to identify the sequences of CpG-ODNs that induce T(H)1 responses in dogs, mRNA expression and protein production of IFN-gamma were examined in peripheral blood mononuclear cells (PBMCs) from healthy dogs treated with 11 kinds of synthetic CpG-ODNs. One of the 11 CpG-ODNs (No. 2 CpG-ODN, 5'-GGTGCATCGATGCAGGGGGG-3') was shown to significantly increase mRNA expression and protein production of IFN-gamma in canine PBMCs in a manner dependent on the sequence of the CpG motif. This CpG-ODN also enhanced the expression of IL-12 p40 mRNA in canine PBMCs, whereas expression of IL-12 p35, IL-18, and IL-4 mRNAs was not induced by this CpG-ODN. These results indicate that this CpG-ODN was able to produce IFN-gamma by induction of T(H)1-skewed immune response in dogs. CpG-ODNs may be useful for inducing prophylactic and therapeutic immunity against allergic diseases, viral infection, and tumors in dogs.  相似文献   

2.
We evaluated the immunogenic and protective potential of a recombinant VapA/CpG oligodeoxynucleotide (ODN) 2395 vaccine in neonatal foals undergoing experimental Rhodococcus equi challenge. Foals (n = 8) were vaccinated by intramuscular injection on days 1 and 15 of the study; control foals (n = 7) received a phosphate-buffered saline (PBS) solution. All foals were challenged by intrabronchial administration of 5 × 106R. equi 103+ on day 29. Bronchoalveolar lavages were done on days 15, 29, and 36 and total cell count, differential cell count, rVapA-stimulated cell proliferation and interferon (IFN)-γ mRNA expression determined. Clinical examination, complete blood (cell) counts, serology for VapA-specific antibodies, and culture of nasal and fecal swabs were done on days 1, 15, 29, 36, 43, and 50. Foals were humanely euthanized on day 50 and severity of pneumonia scored on a 4-point scale. Vaccination resulted in a significant increase in VapA-specific immunoglobulin (Ig) production, with total IgG and IgG(T) being increased by day 15. Expression of VapA-specific IFN-γ mRNA by BAL cells was increased in the vaccinated foals following challenge. Postmortem lung severity scores did not differ between groups. Two foals shed virulent R. equi in feces; however, real-time polymerase chain reaction (PCR) revealed the isolates to be different from the challenge strain.  相似文献   

3.
There is a distinct age-associated susceptibility of horses to Rhodococcus equi infection. Initial infection is thought to occur in the neonatal and perinatal period, and only foals less than 6 months of age are typically affected. R. equi is closely related and structurally similar to Mycobacterium tuberculosis, and causes similar pathologic lesions. Protective immune responses to M. tuberculosis involve classical major histocompatibility complex (MHC)-restricted T cells that recognize peptide antigen, as well as MHC-independent T cells that recognize mycobacterial lipid antigen presented by CD1 molecules. Given the structural similarity between these two pathogens and our previous observations regarding R. equi-specific, MHC-unrestricted cytotoxic T lymphocytes (CTL), we developed 3 related hypotheses: (1) CD1 molecules are expressed on equine antigen presenting cells (APC), (2) CD1 expression on APC is less in foals compared to adults and (3) infection with live virulent R. equi induces up-regulation of CD1 on both adult and perinatal APC. CD1 expression was examined by flow cytometric analysis using a panel of monoclonal CD1 antibodies with different species and isoform specificities.

Results

Three CD1 antibodies specific for CD1b showed consistent cross reactivity with both foal and adult monocyte-derived macrophages (MDM). CD1b and MHC class II expression were significantly higher on adult MDM compared with foals. R. equi infected MDM showed significantly lower expression of CD1b, suggesting that infection with this bacterium induces down-regulation of CD1b on the cell surface. Histograms from dual antibody staining of peripheral blood mononuclear cells also revealed that 45–71% of the monocyte population stained positive for CD1b, and that the majority of these also co-expressed MHC II molecules, indicating that they were APC. The anti-CD1 antibodies showed no binding or minimal binding to bronchoalveolar lavage (BAL)-derived macrophages.

Conclusion

The CD1b isoform is evolutionarily conserved, and is present on equine MDM, as well as on circulating blood monocytes. The unique susceptibility of foals to R. equi infection may be due in part to lower expression of CD1 and MHC class II, as observed in this study. The data also suggests that infection with R. equi induces down-regulation of CD1b on equine MDM. This may represent a novel mechanism by R. equi to avoid detection and killing of infected cells by the immune system, similar to that observed when human APC are infected with M. tuberculosis.  相似文献   

4.
Rhodococcus equi is an intracellular pathogen of macrophages that causes rhodococcal pneumonia in foals and immunocompromised people. Evidence exists that neutrophils play a vital role in resistance to infection with R. equi; however, the means by which neutrophils exert their effects have not been clearly defined. In addition to directly killing bacteria, neutrophils also may exert a protective effect by linking innate and adaptive immune responses. In the present study we evaluated the cytokine expression profiles of adult equine neutrophils in response to stimulation with isogenic strains of virulent and avirulent R. equi in vitro. After 2 and 4 h incubation with virulent or avirulent R. equi, adult equine neutrophils expressed significantly (P < 0.05) greater tumor necrosis factor alpha (TNFα), interleukin (IL)-12p40, IL-6, IL-8 and IL-23p19 mRNA, but not interferon gamma (IFNγ) or IL-12p35 mRNA than unstimulated neutrophils. Furthermore, virulent R. equi induced significantly greater IL-23p19 mRNA than avirulent R. equi. These results demonstrate that R. equi-stimulated neutrophils are a source of many proinflammatory cytokines. Furthermore, these results suggest that IL-23 may be preferentially expressed over IL-12 in response to exposure with R. equi, and that this response may be more strongly induced by virulent R. equi than avirulent R. equi. Collectively, the data presented herein suggest a non-phagocytic role for neutrophils that may influence the type of adaptive immune response to R. equi.  相似文献   

5.
Cytokines produced by T helper (Th) cells are important in orchestrating the immune response during health and disease. Recent reports indicated that cytokine mRNA expression in foals is often quantitatively lower than that of adult horses suggesting that foal T cells are not fully mature. Here, peripheral blood mononuclear cells from foals and adult horses were stimulated with phorbol 12-myristate 13-acetate and analyzed for intracellular interferon-gamma (IFN-γ), interleukin-4 (IL-4) and IL-10 production, representing the Th1, Th2 and regulatory TR1 cell phenotypes respectively, by flow cytometry. In agreement with previous reports, all three cytokines were quantitatively reduced in foals compared to adults. However, the balance between Th1 and Th2 cytokines (IFN-γ/IL-4 ratio) showed a clear Th1-biased response in foals by 6 and 12 weeks of life, while similar IFN-γ/IL-10 ratios were found in foals and adult horses. By day 5 after birth, intracellular IFN-γ production by foal CD4+ and CD8+ T cells resembled that in adults. Overall, IL-4 production was low in foals. IL-4+ cells peaked at day 5 of age when IL-4 was mainly produced by IgE+ cells. Relative percentages of IL-4+ Th2 cells were significantly lower in foals at all time points. The data suggested that equine neonates and young foals have an impaired Th2 response, that the immune response of foals is Th1 biased, that IFN-γ production by Th and cytotoxic T cells is qualitatively similar to adult horses, and regulatory IL-10 production by T cells is developmentally mature in foals during the first three months of life.  相似文献   

6.
Reasons for performing the study: Disease caused by Rhodococcus equi is a significant burden to the horse breeding industry worldwide. Early detection of rhodococcal pneumonia, albeit important to minimise treatment costs, is difficult because of the insidious nature of the disease and the lack of definitive diagnostic tests. Objectives: To investigate air sampling from the breathing zone of neonatal foals as a predictor of subsequent rhodococcal pneumonia. Methods: Air samples were collected from the breathing zone of 53 neonatal foals (age ≤10 days) and again at the time of routine ultrasonographic screening for R. equi pneumonia (age 1–2 months). Results: Pneumonia was diagnosed ultrasonographically in 23% of foals. Virulent R. equi was detected in air from the breathing zone of 19% of neonatal foals and 45% of foals at age 1–2 months. There was no association between virulent R. equi in the breathing zone of foals and the subsequent ultrasonographic diagnosis of rhodococcal pneumonia. The median concentration of virulent R. equi in the breathing zone of both neonates (0 [range 0–4] colony‐forming units [cfu]/250 l) and older foals (0 [range 0–3] cfu/250 l) was not significantly different from that in background air samples (0 [range 0–6] cfu/250 l). There was no difference in the concentration of virulent R. equi in the breathing zone of older foals that were diagnosed with rhodococcal pneumonia or clinically normal foals. Conclusion: Detection of virulent R. equi in air from the breathing zone was not a positive predictor of rhodococcal pneumonia in foals up to age ≤2 months. Potential relevance: Selective culture of air samples from the breathing zone of young foals is not better at diagnosing rhodococcal pneumonia than early ultrasonographic screening. However, culture of air samples from the breathing zone of older foals remains a useful herd‐based epidemiological tool.  相似文献   

7.
Respiratory diseases, including inflammatory airway disease (IAD), viral and bacterial infections, are common problems in exercising horses. The airway epithelium constitutes a major physical barrier against airborne infections and plays an essential role in the lung innate immune response mainly through toll-like receptor (TLR) activation. The aim of this study was to develop a model for the culture of equine bronchial epithelial cells (EBEC) in vitro and to explore EBEC innate immune responses in trained horses. Bronchial epithelial biopsies were taken from 6 adult horses during lower airway endoscopy. EBEC were grown in vitro by an explant method. The innate immune response of EBEC was evaluated in vitro by treatment with TLR ligands. TLR3 is the most strongly expressed TLR at the mRNA level in EBEC and stimulation of EBEC with Poly(I:C), an analog of viral dsRNA, triggers a strong secretion of IFN-β, TNF-α, IL-6 and CXCL8. We further evaluated the EBEC innate immune response in horses that underwent a 4-month-training program. While training had no effect on TLR mRNA expression in EBEC as well as in bronchial biopsies, it increased the production of IFN-β after stimulation with a TLR3 ligand and decreased the secretion of TNF-α and IL-6 after stimulation with a TLR2 and TLR3 ligand. These findings may be implicated in the increased risk for viral and bacterial infections observed in sport horses. Altogether, we report a successful model for the culture of EBEC that can be applied to the investigation of pathophysiologic conditions in longitudinal studies.  相似文献   

8.
Rhodococcus equi is an intracellular bacterium that causes pneumonia in foals and immunocompromised adult horses. Evidence exists that foals become infected with R. equi early in life, a period when innate immune responses are critically important for protection against infection. Neutrophils are innate immune cells that play a key role in defense against this bacterium. Enhancing neutrophil function during early life could thus help to protect foals against R. equi infection. The objective of our study was to determine whether in vitro incubation with the TLR9 agonist CpG 2142 would enhance degranulation and gene expression of cytokines and Toll-like receptor 9 (TLR9) by neutrophils collected from foals at 2, 14, and 56 days of life, and to determine whether these stimulated responses varied among ages. Neutrophil degranulation was enhanced at all ages by in vitro stimulation with either CpG alone, R. equi alone, or in combination with either R. equi or N-formyl-methionyl-leucyl-phenylalanine (fMLP) (P<0.05), but not by in vitro stimulation with fMLP alone. There were no significant differences among ages in CpG-induced cytokine expression, except for IL-12p40, which was induced more at 56 days of age than on days 2 or 14. Collapsing data across ages, CpG 2142 significantly (P<0.05) increased IL-6 and IL-17 mRNA expression. We concluded that in vitro stimulation of foal neutrophils with CpG enhances their function by promoting degranulation and inducing mRNA expression of IL-6 and IL-17, regardless of age.  相似文献   

9.
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10.
Rhodococcus equi is the most common infectious cause of mortality in foals between 1 and 6 months of age. Because of an increase in the number of antibiotic-resistant strains, the optimization of a prophylactic strategy is a key factor in the comprehensive management of R. equi pneumonia.The objectives of this study were to assess the safety and immunogenicity of R. equi-secreted proteins (ReSP) co-administered with either the nanoparticular adjuvant Montanide? IMS 3012 VG, or a new polymeric adjuvant Montanide? PET GEL A, and to further investigate the most immunogenic proteins for subsequent immunization/challenge experiments in the development of a vaccine against rhodoccocal pneumonia. The approach involved two phases. The first phase aimed to investigate the safety of vaccination in six adult horses. The second phase aimed to determine the safety and immunogenicity of vaccination in twelve 3-week-old foals.We set out to develop a method based on ultrasound measurements for safety assessment in adult horses in order to evaluate any in situ changes at the injection site, in the skin or the underlying muscle, with quantitative and qualitative data revealing that administration of ReSP combined with the Pet Gel A adjuvant led to an increase in local inflammation, associated with 4- to 7-fold higher levels of anti-R. equi IgGa, IgGb and IgGT, compared to administration of ReSP associated with IMS 3012 adjuvant, but without any impact on animal demeanor. Investigations were then performed in foals with serological and clinical follow-up until 6 months of age. Interestingly, we observed in foals a much lower incidence of adverse local tissue reactions at the injection site than in adult horses, with transient and moderate swelling for the group that received ReSP combined with Pet Gel A. Immunized foals with Pet Gel A adjuvant exhibited a similar response in both IgGa and IgGT levels, but a lower response in IgGb levels, compared to adult horses, with a subisotype profile that may however reflect a bias favorable to R. equi resistance. From the crude extract of secreted proteins, dot-blot screening enabled identification of cholesterol oxidase, mycolyl transferase 3, and PSP (probable secreted protein) as the most immunogenic candidates. Taken together, these results are encouraging in developing a vaccine for foals.  相似文献   

11.
J. Luo  F.R. Huang  C.L. Xiao  W. Chen  S.W. Jiang  J. Peng   《Livestock Science》2009,126(1-3):286-291
The present study was designed to investigate the effect of dietary fish oil supplementation on piglet T helper cells (Th) polarization in relation to its impact on piglet serum interferon γ (IFN-γ) and interleukin 10 (IL-10) concentrations and splenic expression of Th1/Th2 characteristic genes. The diets of 18 gestating sows were supplemented with 7% lard (C) (n = 10) or 7% fish oil (T) (n = 8) from 10 d before parturition to weaning. At weaning, a split plot experiment was designed, 56 piglets, 28 each from sows fed with fish oil diet or lard diet, were divided into four groups of 7 replicates (one female and one castrated male per replicate) based on both sow diet during lactation and post-weaning piglet diet (C had 7% lard and T had 7% fish oil): CC, CT, TC, TT, and were fed the 7% fish oil or lard diet from day 35 to day 70. Serum concentrations of IFN-γ and IL-10, and Th1/Th2 related genes expression levels in spleen were measured and analyzed. The results showed that piglets fed with fish oil diet during post-weaning tended to have higher serum IFN-γ/IL-10 ratio (P = 0.09) than lard diet fed piglets. Lactation fish oil feeding increased splenic IL-12b, IL-12 receptor β2 (IL-12Rβ2), IL-2 and IFN-γ genes expression (P < 0.05 or P < 0.01) and post-weaning fish oil feeding increased splenic IL-12b (P = 0.06), IL-2 (P < 0.01) and IFN-γ (P = 0.08) mRNA expression than that in lard diet fed piglets at the end of this experiment. On the other hand, IL-4 gene expression (P = 0.01) in spleen was lower in weaned piglet from fish oil diet fed sows than that from lard diet fed sows. However, post-weaning piglets fed fish oil diet had higher splenic IL-4 (P = 0.06), IL-6 (P < 0.01) and IL-10 (P = 0.05) mRNA abundances than that fed with lard diet. These results indicated that dietary fish oil during lactation could increase Th1 polarization and accelerate immune maturation; while 7% fish oil in weaned piglets' diet was likely to increase Th2 cytokines expression.  相似文献   

12.
Of 131 cases of Corynebacterium equi infection in horses submitted for necropsy to the Ontario Veterinary College or Veterinary Laboratory Services, OMAF, Guelph, Ontario from 1958 to 1984, 115 were diagnosed as suppurative pneumonia, and of these 55 had associated ulcerative enterocolitis. Only five animals had intestinal involvement without pulmonary lesions. The remaining 11 cases included arthritis/cellulitis, skin abscesses and submandibular lymphadenitis. While the lung, intestine and associated lymph nodes yielded C. equi most frequently, in 21% of cases C. equi was also cultured from parenchymatous organs (spleen, liver or kidney) or blood. Corynebacterium equi infection accounted for 10% of all foals submitted for postmortem examination and 45% of all foals with pneumonia. Affected foals were one to four months of age. Submissions occurred between the months of May and August with a peak during July. There was a significantly greater prevalence of C. equi infection in Standardbreds when compared with other breeds. Of foals in this study, 36% were from farms which had had other horses succumb to this disease. Of the foals with pulmonary involvement, 21% did not have fever or clinical signs referable to the respiratory or gastrointestinal systems, findings which indicated that a large percentage of cases were subclinical.  相似文献   

13.
Nitric oxide (NO) is a crucial mediator in host defense and is one of the major killing mechanisms within macrophages. Its induction is highly affected by the types of cytokines and the infectious agents present. In the current study, NO production was evaluated after in vitro infection of unfractionated peripheral blood mononuclear cells (PBMCs) with Mycobacterium avium subsp. paratuberculosis (MAP) after 8 h, 3 and 6 days of culture for cows in different stages of disease. In addition, the effects of in vitro exposure to inhibitory cytokines such as interleukin-10 (IL-10) and transforming growth factor β (TGF-β) as well as the pro-inflammatory cytokine IFN-γ were correlated with the level of NO production. Nitric oxide production was consistently higher in cell cultures from subclinically infected animals at all time points. An upregulation of NO production was demonstrated in unfractionated cell cultures from healthy control cows after exposure to MAP infection as compared to noninfected cell cultures. A similar increase in NO due to the addition of MAP to cell cultures was also noted for clinically infected cows. NO level among subclinically infected cattle was greater at all time points tested and was further boosted with the combination of both in vitro MAP infection and IFN-γ stimulation. Alternatively, nonspecific stimulation with LPS from Escherichia coli O111:B4-W resulted in an upregulation of NO production in all infected groups at 3 and 6 days after in vitro infection. Finally, the in vitro exposure to inhibitory cytokines such as IL-10 and TGF-β prior to MAP infection or LPS stimulation resulted in the downregulation of this inflammatory mediator (NO) in all experimental groups at all time points. In summary, a higher level of NO production was associated with cows in the subclinical stage of MAP infection. As well, the results demonstrated an increase in NO production upon infection with MAP and in the presence of exogenous IFN-γ. Finally, the results suggest an important role of IL-10 and TGF-β on the profile of NO production which may explain the low NO production in MAP clinically infected cows.  相似文献   

14.
The effect of strenuous exercise on the mRNA concentrations of interleukin-12p35 subunit (IL-12p35), interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in equine pulmonary and peripheral blood mononuclear cells (PBMCs) was investigated. We hypothesized that strenuous exercise would suppress the expression of IL-12p35, IFN-gamma and augment the expression of IL-4. Eleven horses were randomly divided into two groups, a stall-confined control group (n=5) and an exercise-conditioned treatment group (n=6). Bronchoalveolar and PBMCs were obtained from horses in the treatment group prior to the commencement of a 9-week conditioning program and 24h after the completion of a maximum exercise test conducted in week 12. Samples were obtained simultaneously from control horses. Differential counts were performed on the bronchoalveolar lavage cells. Real-time PCR was performed on the pulmonary and PBMCs to quantitate cytokine expression using equine-specific primers and Taqman probes. Target gene expression was normalized to 18s rRNA expression. With the exception of IL-4 in the BALF cells, mRNA for the three cytokines was detected in the mononuclear cells from all horses at both sampling times. There were no significant differences in the cytokine mRNA concentrations between the two groups of horses at either of the sampling times. These findings demonstrate that strenuous treadmill exercise does not exert a deleterious effect on gene expression for IL-12p35, IFN-gamma or IL-4 when assessed in horses 24h following the intense physical activity.  相似文献   

15.
The effects of selenium (Se) supplementation and source on equine immune function have not been extensively studied. This study examined the effects of oral Se supplementation and Se source on aspects of innate and adaptive immunity in horses. Fifteen horses were assigned to 1 of 3 groups (5 horses/group): control, inorganic Se (sodium selenite), organic Se (Se yeast). Immune function tests performed included: lymphocyte proliferation in response to mitogen concanavalin A, neutrophil phagocytosis, antibody production after rabies vaccination, relative cytokine gene expression in stimulated lymphocytes [interferon gamma (IFNγ), interleukin (IL)-2, IL-5, IL-10, tumor necrosis factor alpha (TNFα)], and neutrophils (IL-1, IL-6, IL-8, IL-12, TNFα). Plasma, red blood cell Se, and blood glutathione peroxidase activity were measured. Plasma and red blood cell Se were highest in horses in the organic Se group, compared with that of inorganic Se or control groups. Organic Se supplementation increased the relative lymphocyte expression of IL-5, compared with inorganic Se or no Se. Selenium supplementation increased relative neutrophil expression of IL-1 and IL-8. Other measures of immune function were unaffected. Dietary Se content and source appear to influence immune function in horses, including alterations in lymphocyte expression of IL-5, and neutrophil expression of IL-1 and IL-8.  相似文献   

16.
The prevalence of equine piroplasmosis caused by Theileria equi and Babesia caballi in Nigde, in central Anatolia, Turkey has remained unknown. Serum samples were obtained from a total of 125 horses and were tested for antibodies to T. equi and B. caballi using the Indirect Fluorescence Antibody Test (IFAT). Twenty-three (18.4%) horses were seropositive for equine piroplasmosis. Anti-T. equi was observed in 16 horses (12.8%) while anti-B. caballi was detected in 12 horses (9.6%). In addition, 5 serum samples were positive for both parasites. The prevalence rates of antibodies to T. equi and B. caballi for female and male horses were statistically indifferent (p = 0.19 and 0.90). The difference between the seropositivity rates to T. equi among age groups was statistically insignificant (p = 0.44) while the difference to B. caballi among age groups is statistically significant (p = 0.01). Seropositivity rates ranged from 2.9% to 25.7% for T. equi and 2.9% to 14.3% for B. caballi from the selected districts in Nigde. A statistically significant difference on seropositivity rates for the study sites was observed for only T.equi (p = 0.03). This study indicates that T. equi is higher than B. caballi in Nigde. This study was supported by the Scientific Research Projects Unit of Nigde University (FEB 2007/08).  相似文献   

17.
Local and systemic cytokine responses were studied in 3 groups of cattle, with 4 animals each, experimentally infested with Hypoderma lineatum (De Villers) first instars (L1). The first group was undergoing a primary infestation (G-1), the second group was undergoing a secondary infestation (G-2) and the third group was infested for their third consecutive year (G-3). Cattle were infested with 25 L1 deposited on the skin. Blood and skin samples were taken at 0, 6, 12, 48, 96 and 144 h post-infestation (h.p.i.). Interleukin 10 (IL-10), IL-4 and interferon gamma (IFN-γ) production was studied by immunohistochemistry and sandwich ELISAs. IL-4+ cells showed a significant increase at 6 h.p.i. in both reinfested groups (G-2 and G-3) when compared with G-1. In all groups the number of IL-4+ cells decreased significantly at 48 h.p.i. IL-10+ cells increased in G-1 at 6 and 48 h.p.i., whereas in both reinfested groups increased at 12 h.p.i. with a peak at 48 h.p.i. IFN-γ+ cells showed a significant increment at 6 h.p.i. in all groups, followed by a rapid descent at 12 (G-1 and G-2) and 48 h.p.i. (G-3). Penetration of the skin by H. lineatum did not have any significant effect on IFN-γ serum concentrations and, except for IL-10 there were no correlation between local production and serum concentrations of cytokines. The increase of both Th1 (IFN-γ) and Th2-type cytokines (IL-4 and IL-10) indicates that bovine T-cell response during the first phases of the infestation by H. lineatum is apparently a Th0 response.  相似文献   

18.

Background

The hypothalamic‐pituitary‐adrenal (HPA) is influenced by the proinflammatory cytokines IL‐6, IL‐1β, and TNF‐α in critically ill humans. Information about the association of cytokines with the HPA axis in neonatal foals is lacking.

Hypothesis/Objectives

The objectives were to describe for hospitalized septic and nonseptic foals (1) temporal changes in blood concentrations of ACTH, and cortisol, and leukocyte cytokine gene expression, and (2) coassociation of these HPA axis hormones with blood leukocyte cytokine gene expression.

Animals

Hospitalized septic foals (N = 15) and hospitalized nonseptic foals (N = 11).

Methods

Blood samples, obtained from study foals at admission (T = 0), and 24 (T = 1), 48 (T = 2), 72 (T = 3), and 96 (T = 4) hours after admission, were processed to isolate RNA from leukocytes and to harvest plasma and serum for hormone assays. Plasma ACTH and serum cortisol concentrations were determined by radioimmunoassay. Leukocyte mRNA expression of IL‐1β IL‐6, IL‐8, IL‐10, and TNF‐α was determined using RT‐PCR.

Results

Cortisol concentrations were greater (P < .05) in foals at admission than at other time points. The expressions of IL‐8 and IL‐10 mRNA were lower (P < .05) at each time point in septic than in nonseptic foals. Among septic foals, ACTH was positively associated (P = .0026) with IL‐6 mRNA expression.

Conclusions

Sepsis influences secretion of the HPA axis hormones and expression of cytokines in foals. A positive association with the HPA axis and IL‐6 expression was detected. The clinical importance of these findings requires additional study.  相似文献   

19.
CAPSULAR SEROTYPES OF RHODOCOCCUS EQUI   总被引：5，自引：0，他引：5  
SUMMARY One hundred strains of Rhodococcus equi from various animal species and sources in Australia were examined for capsular serotype. Eighty-four of the strains fell into the existing 7 serotypes, and just under half of the strains belonged to serotype 1. Isolates from the intestines and faeces of horses, cattle, pigs and other species, and from soil, were found to belong to the same serotypes as those recovered from the lungs of foals with R. equi pneumonia. There was no clear relationships between capsular serotype and source of origin of the isolates.  相似文献   

20.
The objective of this pilot study was to compare the cytokine profile as well as cell-mediated and antibody responses of foals infected with a low inoculum of virulent Rhodococcus equi resulting in subclinical pneumonia to that of foals infected with a high inoculum resulting in severe clinical pneumonia. The mean (±SD) ratio of post-infection to pre-infection anti-R. equi IgG(T) concentration was significantly (P = 0.002) higher in foals infected with the high inoculum (195 ± 145; range 62–328) compared to foals infected with the low inoculum (3.9 ± 4.5; range 0.5–11). Similarly, mean (±SD) ratio of post-infection to pre-infection IgM concentration was significantly (P = 0.002) higher in foals infected with the high inoculum (12 ± 4.0; range 7.4–14) compared to foals infected with the low inoculum (2.5 ± 1.5; range 1.2–4.7). Proliferative responses to R. equi antigens as well as expression of mRNA for IL-2, IL-4, IL-10, and IFN-γ in BLN were not significantly different between the two groups. There was a tendency (P = 0.073) towards a higher IFN-γ/IL-4 ratio in the low inoculum group. This study demonstrates that the size of inoculum modulates the IgG subisotype response and possibly the cytokine profile of foals.  相似文献   

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