Veterinary immunology and immunopathology最新文献

Probiotics are live microorganisms that, confer health benefits to the host when supplemented in adequate amounts. They can promote immunomodulation by inducing phagocyte activity, leukocyte proliferation, antibody production, and cytokine expression. Lactic acid bacteria (BAL) are important probiotic specimens with properties that can improves ruminant nutrition, productivity and immunity. The aim of the present study was to evaluate the immunomodulatory effect of the supplementation with Lacticaseibacillus casei CB054 in calve vaccinated against bovine infectious rhinotracheitis (IBR). Calve were vaccinated with a commercial IBR vaccine, on day 0 and received a booster dose on day 21. L. casei CB054 was orally administered (4 ×10⁹ UFC) for 35 days, while a non-supplemented control group received Phosphate Buffer Saline (PBS). Stimulation of bovine splenocytes with L. casei CB054 markedly enhanced mRNA transcription levels of cytokines IL2, IL4, IL10 and IL17 genes. Calves supplemented with L. casei CB054 showed significantly higher (p < 0.05) specific anti-BoHV-1 IgG levels, higher serum neutralization, as well as higher mRNA transcription for IL2, IL4, IL10 and IL17 genes in Peripheral Blood Mononuclear Cells (PBMCs) comparing with control calves. Supplemented calve had an average weight gain of ∼14 kg more than non-supplemented during the experimental period. These results suggest that L. casei CB054 supplementation increase immunogenicity of a commercial IBR vaccine in cattle and improve weight gain.

Dexamethasone (dex) is a potent glucocorticoid used to treat a variety of diseases. It is widely used in veterinary medicine in many species; for instance, in dogs, it can be used for emergent cases of anaphylaxis or trauma, management of immune-mediated hemolytic anemia or thrombocytopenia, certain cancers, allergic reactions, and topically for skin or eye inflammation. Dex is not without its side effects, especially when administered systemically, which might compromise compliance and effective treatment. Thus, adjunct therapies have been suggested to allow for decreased dex dosing and reduction in side effects while maintaining immunosuppressive efficacy. The goal of this study was to evaluate the potential for cannabinoids to serve as adjunct therapies for dex. Immune function was assessed in canine peripheral blood mononuclear cells (PBMCs) after treatment with dex with and without cannabidiol (CBD) and/or Δ9-tetrahydrocannabinol (THC). Dex suppressed IFN-γ protein secretion in a concentration-dependent manner and this suppression by low concentrations of dex was enhanced in the presence of CBD, THC, or the combination of CBD and THC. Similar effects were found with INFG and TNFA mRNA expression. These findings provide a rationale for using CBD or THC in vivo to reduce dex dosing and side effects.

Clostridium septicum is one of the major causative agents of clostridial dermatitis (CD), an emerging disease of turkeys, characterized by sudden deaths and necrotic dermatitis. Despite its economic burden on the poultry industry, the immunopathological changes and pathogen-specific immune responses are poorly characterized. Here, we used three strains of C. septicum, namely Str. A1, Str. B1 and Str. C1, isolated from CD field outbreaks, to experimentally infect turkeys to evaluate local (skin and muscle) and systemic (spleen) pathological and immunological responses. Results showed that while all three strains produced an acute disease, Str. A1 and B1 caused significantly higher mortality when compared to Str. C1. Gross and histopathology evaluation showed that birds infected with Str. A1 and B1 had severe inflammatory, edematous, granulomatous and necrotic lesions in the skin, muscle and spleen, while these lesions produced by Str. C1 were relatively less severe and mostly confined to skin and/or muscle. Immune gene expression in these tissues showed that Str. B1-infected birds had significantly higher expression of interleukin (IL)−1β, IL-6 and interferon (IFN)γ genes compared to uninfected control, suggesting a robust inflammatory response both locally as well as systemically. The transcription of IL-1β and IFNγ in the muscle or spleen of Str. A1-infected birds and IL-1β in the skin of Str. C1-infected group was also significantly higher than control. Additionally, Str. A1 or B1-infected groups also had significantly higher IL-4 transcription in these tissues, while birds infected with all three strains developed C. septicum-specific serum antibodies. Furthermore, splenic cellular immunophenotyping in the infected turkeys showed a marked reduction in CD4+ cells. Collectively, it can be inferred that host responses against C. septicum involve an acute inflammatory response along with antibody production and that the disease severity seem to depend on the strain of C. septicum involved in CD in turkeys.

Pathogenic Enterococcus cecorum (EC) has gained increasing importance as the cause of skeletal infections in meat-type chicken production. Since effective intervention strategies are scarce, it must be focused on preventive measures. Vaccination of meat-type breeder chicken flocks is common practice to protect the progeny against infection with EC. However, no data are available on seroconversion after infection or vaccination. The aim of the present study was the serological monitoring of chickens for EC-specific immunoglobulin Y (IgY) using a newly established EC-specific, indirect ELISA for chickens. Sera from previous infection studies were used for the establishment of the assay. Serum samples from confirmed EC-positive meat-type chicken flocks, vaccinated, and non-vaccinated meat-type chicken breeder flocks were analyzed for EC-specific IgY. Comparison of ELISA results with results from real-time PCR and/or bacteriological examination via culture revealed fair to substantial agreement. In infected chickens, more samples were classified as positive via ELISA than via real-time PCR and/or bacteriological examination via culture. Focusing on chickens experimentally infected at 1 day post-hatch (dph), the highest proportion of positive results and highest S/P ratios were found at 42 dph (p < 0.05). A similar trend was observed for the samples from naturally infected chickens (p < 0.05). Adjustment of the secondary antibody against immunoglobulin M (IgM) may open possibilities to use the assay during the early phase of the growing period, when there is still a chance to treat the infection. The examination of samples from vaccinated and non-vaccinated meat-type breeder chickens revealed no significant differences of S/P ratios independent of farm and autogenous vaccine used. In addition to that, monitoring of a non-vaccinated meat-type breeder chicken flock at 4, 10, 15, and 19 weeks post-hatch showed a continuous increase of ELISA-positive serum samples associated with an increase of S/P ratios. This may be explained by cross reactivity with antibodies to Enterococcus hirae or natural antibodies. The usage of EC-specific, recombinant proteins for coating of the plates may help to reduce unspecific background and increase the assay’s specificity in future applications. In conclusion, the newly developed ELISA provides a suitable tool for serological monitoring of meat-type chickens during experimental studies with EC under standardized conditions. Remarkably, the assay is able to detect a higher proportion of EC-positive chickens than other methods, which are currently available. However, the assay is not yet suitable for the monitoring of breeder flocks due to high background.

Myeloid-derived suppressor cells (MDSCs) are immature cells with immunosuppressive properties found in the tumor microenvironment. MDSCs are divided into two major subsets: polymorphonuclear MDSCs (PMN-MDSCs) and monocytic MDSCs (M-MDSCs). Both MDSC subsets contribute to the creation of an immunosuppressive environment for tumor progression. In humans, patients with high levels of MDSCs show worse outcomes for several types of cancers. However, the association between MDSCs and clinical features has rarely been investigated in canine studies. In the present study, we measured the proportion of PMN-MDSCs and M-MDSCs in the peripheral blood and tumor tissue of dogs with hepatocellular carcinoma (HCC), prostate cancer (PC), transitional cell carcinoma (TCC), lymphoma, and pulmonary adenocarcinoma. Additionally, we examined immunosuppressive ability of PMN-MDSCs and M-MDSCs in peripheral blood mononuclear cells of TCC case on CD4⁺, CD8⁺ and interferon-γ⁺ cells and investigated the relationships of MDSCs with clinical features and outcomes. PMN-MDSCs increased in HCC, PC, TCC, and lymphoma. In contrast, M-MDSCs increased in the TCC. Both PMN-MDSCs and M-MDSCs exhibited immunosuppressive effects on CD8⁺, CD4⁺ and interferon-γ⁺ cells. In dogs with TCC, lymph node metastasis was associated with high level of PMN-MDSCs but not with M-MDSCs. High levels of both PMN-MDSCs and M-MDSCs were related to advanced tumor stage. Kaplan-Meier analysis revealed that high levels of both PMN-MDSCs and M-MDSCs were significantly associated with shorter overall survival. In addition, the Cox proportional hazard regression model showed that M-MDSCs and the tumor stage were independent prognostic factors for TCC. These results suggest that PMN-MDSCs and M-MDSCs may be involved in tumor progression and could be prognostic factors and promising therapeutic targets in dogs with TCC.

Avian influenza viruses (AIV), including the H9N2 subtype, pose a major threat to the poultry industry as well as to human health. Although vaccination provides a protective control measure, its effect on transmission remains uncertain in chickens. The objective of the present study was to investigate the efficacy of beta-propiolactone (BPL) whole inactivated H9N2 virus (WIV) vaccine either alone or in combination with CpG ODN 2007 (CpG), poly(I:C) or AddaVax™ (ADD) to prevent H9N2 AIV transmission in chickens. The seeder chickens (trial 1) and recipient chickens (trial 2) were vaccinated twice with different vaccine formulations. Ten days after secondary vaccination, seeder chickens were infected with H9N2 AIV (trial 1) and co-housed with healthy recipient chickens. In trial 2, the recipient chickens were vaccinated and then exposed to H9N2 AIV-infected seeder chickens. Our results demonstrated that BPL+ CpG and BPL+ poly(I:C) treated chickens exhibited reduced oral and cloacal shedding in both trials post-exposure (PE). The number of H9N2 AIV+ recipient chickens in the BPL+ CpG group (trial 1) was lower than in other vaccinated groups, and the reduction was higher in BPL+ CpG recipient chickens in trial 2. BPL+ CpG vaccinated chickens demonstrated enhanced systemic antibody responses with high IgM and IgY titers with higher rates of seroprotection by day 21 post-primary vaccination (ppv). Additionally, the induction of IFN-γ expression and production was higher in the BPL+ CpG treated chickens. Interleukin (IL)− 2 expression was upregulated in both BPL+ CpG and BPL+ poly(I:C) groups at 12 and 24 hr post-stimulation.

Apitherapy is a form of alternative medicine that utilizes products from the western honeybee (Apis mellifera), including honey, propolis, and honeybee venom, to improve the health status of human patients by altering host immunity. An added benefit of these products is that they are nutraceuticals and relatively inexpensive to aquire. Currently, little is known about the use of honeybee products in veterinary species, as well as their impact on host immunity. In the present in vitro study, honey, propolis, and honeybee venom were co-cultured with enriched canine, equine, and chicken peripheral blood lymphocytes (PBLs) with cell proliferation, cell viability/apoptosis, and cellular morphology evaluated. Concanavalin A (Con A) and dexamethasone were used as stimulatory and suppressive controls, respectively. Honeybee products’ effects on the three veterinary species varied by product and the species. Honey stimulated the PBLs proliferation in all three species but also displayed some increased cytotoxicity. Propolis stimulated proliferation in canine and equine PBLs, however, it suppressed proliferation in the chicken PBLs. Honeybee venom was the strongest PBL stimulant for all three species and in the equine, surpassed the stimulant response of Con A and yet, enhanced PBL cell viability post culture. In summary, the results of this preliminary in vitro study show that these three honeybee products do impact lymphocyte proliferation and viability in dogs, horses, and chickens, and that more research both in vitro and in vivo will be necessary to draw conclusions regarding their future use as immune stimulants or inhibitors.

Rhodococcus equi (R. equi), a pneumonia-causing intracellular bacterium, results in significant morbidity and mortality in young foals, while healthy adult horses rarely develop disease. Survival and replication within alveolar macrophages (AMφ) are the hallmarks of R. equi’s pathogenicity. The vitamin D receptor (VDR) and its ligand, the active vitamin D metabolite 1,25(OH)₂D, are important in immune responses to intracellular bacteria. The vitamin D/VDR pathway regulates the downstream production of cytokines in infected human AMφ. The immunomodulatory role of the vitamin D/VDR pathway in equine leukocytes is unknown. The objective of the current study was to determine the impact of R. equi infection and age on synthesis of 1,25(OH)₂D, VDR expression, and cytokine production in an ex vivo model of R. equi infection in equine AMφ. AMφ were collected from ten healthy foals at 2-, 4- and 8-weeks old and from nine healthy adult horses once via bronchoalveolar lavage. AMφ were mock infected (CONTROL) or infected with a virulent laboratory strain of R. equi for 7 days (INFECTED). VDR expression was determined via RT-qPCR from cell lysates. 1,25(OH)₂D and cytokines were measured in cell supernatant by immunoassays. VDR expression was impacted by age (P = 0.001) with higher expression in AMφ from 8-week-old foals than from 2-week-old foals and adults. There was no significant effect of infection in foal AMφ, but in adults, relative VDR expression was significantly lower in INFECTED AMφ compared to CONTROL AMφ (P = 0.002). There was no effect of age or infection on 1,25(OH)₂D concentration (P > 0.37). Mean TNFα production was significantly higher from INFECTED compared to CONTROL AMφ from 4- and 8-week-old foals and adults (P < 0.005). Mean IFNγ production was significantly higher from AMφ from foals at 8-weeks-old compared to 2-weeks-old (P = 0.013) and higher from INFECTED AMφ than from CONTROL AMφ in foals at 4-weeks-old and in adults (P < 0.027). The proportion of samples producing IL-1β and IL-10 was also significantly higher from INFECTED compared to CONTROL AMφ isolated from 4-week-old foals (P < 0.008). Similarly, in adult samples, IL-17 was produced from a greater proportion of INFECTED compared to CONTROL samples (P = 0.031). These data document age-associated changes in VDR expression and cytokine production in equine AMφ in response to R. equi infection. This preliminary investigation supports the need for further research to fully elucidate if the vitamin D pathway has an immunomodulatory role in the horse.

The objective of this study was to investigate the mRNA expression of insulin-like growth factor-1 (IGF-1), pro-inflammatory cytokines (IL-1β, IL-6, IL-18, and TNF-α), serum immunoglobulin profiles (IgG and IgM), and lipid peroxidation status (MDA) in relation to pro-inflammatory cytokines. A case-controlled, prospective, and observational investigation was completed on 85 calves. Total RNA was isolated from whole blood samples of both the SIRS and healthy calves, followed by reverse transcription into cDNA. The resulting cDNAs were mixed with iTaq Universal SYBR Green Supermix and primers specific to the relevant genes using the Rotor-Gene Q instrument. After the reaction was completed, gene expressions were normalised against β-actin using the 2^-ΔΔCT method. The mRNA levels of pro-inflammatory cytokines namely (IL-1β [SIRS: 2.15 ± 0.55, Control: 1.13 ± 0.62; P = 0.001], IL-6 [SIRS: 2.82 ± 0.52, Control: 0.91 ± 0.11; P < 0.001], IL-18 [SIRS: 1.92 ± 0.41, Control: 0.99 ± 0.13; P < 0.001], and TNF-α [SIRS: 2.59 ± 0.28, Control: 0.93 ± 0.09; P < 0.001]) and IGF-1 (SIRS: 3.55 ± 0.55, Control: 0.91 ± 0.15; P < 0.001) were up-regulated in calves with SIRS, while serum IgG (SIRS: 4.16 ± 0.26, Control: 1.73 ± 0.17; P < 0.001), IgM (SIRS: 1.55 ± 0.11, Control: 1.09 ± 0.13; P < 0.001), and MDA levels (SIRS: 41.12 ± 3.48, Control: 3.76 ± 0.81; P < 0.001) increased significantly in these calves. Furthermore, significant (P < 0.01) positive correlations were found in calves with SIRS in relation to the expression levels of IL-1β, IL-6, IL-18, TNF-α, IGF-1, serum immunoglobulins, and MDA levels. These results suggest that IGF-1 could be a valuable pro-inflammatory marker, considering its high positive correlation with the expression levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-18, and TNF-α) and markers (MDA, IgG, and IgM) in calves with SIRS.