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Marek's disease (MD), caused by the Marek's disease virus, is a lymphoproliferative disease in chickens that can be controlled by vaccination. However, the current vaccines can limit tumor growth and death but not virus replication and transmission. The present study aimed to evaluate host responses following intramuscular injection of an mRNA vaccine encoding gB and pp38 proteins of the MDV within the first 36 h. The vaccine was injected in low and high doses using prime and prime-boost strategies. The expression of type I and II interferons (IFNs), a panel of interferon-stimulated genes, and two key antiviral cytokines, IL-1ß and IL-2, were measured in spleen and lungs after vaccination. The transcriptional analysis of the above genes showed significant increases in the expression of MDA5, Myd88, IFN-α, IFN-ß, IFN-γ, IRF7, OAS, Mx1, and IL-2 in both the spleen and lungs within the first 36 h of immunization. Secondary immunization increased expression of all the above genes in the lungs. In contrast, only IFN-γ, MDA5, MyD88, Mx1, and OAS showed significant upregulation in the spleen after the secondary immunization. This study shows that two doses of the MDV mRNA vaccine encoding gB and pp38 antigens activate innate and adaptive responses and induce an antiviral state in chickens.
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Pollos , Citocinas , Herpesvirus Gallináceo 2 , Vacunas contra la Enfermedad de Marek , Enfermedad de Marek , Animales , Pollos/inmunología , Enfermedad de Marek/prevención & control , Enfermedad de Marek/inmunología , Enfermedad de Marek/virología , Vacunas contra la Enfermedad de Marek/inmunología , Vacunas contra la Enfermedad de Marek/administración & dosificación , Vacunas contra la Enfermedad de Marek/genética , Citocinas/metabolismo , Citocinas/inmunología , Herpesvirus Gallináceo 2/inmunología , Herpesvirus Gallináceo 2/genética , Pulmón/virología , Pulmón/inmunología , Bazo/inmunología , Bazo/virología , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/virología , Vacunas de ARNm/inmunología , Vacunación , ARN Mensajero/genética , ARN Mensajero/inmunología , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/administración & dosificación , Vacunas Sintéticas/genéticaRESUMEN
Vaccination has proven to be an effective means of controlling pathogens in animals. Since the introduction of veterinary vaccines in the 19th century, several generations of vaccines have been introduced. These vaccines have had a positive impact on global animal health and production. Despite, the success of veterinary vaccines, there are still some pathogens for which there are no effective vaccines available, such as African swine fever. Further, animal health is under the constant threat of emerging and re-emerging pathogens, some of which are zoonotic and can pose a threat to human health. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has highlighted the need for new vaccine platforms that are safe and efficacious, but also importantly, are adaptable and can be modified rapidly to match the circulating pathogens. mRNA vaccines have been shown to be an effective vaccine platform against various viral and bacterial pathogens. This review will cover some of the recent advances in the field of mRNA vaccines for veterinary species. Moreover, various mRNA vaccines and their delivery methods, as well as their reported efficacy, will be discussed. Current limitations and future prospects of this vaccine platform in veterinary medicine will also be discussed.
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Vacunas de ARNm , Animales , Vacunas Sintéticas/inmunología , Vacunas Virales/inmunología , Vacunación/veterinaria , ARN Mensajero/genéticaRESUMEN
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.
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Subtipo H9N2 del Virus de la Influenza A , Vacunas contra la Influenza , Gripe Aviar , Gripe Humana , Humanos , Animales , Pollos , Vacunas de Productos Inactivados , Anticuerpos Antivirales , Adyuvantes Inmunológicos/farmacología , Poli I-C/farmacología , Receptores Toll-LikeRESUMEN
Marek's disease is a contagious proliferative disease of chickens caused by an alphaherpesvirus called Marek's disease virus. A bivalent mRNA vaccine encoding MDV's glycoprotein-B and phosphoprotein-38 antigens was synthesized and encapsulated in lipid nanoparticles. Tumor incidence, lesion score, organ weight indices, MDV genome load and cytokine expression were used to evaluate protection and immunostimulatory effects of the tested mRNA vaccine after two challenge trials. Results from the first trial showed decreased tumor incidence and a reduction in average lesion scores in chickens that received the booster dose. The second trial demonstrated that vaccination with the higher dose of the vaccine (10 µg) significantly decreased tumor incidence, average lesion scores, bursal atrophy, and MDV load in feather tips when compared to the controls. Changes in expression of type I and II interferons suggested a possible role for these cytokines in initiation and maintenance of the vaccine-originated immune responses.
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Herpesvirus Gallináceo 2 , Enfermedad de Marek , Neoplasias , Animales , Pollos , Vacunas de ARNm , Herpesvirus Gallináceo 2/genéticaRESUMEN
The H9N2 subtype avian influenza virus (AIV) is a low pathogenic AIV that infects avian species and lead to huge economical losses in the poultry industry. The unique immunomodulatory properties of Retinoic acid (RA), an active component of vitamin A, highlights its potential to enhance chicken's resistance to infectious diseases and perhaps vaccine-induced immunity. Therefore, the present study evaluated the effects of in ovo supplementation of RA on the immunogenicity and protective efficacy of an inactivated avian influenza virus vaccine. On embryonic day 18, eggs were inoculated with either 90 µmol RA/200 µL/egg or diluent into the amniotic sac. On days 7 and 21 post-hatch, birds were vaccinated with 15 µg of ß-propiolactone (BPL) inactivated H9N2 virus via the intramuscular route. One group received BPL in combination with an adjuvant, while the other group received saline solution and served as a non-vaccinated control group. Serum samples were collected on days 7, 14, 21, 28, 35, and 42 post-primary vaccination (ppv) for antibody analysis. On day 24 ppv, spleens were collected, and splenocytes were isolated to analyze cytokine expression, interferon gamma (IFN-γ) production, and cell population. On day 28 ppv, birds in all groups were infected with H9N2 virus and oral and cloacal swabs were collected for TCID50 (50 % Tissue Culture Infectious Dose) assay up to day 7 post-infection. The results demonstrated that in ovo administration of RA did not significantly enhance the AIV vaccine-induced antibody response against H9N2 virus compared to the group that received the vaccine alone. However, RA supplementation enhanced the frequency of macrophages (KUL01+), expression of inflammatory cytokines and production of IFN-γ by splenocytes. In addition, RA administration reduced oral shedding of AIV on day 5 post-infection. In conclusion, these findings suggest that RA can be supplemented in ovo to enhance AIV vaccine efficacy against LPAIV.
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Subtipo H9N2 del Virus de la Influenza A , Vacunas contra la Influenza , Gripe Aviar , Animales , Gripe Aviar/prevención & control , Tretinoina , Pollos , Inmunidad Celular , Vacunas de Productos Inactivados , Anticuerpos AntiviralesRESUMEN
Necrotic enteritis is an important enteric disease of poultry that can be controlled with in-feed antibiotics. However, with the concerns over antimicrobial resistance, there is an increased interest in the use of alternatives. Probiotics are one of the alternatives that have gained considerable attention due to their antimicrobial and immunomodulatory activities. Therefore, in the present study, we evaluated the effects of two different Lactobacillus species alone or as a cocktail on prevention of necrotic enteritis. Day-old male broiler chickens were divided into five groups and on days 1, 8, 15, and 22, birds in groups 2 and 3 received 1×108 colony forming units (CFU) of L. johnsonii and L. reuteri, respectively. Group 4 received probiotic cocktails containing both bacteria (108 CFU/bird) and the negative and positive control groups did not receive any lactobacilli. Starting on day 23 post-hatch, birds in all groups (except the negative control group) were orally challenged twice per day with 3×108 CFU of a pathogenic C. perfringens strain for 3 days. Tissue and cecal samples were collected before and after challenge to assess gene expression, lymphocyte subsets determination, and microbiome analysis. On day 26 of age, lesion scoring was performed. The results demonstrated that the group that received the lactobacilli cocktail had significantly reduced lesion scores compared to the positive control group. In addition, the expression of interleukin (IL)-12 in the jejunum and CXC motif chemokine ligand 8 (CXCL8), IL-13, and IL-17 in the ileum were downregulated in the group that received the lactobacilli cocktail when compared to the positive control. Treating chickens with the lactobacilli cocktail prior to challenge enhanced the percentage of CD3-CD8+ cells and Bu-1+IgY+ B cells in the ileum and increased the frequency of monocyte/macrophages, CD3-CD8+ cells, Bu-1+IgM+, and Bu-1+IgY+ B cells in the jejunum. Treatment with the lactobacilli cocktail reduced the relative expression of Gamma-Protobacteria and Firmicutes compared to the positive control group. In conclusion, the results presented here suggest that treatment with the lactobacilli cocktail containing L. johnsonii and L. reuteri reduced necrotic enteritis lesions in the small intestine of chickens, possibly through the modulation of immune responses.
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Infecciones por Clostridium , Enteritis , Animales , Masculino , Infecciones por Clostridium/prevención & control , Infecciones por Clostridium/veterinaria , Infecciones por Clostridium/microbiología , Enteritis/prevención & control , Enteritis/veterinaria , Enteritis/microbiología , Pollos/microbiología , Lactobacillus , Clostridium perfringens/fisiología , AntibacterianosRESUMEN
The tumor microenvironment (TME) is generated by the cross-talk among tumor cells, immune system cells, and stromal cells. The TME generated by Marek's disease virus (MDV) is suggested to display an immunosuppressive milieu due to immune inhibitory molecules and cytokines which are possibly induced by MDV-transformed cells and regulatory T cells. Both anti-tumor and pro-tumor gamma delta (γδ) T cells are reported in human cancer. Although anti-tumor like and pro-tumor like γδ T cells are found in MDV-infected chickens at the later phase of infection, how the TME affects circulating and tissue-resident γδ T cells has not been investigated. Here, we demonstrated that the supernatant of the cultured splenocytes derived from MDV-challenegd chickens inhibited interferon (IFN)-γ production and CD25 expression by T cell receptor (TCR)γδ-stimulated tissue-resident γδ T cells, but the supernatant of the cultured MDV-transformed cell line did not affect γδ T cell activation. TCRγδ-stimulated circulating γδ T cells were influenced neither by the supernatant of the cultured splenocytes derived from MDV-challenegd chickens nor by the supernatant of the cultured MDV-transformed cell line. Taken together, activation and IFN-γ production by tissue-resident γδ T cells can be inhibited in the TME generated by MDV while tumor attracted circulating γδ T cells may not be influenced in activation and IFN-γ production by the TME generated by MDV.
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[This corrects the article DOI: 10.3389/fimmu.2021.664387.].
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The host response to pathogenic microbes can lead to expression of interleukin (IL)-17, which has antimicrobial and anti-viral activity. However, relatively little is known about the basic biological role of chicken IL-17A against avian viruses, particularly against Marek's disease virus (MDV). We demonstrate that, following MDV infection, upregulation of IL-17A mRNA and an increase in the frequency of IL-17A+ T cells in the spleen occur compared to control chickens. To elaborate on the role of chIL-17A in MD, the full-length chIL-17A coding sequence was cloned into a pCDNA3.1-V5/HIS TOPO plasmid. The effect of treatment with pcDNA:chIL-17A plasmid in combination with a vaccine (HVT) and very virulent(vv)MDV challenge or vvMDV infection was assessed. In combination with HVT vaccination, chickens that were inoculated with the pcDNA:chIL-17A plasmid had reduced tumor incidence compared to chickens that received the empty vector control or that were vaccinated only (66.6% in the HVT + empty vector group and 73.33% in HVT group versus 53.3% in the HVT + pcDNA:chIL-17A). Further analysis demonstrated that the chickens that received the HVT vaccine and/or plasmid expressing IL-17A had lower MDV-Meq transcripts in the spleen. In conclusion, chIL-17A can influence the immunity conferred by HVT vaccination against MDV infection in chickens.
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Herpesvirus Gallináceo 2 , Enfermedad de Marek , Vacunas , Animales , Pollos , Interleucina-17/genética , Enfermedad de Marek/prevención & control , Factores Inmunológicos , Herpesvirus Gallináceo 2/genéticaRESUMEN
Transmission of H9N2 avian influenza virus (AIV) can occur in poultry by direct or indirect contact with infected individuals, aerosols, large droplets and fomites. The current study investigated the potential of H9N2 AIV transmission in chickens via a fecal route. Transmission was monitored by exposing naïve chickens to fecal material from H9N2 AIV-infected chickens (model A) and experimentally spiked feces (model B). The control chickens received H9N2 AIV. Results revealed that H9N2 AIV could persist in feces for up to 60-84 h post-exposure (PE). The H9N2 AIV titers in feces were higher at a basic to neutral pH. A higher virus shedding was observed in the exposed chickens of model B compared to model A. We further addressed the efficacy of Toll-like receptor (TLR) ligands to limit transmission in the fecal model. Administration of CpG ODN 2007 or poly(I:C) alone or in combination led to an overall decrease in the virus shedding, with enhanced expression of type I and II interferons (IFNs) and interferon-stimulating genes (ISGs) in different segments of the small intestine. Overall, the study highlighted that the H9N2 AIV can survive in feces and transmit to healthy naïve chickens. Moreover, TLR ligands could be applied to transmission studies to enhance antiviral immunity and reduce H9N2 AIV shedding.
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Subtipo H9N2 del Virus de la Influenza A , Gripe Aviar , Enfermedades de las Aves de Corral , Animales , Pollos , Ligandos , Receptores Toll-Like , Heces , Enfermedades de las Aves de Corral/prevención & controlRESUMEN
Gamma delta (γδ) T cells play a significant role in the prevention of viral infection and tumor surveillance in mammals. Although the involvement of γδ T cells in Marek's disease virus (MDV) infection has been suggested, their detailed contribution to immunity against MDV or the progression of Marek's disease (MD) remains unknown. In the current study, T cell receptor (TCR)γδ-activated peripheral blood mononuclear cells (PBMCs) were infused into recipient chickens and their effects were examined in the context of tumor formation by MDV and immunity against MDV. We demonstrated that the adoptive transfer of TCRγδ-activated PBMCs reduced virus replication in the lungs and tumor incidence in MDV-challenged chickens. Infusion of TCRγδ-activated PBMCs induced IFN-γ-producing γδ T cells at 10 days post-infection (dpi), and degranulation activity in circulating γδ T cell and CD8α+ γδ T cells at 10 and 21 dpi in MDV-challenged chickens. Additionally, the upregulation of IFN-γ and granzyme A gene expression at 10 dpi was significant in the spleen of the TCRγδ-activated PBMCs-infused and MDV-challenged group compared to the control group. Taken together, our results revealed that TCRγδ stimulation promotes the effector function of chicken γδ T cells, and these effector γδ T cells may be involved in protection against MD.
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Herpesvirus Gallináceo 2 , Linfocitos Intraepiteliales , Enfermedad de Marek , Animales , Pollos , Leucocitos Mononucleares , Enfermedad de Marek/prevención & control , Receptores de Antígenos de Linfocitos T gamma-delta , MamíferosRESUMEN
Alterations in intestinal microbiota can modulate the developing avian intestinal immune system and, subsequently, may impact on resistance to enteric pathogens. The aim was to demonstrate that early life exposure to Lactococcus lactis, could affect either susceptibility or resistance of broilers to necrotic enteritis (NE). L. lactis NZ9000 (rL. lactis) pre-treatment at 1, 7, 14 and 21 days of age (DOA) led to a significant decrease in NE lesion scores in Clostridium perfringens infected chickens. C. perfringens Infection was associated with spatial and temporal decreases in mononuclear phagocytes and CD4+ αß T cells. However, rL. Lactis pre-treatment and subsequent C. perfringens infection led to a significant increase in mononuclear phagocytes, CD8α + γδ T, αß T cells (CD4+ and CD8α+) and B cells (IgM+, IgA+ and IgY+), as well as IL-12p40, IFN-γ and CD40. Differential expression of interleukin (IL)-6, IL-8, IL-10, IL-13, IL-18, IL-22, and transforming growth factor (TGF)-ß were observed in L. lactis treated chickens when compared to C. perfringens infected chickens. Microbiota analysis in C. perfringens infected chickens demonstrated an increase in abundance of Bacillota, Bacteroidota, Pseudomonadota and Actinomycetota. These findings suggests that modulation of the chicken intestinal immune system by L. lactis confers partial protection 30 against NE.
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[This corrects the article DOI: 10.3389/fimmu.2022.973762.].
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The major histocompatibility complex (MHC) haplotype is one of the major determinants of genetic resistance and susceptibility of chickens to Marek's disease (MD) which is caused by an oncogenic herpesvirus; Marek's disease virus (MDV). To determine differential functional abilities of T cells associated with resistance and susceptibility to MD, we identified immunodominant CD4+TCRvß1 T cell epitopes within the pp38 antigen of MDV in B19 and B21 MHC haplotype chickens using an ex vivo ELISPOT assay for chicken IFN-gamma. These novel pp38 peptides were used to characterize differential functional abilities of T cells as associated with resistance and susceptibility to MD. The results demonstrated an upregulation of cytokines (IL-2, IL-4, IL-10) and lymphocyte lysis-related genes (perforin and granzyme B) in an antigen specific manner using RT-PCR. In the MD-resistant chickens (B21 MHC haplotype), antigen-specific and non-specific response was highly skewed towards Th2 response as defined by higher levels of IL-4 expression as well as lymphocyte lysis-related genes compared to that in the MD-susceptible chicken line (B19 MHC haplotype). Using CD107a degranulation assay, the results showed that MDV infection impairs cytotoxic function of T cells regardless of their genetic background. Taken together, the data demonstrate an association between type of T cell response to pp38 and resistance to the disease and will shed light on our understanding of immune response to this oncogenic herpesvirus and failure to induce sterile immunity.
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Herpesvirus Gallináceo 2 , Enfermedad de Marek , Animales , Antivirales , Pollos , Citocinas , Epítopos de Linfocito T , Granzimas , Interleucina-10 , Interleucina-2 , Interleucina-4/genética , PerforinaRESUMEN
Migratory birds are major reservoirs for avian influenza viruses (AIV), which can be transmitted to poultry and mammals. The H9N2 subtype of AIV has become prevalent in poultry over the last two decades. Despite that, there is a scarcity of detailed information on how this virus can be transmitted. The current study aimed to establish a direct contact model using seeder chickens infected with H9N2 AIV as a source of the virus for transmission to recipient chickens. Seeder chickens were inoculated with two different inoculation routes either directly or via the aerosol route. The results indicate that inoculation via the aerosol route was more effective at establishing infection compared to the direct inoculation route. Shedding was observed to be higher in aerosol-inoculated seeder chickens, with a greater percentage of chickens being infected at each time point. In terms of transmission, the recipient chickens exposed to the aerosol-inoculated seeder chickens had higher oral and cloacal virus shedding compared to the recipient chickens of the directly inoculated group. Furthermore, the aerosol route of infection resulted in enhanced antibody responses in both seeder and recipient chickens compared to the directly inoculated group. Overall, the results confirmed that the aerosol route is a preferred inoculation route for infecting seeder chickens in a direct contact transmission model.
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Gamma delta (γδ) T cells are highly enriched in mucosal barrier sites including intestinal tissues where microbial infections and tumors often originate in mammals. Human γδ T cells recognize stress antigens and microbial signals via their T cell receptor (TCR), natural killer (NK) receptors, and pattern recognition receptors. However, little is known about antigens or ligands capable of stimulating chicken γδ T cells. The results of the present study demonstrated that polyinosinic-polycytidylic acid (poly(I:C)), a Toll-like receptor (TLR)3 ligand, significantly induced upregulation of CD8α molecules on circulating and lung γδ T cells. Moreover, poly(I:C) stimulation induced interferon (IFN)-γ production from splenic and lung CD8α+ γδ T cells while Cytosine-phosphate-Guanine oligodeoxynucleotides (CpG-ODN) 2007, a TLR21 ligand, stimulation induced IFN-γ production by circulating γδ T cells. Neither poly(I:C) nor CpG-ODN 2007 stimulation elicited degranulation of γδ T cells. Additionally, the results revealed that CpG-ODN 2007 induced IFN-γ production from TCR-stimulated γδ T cells sorted from spleen. In our experiments, isopentenyl pyrophosphate (IPP), 4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP), or zoledronate (Zol) stimulation did not induce IFN-γ production or degranulation in γδ T cells. Taken together, a combination of CpG-ODN 2007 and anti-CD3ε monoclonal antibodies (mAbs) can stimulate chicken γδ T cells and induce production of IFN-γ by these cells while IFN-γ production by γδ T cells induced by stimulation of poly(I:C) needs signals from other cells. These results suggest that chicken γδ T cells can sense invading pathogens via TLRs and produce IFN-γ as a first line of defense.
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Linfocitos Intraepiteliales , Receptor Toll-Like 3 , Animales , Pollos/metabolismo , Interferón gamma/metabolismo , Ligandos , Mamíferos , Oligodesoxirribonucleótidos , Poli I-C/farmacología , Receptores de Antígenos de Linfocitos T gamma-delta , Receptor Toll-Like 9RESUMEN
Tissue resident immune system cells in the chicken intestine play a significant role in the protection against pathogens. However, very little is known about these cells. The current study was conducted to further characterize chicken intestinal immune system cells. Furthermore, this study aimed to assess the immune modulatory action of a highly virulent Clostridium perfringens, a commonly found chicken intestinal microbe, in comparison with a non-commensal, Lactococcus lactis, on intestine-derived immune system cells. The results demonstrated varying distribution of innate and adaptive immune cells along the avian gut-associated lymphoid tissue (GALT) in the duodenum, jejunum, ileum, and cecal tonsils. In addition, steady-state and tissue-specific presence of CD25+ cells among αß and γδ T-cell subsets was assessed along the intestine. Ex vivo stimulation with C. perfringens or L. lactis resulted in a significant increase in the frequency of CD25+ T cells (γδ and αß T cells). In addition, significantly more cell death was observed in ex vivo stimulation with C. perfringens, which was indirectly correlated with a decrease in macrophage activation based on nitric oxide (NO) production with no effect on lymphoid cell responsiveness as per intracellular interferon (IFN)-gamma (γ) staining. Ex vivo stimulation with L. lactis activated γδ T cells and αß T cells, based on intracellular IFN-γ staining, while it had limited effect on macrophages. However, the ability of γδ and αß T cells to produce IFN-γ and the ability of macrophages production of NO was rescued in the presence of L. lactis. These results demonstrate the potential application of L. lactis, as a probiotic, against virulent C. perfringens infection in chicken.
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Lactococcus lactis , Animales , Pollos , Clostridium perfringens , Intestino Delgado , Macrófagos , Subgrupos de Linfocitos TRESUMEN
Marek's disease (MD) vaccines reduce the incidence of MD but cannot control virus shedding. To develop new vaccines, it is essential to elucidate mechanisms of immunity to Marek's disease virus (MDV) infection. In this regard, gamma delta (γδ) T cells may play a significant role in prevention of viral spread and tumor surveillance. Here we demonstrated that MDV vaccination induced interferon (IFN)-γ+CD8α+ γδ T cells and transforming growth factor (TGF)-ß+ γδ T cells in lungs. γδ T cells from MDV-infected chickens exhibited cytotoxic activity. Importantly, γδ T cells from the vaccinated/challenged group exhibited maximum cytotoxic activity following ex vivo stimulation. These results suggest that MDV vaccines activate effector γδ T cells which may be involved in the development of protective immune responses against MD. Further, it was demonstrated that MDV infection increases the frequency of a subpopulation of γδ T cells expressing membrane-bound TGF-ß in MDV-infected birds.
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Pollos/inmunología , Enfermedad de Marek/inmunología , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Animales , Biomarcadores , Pollos/virología , Citocinas , Secuenciación de Nucleótidos de Alto Rendimiento , Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Inmunización , Inmunofenotipificación , Activación de Linfocitos , Recuento de Linfocitos , Enfermedad de Marek/prevención & control , Enfermedad de Marek/virología , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/virología , Vacunas Virales/inmunología , Replicación Viral , Esparcimiento de VirusRESUMEN
Infection with pathogenic viruses is often sensed by innate receptors such as Toll-Like Receptors (TLRs) which stimulate type I and III interferons (IFNs) responses, to generate an antiviral state within many cell types. To counteract these antiviral systems, many viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), encode non-structural proteins (NSPs) that mediate immune evasion. Using an overexpression system in A549 âcells, we demonstrated a significant increase (p â≤ â0.0001) in Vesicular Stomatitis Virus (VSV)-EGFP reporter virus replication in cell lines overexpressing either the SARS-CoV-2 NSP1 or NSP15 when compared to control A549 âcells. The increase in VSV-EGFP virus output was associated with a decrease in TLR2, TLR4 and TLR9 protein expression and a lack of antiviral protein production. Truncation of both NSP1 and NSP15 led to an increase in cellular TLR2, TLR4 and TLR9 as well as a decrease in TLR2 expression respectively. This observation can be attributed to the presence of a functional domain in NSP1 and NSP15 between amino acid (aa) 120-180 and aa 230-346, respectively. Both TLR3 and TLR9 ligands but not TLR2 ligand were highly effective at overcoming NSP1 and NSP15 functional interference based on significant decrease (p â≤ â0.0001) in VSV-EGFP virus replication. NSP1 or NSP15 intracellular interactions are likely low affinity interactions that can be easily disrupted by stimulating cells with specific TLR3 and TLR9 ligands. This report provides insights into the role of SARS-CoV-2 NSP1 and NSP15 in limiting specific TLR pathway activation, as an evasive mechanism against host innate responses.
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Growth promoter antibiotics have been commonly used for the control of necrotic enteritis (NE) in broilers for decades. However, due to a ban on the use of these antibiotics, alternatives such as probiotics have been tested widely for NE control. The present study tested the efficacy of four different species of lactobacilli (two isolates of Lactobacillus johnsonii and one of Ligilactobacillus (L.) salivarius, Limosilactobacillus (L.) reuteri, and L. crispatus) against NE. Day-old male broiler chickens were divided into six groups and orally inoculated with 1 × 107 or 1 × 108 colony-forming units (CFU) of lactobacilli on 1, 7, 14, and 20 days of age. While negative and positive control groups did not receive lactobacilli, the latter was challenged with Clostridium perfringens (CP). Chickens, at 21 days old, were challenged for 3 days with 3 × 108 CFU of a virulent strain of CP. Tissues were collected for immune system gene expression, immunophenotyping, intestinal histomorphometry, and microbiota analysis. Lactobacilli inoculation conferred partial protection in chickens against NE, marked by lowered lesion scores and improved villus:crypt ratio. Immunomodulatory effects were demonstrated by the significant alteration of interferon (IFN)-γ, interleukin (IL)-1ß, IL-2, IL-12p35, IL-17, and transforming growth factor beta (TGF-ß) gene transcription in the duodenum and jejunum as well as subtle changes in the frequency of CD8 + T cells and B cells in the cecal tonsil of the treated chickens. Microbiota analysis showed increased levels of some bacterial phyla including Actinobacteria, Lactobacillaceae, and Firmicutes. In conclusion, these findings suggest that the use of certain lactobacilli can reduce NE severity and modulate immune responses and intestinal microbiota composition in chickens.