Cytokine Gene Expression in Lung Mononuclear Cells of Chickens Vaccinated with Herpesvirus of Turkeys and Infected with Marek's Disease Virus.

Marek's disease virus (MDV) enters the chicken host through the respiratory system. However, little is known about the host immune responses induced by MDV in the lungs. To characterize these responses, chickens were vaccinated with herpesvirus of turkeys (HVT) and challenged with the RB1B strain of MDV via the respiratory route.

Avian influenza virus vaccines containing Toll-like receptors 2 and 5 ligand adjuvants promote protective immune responses in chickens.

Vaccination remains a useful means for the control of avian influenza viruses (AIV) in chickens. Current vaccines can protect chickens from morbidity and mortality. However, they do not eliminate virus shedding into the environment.

The effects of administration of ligands for Toll-like receptor 4 and 21 against Marek's disease in chickens.

Ligands for Toll-like receptors (TLRs) are known to stimulate immune responses, leading to protection against bacterial and viral pathogens. Here, we aimed to examine the effects of various TLR ligands on the development of Marek's disease in chickens. Specific-pathogen free chickens were treated with a series of TLR ligands that interact with TLR3, TLR9 and TLR21.

A Toll-like receptor 3 agonist (polyI:C) elicits innate host responses in the spleen and lungs of chickens.

Double-stranded (ds) RNA interacts with host Toll-like receptor (TLR-3), leading to the induction of anti-viral host responses. The present study was designed to compare different routes of administration of a synthetic dsRNA (polyI:C) for induction of innate responses in chicken spleen and lungs. Chickens were treated with polyI:C via the aerosol, intra-air sac (i.

A toll-like receptor 3 ligand enhances protective effects of vaccination against Marek's disease virus and hinders tumor development in chickens.

Marek's disease (MD) is caused by Marek's disease virus (MDV). Various vaccines including herpesvirus of turkeys (HVT) have been used to control this disease. However, HVT is not able to completely protect against very virulent strains of MDV.

Prophylactic treatment with Toll-like receptor ligands enhances host immunity to avian influenza virus in chickens.

Avian influenza viruses (AIV) pose a threat towards the health of both poultry and humans. To interrupt the transmission of the virus, novel prophylactic strategies must be considered which may reduce the shedding of AIV. One potential is the prophylactic use of Toll-like receptor (TLR) ligands.

Vaccination with CpG-adjuvanted avian influenza virosomes promotes antiviral immune responses and reduces virus shedding in chickens.

The use of virosomes as a vaccine platform has proven successful against several viruses. Here we examined the protective efficacy of a virosome-based vaccine consisting of avian influenza virus (AIV) A/Duck/Czech/56/H4N6 in chickens against a homologous AIV challenge. Virosomes adjuvanted with CpG-ODN or recombinant chicken interferon (IFN)-γ significantly reduced virus shedding after virus challenge.

Oral treatment of chickens with lactobacilli influences elicitation of immune responses.

Commensal microbes in the intestine are in constant interaction with host cells and play a role in shaping the immune system. Lactobacillus acidophilus, Lactobacillus reuteri, and Lactobacillus salivarius are members of the chicken intestinal microbiota and have been shown to induce different cytokine profiles in mononuclear cells in vitro. The objective of the present study was to examine the effects of these bacteria individually or in combination on the induction of antibody- and cell-mediated immune responses in vivo.

Interferon-γ influences immunity elicited by vaccines against very virulent Marek's disease virus.

Vaccination of chickens with herpesvirus of turkey (HVT) confers only partial protection against challenge with a very virulent Marek's disease virus (MDV). Here, we evaluated the ability of recombinant chicken interferon-gamma (rChIFN-γ) to enhance protective efficacy of HVT against the very virulent MDV strain, RB1B. The bioactivity of IFN-γ expressed by a plasmid expression vector was confirmed by its ability to stimulate a chicken macrophage cell line (HD11) to produce nitric oxide (NO) in vitro.

Enhancement of immunogenicity of a virosome-based avian influenza vaccine in chickens by incorporating CpG-ODN.

Influenza virosomes are virus-like particles, representing a platform for vaccine development. In this study, we examined the immunogenicity of avian influenza virosomes with or without inclusion of recombinant chicken interferon-gamma (rChIFN-γ) or CpG-ODN in chickens. Immunization with virosomes adjuvanted with CpG-ODN elicited the highest haemagglutination inhibition antibody titres, as well as IgG and IgA serum antibody responses.

Immune responses against Marek's disease virus.

It is more than a century since Marek's disease (MD) was first reported in chickens and since then there have been concerted efforts to better understand this disease, its causative agent and various approaches for control of this disease. Recently, there have been several outbreaks of the disease in various regions, due to the evolving nature of MD virus (MDV), which necessitates the implementation of improved prophylactic approaches. It is therefore essential to better understand the interactions between chickens and the virus.

Expression profiling of genes associated with regulatory functions of T-cell subsets in Marek's disease virus-infected chickens.

The environment of tumours caused by Marek's disease virus (MDV) in chickens has been shown to have an immunoregulatory phenotype. The objective of the present study was to examine the expression of key T-regulatory markers during various stages of MDV pathogenesis. Specific-pathogen free (SPF) as well as major histocompatibility complex-defined chickens were infected with the RB1B and JM-16 strains of MDV, respectively.

Effects of lactobacilli on cytokine expression by chicken spleen and cecal tonsil cells.

Lactobacillus acidophilus, Lactobacillus reuteri, and Lactobacillus salivarius are all normal residents of the chicken gastrointestinal tract. Given the interest in using probiotic bacteria in chicken production and the important role of the microbiota in the development and regulation of the host immune system, the objective of the current study was to examine the differential effects of these bacteria on cytokine gene expression profiles of lymphoid tissue cells. Mononuclear cells isolated from cecal tonsils and spleens of chickens were cocultured with one of the three live bacteria, and gene expression was analyzed via real-time quantitative PCR.

Proteomic analysis of host responses to Marek's disease virus infection in spleens of genetically resistant and susceptible chickens.

Resistance to Marek's disease (MD) in chickens is genetically regulated and there are lines of chickens with differential susceptibility or resistance to this disease. The present study was designed to study comparative changes in the spleen proteomes of MD-susceptible B19 and MD-resistant B21 chickens in response to MDV infection. Spleen proteomes were examined at 4, 7, 14 and 21 days post-infection (d.

Cytokine gene expression in splenic CD4(+) and CD8(+) T-cell subsets of chickens infected with Marek's disease virus.

Specific-pathogen free chickens were infected with the RB1B strain of Marek's disease virus (MDV) and T cells from the spleens of infected as well as age-matched controls were fractionated by flow cytometry at 4, 10, and 21 days post-infection (d.p.i.

Marek's disease virus-induced expression of cytokine genes in feathers of genetically defined chickens.

Marek's disease (MD) vaccines, although effective in reducing lymphoproliferation, cannot control infectious virus production in the feather follicle epithelium (FFE) which is the site of virus shedding. Therefore, we investigated Marek's disease virus (MDV) replication as well as the expression of cytokine genes in feathers of MDV-infected chickens belonging to genetically defined lines (N2a or B(21)/B(21) haplotype-resistant and P2a or B(19)/B(19) haplotype-susceptible). Though there was not a difference in MDV genome load and transcripts between feathers of these chicken lines at 4 and 10 days post-infection (d.

Expression of cytokine genes following pre- and post-hatch immunization of chickens with herpesvirus of turkeys.

Induction of immune response as characterised by expression of cytokine genes in the spleen following immunization of pre- and post-hatch chickens with herpesvirus of turkeys (HVT) vaccine was studied. The pattern of expression of IFN-gamma and IL-10 genes in pre-hatch immunized chickens was different from that observed in post-hatch HVT immunized chickens. This expression pattern of cytokine genes was associated with significantly higher HVT transcripts in pre-hatch immunized chickens than in post-hatch immunized chickens.

Cytokine gene expression patterns associated with immunization against Marek's disease in chickens.

The present study explored the immunological correlates of protection mediated by a live bivalent vaccine consisting of herpesvirus of turkeys (HVT) and SB-1 against infection with the RB1B strain of Marek's disease virus (MDV). Compared to unvaccinated infected chickens, vaccinated protected birds had lower expression of interleukin (IL)-6, IL-10 and IL-18 genes in spleen. However, there was no difference between these two groups of birds in the expression of interferon (IFN)-gamma, IL-4, IL-12 and inducible nitric oxide synthase (iNOS) genes on day 21 post-infection.

Modulation of antibody-mediated immune response by probiotics in chickens.

Probiotic bacteria, including Lactobacillus acidophilus and Bifidobacterium bifidum, have been shown to enhance antibody responses in mammals. The objective of this study was to examine the effects of a probiotic product containing the above bacteria in addition to Streptococcus faecalis on the induction of the chicken antibody response to various antigens, both systemically and in the gut. The birds received probiotics via oral gavage and subsequently were immunized with sheep red blood cells (SRBC) and bovine serum albumin (BSA) to evaluate antibody responses in serum or with tetanus toxoid (TT) to measure the mucosal antibody response in gut contents.