In vitro assessment of immunomodulatory and anti-Campylobacter activities of probiotic lactobacilli.

The present study was undertaken to assess the antimicrobial activity of Lactobacillus spp. (L. salivarius, L.

Immune Responses in the Eye-Associated Lymphoid Tissues of Chickens after Ocular Inoculation with Vaccine and Virulent Strains of the Respiratory Infectious Laryngotracheitis Virus (ILTV).

Infectious laryngotracheitis (ILT) is an acute respiratory disease of poultry caused by infectious laryngotracheitis virus (ILTV). Control of the disease with live attenuated vaccines administered via eye drop build upon immune responses generated by the eye-associated lymphoid tissues. The aim of this study was to assess cytokine and lymphocyte changes in the conjunctiva-associated lymphoid tissues (CALT) and Harderian gland (HG) stimulated by the ocular inoculation of the ILTV chicken embryo origin (CEO) vaccine strain and virulent strain 63140.

PLGA-encapsulated CpG ODN and Campylobacter jejuni lysate modulate cecal microbiota composition in broiler chickens experimentally challenged with C. jejuni.

Campylobacter jejuni is a leading bacterial cause of human gastroenteritis. Reducing Campylobacter numbers in the intestinal tract of chickens will minimize transmission to humans, thereby reducing the incidence of infection. We have previously shown that oral pre-treatment of chickens with C.

Characterizaton of gamma delta T cells in Marek's disease virus (Gallid herpesvirus 2) infection of chickens.

Immunity against Marek's disease (MD), caused by Gallid herpesvirus 2 (GaHV-2), in chickens is mediated by both innate and adaptive responses. The present study evaluated the effects of GaHV-2 infection on distribution and frequency of γδ T cells in tissues, as well as their expression of cytokines. We found that the infected chickens had significantly higher number of γδ T cells in their spleens by 10 and 21 days post-infection (d.

CpG oligonucleotide-mediated co-stimulation of mouse invariant natural killer T cells negatively regulates their activation status.

Invariant natural killer T (iNKT) cells play important roles in antimicrobial defense and immune-regulation. We have previously shown that iNKT cells express certain toll-like receptors (TLR), and that TLR co-stimulation of iNKT cells in the presence of suboptimal concentrations of T cell receptor (TCR) agonists enhances cellular activation. In the present study, we investigated the regulatory effects of CpG oligonucleotides in mouse primary hepatic and splenic iNKT cells and in DN32.

The Golgi associated ERI3 is a Flavivirus host factor.

Dengue virus (DENV) is a mosquito-borne Flavivirus classified into four serotypes (DENV-1-4) that causes Dengue fever (DF), Dengue hemorrhagic Fever (DHF) or Dengue shock syndrome (DSS). An estimated 390 million people are at risk for infection with DENV and there are no effective vaccines or therapeutics. We utilized RNA chromatography coupled with quantitative mass spectrometry (qMS) to identify host RNA binding proteins (RBPs) that interact with DENV-2 RNA.

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.

Characterization of responses elicited by Toll-like receptor agonists in cells of the bursa of Fabricius in chickens.

Toll-like receptors (TLRs) are an evolutionarily conserved group of pattern recognition receptors that play an important role in mediating host-responses to pathogens. Several TLRs have been identified in chickens and their expression has been detected in many immune cell subsets including in B cells. However, the mechanisms through which TLRs modulate B cell responses have not been well characterized in chickens.

Costimulatory activation of murine invariant natural killer T cells by toll-like receptor agonists.

Invariant NKT (iNKT) cells are glycolipid-reactive lymphocytes with anti-microbial properties. Toll-like receptor (TLR)-primed antigen-presenting cells are known to activate iNKT cells, however, the expression and function of TLRs in iNKT cells remain largely unknown. Here, we show that TCR-activation of murine iNKT cells by α-GalactosylCeramide (α-GalCer) or anti-CD3 antibodies can result in increased expression of TLR genes.

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.

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.

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.

Vaccine-induced host responses against very virulent Marek's disease virus infection in the lungs of chickens.

The aim of this study was to investigate the kinetics of virus replication and cellular responses in the lungs following infection with Marek's disease virus (MDV) and/or vaccination with herpesvirus of turkey (HVT) via the respiratory route. Chickens vaccinated with HVT and challenged with MDV had a higher accumulation of MDV and HVT genomes in the lungs compared to the chickens that received HVT or MDV alone. This increase in virus load was associated with augmented expression of interferon (IFN)-gamma and interleukin (IL)-10, and increased T cell infiltration.

Marek's disease virus influences the expression of genes associated with IFN-gamma-inducible MHC class II expression.

Chickens infected with Marek's disease virus (MDV) become lifelong carriers regardless of their susceptibility to clinical disease. Therefore various viral immune-evasive mechanisms must play a role in MDV-host interactions. MDV has previously been shown to influence the expression of major histocompatibility complex (MHC) class II molecules.

Characterization of host responses against a recombinant fowlpox virus-vectored vaccine expressing the hemagglutinin antigen of an avian influenza virus.

There currently are commercial fowlpox virus (FPV)-vectored vaccines for use in chickens, including TROVAC-AIV H5, which expresses the hemagglutinin (HA) antigen of an avian influenza virus and can confer immunity against avian influenza in chickens. Despite the use of recombinant FPV (rFPV) for vaccine delivery, very little is known about the immune responses generated by these viruses in chickens. The present study was designed to investigate host responses to rFPV in vivo and in vitro.

Identification of a dual-specific T cell epitope of the hemagglutinin antigen of an h5 avian influenza virus in chickens.

Avian influenza viruses (AIV) of the H5N1 subtype have caused morbidity and mortality in humans. Although some migratory birds constitute the natural reservoir for this virus, chickens may play a role in transmission of the virus to humans. Despite the importance of avian species in transmission of AIV H5N1 to humans, very little is known about host immune system interactions with this virus in these species.

Establishment of an aerosol-based Marek's disease virus infection model.

Marek's disease virus (MDV), which is the causative agent of Marek's disease (MD), is shed by infected chickens and transmitted to other chickens through the respiratory route. Experimental reproduction of MD has been commonly done either by intra-abdominal inoculation of cell-associated MDV or by exposure to MDV-infected 'seeder' chickens. The former method does not mimic the natural route of MDV infection, whereas the latter method suffers from lack of uniformity in the timing and amount of virus transmission from seeder chickens to susceptible birds.

Induction of innate host responses in the lungs of chickens following infection with a very virulent strain of Marek's disease virus.

The natural route of entry of Marek's disease virus (MDV) is via the respiratory system. However, little is known about host-virus interactions in the lungs. The objective of the present study was to examine MDV replication and induction of innate host responses in the lungs of chickens infected through inhalation.

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 antimicrobial peptides in cecal tonsils of chickens treated with probiotics and infected with Salmonella enterica serovar typhimurium.

Several strategies currently exist for control of Salmonella enterica serovar Typhimurium colonization in the chicken intestine, among which the use of probiotics is of note. Little is known about the underlying mechanisms of probiotic-mediated reduction of Salmonella colonization. In this study, we asked whether the effect of probiotics is mediated by antimicrobial peptides, including avian beta-defensins (also called gallinacins) and cathelicidins.

Expression of cytotoxicity-associated genes in Marek's disease virus-infected chickens.

Cytotoxic host responses to Marek's disease virus (MDV) have been attributed to both natural killer (NK) cells and cytotoxic T lymphocytes (CTLs). However, the mechanisms of cell lysis initiated by these cytotoxic responses during MDV infection are not well defined. Therefore, the current study was aimed at elucidating the molecular mechanisms of host cytotoxic responses to MDV infection by investigating the expression of genes in the cell lysis pathway involving granzyme A.

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.