Hierarchical modelling of immunoglobulin coated bacteria in dogs with chronic enteropathy shows reduction in coating with disease remission but marked inter-individual and treatment-response variability.

Chronic enteropathies are a common problem in dogs, but many aspects of the pathogenesis remain unknown, making the therapeutic approach challenging in some cases. Environmental factors are intimately related to the development and perpetuation of gastrointestinal disease and the gut microbiome has been identified as a contributing factor. Previous studies have identified dysbiosis and reduced bacterial diversity in the gastrointestinal microbiota of dogs with chronic enteropathies.

Characterisation of ovine lymphatic vessels in fresh specimens.

Background And Aim: The development and use of experimental models using lymphatic cannulation techniques have been hampered by the lack of high-quality colour imaging of lymphatic vessels in situ. Most descriptions of lymphatic anatomy in sheep have historically depended on schematic diagrams due to limitations in the ability to publish colour images of the lymphatic vessels with decent resolution. The aim of this work was to encourage more widespread use of the ovine cannulation model by providing clear photographic images identifying the location and anatomical layout of some major lymphatic ducts and their in situ relationship to surrounding tissues.

Lymphatic cannulation models in sheep: Recent advances for immunological and biomedical research.

Lymphatic cannulation models are useful tools for studying the immunobiology of the lymphatic system and the immunopathology of specific tissues in diseases. Sheep cannulations have been used extensively, as models for human physiology, fetal and neonatal development, human diseases, and for studies of ruminant pathobiology. The development of new and improved cannulation techniques in recent years has meant that difficult to access sites, such as mucosal associated tissues, are now more readily available to researchers.

Immunoselected STRO-3 mesenchymal precursor cells reduce inflammation and improve clinical outcomes in a large animal model of monoarthritis.

Background: The purpose of this study was to investigate the therapeutic efficacy of intravenously administered immunoselected STRO-3 + mesenchymal precursor cells (MPCs) on clinical scores, joint pathology and cytokine production in an ovine model of monoarthritis.

Methods: Monoarthritis was established in 16 adult merino sheep by administration of bovine type II collagen into the left hock joint following initial sensitization to this antigen. After 24 h, sheep were administered either 150 million allogeneic ovine MPCs (n = 8) or saline (n = 8) intravenously (IV).

Mapping B lymphocytes as major reservoirs of naturally occurring latent equine herpesvirus 5 infection.

Equine herpesvirus 5 (EHV5) is a commonly detected gammaherpesvirus, which, along with the closely related EHV2, constitute the only two known percaviruses that infect horses. Apart from detection in horse populations worldwide and the recent publication of the whole genome, there is little known about the biology and pathogenesis of this virus, with many assumptions made by parallels with EHV2. The long-term survival of gammaherpesviruses within infected hosts involves the establishment and maintenance of latency in selected cell and tissues types, particularly lymphocytes.

Effect of mesenchymal precursor cells on the systemic inflammatory response and endothelial dysfunction in an ovine model of collagen-induced arthritis.

Background And Aim: Mesenchymal precursor cells (MPC) are reported to possess immunomodulatory properties that may prove beneficial in autoimmune and other inflammatory conditions. However, their mechanism of action is poorly understood. A collagen-induced arthritis model has been previously developed which demonstrates local joint inflammation and systemic inflammatory changes.

Endothelial dysfunction in an ovine model of collagen-induced arthritis.

Background: Rheumatoid arthritis (RA) induces systemic inflammation, producing a range of co-morbidities including cardiovascular disease. An early vascular change is endothelial dysfunction, characterized by reduced endothelium-dependent vasodilation. The aim of this study was to assess endothelial function in isolated coronary and digital arteries using an ovine model of collagen-induced RA.

Cell death and thymic export during fetal life.

In the fetus the peripheral T cell pool expands as the fetus grows, but the mechanisms that regulate T cell homeostasis during fetal life are unknown. Here, we show that the peripheral T cell pool in the sheep fetus is established by the export from the fetal thymus of twice as many CD8+ as CD4+ thymic emigrants every day. Clonal deletion of CD4+ thymocytes in the fetal thymus appeared to be more stringent than was the case for CD8+ thymocytes because only 1 in 35 single-positive CD4 (SPCD4) thymocytes was exported from the thymus whereas the majority (2/3) of the single-positive CD8 (SPCD8) thymocytes were exported from the fetal thymus each day.

Site-directed mutagenesis of the VP2 gene of Chicken anemia virus affects virus replication, cytopathology and host-cell MHC class I expression.

Chicken anemia virus (CAV) is an immunosuppressive pathogen of chickens. To further examine the role of viral protein 2 (VP2), which possesses dual-specificity protein phosphatase (DSP) activity, in viral cytopathogenicity and its influence on viral growth and virulence, an infectious genomic clone of CAV was subjected to site-directed mutagenesis. Substitution mutations C87R, R101G, K102D and H103Y were introduced into the DSP catalytic motif and R129G, Q131P, R/K/K150/151/152G/A/A, D/E161/162G/G, L163P, D169G and E186G into a region predicted to have a high degree of secondary structure.

Embryonic age influences the capacity for cytokine induction in chicken thymocytes.

Thymocyte responses to functional activation are of relevance to the evaluation of the efficacy of in ovo immunotherapies and vaccines in chickens. In this study we have demonstrated differences in chicken thymocyte responses according to developmental age. RNA samples from stimulated and unstimulated chicken thymocytes were assayed for messenger RNA encoding the cytokines interleukin-1beta (IL-1beta), IL-2, interferon-alpha (IFN-alpha), IFN-beta, IFN-gamma and transforming growth factor-beta4 (TGF-beta4), and also components of the major histocompatibility complex (MHC), beta2-microglobulin (beta2M) and the MHC class I alpha-chain (MHC IA).