Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Immunology
The equine immune system is a complex network of cells, tissues, and organs that work collaboratively to defend against pathogens and maintain homeostasis. It consists of innate and adaptive components, each with distinct functions and mechanisms. The innate immune system provides the first line of defense through physical barriers, phagocytic cells, and the complement system. The adaptive immune system involves lymphocytes, such as B cells and T cells, which generate specific responses to antigens and provide immunological memory. Research in equine immunology explores the interactions between these components, the impact of genetic and environmental factors on immune function, and the development of vaccines and therapeutics. This page gathers peer-reviewed studies and scholarly articles focusing on the mechanisms, regulation, and clinical applications of the equine immune system in health and disease.
Freezing or adding trypsin inhibitor to equine intestinal contents extends the lifespan of Clostridium perfringens beta toxin for diagnostic purposes. Clostridium perfringens type C causes necrotizing enteritis mostly in neonatal animals of several species, including horses. The virulence of C. perfringens type C is mostly mediated by beta toxin (CPB). This toxin is highly sensitive to the action of trypsin and other proteases, which explains the increased susceptibility of neonatal animals to type C infections. Final confirmation of type C disease diagnosis should be based on detection of CPB in the intestinal content of affected animals. However, because CPB is so sensitive to the action of proteases, it is believed that this toxin persist...
Gluten-dependent antibodies in horses with inflammatory small bowel disease (ISBD). Equine inflammatory small bowel disease (ISBD) is an idiopathic pathologic condition seeming to increase in prevalence. Objective: To investigate the potential role of gluten in equine ISBD. Methods: Antibodies known to be important in the diagnosis of human coeliac disease (CD): IgA antibodies to human recombinant and guinea pig tissue-transglutaminase (TGA), native gliadin (AGA), deamidated-gliadin-peptides (DGPA), and primate and equine endomysium (EMA) were assessed in blood samples from three different groups of horses: ISBD affected (n = 12) on a gluten-rich diet and controls either ...
Bilateral ovarian adenocarcinoma in a mare causing haemoperitoneum and colic. A 13-year-old Thoroughbred mare was presented with a history of mild colic over 3 days. This colic had acutely exacerbated and was unresponsive to analgesic treatment, and was referred to Massey University Veterinary Teaching Hospital. Results: On examination the heart rate was 100 beats per minute, and mucous membranes were pale and tacky. A large mass was detected on transrectal palpation in the caudal abdomen to the left of midline. Explorative laparotomy revealed severe haemoperitoneum and several masses that were associated with the reproductive tract. The mare was then subject to euthana...
Serology-enabled discovery of genetically diverse hepaciviruses in a new host. Genetic and biological characterization of new hepaciviruses infecting animals contributes to our understanding of the ultimate origins of hepatitis C virus (HCV) infection in humans and dramatically enhances our ability to study its pathogenesis using tractable animal models. Animal homologs of HCV include a recently discovered canine hepacivirus (CHV) and GB virus B (GBV-B), both viruses with largely undetermined natural host ranges. Here we used a versatile serology-based approach to determine the natural host of the only known nonprimate hepacivirus (NPHV), CHV, which is also the closest p...
Equine insect bite hypersensitivity: what do we know? Insect bite hypersensitivity (IBH) is an allergic dermatitis of the horse caused by bites of insects of the genus Culicoides and is currently the best characterized allergic disease of horses. This article reviews knowledge of the immunopathogenesis of IBH, with a particular focus on the causative allergens. Whereas so far hardly any research has been done on the role of antigen presenting cells in the pathogenesis of IBH, recent studies suggest that IBH is characterized by an imbalance between a T helper 2 (Th2) and regulatory T cell (T(reg)) immune response, as shown both locally in the skin...
Expression of essential B cell development genes in horses with common variable immunodeficiency. Common variable immunodeficiency (CVID) is a heterogeneous disorder of B cell differentiation or function with inadequate antibody production. Our laboratory studies a natural form of CVID in horses characterized by late-onset B cell lymphopenia due to impaired B cell production in the bone marrow. This study was undertaken to assess the status of B cell differentiation in the bone marrow of CVID-affected horses by measuring the expression of genes essential for early B cell commitment and development. Standard RT-PCR revealed that most of the transcription factors and key signaling molecules ...
Effect of sample storage on blood crossmatching in horses. Blood samples banked for up to 1 month are typically used to perform pretransfusion testing in humans and small animals, but this has not been validated using blood from horses. Objective: Compatibility of equine blood samples is repeatable using fresh samples, and reproducible using donor blood samples stored for up to 4 weeks. Methods: Six healthy adult horses. Methods: Randomized, blinded experimental study. Immunologic compatibility of the blood of all horses was assessed using a major and minor saline agglutination and hemolysin crossmatch using blood samples refrigerated for 0-4 weeks an...
Towards an inhalative in vivo application of immunomodulating gelatin nanoparticles in horse-related preformulation studies. Delivering active ingredients using biocompatible and biodegradable carriers such as gelatin nanoparticles (GNPs) to the lung constitutes a promising non-invasive route of administration. However, the pulmonary delivery of nanoparticle-based immunotherapy is still a field that requires more clarification. In this study, GNPs loaded with cytosine-phosphate-guanine oligodeoxynucleotides (CpG-ODN)-loaded and plain GNPs were aerosolised either by a conventional pressured metered dose inhaler (pMDI) or by active or passive vibrating-mesh (VM) nebulisers. GNP sizes after nebulisation by active and p...
Miscellaneous vitreous-derived IgM antibodies target numerous retinal proteins in equine recurrent uveitis. In equine recurrent uveitis (ERU), immune reactions are directed toward known antigens like S-antigen, interphotoreceptor retinoid-binding protein, and cellular retinalaldehyde-binding protein, and anti-retinal antibodies were detected in vitreous samples. The aim of this study was the investigation of intraocular immunoglobulin M (IgM) reactivities to retinal proteome. Methods: Retina was separated by one- and two-dimensional gel electrophoresis and blotted semidry on PVDF membranes. To identify intraocular IgM antibody responses to retinal tissue, blots were incubated with vitreous samples o...
Expression of late viral proteins is restricted in nasal mucosal leucocytes but not in epithelial cells during early-stage equine herpes virus-1 infection. Equine herpes virus (EHV)-1 replicates in the epithelial cells of the upper respiratory tract and reaches the lamina propria and bloodstream in infected mononuclear cells. This study evaluated expression of the late viral proteins gB, gC, gD and gM in respiratory epithelial and mononuclear cells using: (1) epithelial-like rabbit kidney cells and peripheral blood mononuclear cells infected with EHV-1 in vitro; (2) an equine ex vivo nasal explant system; and (3) nasal mucosa tissue of ponies infected in vivo. The viral proteins were expressed in all late-infected epithelial cells, whereas expres...
In search for cross-reactivity to immunophenotype equine mesenchymal stromal cells by multicolor flow cytometry. During recent years, cell-based therapies using mesenchymal stem cells (MSC) are reported in equine veterinary medicine with increasing frequency. In most cases, the isolation and in vitro differentiation of equine MSC are described, but their proper immunophenotypic characterization is rarely performed. The lack of a single marker specific for MSC and the limited availability of monoclonal antibodies (mAbs) for equine MSC in particular, strongly hamper this research. In this study, 30 commercial mAbs were screened with flow cytometry for recognizing equine epitopes using the appropriate posit...
C-Terminal region of 48-kDa rhoptry protein for serological detection of Babesia caballi antibodies in horses. A recombinant C-terminal antigen derived from Babesia caballi 48-kDa rhoptry protein (rBc48/CT) was made for the development of a serologically diagnostic test. Antiserum raised against the rBc48/CT reacted specifically with the corresponding native protein by Western blotting and the indirect fluorescent antibody test (IFAT). Next, an indirect enzyme-linked immunosorbent assay (Bc48/CT-ELISA) and an immunochromatographic test based on the Bc48/CT (Bc48/CT-ICT) were constructed and employed for the detection of an antibody to B. caballi in a variety of equine sera. The results of Bc48/CT-ELISA...
Generation and characterization of monoclonal antibodies to equine CD16. The low-affinity Fc receptor CD16 plays a central role in the inflammatory and innate immune responses of many species, but has not yet been investigated in the horse. Using the predicted extracellular region of equine CD16 expressed as a recombinant fusion protein with equine IL-4 (rIL-4/CD16), we generated a panel of mouse monoclonal antibodies (mAbs) that recognize equine CD16. Nine mAbs were chosen for characterization based upon recognition of CD16, but not IL-4, in ELISA. All nine mAbs recognized full-length, cell-surface CD16 expressed as a GFP fusion protein by CHO cells, but not the c...
Experimental infection of horses with Bartonella henselae and Bartonella bovis. Experimental infection of horses with Bartonella species is not documented. Objective: Determine clinical signs, hematologic changes, duration of bacteremia, and pattern of seroconversion in Bartonella henselae or Bartonella bovis-inoculated horses. Methods: Twelve (2 groups of 6) randomly selected healthy adult horses seronegative and culture negative for Bartonella spp. Methods: Experimental/observational study: Group I: B. henselae or saline control was inoculated intradermally into 4 naïve and 2 sentinel horses, respectively. Group II: same design was followed by means of B. bovis. Daily ...
Macrophage sub-populations and the lipoxin A4 receptor implicate active inflammation during equine tendon repair. Macrophages (Mφ) orchestrate inflammatory and reparatory processes in injured connective tissues but their role during different phases of tendon healing is not known. We investigated the contribution of different Mφ subsets in an equine model of naturally occurring tendon injury. Post mortem tissues were harvested from normal (uninjured), sub-acute (3-6 weeks post injury) and chronically injured (>3 months post injury) superficial digital flexor tendons. To determine if inflammation was present in injured tendons, Mφ sub-populations were quantified based on surface antigen expression of...
Seroprevalence of Neospora spp. in Horses in North East of Iran. Neospora caninum, an obligate intracellular protozoan parasite, is recognized as a major cause of abortion in cattle, while limited information is presently available on the seroprevalence of Neospora antibodies in horses' worldwide. The aim of the present study was to determine serologic prevalence of Neospora infection in horses in Iran. Methods: Sera from 150 horses from Mashhad suburb in Razavi Khorasan Province, northeast Iran were examined for antibodies to Neospora spp. using Neospora modified direct agglutination test (N-MAT). Results: Antibodies to this parasite were detected in 45 (3...
Molecular evidence for natural killer-like cells in equine endometrial cups. To identify equine orthologs of major NK cell marker genes and utilize them to determine whether NK cells are present among the dense infiltration of lymphocytes that surround the endometrial cup structures of the horse placenta during early pregnancy. Methods: PCR primers were developed to detect the equine orthologs of NKP46, CD16, CD56, and CD94; gene expression was detected in RNA isolated from lymphocytes using standard 2-step reverse transcriptase (RT) PCR and products were cloned and sequenced. Absolute real-time RT-PCR was used to quantitate gene expression in total, CD3+, and CD3- per...
Isolation and identification of Mycobacterium avium subspecies silvaticum from a horse. Routine cultivation methods are able to distinguish between isolates of the Mycobacterium avium and the Mycobacterium tuberculosis complex. However, molecular tools are needed to further identify the several subspecies in the M. avium complex, especially for the subspecies avium and silvaticum. A rapid technique using HhaI restriction digestion of a 349 bp amplification product of the 85B antigen (α-antigen) gene was used for the identification of M. avium subsp. silvaticum in a three-year-old gelding presenting with caseous, necrotizing, granulomatous lesions. The result was confirmed by seq...
The importance of vertical transmission of Neospora sp. in naturally infected horses. Neospora spp. is a intracellular protozoan phylogenetically closely related to Toxoplasma gondii and Sarcocystis neurona, and it can infect horses leading to the development of reproductive or neurological diseases. We determined the presence of antibodies to Neospora sp. in mares at their parturition time and determine the frequency of vertical transmission in healthy foals to verify the importance of transplacental transmission. The samples were analyzed by indirect immunofluorescence antibody test, showing that seroprevalence in mares is higher than in foals and seropositive mares are likel...
Cytokine production and proliferation upon in vitro oligodeoxyribonucleotide stimulation of equine peripheral blood mononuclear cells. Synthetic oligodeoxyribonucleotides (ODN) may prove useful immune modulators in equine medicine. It is however important to assess the effects of each specific ODN in the species it is intended to be used in. The present study therefore aimed to evaluate some ODN for induction of cytokine production; i.e. type I interferons (IFN), IFN-γ, tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β), and proliferation of equine peripheral blood mononuclear cells (PBMC). A panel of four ODN containing unmethylated cytosine-guanosine sequences (CpG) was used: ODN 1 and ODN 8 repre...
Equine peripheral blood-derived mesenchymal stem cells: isolation, identification, trilineage differentiation and effect of hyperbaric oxygen treatment. Two studies report variability in proliferation and limited adipocyte differentiation of equine peripheral blood-derived adult mesenchymal stem cells, thus casting doubt on their adipogenic potential. Peripheral blood can be a valuable source of adult mesenchymal stem cells if cell culture conditions permissive for their adherence, proliferation and differentiation are defined. Hyperbaric oxygen treatment has been reported to mobilise haematopoietic progenitor stem cells into the peripheral blood in humans and mice, but similar experiments have not been done in horses. Objective: To optimise c...
Antibodies in the treatment of aplastic anemia. Antibodies have been the cornerstone of treatment of acquired aplastic anemia for more than 25 years. Treatment with antithymocyte globulin (ATG) is considered pivotal and the addition of cyclosporine improves the overall response rate. This antibody is heterogeneous and horse ATG is apparently more effective than rabbit ATG. Several issues remain unsolved in relation to the combination of ATG and cyclosporine: cost, toxicity and late clonal disorders. In recent years, alternative immunosuppressive therapy has been proposed and new antibodies have emerged: porcine ATG, alemtuzumab, daclizumab...
Virus-specific CD8⁺ T-cells detected in PBMC from horses vaccinated against African horse sickness virus. African horsesickness (AHS) is an infectious but noncontagious viral disease affecting all species of Equidae. The recall immune response of AHSV naïve horses immunised with an attenuated African horsesickness virus serotype 4 (AHSV4) was characterised using immune assays including ELISPOT, real-time PCR (qPCR) and flow cytometry. The recall immune response detected in PBMC isolated from three inoculated horses showed an upregulation of circulating B lymphocytes that correlated with elevated IL-4 mRNA expression indicative of humoral immunity, but reduced frequency of CD4⁺ cells. In additio...
Expression of thymic stromal lymphopoietin in equine recurrent airway obstruction. Thymic stromal lymphopoietin (TSLP) is a cytokine involved in lymphocyte development. In humans and mice, TSLP drives the differentiation of T helper 2 (Th2) cells and the development of allergic inflammation. The equine TSLP gene has been previously identified and characterized, but its role in the pathogenesis of equine allergic diseases is not known. Our objective was to assess the expression of TSLP in bronchoalveolar lavage (BAL) cells and in primary bronchial epithelial cells (BEC) isolated from horses with recurrent airway obstruction (RAO). RNA was isolated from BAL cells sampled from ...
Evaluation of tyrosinase expression in canine and equine melanocytic tumors. To determine the tissue-restricted expression pattern of tyrosinase mRNA in canine and equine melanocytic tumors and relative tyrosinase and major histocompatibility complex (MHC) I mRNA expression in variants of melanocytic tumors. Methods: 39 canine and 8 equine tumor samples and 10 canine and 6 equine normal tissue samples. Methods: RNA was isolated from formalin-fixed, paraffin-embedded tissues. Real-time PCR assays were designed to amplify canine and equine tyrosinase, S18 ribosomal RNA, and major histocompatibility complex I transcripts. Relative expression was determined by use of S18 a...
Replication and fine-mapping of a QTL for recurrent airway obstruction in European Warmblood horses. Recurrent airway obstruction (RAO), or 'heaves', is a common performance-limiting allergic respiratory disease of mature horses. It is related to sensitization and exposure to mouldy hay and has a familial basis with a complex mode of inheritance. In a previous study, we detected a QTL for RAO on ECA 13 in a half-sib family of European Warmblood horses. In this study, we genotyped additional markers in the family and narrowed the QTL down to about 1.5 Mb (23.7-25.2 Mb). We detected the strongest association with SNP BIEC2-224511 (24,309,405 bp). We also obtained SNP genotypes in an independent...
Identification and characterization of equine herpesvirus type 1 pUL56 and its role in virus-induced downregulation of major histocompatibility complex class I. Major histocompatibility complex class I (MHC-I) molecules play an important role in host immunity to infection by presenting antigenic peptides to cytotoxic T lymphocytes (CTLs), which recognize and destroy virus-infected cells. Members of the Herpesviridae have developed multiple mechanisms to avoid CTL recognition by virtue of downregulation of MHC-I on the cell surface. We report here on an immunomodulatory protein involved in this process, pUL56, which is encoded by ORF1 of equine herpesvirus type 1 (EHV-1), an alphaherpesvirus. We show that EHV-1 pUL56 is a phosphorylated early protein w...
Vitreal IgM autoantibodies target neurofilament medium in a spontaneous model of autoimmune uveitis. Although the presence of IgG autoantibodies in the vitreous of spontaneous cases of equine recurrent uveitis (ERU) has been demonstrated, the potential role of IgM reactivities during ERU pathogenesis remains unexplored. The purpose of this study was to examine the presence of IgM autoantibodies in vitreous specimens of ERU-affected horses and to test their binding specificity to intraocularly expressed proteins. Methods: To test IgM autoantibody responses to retinal tissue, vitreous samples of eye-healthy controls and ERU patients were analyzed via two-dimensional Western blot analysis with e...
