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.
Vaginal lactic acid bacteria in the mare: evaluation of the probiotic potential of native Lactobacillus spp. and Enterococcus spp. strains. Lactic acid bacteria (LAB) are important members of the human vaginal microbiota and their presence is considered beneficial. However, little is known about native vaginal bacteria in other animal species such as the horse. The aim of this work was to quantify the vaginal lactic acid bacteria and lactobacilli of mares and to establish if selected equine vaginal lactic acid bacteria, particularly Lactobacillus and Enterococcus spp. strains, could exhibit potential as probiotics. The vaginal lactic acid bacteria and lactobacilli of 26 mares were quantified by plate counts. Five strains (three La...
The role of p38 mitogen-activated kinase (MAPK) in the mechanism regulating cyclooxygenase gene expression in equine leukocytes. The goal of this study was to define the role for p38 mitogen-activated kinase (MAPK) in the signaling mechanism regulating pro-inflammatory cyclooxygenase (COX) gene expression in lipopolysaccharide (LPS)-activated equine leukocytes for the purposes of identifying novel targets for anti-inflammatory therapy in endotoxemic horses. The p38 MAPK has been shown to positively regulate inflammatory gene expression in human leukocytes and can be activated by a variety of stimuli including LPS, TNF-alpha, and IL-1. Activation-associated phosphorylated p38 MAPK has been implicated in the up-regulation...
Is there a benefit from an early booster vaccination in the control of equine influenza? Conventional equine influenza vaccination schedules consist of a primary course of two vaccinations given 4-6 weeks apart followed by a third vaccination (booster) given approximately 5 months later. In between the primary course and the third vaccination, horses are generally considered not to be adequately protected against influenza. This study aimed to investigate whether Thoroughbred foals would benefit from a vaccination schedule in which the third vaccination was given earlier than in conventional vaccination schedules. The vaccines used were an inactivated whole virus equine influenza ...
The effect of skin allografting on the equine endometrial cup reaction. This research tested the hypothesis that immunological sensitization of mares by skin allografting, followed by the establishment of pregnancy using semen from the skin-graft donor, would give rise to secondary immune responses to the developing horse conceptus, resulting in an earlier demise of the fetally derived endometrial cups. Maiden mares received skin allografts from a stallion homozygous for Major Histocompatibility Complex (MHC) antigens and/or equivalent autografts and were subsequently mated to the skin-graft donor stallion during the next two breeding seasons. Mares that had been ...
Immune responsiveness in the neonatal period. The maintenance of pregnancy requires suppression of the maternal immune system which would naturally recognize the developing fetus as an allograft and seek to destroy it by mounting a Th1 regulated cytotoxic immune response. During pregnancy a range of soluble factors are produced by the placenta which switch maternal immune regulation towards a protective Th2 phenotype. These factors also influence the developing fetal immune system and all newborns initially have an immunological milieu skewed towards Th2 immunity. Vaccination during the neonatal period must therefore overcome the dual cha...
Serum antibodies in mares and foals to Actinobacillus equuli whole cells, outer membrane proteins, and Aqx toxin. Actinobacillus equuli is carried in the alimentary tract of mares and can cause severe septicemia of neonatal foals. A hemolytic subspecies, A. equuli subsp. haemolyticus, and a non-hemolytic subspecies, A. equuli subsp. equuli, have been identified. Hemolytic strains produce the RTX toxin Aqx. The purpose of this study was to demonstrate sequentially in two sets of mare-foal pairs antibodies to A. equuli whole bacterial cells, outer membrane proteins, and recombinant Aqx and to compare the transfer of antibodies to these antigens between mares and their foals. Two mare/foal sets of sera were ...
Identification and characterization of equine granzyme B. In the present study we describe the isolation and characterization of putative equine granzyme B for which we propose the designation 'eqGrzmB'. Sequence analysis revealed characteristic features of a GrzmB protease such as the presence of a signal (leader-) peptide and an activation di-peptide. The isolated eqGrzmB is functionally active when expressed in human or in insect cells. Furthermore, exchange of any of three putative active site amino acids, which are highly conserved along granzyme B enzymes, led to a complete loss of enzymatic activity in the newly identified eqGrzmB. Phylogeneti...
Equine herpesvirus-1-specific interferon gamma (IFNgamma) synthesis by peripheral blood mononuclear cells in thoroughbred horses. An assay has been developed that measures EHV-1 specific interferon gamma synthesis (IFNgamma), a cytokine produced following the activation of memory T lymphocytes and therefore a measure of cell mediated immunity. The method requires validation in the field. Objective: To measure the frequency of EHV-1 specific, IFNgamma synthesising peripheral blood mononuclear cells (PBMC) in a population of Thoroughbred horses, and examine its relationship with age, gender, premises and history of vaccination or field infection with EHV-1. Methods: Lymphocytes from 200 Thoroughbred horses were stimulated ...
Seroprevalence of antibotulinum neurotoxin type C antibodies in horses in Israel. Clostridium botulinum type C is prevalent in Israel and outbreaks recorded in many species, other than horses. Association between levels of anti-BoNT/C antibodies and equine grass sickness (EGS) have been demonstrated but seroprevalence of anti-BoNT/C antibodies in horses has not been reported nor has EGS been reported in Israel. Objective: To determine the seroprevalence of specific anti-BoNT/C antibodies in horses in Israel and to determine whether age, breed and gender, or geographical region of farms are potential risk factors for exposure to BoNT/C. Objective: Anti-BoNT/C antibodies are ...
Immunization by intrabronchial administration to 1-week-old foals of an unmarked double gene disruption strain of Rhodococcus equi strain 103+. Rhodococcus equi causes fatal granulomatous pneumonia in foals and immunocompromised animals and humans. However, there is no effective vaccine against this infection. In this study, the chromosomal genes isocitrate lyase (icl) and cholesterol oxidase (choE) were chosen as targets for mutation and assessment of the double mutant as an intrabronchial vaccine in 1-week-old foals. Using a modification of a suicide plasmid previously developed in this laboratory, we developed a choE-icl unmarked deletion mutant of R. equi strain 103+. Five 1-week-old foals were infected intrabronchially with the m...
Mucus and the mare: how little we know. Uterine infections are a major cause of infertility, but the role of mucus in equine uterine defense is not well understood. Mucociliary currents play an important role in protecting mucous membranes, including the upper and lower respiratory tracts of mammals, and are required for feeding and oxygenation of many aquatic invertebrates. Although phagocytosis has long been considered the first line of uterine defense in the mare, there are concerns about its efficacy in the uterine lumen. Additional local defenses, such as mucociliary currents, have therefore been proposed. The uterine epitheliu...
LC-MS/MS method for confirmation of recombinant human erythropoietin and darbepoetin alpha in equine plasma. Recombinant human erythropoietin (rhEPO) and darbepoetin alpha (DPO) are protein-based drugs for the treatment of anemia by stimulating red blood cell production. Consequently, they are abused in human and equine sports. To deter their abuse in the horse racing industry, a sensitive and reliable method for confirmation of these agents in equine plasma has been in urgent need. Such a method by LC-MS/MS is described in this paper. The method involved analyte enrichment by immunoaffinity separation using anti-rhEPO antibody linked to magnetic beads, digestion by trypsin, and analysis by LC-MS/MS....
Long terminal repeat sequences from virulent and attenuated equine infectious anemia virus demonstrate distinct promoter activities. In the early 1970s, the Chinese Equine Infectious Anemia Virus (EIAV) vaccine, EIAV(DLA), was developed through successive passages of a wild-type virulent virus (EIAV(L)) in donkeys in vivo and then in donkey macrophages in vitro. EIAV attenuation and cell tropism adaptation are associated with changes in both envelope and long terminal repeat (LTR). However, specific LTR changes during Chinese EIAV attenuation have not been demonstrated. In this study, we compared LTR sequences from both virulent and attenuated EIAV strains and documented the diversities of LTR sequence from in vivo and in v...
Experimental infections with West Nile virus. West Nile virus emerged recently in North America as a serious human and animal pathogen. This review summarizes the use of experimental infections with West Nile virus in diverse vertebrate species that have been used to answer fundamental questions about the host response, pathogenesis of West Nile virus infection and virus evolution. Results: West Nile virus has an extremely broad vertebrate host range. Infection of common species of birds has defined those with high vs. low potential to serve as amplifying hosts for the virus. In general, mammals (primates, horses, companion animals) are d...
Infections caused by pathogenic free-living amebas (Balamuthia mandrillaris and Acanthamoeba sp.) in horses. This article describes amebic infections in 4 horses: granulomatous amebic encephalitis caused by Balamuthia mandrillaris and Acanthamoeba culbertsoni and systemic infections caused by Acanthamoeba sp. The former infection occurred in 1 of 4 horses spontaneously without any underlying conditions; the latter amebic infection was perhaps "opportunistic" considering the visceral involvement by this protozoan in association with Aspergillus sp. and/or Escherichia coli and Pseudomonas sp. The clinicopathologic findings and demonstration of the amebic organisms using immunohistochemical techniques, ...
Effects of blood contamination of cerebrospinal fluid on results of indirect fluorescent antibody tests for detection of antibodies against Sarcocystis neurona and Neospora hughesi. The purpose of this study was to determine the effect of blood contamination of cerebrospinal fluid (CSF) on the results of indirect fluorescent antibody tests (IFATs) for Sarcocystis neurona and Neospora hughesi. The in vitro study used antibody-negative CSF collected from non-neurologic horses immediately after euthanasia and blood samples from 40 healthy horses that had a range of IFAT antibody titers against S. neurona and N. hughesi. Serial dilutions of whole blood were made in seronegative CSF to generate blood-contaminated CSF with red blood cell (RBC) concentrations ranging from 10 to ...
Major retinal autoantigens remain stably expressed during all stages of spontaneous uveitis. Equine recurrent uveitis (ERU) is a valuable model for autoimmune diseases, since it develops frequently and occurs spontaneously. We investigated the overall expression level of three major retinal autoantigens in normal retinas and various ERU stages. Analysis of retinal proteomes of both, healthy and diseased retinas revealed an almost unaffected expression of IRBP, S-antigen and cRALBP in ERU cases. Validation of these findings with western blots and immunohistochemistry confirmed constant to increased expression of these autoantigens, although loss of their physiological expression sites ...
Restricted and selective tropism of a Venezuelan equine encephalitis virus-derived replicon vector for human dendritic cells. Dendritic cells (DCs) consist of heterogeneous phenotypic populations and have diverse immunostimulatory functions dependent on both lineage and functional phenotype, but as exceptionally potent antigen-presenting cells, they are targets for generating effective antigen-specific immune responses. A promising replicon particle vector derived from Venezuelan equine encephalitis virus (VEE) has been reported to transduce murine footpad DCs. However, the receptive DC subset, the degree of restriction for this tropism, and the extent of conservation between rodents and humans have not been well cha...
Molecular epidemiology of Streptococcus zooepidemicus infection in naturally occurring equine respiratory disease. The objective of the study was to characterise the molecular epidemiology of Streptococcus zooepidemicus infection among isolates collected sequentially from recently weaned, pasture maintained Welsh mountain ponies with naturally occurring respiratory disease. Weekly nasopharyngeal and tracheal lavage samplings over a 10-week period were conducted in 29 ponies. Two PCR typing methods based on characterisation of the M-protein hypervariable (HV) region and the 16S-23S rRNA gene intergenic spacer were then applied to isolates of S. zooepidemicus recovered from nasopharyngeal swab and tracheal w...
Use of appropriate antimicrobials in wound management. The primary goal of wound management is to achieve a functional closure with minimal scarring. Preventing infection is important to facilitate the healing process. Most simple, uncomplicated wounds do not need systemic antibiotics but benefit from the use of topical antibiotics. Judicious use of antibiotics reduces unnecessary adverse events and helps reduce the development of resistance. Although antibiotics can help reduce infection risk and promote healing, they are not a substitute for good local wound care, in particular irrigation and surgical débridement. This article reviews the role ...
Classes and crossreactivity of proteinases in the excretory-secretory products of Caenorhabditis elegans. Proteinases released during the in vitro maintenance of asynchronous cultures of the free-living nematode Caenorhabditis elegans were characterized on the basis of subunit composition, fluorogenic substrate specificity, inhibitor sensitivity and pH optima. Cysteine proteinases are present in the excretory-secretory products (ESP) as indicated by the hydrolysis of cathepsin fluorogenic substrates and confirmed by immunoblotting. Serine proteinases were predominant as indicated by substrate gel analysis and inhibitor studies. The presence of metallo-proteinases was also indicated by inhibitor st...
Envelope-specific T-helper and cytotoxic T-lymphocyte responses associated with protective immunity to equine infectious anemia virus. Equine infectious anemia virus (EIAV) infection of horses provides a valuable model for examining the natural immunological control of lentivirus infection and disease and the mechanisms of protective and enhancing vaccine immunity. We have previously hypothesized that the EIAV envelope (Env) proteins gp90 and gp45 are major determinants of vaccine efficacy, and that the development of protective immunity by attenuated viral vaccines may be associated with the progressive redirection of immune responses from immunodominant, variable Env segments to immunorecessive, conserved Env sequences. Whi...
Burkholderia Hep_Hag autotransporter (BuHA) proteins elicit a strong antibody response during experimental glanders but not human melioidosis. The bacterial biothreat agents Burkholderia mallei and Burkholderia pseudomallei are the cause of glanders and melioidosis, respectively. Genomic and epidemiological studies have shown that B. mallei is a recently emerged, host restricted clone of B. pseudomallei. Results: Using bacteriophage-mediated immunoscreening we identified genes expressed in vivo during experimental equine glanders infection. A family of immunodominant antigens were identified that share protein domain architectures with hemagglutinins and invasins. These have been designated Burkholderia Hep_Hag autotransporter (BuHA)...
Avian titer development against West nile virus after extralabel use of an equine vaccine. West Nile virus affects many animals, but the highest prevalence of morbidity and mortality is observed in birds, horses, and humans. The purpose of this study was to determine a protocol in birds of prey and corvids, using a vaccine developed for horses. The birds were assigned to five groups. Groups 1-4 received 0.25 ml, 0.5 ml, 0.75 ml, and 1.0 ml, respectively, and group 5 served as a control group. The greatest percentage of seroconversion (58.3%) was observed in the vaccine group that received a dose of 1.0 ml administered thrice, 3 wk apart. This report demonstrates that a vaccine devel...
Correlation between the induction of Th1 cytokines by an attenuated equine infectious anemia virus vaccine and protection against disease progression. The equine infectious anemia virus (EIAV) donkey-leukocyte attenuated vaccine (DLV) has been used to protect against equine infectious anaemia (EIA) disease for several decades in China. The attenuated mechanism and immunological protective mechanisms remain to be elucidated. To identify responses that correlate with the protection against disease, we immunized horses with DLV, followed by challenge with an EIAV wild-type strain LN. All vaccinated horses were asymptomatic and had a low level of virus replication (<10 copies ml-1). The expression level of cytokines including gamma interferon...
Immune selection of equine infectious anemia virus env variants during the long-term inapparent stage of disease. The principal neutralizing domain (PND) of equine infectious anemia virus (EIAV) is located in the V3 region of SU. Genetic variation in the PND is considered to play an important role in immune escape and EIAV persistence; however, few studies have characterized genetic variation in SU during the inapparent stage of disease. To better understand the mechanisms of virus persistence, we undertook a longitudinal study of SU variation in a pony experimentally inoculated with the virulent EIAV(Wyo). Viral RNA isolated from the inoculum and from sequential sera samples was amplified by RT-PCR, clon...
A comparison of Freund’s Complete and Freund’s Modified Adjuvants used with a contraceptive vaccine in wild horses (Equus caballus). Fifteen captive wild mares (Equus caballus) were treated with porcine zona pellucida contraceptive vaccine and either Freund's Complete Adjuvant (n = 7) or Freund's Modified Adjuvant (n = 8). All mares received a booster inoculation of porcine zona pellucida plus Freund's Incomplete Adjuvant a month later. Anti-porcine zona pellucida antibodies were measured over 10 mo following the initial inoculation. There were no significant differences in antibody titers at any point during the 10 mo, and seven of the eight mares in the Freund's Modified Adjuvant group were above the 60% level at the end ...
