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.
Naveed A, Eertink LG, Wang D, Li F.Humans and equines are two dead-end hosts of the mosquito-borne West Nile virus (WNV) with similar susceptibility and pathogenesis. Since the introduction of WNV vaccines into equine populations of the United States of America (USA) in late 2002, there have been only sporadic cases of WNV infection in equines. These cases are generally attributed to unvaccinated and under-vaccinated equines. In contrast, due to the lack of a human WNV vaccine, WNV cases in humans have remained steadily high. An average of 115 deaths have been reported per year in the USA since the first reported case in 1999. ...
Onzere CK, Bastos RG, Bishop RP, Suarez CE, Fry LM. () is an apicomplexan parasite that causes severe hemolytic anemia in equids. Presently, there is inadequate knowledge of the immune responses induced by in equid hosts impeding understanding of the host parasite relationship and development of potent vaccines for control of infections. The objective of this study was to evaluate the host-parasite dynamics between merozoites and infected horses by assessing cytokine expression during primary and secondary parasite exposure, and to determine whether the pattern of expression correlated with clinical indicators of disease. Our findings showe...
Witkowska-Piłaszewicz O, Malin K, Dąbrowska I, Grzędzicka J, Ostaszewski P, Carter C.Domestic horses routinely participate in vigorous and various athletic activities. This enables the horse to serve as a model for studying athletic physiology and immunology in other species, including humans. For instance, as a model of physical efforts, such as endurance rides (long-distance running/aerobic exercise) and races (anaerobic exercise), the horse can be useful in evaluating post-exercise response. Currently, there has been significant interest in finding biomarkers, which characterize the advancement of training and adaptation to physical exercise in the horse. The parallels in c...
Hamond C, Adam EN, Stone NE, LeCount K, Anderson T, Putz EJ, Camp P, Hicks J, Stuber T, van der Linden H, Bayles DO, Sahl JW, Schlater LK, Wagner DM....Equine leptospirosis can result in abortion, stillbirth, neonatal death, placentitis, and uveitis. Horses can also act as subclinical reservoir hosts of infection, which are characterized as asymptomatic carriers that persistently excrete leptospires and transmit disease. In this study, PCR and culture were used to assess urinary shedding of pathogenic Leptospira from 37 asymptomatic mares. Three asymptomatic mares, designated as H2, H8, and H9, were PCR-positive for lipL32, a gene specific for pathogenic species of Leptospira. One asymptomatic mare, H9, was culture-positive, and the recovered...
Wagner B.Host immune analyses require specific reagents to identify cellular and soluble components of the immune system. These immune reagents are often species-specific. For horses, various immunological tools have been developed and tested by different initiatives during the past decades. This article summarizes the development of well characterized monoclonal antibodies (mAbs) for equine immune cells, immunoglobulin isotypes, cytokines, and chemokines.
Soliman R, Yousef M, Gelil SA, Aboul-Ella H.Strangles is a highly contagious disease of the equine upper respiratory tract caused by Streptococcus equi subspecies. Streptococcus equi subsp. equi (S. equi) and Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) was isolated, as local, hot, and field strains, from horses clinically suffering from respiratory distress. The isolated Streptococci were identified using bacteriological and molecular techniques. Four formulations of inactivated S. equi vaccines were developed and evaluated. The first formulation was prepared using the S. equi isolates, adjuvanted with MONTANIDE GEL adjuv...
Leduc L, Leclère M, Lavoie JP.Although horses with asthma share similar clinical signs, the heterogeneity of the disease in terms of severity, triggering factors, inflammatory profile, and pathological features has hindered our ability to define biologically distinct subgroups. The recognition of phenotypes and endotypes could enable the development of precision medicine, including personalized, targeted therapy, to benefit affected horses. While in its infancy in horses, this review outlines the phenotypes of equine asthma and discusses how knowledge gained from targeted therapy in human medicine can be applied to evaluat...
Cendejas PM, Goodman AG.West Nile virus (WNV) is capable of causing severe neurologic disease in both humans and equines, making it a disease of importance in both human medicine and veterinary medicine. No targeted treatments exist for WNV infection in either humans or equines. Infection is treated symptomatically through management of symptoms like fever and seizures. As treatment for WNV is purely supportive, the response to WNV has focused primarily on methods of disease prevention. To this end, research efforts have yielded several effective vaccines for equine use as well as numerous conventional mosquito contr...
May A, Gerhards H, Wollanke B.During hospitalization horses may develop gastrointestinal conditions triggered by a stress-associated weak local immune system. The prospective, clinical trial was conducted to find out whether fecal immunoglobulin A (IgA) concentrations could be determined in hospitalized horses and how they changed during hospitalization and in response to various stressors. Samples were obtained from 110 horses and a control group (n = 14). At arrival in the hospital, horses were categorized into pain grades (1-5), and elective versus strenuous surgery (> 2 hours, traumatic and emergency procedures). Feces...
Holmes CM, Babasyan S, Wagner B.The end of gestation, ensuing parturition, and the neonatal period represent highly dynamic phases for immunological changes in both mother and offspring. The regulation of innate immune cells at the maternal-fetal interface during late term pregnancy, after birth, and during microbial colonization of the neonatal gut and other mucosal surfaces, is crucial for controlling inflammation and maintaining homeostasis. Innate immune cells and mucosal epithelial cells express antileukoproteinase (SLPI), which has anti-inflammatory and anti-protease activity that can regulate cellular activation. Unas...
Vaske A, Gautier C, Winter J, Aurich C.We followed the hypothesis that equine neonates with reduced transfer of tumor necrosis factor-α (TNFα) are at increased risk of neonatal infection. We investigated TNFα concentrations in colostrum of healthy mares and blood of their neonates in a non-hospitalized population of Warmblood mares where delivery, neonatal adaptation and health was closely monitored by veterinarians. Concentration of TNFα and IgG was determined in colostrum respective milk and in neonatal blood collected immediately after delivery and 18 h thereafter in 97 foals that were assigned to groups failure of passive ...
O'Kennedy MM, Roth R, Ebersohn K, du Plessis LH, Mamputha S, Rutkowska DA, du Preez I, Verschoor JA, Lemmer Y.A safe, highly immunogenic multivalent vaccine to protect against all nine serotypes of African horse sickness virus (AHSV), will revolutionise the AHS vaccine industry in endemic countries and beyond. Plant-produced AHS virus-like particles (VLPs) and soluble viral protein 2 (VP2) vaccine candidates were developed that have the potential to protect against all nine serotypes but can equally well be formulated as mono- and bi-valent formulations for localised outbreaks of specific serotypes. In the first interferon α/β receptor knock-out (IFNAR-/-) mice trial conducted, a nine-serotype (nona...
Kleij L, Bruder E, Raoux-Barbot D, Lejal N, Nevers Q, Deloizy C, Da Costa B, Legrand L, Barrey E, Chenal A, Pronost S, Delmas B, Dhorne-Pollet S.Equine influenza virus (EIV) remains a threat to horses, despite the availability of vaccines. Strategies to monitor the virus and prevent potential vaccine failure revolve around serological assays, RT-qPCR amplification, and sequencing the viral hemagglutinin (HA) and neuraminidase (NA) genes. These approaches overlook the contribution of other viral proteins in driving virulence. This study assesses the potential of long-read nanopore sequencing for fast and precise sequencing of circulating equine influenza viruses. Therefore, two French Florida Clade 1 strains, including the one circulati...
Luciani M, Armillotta G, Di Febo T, Krasteva I, Ulisse S, Di Pancrazio C, Laguardia C, Perletta F, Serroni A, Maggetti M, Testa L, Sacchini F....The significance of as the causative agent of dourine cannot be understated, especially given its high mortality rate among equids. International movement of equids should be subject to thorough health checks and screenings to ensure that animals are not infected with . This involves the implementation of quarantine protocols, testing procedures, and the issuance of health certificates to certify the health status of the animals. Three proteins, the peptidyl-prolyl cis-trans isomerase (A0A1G4I8N3), the GrpE protein homolog (A0A1G4I464) and the transport protein particle (TRAPP) component, put...
Hassanien RT, Thieulent CJ, Carossino M, Li G, Balasuriya UBR.(1) Background: equid alphaherpesvirus-1 (EHV-1) is a highly contagious viral pathogen prevalent in most horse populations worldwide. Genome-editing technologies such as CRISPR/Cas9 have become powerful tools for precise RNA-guided genome modifications; (2) Methods: we designed single guide RNAs (sgRNA) to target three essential (ORF30, ORF31, and ORF7) and one non-essential (ORF74) EHV-1 genes and determine their effect on viral replication dynamics ; (3) Results: we demonstrated that sgRNAs targeting essential lytic genes reduced EHV-1 replication, whereas those targeting ORF74 had a negligi...
Hellman S, Martin F, Tydén E, Sellin ME, Norman A, Hjertner B, Svedberg P, Fossum C.Stem cell-derived organoid cultures have emerged as attractive experimental models for infection biology research regarding various types of gastro-intestinal pathogens and host species. However, the large size of infectious nematode larvae and the closed structure of 3-dimensional organoids often hinder studies of the natural route of infection. To enable easy administration to the apical surface of the epithelium, organoids from the equine small intestine, i.e. enteroids, were used in the present study to establish epithelial monolayer cultures. These monolayers were functionally tested by s...
Goehring L, Dorman DC, Osterrieder K, Burgess BA, Dougherty K, Gross P, Neinast C, Pusterla N, Soboll-Hussey G, Lunn DP.Equine herpes virus type 1 (EHV-1) infection in horses is associated with upper respiratory disease, neurological disease, abortions, and neonatal death. Objective: Does pharmacological therapy decrease either the incidence or severity of disease or infection caused by EHV-1 in domesticated horses? Methods: A systematic review was preformed searching AGRICOLA, CAB Abstracts, Cochrane, PubMed, Web of Science, and WHO Global Health Index Medicus Regional Databases to identify articles published before February 15, 2021. Selection criteria were original research reports published in peer reviewed...
Bubenikova J, Plasil M, Futas J, Stejskalova K, Klumplerova M, Oppelt J, Suchentrunk F, Burger PA, Horin P.The immunogenome is the part of the genome that underlies immune mechanisms and evolves under various selective pressures. Two complex regions of the immunogenome, major histocompatibility complex (MHC) and natural killer cell receptor (NKR) genes, play an important role in the response to selective pressures of pathogens. Their importance is expressed by their genetic polymorphism at the molecular level, and their diversity associated with different types of diseases at the population level. Findings of associations between specific combinations of MHC/NKR haplotypes with different diseases i...
Kim EY, Lee EJ, Kim RE, Kil TY, Kim MK.Amniotic fluid mesenchymal stem cells (AF-MSCs), which can be obtained from fetal tissue, reportedly have self-renewal capacity and multi-lineage differentiation potential. The aim of this study was to identify the biological characteristics of AF-MSCs and evaluate their stability and safety in long-term culture. To confirm the biological characteristics of AF-MSCs, morphology, proliferation capacity, karyotype, differentiation capacity, gene expression level, and immunophenotype were analyzed after isolating AF-MSCs from equine amniotic fluid. AF-MSCs were differentiated into adipocytes, chon...
Julia M, Felippe B.The clinical manifestation of recurrent fevers and infections alerts the clinician to the possibility of an underlying immunodeficiency. Common variable immunodeficiency (CVID) in the horse is a rare late-onset, non-familial immunologic disorder of B cell depletion and/or dysfunction with resultant inadequate antibody production. The most common clinical presentations in horses with CVID are recurrent upper and/or lower respiratory infections, meningitis and/or ataxia, cholangiohepatitis, infectious colitis, infectious dermatitis, and severe gastrointestinal parasitism. Immune-mediated and lym...
Atwa AS, Gomaa L, Elmenofy W, Amer HM, Ahmed BM.Equine influenza (EI) is a transmissible viral respiratory sickness of the family. Two viruses, H7N7 and H3N8 caused EI; however, H7N7 has not been detected for decades. H3N8 has circulated and bifurcated into Eurasian and American lineages. The latter subsequently diversified into Kentucky, South America, and Florida sub-lineages. Florida clade 1 (FC1) and Florida clade 2 (FC2) strains are the only circulating EI viruses (EIVs) in the meantime. Immunization is considered the major means for the prevention and control of EI infection. Using disparate technologies and platforms, several vaccin...
Oliveira Orsi R, Zaluski R, de Barros LC, Barraviera B, Pimenta DC, Ferreira Junior RS.Africanized bees have spread across the Americas since 1956 and consequently resulted in human and animal deaths attributed to massive attacks related to exposure from Argentina to the USA. In Brazil, more than 100,000 accidents were registered in the last 5 years with a total of 303 deaths. To treat such massive attacks, Brazilian researchers developed the first specific antivenom against Africanized honey bee sting exposure. This unique product, the first of its kind in the world, has been safely tested in 20 patients during a Phase 2 clinical trial. To develop the antivenom, a standardize...
Carossino M, Vissani MA, Barrandeguy ME, Balasuriya UBR, Parreño V.Group A rotaviruses are a well-known cause of viral gastroenteritis in infants and children, as well as in many mammalian species and birds, affecting them at a young age. This group of viruses has a double-stranded, segmented RNA genome with high genetic diversity linked to point mutations, recombination, and, importantly, reassortment. While initial molecular investigations undertaken in the 1900s suggested host range restriction among group A rotaviruses based on the fact that different gene segments were distributed among different animal species, recent molecular surveillance and genome c...
Lection J, Wagner B, Byron M, Miller A, Rollins A, Chenier T, Cheong SH, Diel de Amorim M.Endometrial biopsy is required to diagnose mares with chronic endometritis and endometrial degenerative fibrosis. An increase in understanding of equine reproductive immunology could be utilised to create less-invasive, time-efficient diagnostic tools especially when evaluating mares for chronic endometritis. Objective: To evaluate inflammatory cytokine and chemokine concentrations in uterine fluid samples collected by low-volume lavage (LVL) as a potential screening diagnostic biomarker for endometritis. Methods: Prospective cross-sectional clinical study. Methods: Forty-six mares underwent a...
Cain JL, Norris JK, Swan MP, Nielsen MK.The microbiome plays an important role in health, where changes in microbiota composition can have significant downstream effects within the host, and host-microbiota relationships can be exploited to affect health outcomes. Parasitic helminths affect animals globally, but an exploration of their microbiota has been limited, despite the development of anti-Wolbachia drugs to help control infections with some filarial nematodes. The equine ascarids, Parascaris spp., are considered the most pathogenic nematodes affecting juvenile horses and are also the only ascarid parasite to have developed wi...
Schnabel CL, Jentsch MC, Lübke S, Kaiser-Thom S, Gerber V, Vrtala S, Huang HJ, Rhyner C, Wagner B, Hoffmann R, Volke D.Severe equine asthma (SEA) is a common, chronic respiratory disease of horses characterized by hyperreactivity to hay dust which has many similarities to severe neutrophilic asthma in humans. SEA-provoking antigens have not been comprehensively characterized, but molds and mites have been suggested as relevant sources. Here, we identified relevant antigen candidates using immunoproteomics with IgG isotype-binding analyses. Proteins from () were separated by two-dimensional gel electrophoresis followed by immunoblotting (2D immunoblots) resulting in a characteristic pattern of 440 spots. After...
Faber E, van Schalkwyk A, Ivy Tshilwane S, Van Kleef M, Pretorius A.The viral proteins VP1-1, VP2, VP4, VP7 and NS3, of African horse sickness virus serotype 4 (AHSV4), have previously been identified to contain CD8+ T cell epitopes. In this study, overlapping peptides spanning the entire sequences of these AHSV4 proteins were synthesized and used to map epitopes. Peripheral blood mononuclear cells (PBMC) isolated from five horses immunized with an attenuated AHSV4 were stimulated in vitro with the synthesized peptides. Various memory immune assays were used to identify the individual peptides that contain CD8+ T cell epitopes, CD4+ T cell epitopes and linear ...
Zhang Y, Guo X, Yu M, Sun L, Qu Y, Guo K, Hu Z, Liu D, Zhang H, Wang X.Host ANP32 family proteins are crucial for maintaining the activity of influenza RNA polymerase and play an important role in the cross-species transmission of influenza viruses. To date, the molecular properties of equine ANP32 (eqANP32) protein are poorly understood, particularly the mechanisms that affect equine influenza virus (EIV) RNA polymerase activity. Here, we found that there are six alternative splicing variants of equine ANP32A (eqANP32A) with different levels of expression. Further studies showed that these six splicing variants of eqANP32A supported the activity of EIV RNA polym...
Han SW, Cho YK, Rim JM, Kang JG, Choi KS, Chae JS. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging zoonotic tick-borne disease in East Asia caused by the SFTS virus (SFTSV). It is to investigate the presence of SFTSV RNA and antibodies in horses from a slaughterhouse and equestrian centers in the Republic of Korea (ROK). A prevalence study of SFTSV-specific RNA and antibodies was designed from 889 horses in the ROK. Serum samples were collected from horses at a slaughterhouse and equestrian centers from 2018 to 2020. To detect the presence of SFTSV, RNA was extracted from the serum samples, and a nested reverse transcriptio...
subsp. is a rare etiologic agent of bacterial meningitis in humans. The disease is a zoonotic infection and is transmitted through close contact with domestic animals, mainly horses. Only 37 cases of meningitis have been reported in the literature until July 2023. The aim of this study is to present a rare clinical case of -related meningitis in a human immunodeficiency virus (HIV)-positive patient and analyze the literature. We present a 23-year-old horse breeder patient with advanced immunosuppression due to acquired immunodeficiency syndrome (AIDS) and meningitis, admitted at the Clinic...
Tuntasuvan D, Jarabrum W, Viseshakul N, Mohkaew K, Borisutsuwan S, Theeraphan A, Kongkanjana N.During June-July 2000, an outbreak of surra occurred on an equine breeding farm in Khonkaen Province, Thailand. Forty-two percent of pregnant mares aborted or gave stillbirth and 40% (19/47) of horses and 10% (1/10) of mules died from surra. In August 2000 Trypanosoma evansi were detected in the remaining animals (28 horses and nine mules) on the farm by blood smear and/or the haematocrit centrifuge technique. All animals were treated with diminazene aceturate at 3.5 mg/kg body weight by intramuscular injection on days 0 and 41 of the study. Blood samples of eight randomly selected horses and ...
Lazary S, Antczak DF, Bailey E, Bell TK, Bernoco D, Byrns G, McClure JJ.Six laboratories participated in the Fifth International Workshop on Lymphocyte Alloantigens of the Horse, testing 132 alloantisera against lymphocytes of 880 horses chosen to represent different families and breeds. Most of the alloantisera were produced by lymphocyte immunization between horses matched at the ELA-A locus. All horses were also tested with antisera contributed to the workshop by participating laboratories which identified ELA specificities A1-A10 and W12-W21. Previously identified workshop specificities ELA-W14, W15 and W19 were accepted as products of the ELA-A locus based on...
Egberink HF, Ederveen J, Montelaro RC, Pedersen NC, Horzinek MC, Koolen MJ.Feline immunodeficiency virus (FIV) grown in cat lymphocyte and thymocyte cultures was labelled with L-[35S]methionine or [3H]glucosamine and virus-coded proteins were identified using immunoprecipitation. Polypeptides with apparent Mr values of 15K, 24K, 43K, 50K, 120K and 160K were detected. An additional polypeptide of 10K was detected by Western blot analysis. The two highest Mr species sometimes appeared as one band, of which only the 120K polypeptide was glycosylated. In the presence of tunicamycin gp120 was no longer detectable and a non-glycosylated precursor of 75K was found instead. ...
Shin SH, Yoon JH, Yahng SA, Lee SE, Cho BS, Eom KS, Kim YJ, Lee S, Min CK, Kim HJ, Cho SG, Kim DW, Min WS, Park CW, Lee JW.Antithymocyte globulin (ATG) is the drug of choice for immunosuppressive therapy (IST) in patients with severe aplastic anemia (SAA) ineligible for allogeneic stem cell transplantation. Recently, rabbit ATG with cyclosporine A has been used as a first-line IST regimen in patients with SAA because of unavailability of horse ATG. We retrospectively analyzed adult SAA patients who were treated with horse ATG (n=46) or rabbit ATG (n=53) between Feb 2001 and May 2010 to compare hematologic response and survival. Overall response rates at 3, 6, 12, and 18 months were similar in both the horse and ra...
Tallmadge RL, Campbell JA, Miller DC, Antczak DF.The genomic sequences of 15 horse major histocompatibility complex (MHC) class I genes and a collection of MHC class I homozygous horses of five different haplotypes were used to investigate the genomic structure and polymorphism of the equine MHC. A combination of conserved and locus-specific primers was used to amplify horse MHC class I genes with classical and nonclassical characteristics. Multiple clones from each haplotype identified three to five classical sequences per homozygous animal and two to three nonclassical sequences. Phylogenetic analysis was applied to these sequences, and gr...
Tseng CT, Miller D, Cassano J, Bailey E, Antczak DF.A system for identifying equine major histocompatibility complex (MHC) haplotypes was developed based on five polymorphic microsatellites located within the MHC region on ECA 20. Molecular signatures for 50 microsatellite haplotypes were recognized from typing 353 horses. Of these, 23 microsatellite haplotypes were associated with 12 established equine leucocyte antigen (ELA) haplotypes in Thoroughbreds and Standardbreds. Five ELA serotypes were associated with multiple microsatellite subhaplotypes, expanding the estimates of diversity in the equine MHC. The strong correlations between serolog...
Becker K, Keller B, von Eiff C, Brück M, Lubritz G, Etienne J, Peters G.Staphylococcal food poisoning (SFP) caused by enterotoxigenic staphylococci is one of the main food-borne diseases. In contrast to Staphylococcus aureus, a systematic screening for the enterotoxins has not yet been performed on the genomic level for the coagulase-positive species S. intermedius. Therefore, the enterotoxigenic potential of 281 different veterinary (canine, n = 247; equine, n = 23; feline, n = 9; other, n = 2) and 11 human isolates of S. intermedius was tested by using a multiplex PCR DNA-enzyme immunoassay system targeting the staphylococcal enterotoxin genes sea, seb, sec, sed...
Viļuma A, Mikko S, Hahn D, Skow L, Andersson G, Bergström TF.The mammalian Major Histocompatibility Complex (MHC) region contains several gene families characterized by highly polymorphic loci with extensive nucleotide diversity, copy number variation of paralogous genes, and long repetitive sequences. This structural complexity has made it difficult to construct a reliable reference sequence of the horse MHC region. In this study, we used long-read single molecule, real-time (SMRT) sequencing technology from Pacific Biosciences (PacBio) to sequence eight Bacterial Artificial Chromosome (BAC) clones spanning the horse MHC class II region. The final asse...
Deeg CA, Pompetzki D, Raith AJ, Hauck SM, Amann B, Suppmann S, Goebel TW, Olazabal U, Gerhards H, Reese S, Stangassinger M, Kaspers B, Ueffing M.The development, progression, and recurrence of autoimmune diseases are frequently driven by a group of participatory autoantigens. We identified and characterized novel autoantigens by analyzing the autoantibody binding pattern from horses affected by spontaneous equine recurrent uveitis to the retinal proteome. Cellular retinaldehyde-binding protein (cRALBP) had not been described previously as autoantigen, but subsequent characterization in equine recurrent uveitis horses revealed B and T cell autoreactivity to this protein and established a link to epitope spreading. We further immunized h...
Roy P, Bishop DH, Howard S, Aitchison H, Erasmus B.African horsesickness virus serotype 4 (AHSV-4) outer-capsid proteins VP2 or VP2 and VP5, prepared from single or dual recombinant baculovirus expression vectors grown in Sf9 insect cells, were administered in different amounts to horses and the neutralizing antibody responses were measured. Control and vaccinated horses were challenged with virulent AHSV-4 6 months later and monitored post challenge. The results indicated that two inoculations of extracts containing VP2 and VP5, or VP2 alone, in doses of 5 micrograms VP2 or more per horse, were sufficient to elicit protection against African ...
McCoy HE, Broder CC, Lottenberg R.The species specificities of plasminogen activation and binding of plasmin by pathogenic group C streptococci isolated from humans, horses, and pigs were examined. Of 56 streptococcal isolates, 52 elaborated plasminogen activator activity and 49 of these had specificity for plasminogen of the homologous host. Analysis of supernatants from 13 isolates indicated that the plasminogen activator activity resulted from secreted streptokinases. These 13 streptokinases were antigenically related and bound all three plasminogens, indicating that the binding recognition sites were conserved despite the ...
Timoney JF, Walker J, Zhou M, Ding J.Streptococcus equi subsp. zooepidemicus, a Lancefield group C streptococcus, is a frequently isolated opportunist pathogen from a variety of animal hosts, including the horse. Previous studies have indicated that equine strains carry antigens with characteristics of the antiphagocytic M proteins on the Lancefield groups A and G streptococci. We have cloned a protective M-like protein gene (SzPW60) of an equine strain of S. equi subsp. zooepidemicus W60 and determined its sequence. This gene encodes a protein with a molecular weight of 40,123 which protects mice against subsp. zooepidemicus but...
Dal Canto MC, Rabinowitz SG.Arboviruses are important pathogens for both animals and humans. Venezuelan equine encephalomyelitis virus (VEEV) is an arbovirus whose pathogenicity for grey matter structures has been previously studied. To our knowledge, the present study is the first to describe extensive inflammation and demyelination in spinal cord white matter of mice infected with VEEV. To probe a possible immunepathogenesis of white matter alterations in this infection, nude mice and heterozygous controls were similarly infected. Whereas controls still showed inflammatory demyelination, nude mice showed no white matte...
Long MT, Gibbs EP, Mellencamp MW, Bowen RA, Seino KK, Zhang S, Beachboard SE, Humphrey PP.West Nile virus (WNF) is a Flavivirus responsible for a life-threatening neurological disease in man and horses. Development of improved vaccines against Flavivirus infections is therefore important. Objective: To establish that a single immunogenicity dose of live Flavivirus chimera (WN-FV) vaccine protects horses from the disease and it induces a protective immune response, and to determine the duration of the protective immunity. Methods: Clinical signs were compared between vaccinated (VACC) and control (CTRL) horses after an intrathecal WNV challenge given at 10 or 28 days, or 12 months p...
Chance MR, Sagi I, Wirt MD, Frisbie SM, Scheuring E, Chen E, Bess JW, Henderson LE, Arthur LO, South TL.Zinc finger arrays have been established as a critical structural feature of proteins involved in DNA recognition. Retroviral nucleocapsid proteins, which are involved in the binding of viral RNA, contain conserved cysteine-rich arrays that have been suggested to coordinate zinc. We provide metalloprotein structural data from an intact virus preparation that validate this hypothesis. Extended x-ray absorption fine structure (EXAFS) spectroscopy of well-characterized and active preparations of equine infectious anemia virus, compared with a peptide with known coordination and in combination wit...
Konishi E, Shoda M, Ajiro N, Kondo T.Antibodies to Japanese encephalitis virus (JEV) nonstructural 1 (NS1) protein constitute a marker of natural JEV infection among populations vaccinated with inactivated JE vaccine. In Japan, with few recent human JE cases, the natural infection rate is critical to evaluate the necessity of continuing JE vaccination. A sensitive immunochemical staining method for detecting NS1 antibodies in individuals naturally and subclinically infected with JEV was previously established. Here, an enzyme-linked immunosorbent assay (ELISA) to detect NS1 antibodies in equine sera was developed and evaluated as...
Lopez AM, Hines MT, Palmer GH, Alperin DC, Hines SA.Rhodococcus equi infects and causes pneumonia in foals between 2 and 4 months of age but does not induce disease in immunocompetent adults, which are immune and remain clinically normal upon challenge. Understanding the protective response against R. equi in adult horses is important in the development of vaccine strategies, since those mechanisms likely reflect the protective phenotype that an effective vaccine would generate in the foal. Twelve adult horses were challenged with virulent R. equi and shown to be protected against clinical disease. Stimulation of cells obtained from bronchoalve...
Waller AS.Strangles, characterized by abscessation of the lymph nodes of the head and neck, is the most frequently diagnosed infectious disease of horses worldwide. The persistence of the causative agent, Streptococcus equi, in a proportion of convalescent horses plays a critical role in the recurrence and spread of disease. Recent research has led to the development of effective diagnostic tests that assist the eradication of S equi from local horse populations. This article describes how these advances have been made and provides advice to assist the resolution and prevention of outbreaks. New perspec...
Moore JN, Vandenplas ML.Some veterinarians describe particularly sick horses or neonatal foals as being endotoxemic, whereas others refer to the same animals as having the systemic inflammatory response syndrome. This article reviews the basis for the use of each of these terms in equine practice, and highlights the mechanisms underlying the response of the horse's innate immune system to key structural components of the microorganisms that initiate these conditions, including how some of those responses differ from other species. Current approaches used to treat horses with these conditions are summarized, and cauti...
Wagner B, Freer H, Rollins A, Erb HN, Lu Z, Gröhn Y.Lyme disease is a zoonotic, vector-borne disease and occurs in mammals including horses. The disease is induced by infection with spirochetes of the Borrelia burgdorferi sensu lato group. Infection of mammalian hosts requires transmission of spirochetes by infected ticks during tick bites. Lyme disease diagnosis is based on clinical signs, possible exposure to infected ticks, and antibody testing which is traditionally performed by ELISA and Western blotting (WB). This report describes the development and validation of a new fluorescent bead-based multiplex assay for the detection of antibodie...
Tessier L, Bienzle D, Williams LB, Koch TG.Multipotent mesenchymal stromal cells (MSC) have attracted interest for their cytotherapeutic potential, partly due to their immunomodulatory abilities. The aim of this study was to test the robustness of our equine cord blood (CB) MSC isolation protocol, to characterize the CB-MSC before and after cryopreservation, and to evaluate their immunosuppressive phenotype. We hypothesized that MSC can be consistently isolated from equine CB, have unique and reproducible marker expression and in vitro suppress lymphoproliferation. Preliminary investigation of constitutive cytoplasmic Toll-like recepto...
Longhini ALF, Salazar TE, Vieira C, Trinh T, Duan Y, Pay LM, Li Calzi S, Losh M, Johnston NA, Xie H, Kim M, Hunt RJ, Yoder MC, Santoro D, McCarrel TM....Previously, we showed that mesenchymal stem cells (MSC) can be mobilized into peripheral blood using electroacupuncture (EA) at acupoints, LI-4, LI-11, GV-14, and GV-20. The purpose of this study was to determine whether EA-mobilized MSC could be harvested and expanded in vitro to be used as an autologous cell therapy in horses. Peripheral blood mononuclear cells (PBMC) isolated from young and aged lame horses (n = 29) showed a marked enrichment for MSCs. MSC were expanded in vitro (n = 25) and administered intravenously at a dose of 50 x 106 (n = 24). Treatment resulted in significant improve...
McGuire TC, Poppie MJ, Banks KL.Thirty sick Arabian foals and 78 clinically normal Arabian foals were examined for combined (B- and T-lymphocyte) immunodeficiency. Diagnosis was based on lymphocyte counts and serum immunoglobulin (Ig) content or microscopic examination of lymphoid organs. Ten of the 30 sick foals and 2 of the 78 clinically normal foals had combined immunodeficiency. The 2 affected foals in the group of 78 subsequently developed fatal pneumonia.
Lymphocyte counts were made from 9 of the 12 immunodeficient foals; the range was 0 to 936/cmm., whereas the normal mean was 4,119/cmm., with a standard deviation ...
Eberhardt C, Amann B, Feuchtinger A, Hauck SM, Deeg CA.Reactive gliosis is a well-established response to virtually every retinal disease. Autoimmune uveitis, a sight threatening disease, is characterized by recurrent relapses through autoaggressive T-cells. The purpose of this study was to assess retinal Müller glial cell function in equine recurrent uveitis (ERU), a spontaneous disease model resembling the human disease, by investigating membrane proteins implicated in ion and water homeostasis. We found that Kir2.1 was highly expressed in diseased retinas, whereas Kir4.1 was downregulated in comparison to controls. Distribution of Kir2.1 appea...
Fine DL, Roberts BA, Teehee ML, Terpening SJ, Kelly CL, Raetz JL, Baker DC, Powers AM, Bowen RA.A new vaccine, V3526, is a live-attenuated virus derived by site-directed mutagenesis from a virulent clone of the Venezuelan equine encephalitis virus (VEEV) IA/B Trinidad donkey (TrD) strain, intended for human use in protection against Venezuelan equine encephalitis (VEE). Two studies were conducted in horses to evaluate the safety, immunogenicity, ability to boost and protective efficacy of V3526 against challenges of TrD and VEEV IE 64A99. Horses were vaccinated subcutaneously (SC) with 10(7), 10(5), 10(3) or 10(2) plaque-forming units (pfu) of V3526. Control horses were sham immunized. I...
Marsh AE, Barr BC, Packham AE, Conrad PA.Neospora hughesi n. sp. was isolated from the central nervous system tissue of an adult equine (Equus caballus) from California. The tachyzoites are crescent-shaped, approximately 2 x 5 microm (1.8-3.0 x 4.0-7.0 microm), with characteristic apical complex structures consisting of an anterior polar ring, conoid, numerous rhoptries filled with a uniform electron-dense material, and 22 microtubules extending posteriorly from the polar ring. Comparison of N. hughesi to canine and bovine Neospora caninum isolates showed phenotypic differences in immunoreactive proteins. Molecular analysis of the sm...
McGuire TC, Poppie MJ.A severe combined immunodeficiency disorder was demonstrated in two Arabian foals which were full siblings. The defect in the B-lymphocyte system was shown by hypogammaglobulinemia, lymphopenia, and absence of germinal centers. The almost total absence of thymic tissue in one foal and the lack of thymic dependent lymphocytes in the spleens of both foals demonstrate a T-lymphocyte defect. In a retrospective study of total available Arabian foal cases, 4 of 15 had evidence of immunodeficiency.
Bourgeois MA, Denslow ND, Seino KS, Barber DS, Long MT.Gene expression associated with West Nile virus (WNV) infection was profiled in the central nervous system of horses. Pyrosequencing and library annotation was performed on pooled RNA from the CNS and lymphoid tissues on horses experimentally infected with WNV (vaccinated and naïve) and non-exposed controls. These sequences were used to create a custom microarray enriched for neurological and immunological sequences to quantitate gene expression in the thalamus and cerebrum of three experimentally infected groups of horses (naïve/WNV exposed, vaccinated/WNV exposed, and normal).From the sequ...
Cleton NB, van Maanen K, Bergervoet SA, Bon N, Beck C, Godeke GJ, Lecollinet S, Bowen R, Lelli D, Nowotny N, Koopmans MPG, Reusken CBEM.The genus Flavivirus in the family Flaviviridae includes some of the most important examples of emerging zoonotic arboviruses that are rapidly spreading across the globe. Japanese encephalitis virus (JEV), West Nile virus (WNV), St. Louis encephalitis virus (SLEV) and Usutu virus (USUV) are mosquito-borne members of the JEV serological group. Although most infections in humans are asymptomatic or present with mild flu-like symptoms, clinical manifestations of JEV, WNV, SLEV, USUV and tick-borne encephalitis virus (TBEV) can include severe neurological disease and death. In horses, infection wi...
Payne SL, Rushlow K, Dhruva BR, Issel CJ, Montelaro RC.Previous characterizations of equine infectious anemia virus (EIAV) glycoprotein variation by DNA sequence analysis and epitope mapping using monoclonal antibodies (MAbs) have revealed the presence of conserved and variable regions within the EIAV env gene. To extend these studies, fragments of the EIAV envelope proteins gp90 and gp45 were expressed in Escherichia coli and used in Western blot analysis with a diverse panel of equine immune sera to identify antigenic segments. All sera from EIAV-infected animals reacted with the carboxyl terminal portion of gp90 and the amino terminal portion o...
