The immune response in horses involves a complex network of cells, tissues, and molecules that work together to protect the animal from pathogens and other harmful agents. This process includes both innate and adaptive immune mechanisms. Innate immunity provides the first line of defense and involves components such as physical barriers, phagocytic cells, and the complement system. Adaptive immunity, on the other hand, is characterized by the activation of lymphocytes and the production of antibodies, which provide a targeted response to specific antigens. Key components of the equine immune system include T cells, B cells, and various cytokines that facilitate communication between immune cells. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and implications of immune responses in equine health.
Slater JD, Gibson JS, Field HJ.Both intranasal (i.n.) and intracerebral (i.c.) inoculation of mice with wild-type equine herpesvirus type 1 (wt EHV-1) caused clinical signs and mortality. Virus could be recovered from target organs (turbinates, lungs and blood) for several days. By contrast, the thymidine kinase (TK)-deficient deletion mutant PR1 produced markedly less clinical disease following both i.n. and i.c. inoculation, and, in particular, no mortality occurred. PR1 did, however, establish productive infections following either route of inoculation. High titres of virus were recovered from target organs although viru...
Threadgill DS, Steagall WK, Flaherty MT, Fuller FJ, Perry ST, Rushlow KE, Le Grice SF, Payne SL.The putative dUTPase domain was deleted from the polymerase (pol) gene of equine infectious anemia virus (EIAV) to produce a recombinant delta DUpol Escherichia coli expression cassette and a delta DU proviral clone. Expression of the recombinant delta DUpol polyprotein yielded a properly processed and enzymatically active reverse transcriptase, as determined by immunoblot analysis and DNA polymerase activity gels. Transfection of delta DU provirus into feline (FEA) cells resulted in production of virus that replicated to wild-type levels in both FEA cells and fetal equine kidney cells. In con...
Troedsson MH, deMoraes MJ, Liu IK.The relationship between histologic lesions in endometrial biopsy specimens and susceptibility to chronic uterine infection (CUI) in mares was investigated. Mares were allotted to 4 groups on the basis of degree of endometrial lesions. Mares in group 1 (n = 6) had no pathologic changes, mares in group 2 (n = 5) had only mild pathologic changes, group-3 mares (n = 7) had moderate changes, and group-4 mares (n = 7) had severe inflammatory and fibrotic endometrial changes. Susceptibility to CUI was determined by the inflammatory response to intrauterine inoculation of 5 x 10(6) Streptococcus zooe...
McGorum BC, Dixon PM, Halliwell RE.A commercial radioimmunoassay kit was used to quantify histamine concentrations of plasma, bronchoalveolar lavage fluid (BALF) and pulmonary epithelial lining fluid (PELF) of normal horses and horses with chronic obstructive pulmonary disease (COPD), before and after 'natural (hay and straw) challenge' (NC). There were no significant changes in the concentrations of histamine in plasma or BALF at 0.5 or 5 h after NC, but the PELF histamine concentration of COPD affected horses was significantly increased at 5 h, but not at 0.5 h, following NC. As the histamine concentrations of whole BALF lysa...
Watson ED, Dixon CE.The distribution of T lymphocytes and of cells bearing MHC Class II antigens in the endometrium of the mare was studied using an avidin-biotin-peroxidase staining method. The cells within the endometrium which expressed MHC Class II were macrophages, lymphocytes, monocytes, dendritic cells, epithelial cells and endothelial cells. MHC Class II expression increased significantly (P < 0.05) in the luminal epithelium and tended (P = 0.0573) to increase in the subepithelial layers during oestrus. Numbers of T lymphocytes did not differ between oestrus and dioestrus. MHC Class II expression and T...
Carrick JB, Morris DD, Moore JN.Platelet-activating factor (PAF) is an important mediator of endotoxaemia and various PAF receptor antagonists prevent many of the adverse effects of experimental endotoxaemia in laboratory animals. In this study a specific PAF receptor antagonist was used to investigate the role of PAF in equine endotoxaemia. At an interval of not greater than 10 days, 6 horses were each challenged with endotoxin and endotoxin with concurrent administration of SRI 63-441, a PAF receptor antagonist. The order of the treatments was randomised. Clinical signs, serum biochemical and coagulation profiles, and plat...
Madison JB, Ziemer EL.Purified streptococcal M protein was injected into one intercarpal joint in three horses hyperimmunised with Streptococcus equi M protein vaccine. The contralateral joints were injected with pH adjusted polyionic solution. All antigen-injected joints developed a severe suppurative synovitis (mean synovial fluid nucleated cell count = 102,200 x 10(6) cells litre-1). Eosinophils were found in the synovial fluid and in synovial membrane biopsy specimens of two of the horses. Immune complexes were not demonstrated in the synovial membrane. Two horses are described that developed synovial fluid eos...
Hakansson A, Albihn A, Magnusson U.The aim of the present study was to investigate if complement contributes to opsonic activity in the uterine secretions of mares with normal reproductive functions. Five mares with a mean age of 9 years were used in the study. The mares were considered to be free of endometritis based upon clinical history, palpation per rectum and ultrasonogaraphy of the genital tract, videoendoscopic inspection of the uterus, electronmicroscopy of endometrial biopsies, and bacteriological and cytological examination of swabs from the endometrium. The hormonal status of the mares was also determined. Uterine ...
Goto H, Yamamoto Y, Ohta C, Shirahata T, Higuchi T, Ohishi H.A total of 305 horse sera collected in the Hidaka district of Hokkaido in the years 1988-90 were tested for the presence of hemagglutination-inhibition (HI) antibodies to A/equine/Newmarket/1/77 (H7N7), A/equine/Tokyo/2/71 (H3N8) and A/equine/Kentucky/1/81 (H3N8, Kentucky) strains of equine influenza (EI) virus. Antibodies to the 3 strains were detected in hardly of the 45 sera from 2-years-old horses which were collected before vaccination. Many of the 51 horses, after vaccination with inactivated EI virus, had HI antibodies to the 3 strains in 37 to 88 per cent. However, the number of positi...
Lunn DP.Monoclonal antibody technology has allowed the recognition and study of numerous leucocyte antigens in man and laboratory animals for over a decade. Numerous advances in the understanding of immune responses and immunopathology have resulted. In recent years equine researchers have started to develop similar reagents, which now offer a powerful tool to investigators of equine immunology and disease.
Soulé C, Dupouy-Camet J, Georges P, Fontaine JJ, Ancelle T, Delvigne A, Perret C, Collobert C.Seven mares were infected with 20,000 Trichinella spiralis larvae; 2 of them were reinfected 22 wk later with the same amount of larvae. The course of infection in horses was assessed by serology (ELISA), biochemistry (aldolase activity), parasitology and histopathology. In each animal, infection was followed by a significant rise in specific antibody titers culminating at 5-10 wk post-infection (pi) and decreasing thereafter. Reinfection was followed by a slight rise in antibody levels. Aldolase activity increased during the first infection, but was not modified by reinfection. The parasite b...
House JA.African horse sickness (AHS), which causes mortality up to 95%, is caused by orbiviruses and is transmitted by Culicoides. The goal of a control and eradication program for AHS is to prevent the spread of the virus via the biological vector. Control measures include slaughter of infected animals, housing of suspected infected animals in insect-proof stalls, and vaccination. Vaccination has played a key role in eradication when AHS occurred outside of Africa. Both modified live vaccines (MLV) and inactivated vaccines have been used to control AHS. An acceptable vaccine should be: safe, efficaci...
Lunn DP, Holmes MA, Duffus WP.This paper describes the characteristics of a monoclonal antibody (CVS10) that reacts with an equine leukocyte antigen. On the basis of tissue distribution and biochemical characteristics, this antigen is equine MHC II. The equine MHC II antigen was found on a large subset of T-lymphocytes in addition to all B-lymphocytes, as has been reported previously. In addition MHC II was found to be present on a large proportion of both the mutually exclusive equine T-lymphocyte subpopulations which express either the equine homologues of CD4, or CD8. In a study of changes in equine MHC II expression wi...
Webster RG, Thomas TL.A new H3N8 equine influenza virus [A/Equine/Jilin/1/89 (Eq/Jilin)] appeared in Northeastern China in 1989 and caused high mortality in horses; the available evidence indicates that it has not yet spread outside this region of the world. Serological analysis with postinfection ferret sera in haemagglutination inhibition (HI) tests confirmed that Eq/Jilin is antigenically distinct from H3N8 equine influenza viruses isolated between 1963 and 1991 and also showed that a current equine influenza virus [A/Equine/Alaska/1/91 (H3N8)] had undergone antigenic drift. In the present study we determine if ...
Tewari D, Gibson JS, Slater JD, O'Neill T, Hannant D, Allen GP, Field HJ.EHV-1 was inoculated into specific pathogen-free (SPF) foals in order to study uncomplicated primary responses. Infection resulted in a strong serological response recognizing EHV-1-specific antigens; this contrasts with a previous publication where a weak response was recorded in SPF animals. Antibodies to EHV-1 were readily detected by four techniques (virus neutralization, complement fixation, Western blots and immune precipitation), yet there was comparatively little cross-reaction to EHV-4 target antigen. Re-inoculation with the same virus strain stimulated antibodies to EHV-1 but no addi...
Stitz L, Bilzer T, Richt JA, Rott R.Borna disease represents a unique model of a virus-induced immunological disease of the brain. Naturally occurring in horses and sheep, the mechanisms of pathogenesis have been studied in experimental animals, namely in the rat. Many investigations have revealed that the infection of the natural hosts principally follows the same pathogenic pathways as observed in rats, leading to a severe encephalomyelitis. This affliction of the central nervous system results in severe neurological disorders that again, are fully comparable in laboratory animals to those in the natural and the different expe...
McConnico RS, Roberts MC, Tompkins M.A 5-year-old female American Quarter Horse was determined to have immune-mediated hemolytic anemia after detection of a positive response to a direct Coombs' test. Penicillin-induced immune-mediated hemolytic anemia was confirmed via a direct antiglobulin test, using penicillin-coated RBC. The horse was clinically improved and the anemia resolved in response to supportive care and discontinuation of penicillin treatment. Penicillin should be considered a possible cause of immune-mediated hemolytic anemia in horses.
Fitzpatrick JL, Bailey M, Harbour DA, Stokes CR.Adult ponies which were fed ovalbumin (OVA) daily for 2 weeks had significantly greater serum anti-OVA IgG (P = 0.001) and antigen specific lymphocyte responses (P = 0.031) after intramuscular injection with OVA given with saponin than control ponies which had not been fed the antigen. This suggests that, despite the lack of evidence of B- or T-cell activation in peripheral blood during the period of OVA feeding, the animals were primed for an active secondary immune response. Adult ponies were challenged with equine rotavirus, strain H-2, but no statistically significant differences were foun...
Chong YC, Duffus WP.Four foals were raised under specific pathogen free (SPF) conditions. At 3 to 4 months of age, SPF foals and 1 other non-SPF foal were intranasally inoculated with equine herpes virus type 1 (EHV-1). Clinical signs included depression, fever, inappetence and intermittent coughing. Clinical recovery was complete by seven days but high titres of virus were detected in nasal mucus for at least 10 days after inoculation. Clinical illness was less severe in the non-SPF foal. Interferon was detected in the nasal mucus of all foals from 2 days post infection (dpi), persisting until 8 or 10 dpi. ELISA...
Milam SB, Mackay RJ, Skelley LA.Secretion of tumor necrosis factor (TNF) by equine mammary exudate macrophages (MEM phi) exposed to bacterial lipopolysaccharide (LPS) was dose-dependent and was maximal (216.5 +/- 51.9 U/ml) at 100 micrograms LPS/ml, the highest concentration tested. All concentrations of dexamethasone tested (10(-8) to 10(-4) M) significantly (P less than or equal to 0.05) inhibited TNF production by MEM phi when the agent was added 1 hour before LPS. Pretreatment with pentoxifylline at concentrations greater than 3 micrograms/ml also significantly (P less than or equal to 0.05) reduced secretion of TNF by M...
Roth TL, White KL, Thompson DL, Rahmanian S, Horohov DW.The mechanism by which a horse conceptus-derived immunosuppressive factor (HCS) of M(r) > 100,000 inhibits lymphocyte proliferation was investigated. The factor was obtained from the culture supernatants of 20-day-old horse conceptuses; activity, identified by reduced uptake of [3H]thymidine by mitogen-stimulated lymphocytes, was greatest (P < 0.01) in cultures stimulated by mitogen from pokeweed. HCS also suppressed cell proliferation stimulated by phytohaemagglutinin (P 0.05). Data from a fluorescence-activated cell sorter indicated that supplementation with HCS reduced the number of ...
Troedsson MH, Liu IK.Undiluted uterine secretion was used to determine the concentration of total protein and the accumulated volume of uterine secretion after a bacterial inoculation in mares susceptible and resistant to chronic uterine infection (CUI). The uterus of 6 susceptible and 5 resistant mares was inoculated with 5 x 10(6) Streptococcus zooepidemicus on the third day of estrus. Using a tampon inserted in the uterus, secretions were sampled at 5, 12, 24, and 36 hours after inoculation, followed by intrauterine lavage with phosphate buffered saline solution. The concentration of protein was determined in t...
O'Brien MA, Holmes MA, Duffus WP.Anti-tetanus toxoid (TT) antibody (Ig) levels in the supernatant of cultured, pre-immunised equine peripheral blood mononuclear cells (PBMC) were measured by an indirect enzyme-linked immunoabsorbent assay (ELISA). Optimal anti-TT Ig production occurred at concentrations of stimulating, purified TT of between 0.001 and 0.1 micrograms ml-1, which varied depending on the cell concentration. Optimal anti-TT Ig production was most consistently produced when the cell concentration was 5 x 10(6) ml-1. At this cell concentration maximal anti-TT Ig was induced using 0.1 micrograms ml-1 TT. At a cell c...
MacKay RJ, Lester GD.Because hepatocyte-stimulating factor/interleukin 6 (IL-6) is the principal inducer of acute-phase protein synthesis in the liver, quantification of its activity in blood provides an early and sensitive assessment of the acute-phase response. Circulating IL-6 activity was monitored in 4 adult horses for 72 hours after IV administration of endotoxin. In 4 experiments performed at weekly intervals and in randomized order, each horse was given endotoxin--1,000 30, 1, and 0 ng/kg of body weight. Plasma IL-6 activity was quantified as the ability to promote growth of the IL-6-dependent B-cell hybri...
Böse R, Daemen K.Babesia caballi-infected or normal equine erythrocytes were solubilized in sodium dodecyl sulfate (SDS) buffer and analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Antigens were allowed to react with sera from horses experimentally or field-infected with B. caballi and with sera from non-infected horses. Major babesial antigens recognized by immune sera had apparent mol. wts of 141, 112, 70, 50, 48, 34, and 30 kDa. The polypeptides at 50 and 48 kDa were recognized earliest and throughout infection, but also weakly by 3/100 equine sera tested negative and 1/33...
Morris DD, Crowe N, Moore JN, Moldawer LL.A study was performed to determine whether equine peritoneal macrophages produce interleukin 6 (IL-6) in vitro in response to endotoxin. Peritoneal fluid was collected from 14 clinically normal adult horses and was used as the source of peritoneal macrophages. Macrophages from each horse were isolated and cultured separately in vitro in the absence or presence of various concentrations (0.5, 5, 500 ng/ml) of endotoxin (lipopolysaccharide from Escherichia coli 055:B5). Culture medium supernatants were collected after 3, 6, 12, and 24 hours' incubation and were frozen at -70 C until assayed for ...
Adeyefa CA.The precipitin response of the mitogen produced by Strongylus vulgaris arterial larvae was investigated. IgG (T) from the sera of horses naturally infected with S. vulgaris adults and arterial larvae recognised the presence of two antigenic components of the mitogenic fractions. The results obtained seem to confirm that these antigens are immunogenic in stimulating the production of increased levels of IgG(T) in infected animals, and showed that the procedures could be used as immunological tools in the diagnosis of S. vulgaris infection.
Issel CJ, Horohov DW, Lea DF, Adams WV, Hagius SD, McManus JM, Allison AC, Montelaro RC.We report here on a series of vaccine trials to evaluate the effectiveness of an inactivated equine infectious anemia virus (EIAV) whole-virus vaccine and of a subunit vaccine enriched in EIAV envelope glycoproteins. The inactivated vaccine protected 14 of 15 immunized ponies from infection after challenge with at least 10(5) 50% tissue culture-infective doses of the homologous prototype strain of EIAV. In contrast, it failed to prevent infection in any of 15 immunized ponies that were challenged with the heterologous PV strain. Levels of PV virus replication and the development of disease, ho...
Klei TR, Chapman MR, Dennis VA.The adherence of equine leukocytes to Strongylus vulgaris infective larvae (L3) in the presence of normal and immune sera was examined in vitro. Immune sera promoted adherence of buffy coat cells from ponies with S. vulgaris-induced eosinophilia (eosinophilic ponies) to S. vulgaris L3. However, eosinophils in the buffy coat cells were the predominant adherent cell type. Studies using leukocyte populations enriched for eosinophils, neutrophils, and mononuclear cells from eosinophilic ponies support the observations using buffy coat cells that eosinophils were the main effector cells. Adherent e...
Frontiers in geneticsAugust 29, 2025
Volume 16 1651628 doi: 10.3389/fgene.2025.1651628
Su Y, Ren W, Ma S, Meng J, Yao X, Zeng Y, Li Z, Li L, Wang R, Wang J.This study employed Yili horses participating in a 5000-meter race as a model to investigate exercise-induced gene expression alterations in peripheral blood using whole transcriptome sequencing. Jugular vein blood samples from the three leading horses were collected pre- and immediately post-race, yielding 2,171 differentially expressed mRNAs (2,080 upregulated, 91 downregulated), 4,375 differentially expressed LncRNAs (4,354 upregulated), and 68 differentially expressed circRNAs (64 upregulated). GO/KEGG analyses demonstrated significant enrichment of differential mRNAs in transmembrane tran...
Angwin CJ, de Assis Rocha I, Reed SM, Morrow JK, Graves A, Howe DK.Equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona is one of the most important neurological diseases of horses in the Americas. While seroprevalence of S. neurona in horses is high, clinical manifestation of EPM occurs in less than 1 % of infected horses. Antemortem diagnosis has proven challenging as serum antibodies against S. neurona are an indicator of infection but not necessarily disease. Factors governing the occurrence of EPM are largely unknown, although horse immunity might contribute to EPM pathogenesis. Immunoglobulin G is the predominant antibody class in eq...
Gröndahl G, Righetti F, Aspán A, Bjerketorp J, Frosth S, Frykberg L, Jacobsson K, Guss B, Paillot R, Flock JI, Henriques-Normark B, Waller AS.Strangles, caused by Streptococcus equi subspecies equi (S. equi), is a prevalent infectious disease of horses. This is the first report on the use of a new vaccine, Strangvac, in a natural outbreak of strangles. Objective: To measure the effects of Strangvac vaccination during an outbreak of strangles at a Swedish farm. Methods: Longitudinal cohort study. Methods: Healthy horses (n = 17) were vaccinated on day 0, which occurred 23 days after strangles was first confirmed in three unvaccinated horses on the same farm. Blood serum samples were collected on day 0, day 28 and day 489. A com...
El-Geneady MA, Ramadan RM, Mahdy OA, Kamel MS, Salem MA.Hippobosca equina, a common ectoparasite of horses, poses a significant challenge to equine health worldwide. This study provides a molecular characterization of H. equina and examines its impact on host immune responses and oxidative stress. Genetic analysis of samples from various regions revealed notable homogeneity, indicating limited genetic variation among populations. Phylogenetic analysis demonstrated close genetic relationships among sequences from Egypt, France, Kazakhstan and Portugal, while also showing comparable but more distant identities to sequences from China, Denmark, Finlan...
Migliorisi A, Hassel DM, Moore AR, Blair BW, Wilkins PA.To characterize coagulopathies before and after antivenom administration in rattlesnake-envenomated equids. Unassigned: Client-owned envenomated equids treated with antivenom at Colorado State University (2023 to 2024). Rattlesnake bite severity score (RBSS), platelet count, prothrombin time, activated thromboplastin time, D-dimers, antithrombin, and viscoelastic testing variables were assessed before and after antivenom administration. Paired comparisons of hemostatic variables between admission and approximately 24 hours, and correlation analysis with RBSS, were performed. Length of hospital...
Righetti F, Hentrich K, Flock M, Frosth S, Jacobsson K, Bjerketorp J, Pathak A, Ido N, Henriques-Normark B, Frykberg L, Paillot R, Guss B, Wood T.... subspecies () is the cause of strangles, one of the most prevalent diseases of horses worldwide. The disease is characterised by fever and the formation of abscesses in the lymph nodes of the head and neck, which can restrict the airway. A multicomponent subunit vaccine, Strangvac, has been shown to effectively reduce clinical signs of strangles and to reduce its incidence. The aim of this study was to determine the immune response against the immunoglobulin-cleaving endopeptidase IdeE, a key protective component within the vaccine and the ability of antibodies to neutralize the proteolytic...
Murillo A, Lebrero ME, Valdés M, Ramos J, Villanueva-Saz S, Davies JE, Gómez Á, Pérez E, Riera C, Marteles-Aragüés D.Equine leishmaniosis, caused by Leishmania infantum and transmitted by infected sand flies, has been increasingly reported in Europe, although clinical and immunological data remain scarce. We describe a 10-year-old mare from southern Spain presenting with periocular nodular lesions. Histopathology and immunohistochemistry confirmed granulomatous dermatitis with intrahistiocytic Leishmania amastigotes. Additionally, Leishmania infantum DNA was detected in paraffin embedded skin biopsy. Following surgical removal of the lesions, sequential serological monitoring using enzyme-linked immunosorben...
Jebbawi F, Olomski F, Inversini V, Keller G, Rhiner T, Waldern N, Lam J, Pantelyushin S, Canonica F, Birkmann K, Johansen P, Kündig TM....Skin allergies are among the most frequent types of allergies, where continuous investigation of the pathological immune mechanisms is required for a better understanding and a more effective treatment of the disease. In this study, we aimed to investigate the effect of interleukin (IL)-5 vaccination on allergen-specific IgE antibodies as well as T cell cytokine modulation in skin allergy using a mouse model and a naturally occurring disease in horses. Methods: Ovalbumin (OVA)-sensitized mice, as well as horses affected by equine insect bite hypersensitivity (IBH) were administered an anti-IL-...
Modrý D, Hainisch EK, Fuehrer HP, Kniha E, Unterköfler MS, Sádlová J, Jahn P, Řeháková K, Sedlák K, Votýpka J.We report 4 cases of equine cutaneous leishmaniasis caused by Leishmania martiniquensis in Czech Republic and Austria, outside the known endemic range of leishmaniases. The parasite should be considered as a potential cause of cutaneous lesions in horses; the risk for zoonotic transmission to immunocompromised humans is anticipated throughout central Europe.
Janshoff S, Plümers R, Ramsauer AS, Cavalleri J, Vollmer T, Todt D, Brown RJP, Steinmann E, Gömer A.The emergence of new pathogens poses a significant threat to global health, exacerbated by climate change, biodiversity loss, and increased globalization. Ticks, as vectors for various pathogens, contribute to the rising incidence of diseases. Surveillance programs are crucial for identifying and controlling emerging pathogens. This study focuses on the Alongshan virus (ALSV), a segmented flavi-like virus first identified in humans in China in 2017. Despite its ability to infect a wide range of mammals, the natural hosts and transmission pathways of ALSV remain poorly understood. Therefore, we...
de la Cuesta-Torrado M, Velloso Alvarez A, Cárdenas-Rebollo JM, Neira-Egea P, Vitale V, Cuervo-Arango J.Understanding of equine herpesvirus-1 (EHV-1) myeloencephalopathy (EHM) is complicated by disparities among studies. Objective: Compare clinical findings and outcome in horses involved in 2 recent EHM outbreaks. Methods: Twenty-five and 10 horses affected during 2 natural EHM outbreaks were admitted to a veterinary teaching hospital (VTH) in 2021 and 2023, respectively. Methods: Data collected from the VTH and surveys completed by riders and horse owners were analyzed retrospectively. Results: No risk factors associated with EHM development showed significant differences between the outbreaks;...
Young K, Hasegawa T, Vridhachalam N, Henderson N, Salmon JH, McCall TF, Hirsch ML, Gilger BC.Non-infectious uveitis (NIU) is a painful recurrent disease affecting 2%-5% of horses. Current treatments require frequent administration with associated adverse events. In a previous study, intravitreal (IVT) adeno-associated virus (AAV) harboring equine interleukin-10 (eqIL-10) cDNA inhibited experimental uveitis in rats. The goal of this study was to evaluate the ocular tolerability, vector genome (vg) distribution, and vector shedding following an IVT injection of AAV8-eqIL-10 in normal horses with the hypothesis that it would be well tolerated in a dose-dependent manner in horses. Inject...
Carey KJ, Smith I, Barr J, Caruso S, Au GG, Hartley CA, Bailey KE, Perriam W, Broder CC, Gilkerson JR.Hendra virus (HeV) is lethal to horses and a zoonotic threat to humans in Australia, causing severe neurological and/or respiratory disease with high mortality. An equine vaccine has been available since 2012. Foals acquire antibodies from their dams by ingesting colostrum after parturition, therefore it is assumed that foals of mares vaccinated against HeV will have passive HeV antibodies circulating during the first several months of life until they are actively vaccinated. However, no studies have yet examined passive or active immunity against HeV in foals. Here, we investigated anti-HeV a...
Wagner B, Babasyan S, Wilford S, Robbin MG, de Mestre AM.CD25, the interleukin-2 receptor α-chain, is expressed on cell surfaces of different immune cells and is commonly used for phenotyping of regulatory T cells (Tregs). CD25 has essential roles in the maintenance of hemostasis and immune tolerance and Treg cell involvement has been shown in human diseases and murine models for allergy, autoimmunity, cancer, chronic inflammation, and many others. In horses, a cross-reactive anti-human CD25 antibody has previously been used for characterizing Tregs. Here, we developed monoclonal antibodies (mAbs) to equine CD25 and compared their staining pattern ...
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...
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...
Hickman E, Carberry V, Carberry C, Cooper B, Mordant AL, Mills A, Sokolsky M, Herring LE, Alexis NE, Rebuli ME, Jaspers I, Sheats K, Rager JE.Growing evidence supports the importance of extracellular vesicle (EV) as mediators of communication in pathological processes, including those underlying respiratory disease. However, establishing methods for isolating and characterizing EVs remains challenging, particularly for respiratory samples. This study set out to address this challenge by comparing different EV isolation methods and evaluating their impacts on EV yield, markers of purity, and proteomic signatures, utilizing equine/horse bronchoalveolar lavage samples. Horses can serve as effective translational animal models for respi...
Pradhan SS, Balena V, Bera BC, Anand T, Khetmalis R, Madhwal A, Kandasamy S, Pavulraj S, Bernela M, Mor P, Tripathi BN, Virmani N.Equine herpesvirus type 1 (EHV1) is a ubiquitous viral pathogen infecting the equine population worldwide. EHV1 infection causes respiratory illness, abortion, neonatal foal mortality, and myeloencephalopathy. The currently available modified live EHV1 vaccines have safety and efficacy limitations. The two mutant EHV1 viruses (vToH-DMV (∆IR6/gE) and vToH-QMV (∆IR6/UL43/gE/UL56)), generated by the deletion of genes responsible for virulence (gE and IR6) and immunosuppression (uL43 and uL56), have been previously characterized by our group and found to generate good immune responses. The pre...
Kälin D, Becsek A, Stürmer H, Bachofen C, Siegrist D, Jonsdottir HR, Schoster A.(1) Background: Horses infected by a tick-borne encephalitis virus (TBEV) can develop clinically apparent infections. In humans, vaccination is the most effective preventive measure, while a vaccine is not available for horses. The objective of this study was to describe the immune response in horses after a TBEV vaccination with a human vaccine. (2) Materials and Methods: Seven healthy horses were randomised to a treatment or a control group in a stratified fashion based on TBEV-IgG concentrations on day -4. The treatment group ( = 4) was intramuscularly vaccinated using an inactivated human ...
Hu Y, Zhang SY, Sun WC, Feng YR, Gong HR, Ran DL, Zhang BZ, Liu JH.Equid alphaherpesvirus 1 (EHV-1) has been linked to the emergence of neurological disorders, with the horse racing industry experiencing significant impacts from outbreaks of equine herpesvirus myeloencephalopathy (EHM). Building robust immune memory before pathogen exposure enables rapid recognition and elimination, preventing infection. This is crucial for effectively managing EHV-1. Removing neuropathogenic factors and immune evasion genes to develop live attenuated vaccines appears to be a successful strategy for EHV-1 vaccines. We created mutant viruses without ORF38 and ORF37/38 and vali...
Mizuguchi Y, Tsuzuki N, Ebana MD, Suzuki Y, Kakuda T. is an intracellular bacterium that causes suppurative pneumonia in foals. T-helper (Th) 1 cells play an important role in the protective response against . In mice and humans, the directionality of IgG switching reflects the polarization of Th-cell responses, but this has not been fully elucidated in horses. In this 4-year study, we classified -infected foals into surviving and non-surviving group and investigated differences in IgG subclass response to virulence-associated protein A, the main virulence factor of , between the groups. IgGa, IgGb, and IgG(T) titers were significantly higher in...
Yuen NKY, Eng M, Hudson NJ, Sole-Guitart A, Coyle MP, Bielefeldt-Ohmann H.Our current understanding of the pathogenesis of Ross River virus (RRV) infection has been derived from murine models, which do not reproduce clinical disease as experienced by infected humans and horses. This prompted us to establish more relevant host model systems to study host-virus interactions using ex vivo peripheral blood mononuclear cells (PBMCs) and in vitro primary synovial fibroblast and epidermal keratinocyte cultures. Transcriptomic analysis revealed that the expression of the transmembrane protein matrix remodelling associated 8 (mxra8), recently found to be responsible for RRV ...
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 ...
Bai B, Zhang X, Zhang M, Ma W, Li J, Zhang H, Na L, Guo X, Lin Y, Wang XF, Wang X.Equine infectious anemia virus (EIAV) is an important model for the study of pathogenesis in lentiviruses. Studies of viral genome organization and replication mechanisms are fundamental to the understanding of virus pathogenicity. In this study, we identified an unique transcript from EIAV in vivo and in vitro by Sanger sequencing and Northern blotting. The transcript contains a complete open reading frame and has length 369 nt. We named the protein encoded by this transcript S4 and demonstrated its expression in EIAV-infected cells. An S4-deficient EIAV infectious clone displayed obviously i...
Parashar B, Malviya R, Sridhar SB, Wadhwa T, Talath S, Shareef J.Eastern equine encephalitis virus (EEEV) is a lethal transmitted by mosquitoes that primarily cycles between birds. Although rare, infections in humans and horses are associated with high mortality rates and severe neurological effects. Climate change appears to be increasing the spread of this virus. This study aims to provide a comprehensive analysis of EEEV, including its transmission dynamics, pathogenesis, induced host immune response, and long-term impacts on survivors. It also highlights the virus's unique immune evasion strategies that complicate disease management and contribute to ...
Jiang X, Ma X, Su L, Zhang B, He Z, Su Y.Streptococcus equi subspecies equi (S. equi) causes strangles, one of the most prevalent and highly contagious equine infectious diseases with significant welfare and economic impacts. Alpha 2-macroglobulin and immunoglobulin G binding protein (EAG) has been identified as a key antigen and plays a crucial role in the immune evasion of S. equi. In this study, we aimed to investigate the genetic polymorphism of EAG and to determine the effects of genetic variation on its function and immunogenicity. Methods: Phylogenetic analysis indicated these EAG mutants belong to two clades, respectively. Th...
Liu L, Cai P, Gu W, Duan X, Gao S, Ma X, Ma Y, Ma S, Li G, Wang X, Cai K, Wang Y, Cai T, Zhao H.Rhodococcus equi (R. equi) is a zoonotic opportunistic pathogen that mainly causes fatal lung and extrapulmonary abscesses in foals and immunocompromised individuals. To date, no commercial vaccine against R. equi exists. We previously screened all potential vaccine candidates from the complete genome of R. equi using a reverse vaccinology approach. Five of these candidates, namely ABC transporter substrate-binding protein (ABC transporter), penicillin-binding protein 2 (PBD2), NlpC/P60 family protein (NlpC/P60), esterase family protein (Esterase), and M23 family metallopeptidase (M23) were se...
Loubière C, Moreau P, Marine R, Hélie P, Jean D.The objectives of this study were to quantify lymphocytes and eosinophils in the mucosa of the duodenum and rectum in asthmatic horses. Asthmatic horses were evaluated in a symptomatic (after 6 weeks of exposure to moldy hay) and asymptomatic status (3 and 7 months after being fed alfalfa pellets [n = 4] or treated with inhaled fluticasone [6]). Duodenal and rectal biopsies were endoscopically (n = 4 to 6) taken in each horse. Eosinophils were counted on slides stained with hematoxylin, eosin, phloxine, and saffron, and immunohistochemistry was used to evaluate T and B lymphocytes using CD3 an...
