The immune system in horses is a complex network of cells, tissues, and organs that work together to protect the body from pathogens, such as bacteria, viruses, and parasites. This system includes both innate and adaptive immune responses, which function to identify and eliminate foreign invaders. The innate immune response provides an immediate, non-specific defense, while the adaptive immune response involves a more targeted and long-lasting protection through the production of antibodies. Key components of the equine immune system include white blood cells, such as lymphocytes and macrophages, as well as various signaling molecules like cytokines. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and regulation of the immune system in horses, with an emphasis on understanding its role in maintaining equine health and its response to diseases.
Ferlini Agne G, Barratt DT, May BE, Hutchinson MR, Holmes J, Steel C, Simon O, Evans SG, Somogyi AA, Sykes BW, Franklin S.Equine gastric ulcer syndrome (EGUS) is highly prevalent in horses. Despite its presumed painful nature, evaluation of objective biomarkers associated with EGUS presence and severity remains limited. The objective of this study was to investigate the potential of interleukin-1 beta (IL-1β) release by peripheral blood mononuclear cells (PBMCs) following ex vivo stimulation of toll-like receptors 2 and 4 (TLR2 and TLR4) as a potential biomarker for EGUS status, with gastric lesions used as a proxy for presumed EGUS-associated pain. Venous blood was collected from 77 horses, PBMCs were isolated ...
Tamulionytė-Skėrė R, Mickevičienė I, Gruodytė R, Paulavičiūtė B, Šiugždinienė R, Hinksman J, Urbonavičiūtė A, Driukė MU.Rhodococcus equi infection in foals is primarily associated with pulmonary disease but may also present with extrapulmonary manifestations (Giguère et al. 2011; Reuss et al. 2009). Hemolytic anemia is a rare and poorly described complication, with only a single previous report of presumed immune-mediated hemolytic anemia in foals affected by R. equi. This case report describes the clinical presentation, diagnostic findings, disease progression, and postmortem examination of a 4-month-old Holsteiner foal with confirmed R. equi infection and severe anemia consistent with a presumed immune-media...
Zhang B, Agdour H, Riihimäki M, Hansen S, Raine A.Circulating cell-free RNA (cfRNA) has emerged as a promising minimally invasive biomarker capable of capturing transcripts originating from multiple tissues and cell types, but its utility in chronic inflammatory airway diseases remains poorly understood. Equine asthma (EA), a naturally occurring respiratory disease that shares key clinical and immunopathological features with human asthma, provides a valuable comparative model for evaluating plasma cfRNA in this context. We performed transcriptomic profiling of plasma cfRNA from horses with EA and healthy controls and compared these findings ...
Liu Y, He Q, Wang G, Wu Z, Du M, Bai D, Dugarjaviin M, Zhang X.Lactation is a critical reproductive trait that influences offspring survival and livestock productivity in equine production. Characterizing physiological transitions during the perinatal period can improve our understanding of how mares adapt to late gestation, parturition, and early lactation. However, in horses-a typical monogastric herbivore with unique digestive characteristics-the associations between gut microbiota and perinatal physiological adaptation, as well as related stage-associated microbial and metabolic features, remain largely uncharacterized. Unassigned: In this study, para...
Fukushi N, Kirisawa R, Nishimura F, Tsujimura K, Toishi Y, Fukushi H.Equine herpesvirus myeloencephalopathy (EHM), caused by equine herpesvirus type 1 (EHV-1), poses a major threat to the equine industry because of its devastating impact on animal welfare and athletic performance. A single-nucleotide polymorphism (SNP), G2254, in ORF30 (UL30), which encodes the viral DNA polymerase, has been used as a marker of neuropathogenic EHV-1 strains, although its contribution to EHM pathogenesis remains controversial. In addition, other ORF30 SNPs have been reported in association with EHM, but their functional significance is unclear. Clinical observations indicate tha...
Wu Y, Ma Y, Zan Y, Bai X, Li J, Li H.The equine gastrointestinal microbiome plays an essential role in digestion, energy metabolism, immune regulation, and maintenance of intestinal homeostasis. Increasing evidence suggests that microbial-derived metabolites provide a functional link between diet, the microbiome, and host physiology. This narrative review summarizes current knowledge on how dietary factors, including structural carbohydrates, non-structural carbohydrates, protein, and lipids, influence microbial function and metabolite production in horses. Relevant publications available up to June 2026 were identified through s...
Alkhamees ASA, Cavalleri JV, Hammer SE.Understanding the immunogenetic structure of the major histocompatibility complex (MHC) in Arabian horses helps to clarify the population health structure-related phenotypes of this historically influential breed. Straight Egyptian (SE) Arabian horses, which fall under , are of global value but are limited in number, raising concerns about their distribution and the genetic diversity associated with immunity. In this study, we examined 57 Egyptian Arabian horses from two breeding programs: one in Germany (AR-DE) and the other in Qatar (AR-QA). Sixteen polymorphic intra-MHC microsatellite marke...
Deniz Ö, Ekinci G, Çitil M, Onmaz AC, Derelli FM, Timur MC, Altınbay K, Mete A, Yeğen E, Hoven RVD, Fazio F, Aragona F.Equine herpesvirus type 1 (EHV-1) is a major cause of reproductive loss in mares. This cross-sectional field study evaluated serum concentrations of interleukin-2 (IL-2), interleukin-10 (IL-10), interferon-alpha (IFN-α), and interferon-gamma (IFN-γ), together with the IL-10/IL-2 and IFN-γ/IL-10 ratios, in 26 vaccinated pregnant Thoroughbred mares. The analytical cohort comprised healthy, EHV-1 PCR-negative mares (HM, n = 10), EHV-1 PCR-positive mares sampled within 4 h after fetal expulsion at approximately the sixth month of gestation (AM, n = 9), and EHV-1 PCR-positive pregnant mares with...
Lam J, Eckert A, Rhiner T, Waldern N, Schwarz E, Birkmann K, Widmer D, Dietrich M, Kündig TM, Fettelschoss-Gabriel A.Insect bite hypersensitivity (IBH) is the most common allergic skin disease in horses, but existing clinical scoring systems lack extensive validation, limiting standardized disease monitoring and therapeutic evaluation. Objective: Develop and validate a standardized, sensitive, and reproducible clinical scoring system for IBH in horses. Methods: Forty-four privately-owned horses with clinically diagnosed IBH examined under field conditions in Switzerland. Methods: In this prospective field validation study, the equine IBH severity score (EqIS) integrates a lesion severity score and an area sc...
Chen K, Du C, Duan Y, Guo K, Liu D, Wang F, Wang X, Wen Y.Macrophage phenotypic adaptation critically regulates inflammatory balance during infection; however, progress in equine immunology has been limited by a lack of specific tools for standardized identification. To address this gap, we established a reliable, antibody-based detection method for characterizing equine macrophage M1-like and M2-like marker profiles. After initially validating canonical marker genes via qPCR, we developed specific monoclonal antibodies targeting the differentially expressed surface proteins CD80 (M1-like) and CD163 (M2-like). These novel antibodies enabled the creat...
Khanahmadi A, Rahimi Mianji G, Moradi Shahrebabak H, Hafezian SH, Zandi MB.Breakthroughs in genomic technologies have enabled the formulation of methods to identify genomic variation in domestic animal species. Detection of the variation is necessary because it is associated with breed characteristics and economic importance in domestic animal genetics. Unassigned: This study aimed to identify the genomic regions in Turkmen and Kurdish horse breeds that have been the target of different selections over many years. It also sought to locate the genes and Quantitative trait loci (QTL) in these regions that contributed to the differentiation of these two breeds or the di...
Jagannathan V, Leeb T, Gerber V, Sage SE. Bulk RNA sequencing (RNA-seq) averages signals across heterogeneous cell populations. Computational deconvolution methods aim to infer cell type composition and cell type-specific gene expression from bulk data, but their performance in equine samples has not been evaluated. In this study, we assessed the ability of computational deconvolution to recover cellular composition and differential expression signals in bronchoalveolar lavage fluid (BALF) from horses with severe equine asthma (SEA) and controls (CTL). Cryopreserved BALF samples from six SEA and five CTL horses previously analyzed b...
Baillou A, Botos M, Oberhaensli S, Cvitas I, Jonsdottir S, Ziegler A, Brito F, Summerfield A, Marti E, Talker SC.Detailed classification of equine dendritic cells (DC) is necessary to address various research questions, such as the role of DC subsets in immune-mediated diseases of horses. Unassigned: We applied single-cell RNA sequencing (scRNA-seq) on DC enriched from the blood of two horses. Unassigned: All main DC subsets were detected by key gene expression, including conventional DC type 1 (cDC1; ) and type 2 (cDC2; , ), as well as plasmacytoid DC (pDC; ). In addition, we detected a small cluster of hematopoietic progenitors, as well as transitional DC (tDC; , ) and putative DC type 3 (DC3; , ). Our...
Chavatte-Palmer P, Dahl GE, Couturier-Tarrade A.The developmental origins of health and disease (DOHaD) is based on the observation that environmental conditions during sensitive windows of development shape lifelong physiology and disease susceptibility. While fetal organs are often viewed as direct programming targets, the placenta is a crucial mechanistic hub because it senses maternal conditions and actively constructs the fetal environment through nutrient transport, endocrine signaling, and immune regulation. Placental plasticity spans morphology and how exchanges are favored by tissue topology, vascular development and perfusion, tra...
Chow L, Contino E, Seabaugh K, Goodrich L, McIlwraith CW, Impastato R, Singer J, Das S, Dow S, Pezzanite LM.To determine differential gene expression in synovial tissues following injection of IA 2.5% polyacrylamide hydrogel (2.5% iPAAG), a biocompatible nondegradable synthetic polymer, to treat osteoarthritis (OA). Unassigned: Osteoarthritis was induced in 1 middle carpal joint of 16, 2- to 5-year-old horses (7 mares and 9 geldings) via surgical osteochondral fragment creation in combination with exercise on a high-speed treadmill; the contralateral limb underwent a sham operation. Horses were exercised 5 days per week, beginning on day 16 postoperatively. The osteochondral fragment joint was injec...
Bou T, Ding W, Gong W, Li Z, Shi X, Dugarjaviin M, Bai D, Yang L.The Grassland Xichun horse is an emerging crossbred population developed from Xilingol mares and Thoroughbred stallions in Inner Mongolia, China, yet its blood physiological profile has not been systematically characterized. In this study, we compared 32 hematological and serum biochemical parameters between 177 Grassland Xichun horses and 35 Xilingol horses maintained under the same extensive grazing conditions. Following Benjamini-Hochberg FDR correction, 17 of 32 parameters differed significantly between breeds. Grassland Xichun horses showed markedly higher RBC count (9.145 vs 7.905 × 10...
Wierzbicka M, Samsel A, Siemieniuch-Tartanus M.Equine asthma is a chronic inflammatory disease of the lower respiratory tract, primarily associated with inhalation of organic dust, microbial particles and environmental aeroantigens. Although the inflammatory and immunological mechanisms underlying equine asthma have been extensively investigated, the potential contribution of neuroimmune pathways remains poorly understood. In humans and rodent models, asthma is increasingly recognised as a disorder involving complex bidirectional interactions between the nervous and immune systems. Sensory nerve activation, neuropeptide release, autonomic ...
Yoshida S, Takeyama A, Maeda Y, Nambo Y.Maternal cells and antibodies are present in equine colostrum, but their relationship with immune cells in foals after colostrum ingestion remains unclear. This study longitudinally analyzed immune cells in the peripheral blood of neonatal foals at short intervals and investigated their relationship with colostral immune cells. Eleven clinically healthy draft mares and their foals were examined. Foal blood was collected before colostrum intake (0 hr) and at 2-3, 6, 12, 36-48 hr, and 3 and 7 days after ingestion. Mare blood and milk (0, 36-48 hr; 0 hr milk defined as colostrum) were also collec...
Nuchprayoon N, Maneephan P, Tovanakasame N, Kampang C, Jandee P, Sangsuriya P, Tunhikorn M.Oclacitinib is a Janus kinase inhibitor approved for the treatment of pruritus associated with allergic dermatitis in dogs and may be effective in horses. Objective: To evaluate the efficacy of oclacitinib in reducing pruritus and skin lesions in horses with allergic dermatitis. Methods: Sixteen horses aged ≥ 18 months. Methods: Horses received oclacitinib at 0.25 mg/kg orally once daily for 21 days. Changes in haematological and biochemical parameters were measured on Day (D)0 and D21. The owners were instructed to evaluate the horses using the pruritus Visual Analog Scale (PVAS) on...
Nascimento RCMD, Guedes EAB, Silva RBD, Cerqueira ITI, Freire CCDS, Câmara DR, Moura FA, Escodro PB, Goulart MOF.Vaquejada (VQ) is a traditional Brazilian sport demanding high performance from Quarter Horse (QH) athletes. This study aimed to identify modifications in hematological, biochemical, inflammatory, and oxidative stress biomarkers associated with VQ training, comparing conditioned and non-conditioned horses. Blood samples were collected at rest from 70 healthy QH horses: 60 athletes (VQ-conditioned athlete group-AG) and 10 sedentary controls (breeding horses-CG). Using Linear Mixed Models alongside comprehensive hematological and biochemical analyses, the study found that AG horses exhibited an ...
This narrative review presents examples of omega-3 fatty acids supplementation in horse nutrition. Fats are essential in equine nutrition, serving not only as an energy source but also as functional components influencing health. Among them, omega-3 polyunsaturated fatty acids (PUFAs), particularly EPA and DHA, play a key role in modulating inflammatory and metabolic processes. This review summarizes their effects on respiratory health, equine metabolic syndrome (EMS), musculoskeletal function, reproduction, and early development. Omega-3 supplementation has been shown to support airway inflam...
Tanner K, Mays M, Nguyen TA, Lugo T.Multisystemic eosinophilic epitheliotropic disease (MEED) is a rare and severe equine disorder characterized by chronic eosinophilic inflammation, epithelial disruption, and multi-organ involvement, with an undefined genetic basis. We performed the high-depth (~40×) whole-genome sequencing of an affected horse and compared it to 40 control genomes. Over 6.3 million variants were identified, with moderate- and high-impact variants enriched in low-frequency categories, including rare and private variants absent from the controls. The affected horse was dominated by missense mutations, with rela...
Zhou B, Chen K, Liang H, Qi T, Guo X, Wen Y-J, Du C, Wang X.Equine arteritis virus (EAV) is a positive-sense, single-stranded RNA virus that belongs to the family , which also includes porcine reproductive and respiratory syndrome virus (PRRSV). EAV is the causative agent of equine viral arteritis (EVA), an economically important systemic, reproductive, and respiratory disease of equids. EAV infection triggers host innate immunity, yet the precise strategies employed by the virus to evade immune defenses and achieve productive infection are poorly characterized. In this study, it was observed that EAV infection can induce a cellular IFN response; howev...
Carvalho Seabra J, Hess T, Finnestead T, Grandin T.Equine-Assisted Service (EAS) horses can be exposed to stressors that affect their behavior and welfare. Previous studies investigated behavioral and physiological indicators (PI) only during therapy sessions. This study evaluated the frequency of stress and pain behaviors (FSPB) in horses with different riders, while assessing welfare through housing, management, and PI. Ten horses were observed during EAS sessions with three rider groups: able-bodied, clients with significant physical impairment, and clients with no significant physical impairment, totaling twenty-six riders. Behavioral data...
Attia MM, Mohamed HI.Equine piroplasmosis caused by Theileria equi exhibits a wide clinical spectrum ranging from acute disease to lifelong asymptomatic carriage, posing significant diagnostic and epidemiological challenges. In this cross-sectional case-control study, equines were classified as acutely infected, asymptomatic carriers, or uninfected controls based on clinical examination and quantitative PCR. Hematological and biochemical alterations were assessed, and plasma miRNA profiles were characterized using small RNA sequencing, followed by qRT-PCR validation of selected miRNAs. Cytokine gene expression in ...
Malsa J, Chereau A, Guégnard F, Serreau D, Gesbert A, Reigner F, Chamoin L, Guillot J, Vernudachi A, Mach N, Fleurance G, Lacroix-Lamandé S....The emergence of anthelmintic-resistant parasite isolates necessitates alternative control strategies. The use of dietary additives with anti-parasitic or immunomodulatory activities has been proposed as a solution, but whether such additives can simultaneously exert dual bioactivities within this context has rarely been explored. Here, we evaluated whether selected terpenes could exert dual bioactivities (anti-parasitic and immunomodulatory) with a view to their use as food additives that can limit strongyle infections in horses. In vitro tests with cyathostomin larval development, larval mig...
Salewski KE, Talavera MA, Gonzalez GA, Waldridge BM, White JM, Williams MJ, Williams ML.This case reports the successful use of vincristine in a Quarter Horse with presumed immune-mediated thrombocytopenia. A 15-year-old Quarter Horse gelding presented for a pinch skin graft procedure on the left forelimb over the cannon bone. On day 10 of hospitalization, the horse developed a fever (102.6°F, RI: 99-101°F), and severe petechiae of the mucous membranes. A complete blood count (CBC) (Advia 2120i) revealed a severe thrombocytopenia (16,000 platelets/μL, RI:100,000-400,000/μL). Diagnostic testing was negative for Anaplasma phagocytophilum by PCR, Theileria equi and Babesia cabal...
Kapadia CL, Crook RA, Coleman S, Unger G, Douglas RH, Fedorka CE.Altrenogest is commonly used in equine veterinary medicine for the control of estrus, behavioral modifications, and maintenance of pregnancy. Recent studies have found that altrenogest may impact aspects of the immune system, including altering cytokine production in circulation and within the reproductive tract. Therefore, we hypothesize that this alteration may lead to a deviated immune response to vaccination. Sixteen mares were divided into two groups, with ten mares (n = 10) receiving long-acting injectable altrenogest (100 mg/mL; IM) administered every 10 days, and six mares (n =...
Błaszczak A, Olczak K, Stefaniuk-Szmukier M, Tomczyk-Wrona I, Musiał AD, Grzegorczyk J, Długosz B, Szmatoła T, Ropka-Molik K.Insect bite hypersensitivity (IBH) is a prevalent allergic skin disease in horses that significantly affects animal welfare and shows evidence of genetic predisposition. Objective: Understanding the genetic basis of IBH can improve management and breeding strategies. The Equine80K BeadChip microarray was used to identify genomic regions associated with the occurrence of IBH in Hucul horses. Methods: Hair samples were collected from 127 Hucul horses, including both affected individuals and controls. DNA was extracted and genotyped. A genome-wide association study (GWAS) was performed to identif...
Orlando L, Ginolhac A, Zhang G, Froese D, Albrechtsen A, Stiller M, Schubert M, Cappellini E, Petersen B, Moltke I, Johnson PL, Fumagalli M....The rich fossil record of equids has made them a model for evolutionary processes. Here we present a 1.12-times coverage draft genome from a horse bone recovered from permafrost dated to approximately 560-780 thousand years before present (kyr BP). Our data represent the oldest full genome sequence determined so far by almost an order of magnitude. For comparison, we sequenced the genome of a Late Pleistocene horse (43 kyr BP), and modern genomes of five domestic horse breeds (Equus ferus caballus), a Przewalski's horse (E. f. przewalskii) and a donkey (E. asinus). Our analyses suggest that ...
Petersen HH, Nielsen JP, Heegaard PM.The body's early defence in response to trauma, inflammation or infection, the acute phase response, is a complex set of systemic reactions seen shortly after exposure to a triggering event. One of the many components is an acute phase protein response in which increased hepatic synthesis leads to increased serum concentration of positive acute phase proteins. The serum concentration of these acute phase proteins returns to base levels when the triggering factor is no longer present. This paper provides a review of the acute phase proteins haptoglobin, C-reactive protein and serum amyloid A an...
Prescott JF.Recent isolations of Rhodococcus equi from cavitatory pulmonary disease in patients with AIDS have aroused interest among medical microbiologists in this unusual organism. Earlier isolations from humans had also been in immunosuppressed patients following hemolymphatic tumors or renal transplantation. This organism has been recognized for many years as a cause of a serious pyogranulomatous pneumonia of young foals and is occasionally isolated from granulomatous lesions in several other species, in some cases following immunosuppression. The last decade has seen many advances in understanding o...
Chaucheyras-Durand F, Durand H.The use of probiotics for farm animals has increased considerably over the last 15 years. Probiotics are defined as live microorganisms which can confer a health benefit for the host when administered in appropriate and regular quantities. Once ingested, the probiotic microorganisms can modulate the balance and activities of the gastrointestinal microbiota, whose role is fundamental to gut homeostasis. It has been demonstrated that numerous factors, such as dietary and management constraints, can strongly affect the structure and activities of the gut microbial communities, leading to impaired...
Saenz RA, Quinlivan M, Elton D, Macrae S, Blunden AS, Mumford JA, Daly JM, Digard P, Cullinane A, Grenfell BT, McCauley JW, Wood JL, Gog JR.A key question in pandemic influenza is the relative roles of innate immunity and target cell depletion in limiting primary infection and modulating pathology. Here, we model these interactions using detailed data from equine influenza virus infection, combining viral and immune (type I interferon) kinetics with estimates of cell depletion. The resulting dynamics indicate a powerful role for innate immunity in controlling the rapid peak in virus shedding. As a corollary, cells are much less depleted than suggested by a model of human influenza based only on virus-shedding data. We then explore...
Carrade DD, Lame MW, Kent MS, Clark KC, Walker NJ, Borjesson DL.Mesenchymal stem cells (MSCs) derived from bone marrow (BM), adipose tissue (AT), umbilical cord blood (CB), and umbilical cord tissue (CT) are increasingly being used to treat equine inflammatory and degenerative lesions. MSCs modulate the immune system in part through mediator secretion. Animal species and MSC tissue of origin are both important determinants of MSC function. In spite of widespread clinical use, how equine MSCs function to heal tissues is fully unknown. In this study, MSCs derived from BM, AT, CB, and CT were compared for their ability to inhibit lymphocyte proliferation and ...
van Kasteren PB, Bailey-Elkin BA, James TW, Ninaber DK, Beugeling C, Khajehpour M, Snijder EJ, Mark BL, Kikkert M.Protein ubiquitination regulates important innate immune responses. The discovery of viruses encoding deubiquitinating enzymes (DUBs) suggests they remove ubiquitin to evade ubiquitin-dependent antiviral responses; however, this has never been conclusively demonstrated in virus-infected cells. Arteriviruses are economically important positive-stranded RNA viruses that encode an ovarian tumor (OTU) domain DUB known as papain-like protease 2 (PLP2). This enzyme is essential for arterivirus replication by cleaving a site within the viral replicase polyproteins and also removes ubiquitin from cell...
Hu S, Vincenz C, Buller M, Dixit VM.Molluscum contagiosum virus proteins MC159 and MC160 and the equine herpesvirus 2 protein E8 share substantial homology to the death effector domain present in the adaptor molecule Fas-associated death domain protein (FADD) and the initiating death protease FADD-like interleukin-1beta-converting enzyme (FLICE) (caspase-8). FADD and FLICE participate in generating the death signal from both tumor necrosis factor receptor-1 (TNFR-1) and the CD-95 receptor. The flow of death signals from TNFR-1 occurs through the adaptor molecule tumor necrosis factor receptor-associated death domain protein (TRA...
Montelaro RC, Parekh B, Orrego A, Issel CJ.The recurrent nature of equine infectious anemia has been attributed to relatively rapid antigenic variations in equine infectious anemia virus (EIAV) during persistent infection under selective immune pressures. This model was tested by serological and biochemical analysis of virus isolates recovered from separate febrile episodes in two experimentally infected ponies. Neutralization assays employing immune sera from the experimentally infected ponies demonstrated that distinct antigenic strains of virus predominate during sequential febrile episodes in a single pony. Analysis of the test str...
Hosnedlova B, Kepinska M, Skalickova S, Fernandez C, Ruttkay-Nedecky B, Malevu TD, Sochor J, Baron M, Melcova M, Zidkova J, Kizek R.Selenium is an essential trace element important for many physiological processes, especially for the functions of immune and reproductive systems, metabolism of thyroid hormones, as well as antioxidant defense. Selenium deficiency is usually manifested by an increased incidence of retention of placenta, metritis, mastitis, aborts, lowering fertility and increased susceptibility to infections. In calves, lambs and kids, the selenium deficiency demonstrates by WMD (white muscle disease), in foals and donkey foals, it is associated with incidence of WMD and yellow fat disease, and in pigs it cau...
Hammond SA, Cook SJ, Lichtenstein DL, Issel CJ, Montelaro RC.Equine infectious anemia virus (EIAV) provides a natural model system by which immunological control of lentivirus infections may be studied. To date, no detailed study addressing in parallel both the humoral and cellular immune responses induced in horses upon infection by EIAV has been conducted. Therefore, we initiated the first comprehensive characterization of the cellular and humoral immune responses during clinical progression from chronic disease to inapparent stages of EIAV infection. Using new analyses of antibody avidity and antibody epitope conformation dependence that had not been...
Murcia PR, Wood JL, Holmes EC.Equine influenza viruses (EIVs) of the H3N8 and H7N7 subtypes are the causative agents of an important disease of horses. While EIV H7N7 apparently is extinct, H3N8 viruses have circulated for more than 50 years. Like human influenza viruses, EIV H3N8 caused a transcontinental pandemic followed by further outbreaks and epidemics, even in populations with high vaccination coverage. Recently, EIV H3N8 jumped the species barrier to infect dogs. Despite its importance as an agent of infectious disease, the mechanisms that underpin the evolutionary and epidemiological dynamics of EIV are poorly und...
Canisso IF, Segabinazzi LGTM, Fedorka CE.Post-breeding endometritis (i.e., inflammation/infection of the endometrium), is a physiological reaction taking place in the endometrium of mares within 48 hours post-breeding, aimed to clear seminal plasma, excess sperm, microorganisms, and debris from the uterine lumen in preparation for the arrival of an embryo. Mares are classified as susceptible or resistant to persistent breeding-induced endometritis (PBIE) based on their ability to clear this inflammation/infection by 48 hours post-breeding. Mares susceptible to PBIE, or those with difficulty clearing infection/inflammation, have a def...
Whittle BJ, Moncada S, Vane JR.The activity of prostacyclin (PGI2), PGE1 or PGD2 as inhibitors of platelet aggregation in plasma from human, dog, rabbit, rat, sheep and horse was investigated. Prostacyclin was the most potent inhibitor in all species. PGD2 was a weak inhibitor in dog, rabbit and rat plasma whereas PGE1 and prostacyclin were highly active. Theophylline or dipyridamole potentiated the inhibition of human platelet aggregation by prostacyclin, PGE1 or PGD2. Compound N-0164 abolished the inhibition by PGD2 of human platelet aggregation but did not inhibit the effects of PGE1 or prostacyclin. The results suggest ...
Elghandour MMY, Tan ZL, Abu Hafsa SH, Adegbeye MJ, Greiner R, Ugbogu EA, Cedillo Monroy J, Salem AZM.The production of livestock and poultry faces major challenges to meet the global demand for meat and dairy products and eggs due to a steady increase in the world's population and the ban of antibiotics in animal production. This ban has forced animal nutritionists to seek for natural alternatives to antibiotics. In this context, the yeast Saccharomyces cerevisiae has received considerable attention in the last decade. It has been reported that feed supplementation with live yeast cells improve feed efficiency, enhance feed digestibility, increase animal performance, reduce the number of path...
Lindenberg F, Krych L, Fielden J, Kot W, Frøkiær H, van Galen G, Nielsen DS, Hansen AK.Billions of bacteria inhabit the gastrointestinal tract. Immune-microbial cross talk is responsible for immunological homeostasis, and symbiotic microbial species induce regulatory immunity, which helps to control the inflammation levels. In this study we aimed to identify species within the equine intestinal microbiota with the potential to induce regulatory immunity. These could be future targets for preventing or treating low-grade chronic inflammation occurring as a result of intestinal microbial changes and disruption of the homeostasis. 16S rRNA gene amplicon sequencing was performed on ...
Wagner B, Freer H.The detection and quantification of equine cytokines has been hampered by the lack of antibodies for many years. With the development of antibody pairs for equine cytokines during the past years, the quantification of these essential regulators of the immune response became possible. After being successfully tested by enzyme-linked immunosorbent assays (ELISA), three of these anti-cytokine reagents were used here to establish the first cytokine multiplex assay for equine IL-4, IL-10 and IFN-alpha. A fluorescent bead-based system was used as matrix for this assay that allows the simultaneous de...
Kappmeyer LS, Thiagarajan M, Herndon DR, Ramsay JD, Caler E, Djikeng A, Gillespie JJ, Lau AO, Roalson EH, Silva JC, Silva MG, Suarez CE, Ueti MW....Transmission of arthropod-borne apicomplexan parasites that cause disease and result in death or persistent infection represents a major challenge to global human and animal health. First described in 1901 as Piroplasma equi, this re-emergent apicomplexan parasite was renamed Babesia equi and subsequently Theileria equi, reflecting an uncertain taxonomy. Understanding mechanisms by which apicomplexan parasites evade immune or chemotherapeutic elimination is required for development of effective vaccines or chemotherapeutics. The continued risk of transmission of T. equi from clinically silent,...
Scheel TK, Kapoor A, Nishiuchi E, Brock KV, Yu Y, Andrus L, Gu M, Renshaw RW, Dubovi EJ, McDonough SP, Van de Walle GR, Lipkin WI, Divers TJ....Nonprimate hepacivirus (NPHV) is the closest known relative of hepatitis C virus (HCV) and its study could enrich our understanding of HCV evolution, immunity, and pathogenesis. High seropositivity is found in horses worldwide with ∼ 3% viremic. NPHV natural history and molecular virology remain largely unexplored, however. Here, we show that NPHV, like HCV, can cause persistent infection for over a decade, with high titers and negative strand RNA in the liver. NPHV is a near-universal contaminant of commercial horse sera for cell culture. The complete NPHV 3'-UTR was determined and consists...
Katila T.This review attempts to summarize the current knowledge on uterine inflammatory response after mating in horses, pigs and cattle. Post-mating endometritis has been extensively studied in horses as it has been considered to cause infertility. The inflammation is known to occur also in cattle, but it has not been investigated to a similar extent. There are a number of publications about mechanisms of post-mating uterine inflammation in pigs, which seem to resemble those in horses. The major focus of this review is the horse, but relevant literature is presented also on swine and cattle. Spermato...
Grieder FB, Vogel SN.To investigate the role of type I interferon (IFN) and its regulatory transacting proteins, interferon regulatory factors (IRF-1 and IRF-2), in early protection against infection with virulent Venezuelan equine encephalitis virus (VEE), we utilized mice with targeted mutations in the IFN-alpha/beta receptor, IRF-1, or IRF-2 genes. IFN-alpha/beta-receptor knockout mice are highly susceptible to peripheral infection with virulent or attenuated VEE, resulting in their death within 24 and 48 h, respectively. Treatment of normal macrophages with anti-IFN-alpha/beta antibody prior to and during infe...
Carrade DD, Affolter VK, Outerbridge CA, Watson JL, Galuppo LD, Buerchler S, Kumar V, Walker NJ, Borjesson DL.BACKGROUND AIMS. The use of allogeneic mesenchymal stem cells (MSC) to treat acute equine lesions would greatly expand equine cellular therapy options; however, the safety and antigenicity of these cells have not been well-studied. We hypothesized that equine allogeneic umbilical cord tissue (UCT)-derived MSC would not elicit acute graft rejection or a delayed-type hypersensitivity response when injected intradermally. METHODS. Six Quarterhorse yearlings received 12 intradermal injections (autologous MSC, allogeneic MSC, positive control and negative control, in triplicate) followed by the sam...
Stewart AS, Pratt-Phillips S, Gonzalez LM.All species, including horses, suffer from alterations that increase intestinal permeability. These alterations, also known as "leaky gut," may lead to severe disease as the normal intestinal barrier becomes compromised and can no longer protect against harmful luminal contents including microbial toxins and pathogens. Leaky gut results from a variety of conditions including physical stressors, decreased blood flow to the intestine, inflammatory disease, and pathogenic infections, among others. Several testing methods exist to diagnose these alterations in both a clinical and research setting....
Nara PL, Garrity RR, Goudsmit J.The production of immunoglobulin capable of neutralizing the infectivity of a virus represents one of the most remarkable molecular accomplishments of the host's available immune defenses. It should be no surprise that a virus that has existed in the parenchyma of the immune system has evolved as an equally dynamic molecule (i.e., viral envelope) for survival. Neutralizing immunoglobulin (Ig) can best serve the host under conditions where the invading pathogen requires a well-defined cell-free state for establishing an infection or transmission. Evidence for a controlling and therefore protect...
Beck C, Desprès P, Paulous S, Vanhomwegen J, Lowenski S, Nowotny N, Durand B, Garnier A, Blaise-Boisseau S, Guitton E, Yamanaka T, Zientara S....West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus (TBEV) are flaviviruses responsible for severe neuroinvasive infections in humans and horses. The confirmation of flavivirus infections is mostly based on rapid serological tests such as enzyme-linked immunosorbent assays (ELISAs). These tests suffer from poor specificity, mainly due to antigenic cross-reactivity among flavivirus members. Robust diagnosis therefore needs to be validated through virus neutralisation tests (VNTs) which are time-consuming and require BSL3 facilities. The flavivirus envelop...
Antwis RE, Lea JMD, Unwin B, Shultz S.Microbiome composition is linked to host functional traits including metabolism and immune function. Drivers of microbiome composition are increasingly well-characterised; however, evidence of group-level microbiome convergence is limited and may represent a multi-level trait (i.e. across individuals and groups), whereby heritable phenotypes are influenced by social interactions. Here, we investigate the influence of spatial structuring and social interactions on the gut microbiome composition of Welsh mountain ponies. We show that semi-feral ponies exhibit variation in microbiome composition ...
Berglund AK, Schnabel LV.Allogeneic mesenchymal stem cells (MSCs) are a promising cell source for treating musculoskeletal injuries in horses. Controversy exists, however, over whether major histocompatibility complex (MHC)-mismatched MSCs are recognised by the recipient immune system and targeted for death by a cytotoxic antibody response. Objective: To determine if cytotoxic anti-MHC antibodies generated in vivo following MHC-mismatched MSC injections are capable of initiating complement-dependent cytotoxicity of MSCs. Methods: Experimental controlled study. Methods: Antisera previously collected at Days 0, 7, 14 an...
Ma G, Azab W, Osterrieder N.The equine herpesviruses type 1 (EHV-1) and 4 (EHV-4) are ubiquitous pathogens that affect horse populations on all continents. Despite widespread vaccination, EHV-1 and EHV-4 infections remain a permanent risk. While the two viruses share a high degree of genetic and antigenic similarity, they differ significantly in host range and pathogenicity. Compared to EHV-4, which mainly infects horses and causes respiratory disease, EHV-1 has a broader host range and can result in respiratory disease, abortions, neonatal death, and equine herpesvirusmyeloencephalopathy (EHM). Recent studies have eluci...
Radin MJ, Sharkey LC, Holycross BJ.In addition to its role as an energy storage depot, adipose tissue is now recognized as a complex endocrine organ. Adipose tissue releases a variety of factors, termed adipokines, that regulate energy metabolism, cardiovascular function, reproductive status, and immune function. Some of the better-studied adipokines include leptin, adiponectin, and components of the renin-angiotensin system such as angiotensinogen. The function of more recently discovered adipokines such as resistin are under intense scrutiny. Abnormal production or regulation of adipokines occurs in obese individuals and is i...
