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.
TOMCSIK J, SCHWARZWEISS H.1. From beef stroma pretreated at room temperature with acetone and alcohol, a fraction was isolated with boiling 100% alcohol which, in a dilution of 1:500,000, combines with the sheep blood agglutinin of human serum produced during serum sickness. Using the terminology of Schiff, this fraction corresponds to the heterogenetic serum sickness antigen; it could be separated to a large extent from the heterogenetic mononucleosis antigen which also occurs in beef stroma.
2. The so-called serum sickness antigen also occurs heterogenetically in guinea pig kidney and it could also be isolated from ...
Treffers HP, Heidelberger M, Freund J.1. Two horses were injected subcutaneously with alum-precipitated rabbit serum albumin. 2. The resulting antibody resembled diphtheria antitoxin and anti-egg albumin in the horse in giving a sharp zone of flocculation with antigen, in being water-soluble, in reactivity toward an anti-antibody rabbit serum, and in its electrophoretic properties. 3. The effect of continued immunization, and of variation in volume and temperature on the reactivity of the antibody are discussed. 4. Intravenous injection of the same antigen into horses did not give rise to detectable amounts of antibody of the same...
Todd EW.Antiproteinase sera were prepared by immunizing horses with filtrates from a selected strain of group A streptococcus. This strain, which produced high titred proteinase but no erythrogenic toxin, was selected from forty-two strains of group A streptococci which produced varying amounts of proteinase. A few strains belonging to groups B, C, and G were also tested; they were all proteinase-negative. Methods are described for titrating streptococcal proteinase in crude culture filtrates and for measuring the antiproteinase activity of serum. The antiproteinase titres of sera from immunized horse...
Profaska M, Zarzycka M, Dubniewicz K, Witkowski M, Wieczorek J, Gil D, Wafula S, Lanh DK, Kotula-Balak M.Mare endometrosis remains a poorly understood pathological process. Objective: Mare endometrial tissue with endometrosis was used to determine the effects of relaxin (RLX). Healthy tissues that were left untreated (H), or treated with vehicle (Hveh), and tissues with endometrosis that were left untreated (E), treated with vehicle (Eveh), and treated with RLX (10, 25, 50 nM; ER) were used for an ex vivo system for 72 h. Methods: Tissue histological examination, and immunoenzymatic measurement of the concentrations of transforming growth factor β (TGF-β), interleukins (IL-6 and IL-8), and pr...
Parker JL, Berghaus LJ, Gordon J, Mathews L, Akinde MA, Hall DB, Peroni JF.Mesenchymal stromal cells (MSCs) support wound healing through immunomodulation and by promoting tissue organization. Cell tracking studies demonstrate that MSCs must 'home' to injuries in order to participate in reparative processes. It has been reported that in vivo cell tracking labels, including superparamagnetic iron oxide particles (SPIOs), can alter MSC homing. Homing is thought to occur in coordinated steps including tethering, activation, arrest, diapedesis, and migration, guided by chemotactic stimuli. Equine distal limb injuries, which are commonly treated with MSCs, possess a disti...
Sprenzel CJ, Amann B, Deeg CA, Degroote RL.Glycosylation of surface proteins is a crucial post-translational modification that reflects the activation status of neutrophils, the predominant leukocyte subset in humans and horses. Neutrophils have emerged as active contributors to diseases mediated by the adaptive immune system, such as equine recurrent uveitis (ERU), a sight-threatening disease in horses and a unique model for studying the pathogenesis of autoimmune uveitis in humans. Since changes in surface glycosylation can impact neutrophil function, we were interested in the surface glycosylation landscape on neutrophils from healt...
Wójtowicz A, Sadowska A, Molcan T, Słyszewska M, Drzewiecka EM, Tobolski D, Ferreira-Dias G, Szóstek-Mioduchowska A.Mare endometrosis is a chronic degenerative condition of the endometrium, primarily characterized by fibrosis, involving interactions among fibroblasts, immune cells, and epithelial cells regulated by cytokines and growth factors. T helper (Th)1 and Th2 cells seem to play a pivotal role in fibrosis. However, their roles in equine endometrial fibrosis remain unknown. This study explores Th1 and Th2 cell distribution across different stages of endometrium histopathological Kenney and Doig categories; and evaluated their secretome effects on non-fibrotic endometrium derived fibroblast functional ...
Bourebaba L, Panek M, Piedra LCC, Bourebaba N.Fetuin-A (FetA) is a multifactorial glycoprotein primarily synthesized by the liver with additional expression in adipose tissue, the abundance of which is tightly regulated by the FBXW7 E3 ubiquitin ligase. Recently, FetA has been implicated in the pathogenesis of insulin resistance and associated metabolic failures in humans through its potent and selective inhibition of insulin receptor tyrosine kinase activity, however, no studies have yet directly investigated its role in the development and progression of equine obesity. In this investigation, FetA levels were measured in serum, liver, a...
Pipitpornsirikul P, Thangthamniyom N, Laikul A, Songkasupa T, Pathomsakulwong W, Apichaimongkonkun T, Kasemsuwan S, E-Kobon T, Lekcharoensuk P.African horse sickness (AHS), a life-threatening disease caused by African horse sickness virus serotype 1 (AHSV-1), emerged in Thailand in February 2020 with 607 cases and a 93% fatality rate. The outbreak was mitigated by vector control and a live attenuated virus (LAV) vaccine. Information regarding viremia and immunity after infection and vaccination during outbreaks are essential for controlling disease transmission. This study evaluated these parameters in 15 infected naïve horses and 11 vaccinated horses during the 2020 outbreak. Whole blood was collected and subjected to RT real-time ...
Larson MK, Gaffney C, Hoagland C, Jayawickrama J, Kamm JL.To determine the xenogen-free serum source that provides the greatest number of live equine mesenchymal stromal cells (MSCs) while maintaining the MSC phenotype. Unassigned: Equine bone marrow-derived MSCs from 8 horses were cultured for 7 days in media containing one of the following serum treatments: 10% xenogeneic serum, 10% or 20% commercial allogeneic equine serum, 10% autologous serum, 10% equine pooled platelet lysate (PPL), or a staged media reduction of xenogeneic media. Live cell numbers, MSC viability, and MSC immunophenotype were compared. Unassigned: The use of 10% commercial allo...
van Rijn PA, Wernery U, Feddema AJ, Maris-Veldhuis MA, Joseph S, van Gennip RGP.African Horse Sickness (AHS) is a devastating vector-borne viral disease of equids with a mortality up to 95 % in naïve domestic horses. The causative African horse sickness virus (AHSV) is a distinct species of the genus Orbivirus of the family Sedoreoviridae, consisting of nine serotypes showing limited cross protection. AHSV is transmitted by Culicoides biting midges. Outbreaks cause huge economic losses in developing African countries. AHS has become a serious threat for countries outside Africa, since endemic Culicoides species in moderate climates appear competent vectors of the closel...
Greenberg CB, Suckow MA, Clauson RM, Kalinauskas AE, Lucroy MD.Precision medicine is a therapeutic strategy to provide treatment that is tailored to a specific patient based on factors unique to that individual, such as the genetic makeup or the environment. Autologous cancer vaccines (ACVs) are ideal for a precision medicine approach because they incorporate antigens specific to the patient's tumor and provide an elegant solution to identifying and selecting relevant immunogenic neoantigens. ACVs are an appealing option for veterinary medicine because they are cancer-type and species agnostic. Over the past 50 years, many innovative ACVs have been evalua...
Koçali B, Ocak M, Şekerel BE.Animal allergens, particularly those from cats, dogs, and horses, are significant risk factors for the development of allergic diseases in childhood. Managing animal allergies requires allergen avoidance and, when this is not feasible, specific immunotherapy. Patient history remains the cornerstone of diagnosis, providing the foundation for diagnostic algorithms. Extract-based tests, such as skin prick tests and specific IgE measurements, are essential for confirmation and screening. However, traditional extract-based diagnostic methods have notable limitations, as they are unable to distingui...
Hosseini SH, Sharafi H, Emamjomeh A, Nasri F, Hosseini A, Mardani S, Moradi M.Postbiotics and parabiotics (PP) are innovative concepts in veterinary medicine that have garnered substantial interest owing to their unique properties and potential benefits. PP offers a promising alternative to live bacteria, demonstrating properties such as prebiotic, immunomodulatory, antimicrobial, anti-inflammatory, antioxidant, and anticancer effects, while potentially mitigating some of the common challenges associated with live bacterial applications. PP products are manufactured and commercially employed in livestock, poultry, and pets. Moreover, postbiotic-based commercial products...
Isoardi KZ, Chiew AL, Dhital A, Isbister GK.Antivenom is used to treat systemic envenomation and is immunoglobulin G raised from animals, mainly horses, inoculated by venom. Unassigned: We report two cases of life-threatening anaphylaxis following the administration of antivenom in patients with known horse dander allergy. Unassigned: A 14-year-old boy presented with redback spider envenomation. He had a known horse dander allergy. He received antivenom to treat severe pain and developed immediate severe anaphylaxis requiring endotracheal intubation and inotropic support. A 52-year-old man with horse dander allergy presented with suspec...
Accorroni L, Dini F, Pilati N, Marchegiani A, Bazzano M, Spaterna A, Laus F.Wound management is a fundamental skill for veterinarians, requiring a systematic approach to wound care and a deep understanding of the biological principles underlying healing. Sucralfate, widely known as a mucoprotective agent for gastroduodenal ulcers, has recently shown promising topical effects in human skin lesions by binding and protecting growth factors from proteolytic degradation, thereby enhancing their local availability. This action promotes angiogenesis, chemotaxis and cell proliferation, while reducing oxidative stress and exerting bacteriostatic and bactericidal effects agains...
Birckhead EM, Raidal SL, Das S, Raidal SR.Sepsis is a main cause of death in neonatal foals. While the syndrome is not completely understood, sepsis is a dysregulated inflammatory response of the host to infection. It can be difficult to diagnose because of varying and non-specific clinical signs and imperfect diagnostic tests. Increased circulating nucleosome levels have been detected in humans and animals with sepsis, but this has not been documented in foals. Nucleosomes are released extracellularly during neutrophil extracellular trap formation, as well as from damaged and dead cells. We analysed plasma samples from clinically hea...
Pettersson J, Levanov L, Tervo S, Hautala K, Aaltonen K, Utriainen M, Kareinen L, Gadd T, Sironen T, Vapalahti O, Kinnunen PM.Parapoxviruses (PPV) cause skin and mucous membrane signs to several animal species and humans worldwide. Equine parapoxvirus (EqPPV) was first detected in a sick horse in Finland in 2013. It is potentially zoonotic, and a similar virus has been detected in humans in the USA. In winter 2021–2022, EqPPV caused a large-scale pastern dermatitis epidemic in racehorses all over Finland. Field reports suggest that similar epidemics of unverified cause have also occurred in 2015 and 2019. The aim of this study was to develop a serological test and study the immune response, seroprevalence, and hist...
Qiu Y, Lei Y, Yi X, Tang X, Zhang B, Wang S, Sun X.This study investigated three donkey breeds-Guanzhong, Jiami, and Northern Shaanxi-to characterize the structural organization and diversification mechanisms of the immunoglobulin light-chain (IgL) loci and to conduct both intra-breed and interspecies comparisons with horses. The donkey IGλ locus is located on chromosome 8 and arranged in a Vλ-(Jλ-Cλ)-Vλ configuration. It contains 7 Cλ genes, each preceded by a corresponding Jλ gene to form a Jλ-Cλ cluster. Upstream of this cluster, 156 Vλ genes were identified, including 29 potential functional genes; downstream, 98 Vλ genes were d...
Mules (Equus mulus), as sterile hybrids between mares and donkeys, present a unique uterine morphology and physiology that remains poorly characterized. This study provides the first histomorphometric evaluation and transcriptional profiling of the endometrium in adult mules. To achieve this, endometrial biopsies were analysed using quantitative stereology, histological classification (Kenney-Doig system), and qPCR of key immune-related and fibrotic genes. Histometric analyses revealed that the stratum spongiosum was the predominant component of the mule endometrium (mean volume density: 84.7â...
Domańska D, Witkowska-Piłaszewicz O, Trela M, Pawłowski K, Pawliński B, Domino M.Mastitis is an emerging health concern in lactating mares, particularly given the growing commercial interest in mare's milk. This study evaluated the diagnostic potential of acute phase proteins (APPs), specifically serum amyloid A (SAA), milk amyloid A (MAA), and haptoglobin (Hp), measured in blood and milk as indicators of clinical and subclinical mastitis. Twenty-four Thoroughbred mares were prospectively monitored during lactation and weaning. Plasma and milk samples were collected and analyzed using commercial ELISA kits. Plasma SAA concentrations were significantly higher in mares with ...
Centers A, Barnaby K, Goedeker S, Pignataro A, Tretyakova I, Lukashevich I, Pushko P, Chung D.There is a need for safe and effective vaccines against the Venezuelan equine encephalitis virus that infects both humans and equines. However, development of a live-attenuated vaccine using the TC-83 strain has been hampered by substantial reactogenicity and the potential for neuroinvasion. In this study, we demonstrate that V4020, a new TC-83-based investigational VEEV vaccine with redundant safety features preventing neuroinvasion and reversion, exhibited no neuroinvasion potential in a murine model. Following subcutaneous or intramuscular administration, a subset of mice that received the ...
Richards S, Palmer D, Cawley A, Wainscott M, Keledjian J.An improved screening workflow and a robust capillary flow LC-MS confirmatory method for the detection of recombinant human erythropoietin (rHuEPO) has been implemented to increase the sensitivity of rHuEPO detection and to reduce the number of suspect samples committed to confirmatory testing. The influence of repeated dosing of epoetin-β on the detection window of rHuEPO in equine plasma was assessed using the optimised method. Samples were initially assessed using an economical R&D Human EPO Duo-Set ELISA Development System. Samples indicating a result greater than the batch baseline were ...
Friend MM, Nicodemus MC, Lemley CO, Cavinder CA, Prince P, Holtcamp K.Substance withdrawal presents a barrier to substance use disorder (SUD) recovery in part due to symptoms implicating neurotransmitters and their metabolites. Despite this relationship, research investigating alternative treatments such as psychotherapy incorporating equines (PIE) have primarily targeted vital signs and cortisol concentrations. Previous research has also proposed benefits of human-horse physiological coupling, but the role of neurotransmitters in the relationship between humans and horses during PIE has not yet been investigated. The purpose of this study was to characterize ne...
To provide some glimpses on the possibility of shaping the human gut microbiome (GM) through probiotic exchange with natural ecosystems, here we explored the impact of 15Â days of daily interaction with horses on the GM of 10 urban-living Italian children. Specifically, the children were in close contact with the horses in an "educational farm", where they spent almost 10Â h/day interacting with the animals. The children's GM was assessed before and after the horse interaction using metabarcoding sequencing and shotgun metagenomics, along with the horses' skin, oral and fecal microbiomes. Targ...
Wu Y, Li L, Bai W, Li T, Qian X, Liu Y, Wang S, Liu C, Wan F, Zhang D, Liu Y, Wu K, Ling Y, Zhou H, Meng F, Zhang Y, Cao J.Foot-and-mouth disease virus (FMDV) is an important pathogen of the MicroRNA virus family. Infection of livestock can cause physical weakness, weight loss, reduced milk production, and a significant reduction in productivity for an extended period. It also causes a high mortality rate in young animals, seriously affecting livestock production. The host range of FMDV is mainly limited to cloven-hoofed animals such as cattle and sheep, while odd-toed ungulates such as horses and donkeys have natural resistance to FMDV. The mechanism underlying this resistance in odd-toed ungulates remains unclea...
Azócar-Aedo L, Meniconi G, Pino-OlguÃn C, Gallardo M.At a veterinary hospital in southern Chile, we conducted an epidemiological study involving domestic dogs, cats, and horses to determine the seropositivity for pathogenic spp., identify the infecting serogroups, measure antibody titers, and characterize seropositive animals by sex and age. None of the sampled animals showed clinical signs of leptospirosis. The microscopic agglutination test, using a panel of eight serogroups, was used for diagnosis. The seropositivity was 36.5% (95% confidence interval [CI] = 24.5-48.4) in dogs, 12.9% (95% CI = 2.6-23.1) in cats, and 45.2% (95% CI = 30.1-60.2...
Schmitz M, Neugebauer E, Full F, Conn KL.Comparative transcriptomics offers a powerful approach to elucidate host-virus interactions across related pathogens, yet systematic evaluations across species-matched cellular systems remain limited. We performed a cross-species RNA sequencing analysis of respective species' cells infected with three alphaherpesviruses-herpes simplex virus 1 (HSV-1), bovine alphaherpesvirus 1 (BHV-1), and equid alphaherpesvirus 1 (EHV-1)-to dissect conserved and virus-specific transcriptional responses. We show that certain orthologous genes and orthologous pathways are differentially regulated upon infection...
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...
Tinarwo M, Dennis SJ, Hitzeroth II, Meyers AE, Rybicki EP, Mbewana S.African horse sickness (AHS) is a severe, noncontagious disease of equines caused by the African horse sickness virus (AHSV). The virus has nine serotypes and is transmitted by the midge. AHS is endemic in South Africa and other sub-Saharan African countries. Currently, the disease is managed using a live attenuated vaccine manufactured by Onderstepoort Biological Products (OBP). Although this vaccine has been in use for decades, it has several drawbacks, including the possibility of reversion to virulence, and it does not allow for the differentiation of infected horses from vaccinated horse...
Al-Rammahi HM, Mohsen RK, Othman RM.West Nile virus (WNV) circulates between birds and mosquitoes, with horses and humans as incidental dead-end hosts. Despite documented cases in neighboring countries and human cases in southern Iraq, no previous studies have investigated WNV in Iraqi horses. Unassigned: To determine the seroprevalence of WNV in horses from three southern Iraqi governorates (Thi-Qar, Misan, and Basrah) between March and June 2024. Unassigned: Blood samples were collected from 236 horses regardless of age, sex, or health status. Serum samples were analyzed using commercial competitive enzyme-linked immunosorbent...
Souto PC, Santos MR, Orozco AMO, Bento LD, Ramirez-Lopez CJ, Girardi FM, Machado JCA, de Oliveira LL, da Fonseca LA.We aimed to develop a species-specific ELISA for qualitatively and quantitatively determining serum amyloid A (SAA) in horses. Current methods for measuring SAA in horses utilize ELISA or immunoturbidimetric tests designed for human SAA, which are not specific to horses. Mice and rabbits were used to generate polyclonal antibodies against equine SAA. The study examined serum samples from 32 horses with acute inflammatory disease (SG) and 25 clinically healthy horses. Furthermore, the SAAeq kinetics were observed in three horses from the SG group at three different timepoints. The SAA-ELISA est...
