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.
de Oliveira Ferreira LV, Maia L, Barberini DJ, Takahira RK, de Vasconcelos Machado VM, Machado GF, de Melo GD, Amorim RM.Mesenchymal stem cells (MSCs) have emerged as a promising alternative for treating neurological disorders due to their neuroprotective, neuroregenerative, immunomodulatory, anti-inflammatory, and anti-apoptotic properties. The use of allogeneic MSCs offers advantages such as the selection of specific cells and their immediate availability. This study aimed to evaluate the safety and feasibility of intrathecal transplantation of allogeneic equine bone marrow-derived MSCs (EqBM-MSCs) in healthy horses. Ten healthy horses (five-12 years old) were randomly divided into two groups. In the control g...
Muderspach ND, Daucke R, Nielsen MW, Scoggin KE, Fedorka CE, Miller LMJ, May MG, Troedsson MHT, Ferreira-Dias G, Agerholm JS, Schoof EM....Endometrial fibrosis leads to subfertility when periglandular fibrosis impairs endometrial gland function. Identifying distinct protein expressions in mares suffering from this condition is essential for understanding the pathogenesis and developing treatments to delay fibrotic progression. To gain a better understanding of protein dynamics underlying this condition, Data-Independent Acquisition Mass Spectrometry was utilized to comprehensively characterize and compare the equine endometrial and plasma proteome from mares with different severities of endometrial fibrosis. Mares in diestrus wer...
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...
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...
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...
Wang T, Yang X, Wang C, Wang J, Meng J, Yao X, Zeng Y, Ren W.Studying the genetic characteristics and molecular mechanisms of immune regulation in horses is of great significance for protecting their genetic resources, improving breeding strategies, and enhancing their disease resistance, thereby ensuring their healthy performance in both sports and production. Objective: This study investigates the genetic characteristics and molecular mechanisms underlying immune regulation in Yili horses, comparing them with Thoroughbreds and Kazakh horses. Methods: Blood samples from each breed were analyzed for physiological, biochemical, and immune indices alongsi...
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...
Sadowska A, Wójtowicz A, Molcan T, Drzewiecka EM, Kaczmarek MM, Słyszewska M, Ferreira-Dias G, Szóstek-Mioduchowska A.Equine endometrosis is a chronic degenerative condition with fibrosis being one of the most significant characteristics. A growing body of evidence indicates the critical role of interleukin (IL)-17 in fibrotic disorders. However, its exact role during equine endometrosis remains to be discovered and explained. The main aim of the current study was to establish the expression of IL-17A signaling components in equine endometria with and without endometrosis as well as the effects of IL-17A on the transcriptomic signature, cellular functional characteristics, expression of extracellular matrix (...
Carey KJ, Smith I, Hartley CA, Bailey KE, McIntosh K, Broder CC, Gilkerson JR.Hendra virus (HeV) is a high consequence pathogen that causes severe respiratory and/or neurological disease in both horses and humans with high mortality. The equine vaccine, Equivac® HeV, is a recombinant soluble version of the G glycoprotein of HeV (HeV-sG) that elicits a potent HeV-neutralising antibody response in adult horses and also provides indirect protection for humans. Maternally derived HeV-G specific antibodies could interfere with subsequent foal vaccination, although other factors such as foal age and the suitability of vaccination protocols that have been optimised for adult ...
Robel M, Grest P, Riond B, Zablotski Y, Schoster A.Limited data are available on immune cells in the intestinal wall of healthy horses, hampering interpretation of results in case of disease. Objective: Characterize and quantify the immune cell populations and their distribution in duodenal and rectal biopsies of horses without gastrointestinal disease; compare immune cell counts (ICCTs) between full thickness- and mucosal biopsies. Methods: Twenty horses fit for slaughter, slaughtered for meat production. Methods: Full-thickness and endoscopic forceps obtained mucosal biopsies were taken within 30 min after slaughter from the duodenum and rec...
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 ...
Aragona F, Rizzo M, Arfuso F, Arrigo F, Fazio F, Giudice E, Faggio C, Piccione G, Giannetto C.Homeostasis and inflammation are two opposing physiological processes that are driven by the circadian clock. Objective: The study aim was to investigate the biological rhythm of the C-reactive protein (CRP) and Interleukin-6 (IL-6) in horses. Methods: Eight clinically healthy Italian saddle gelding horses, housed in individual boxes and subjected to a natural 12/12 L/D cycle, were enrolled. Blood samples were performed every 4 hours over a 48-hour period. Results: A positive correlation was found between CRP and IL-6 on both days of monitoring. Both parameters showed a daily rhythm; CRP acrop...
Cequier A, Serrano MB, Soler-Monsó MT, Bernad E, Vázquez FJ, Vitoria A, Fuente S, Zaragoza P, Romero A, Rodellar C, Barrachina L.The allogeneic administration of equine mesenchymal stem/stromal cells (MSCs) has numerous advantages over autologous therapy, but their interactions with the patient's immune system need to be further elucidated. These interactions can be influenced by factors such as the compatibility between donor-receptor for the major histocompatibility complex (MHC) and by the MHC expression levels, which can change under different conditions like inflammatory exposure and chondrogeneic differentiation. In this study, we evaluated the local immune response induced by chondrogeneically differentiated (MSC...
Azócar-Aedo L, Meniconi G, Pino-Olguín 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...
Dong-Ha L, Eun-Bee L, Jong-Pil S, Eun-Ju K.Despite routine vaccination, equine influenza outbreaks occur due to disparities of virus strains between vaccine and field, and immunity gaps between vaccinations. Objective: To evaluate whether a combination of adjuvants can enhance immune responses to equine influenza virus (EIV) vaccines. Methods: In vivo experimental study. Methods: Eight mixed-breed horses were immunised intramuscularly with a recombinant canarypox-based EIV vaccine, either alone or in combination with monophosphoryl lipid A (MPL) and polyinosinic-polycytidylic acid (poly I:C). A single vaccine dose was administered, and...
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...
Valderrama-Martinez C, Packham A, Smith W, Mendoza-Flores JE, Zheng S, Chigerwe M, Plancarte M, Aleman M.Long-term freezing storage can alter the stability of proteins, thereby compromising accurate determination of indirect fluorescent antibody test (IFAT) titers that support the diagnosis of equine protozoal myeloencephalitis. Objective: Assess the effect of long-term storage at -80°C on IFAT against S. neurona and N. hughesi in equine serum and cerebrospinal fluid (CSF). Methods: Paired serum and CSF (n = 46), and serum only (n = 25) samples. Methods: Prospective study of samples stored 6-12, 13-18, and 19-24 months. Comparing antibody titers across time points, McNemar and Wilcoxon...
Nemoto M, Kawanishi N, Kamei R, Furusho K, Kawauchi K, Yabuuchi Y, Oue Y, Uchida Y, Nishiura H, Reedy SE, Chambers TM, Li F, Bannai H, Yamanaka T....In April and May 2025, outbreaks of equine influenza occurred for the first time in 17 years in Japan. Equine influenza virus (EIV) of the H3N8 subtype was mainly detected in heavy draft horse populations in Kumamoto Prefecture and the Tokachi area of Hokkaido. In total, 10 EIVs were isolated from infected horses and then were used for genetic and serological analyses. Phylogenetic analysis of all eight genes revealed that all Japanese isolates were clustered with the Florida sublineage clade 1 (Fc1) viruses and were closely related to North American Fc1 viruses detected in 2024-2025. The resu...
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...
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.
Cormier KV, Fontenot RL, Eddy A, Williams ML, Wills RW, Jumper WI, Mochal-King CA.The objective of the study was to evaluate effects of intra-articular decellularized porcine amnion/chorion suspension (dPACLS) in horses. Methods: Controlled, randomized, prospective study. Methods: A total of 10 adult horses. Methods: One randomly selected radiocarpal joint (RCJ) was injected with a high dose (HD) of 50 mg (n = 5) or low dose (LD) of 5 mg of dPACLS (n = 5). The contralateral RCJ received saline as control. Systemic serum amyloid A (SAA), synovial fluid analysis (including SAA) and subjective lameness evaluation were performed prior to injection (time 0) and 24, 4...
Yang Y, Guo K, Xu L, Guo W, Dong M, Liu W, Li S, Zhang Z, Chu X, Wang Y, Zhang Z, Hu Z, Wang X.Equine influenza (EI), caused by the equine influenza virus (EIV), is an acute respiratory disease that has become enzootic worldwide, resulting in frequent outbreaks and substantial economic losses within the equine industry. In this study, we developed a competitive enzyme-linked immunosorbent assay (NP-cELISA) for the detection of antibodies against the EIV nucleoprotein (NP). The assay was designed by coating plates with purified monoclonal antibodies (mAbs) against the NP protein, followed by simultaneous incubation of the test serum samples and HRP-NP antigen in a competitive binding rea...
Chinyere CN, Ajaebili AC, Peter-Ajuzie IK, Galadima HB, Daodu OB, Fatola OI, Okolo CC, Alaba BA, Akinniyi OO, Omoniwa DO, Edeh ER, Olorunfemi AB....African horse sickness (AHS) is a severe, infectious arthropod-borne disease of equids caused by the AHS virus (AHSV). It is endemic in Sub-Saharan Africa, and several sporadic outbreaks of the disease have been reported in Nigeria in the past 5 decades. Following a recent outbreak of the disease in Lagos State, this study was conducted to investigate the prevalence of (AHSV) antibodies in apparently healthy horses and some selected wildlife sampled in four geographical regions of Nigeria. Using a competitive enzyme-linked immunosorbent assay, 575 serum samples collected from horses in five ...
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 ...
Hobbs KJ, Ueda Y, Le Sueur ANV, Cooper BL, Burke MJ, Sheats MK.To determine the effect of hemoperfusion with a polymer-based column on systemic cytokine concentrations and neutrophil dysfunction in lipopolysaccharide-treated horses in vivo. Unassigned: 6 university-owned horses received 60 ng/kg lipopolysaccharide, IV, as a bolus and then 60 ng/kg, IV, as a constant rate infusion over 1 hour. Endotoxemia was confirmed by clinical signs and neutropenia. In a crossover model that was completed from January 2024 through July 2024, hemoperfusion was performed for 4 hours with either a sham or polymer column. Blood was collected at 5 time points over a 72-hour...
Davoudi N, Behbahani M, Mohabatkar H, Dini G, Bakhshesh M.Equine herpesvirus type 1 (EHV-1) is a globally prevalent equine pathogen responsible for severe respiratory, neurological, and reproductive disorders. Accurate and ultrasensitive detection of EHV-1 is critical for timely disease management. In this study, we report the development of the first G-quadruplex-forming aptamer specifically designed for EHV-1 detection. The aptamer was generated using an in silico approach, and its G-quadruplex conformation was confirmed using circular dichroism (CD) spectroscopy and crystal violet fluorescence assays. Binding affinity and specificity were assessed...
This cross-sectional study evaluated the seroprevalence and clinical impact of West Nile virus (WNV) infection in horses from three ecologically high-risk counties in western Romania (Timiș, Arad, and Bihor) between 2023 and 2025. A total of 306 unvaccinated horses were tested using a commercial ELISA, with 8.17% testing positive for WNV antibodies, indicating prior exposure. Passive surveillance for clinical signs during mosquito seasons identified 16 horses with acute neurological symptoms, four of which were confirmed as clinical cases based on WNV-specific IgM positivity, suggesting proba...
Carmona JU, López C, Jurado-Grisales C.Platelet-rich plasma (PRP) is widely utilized as a routine treatment for chronic musculoskeletal conditions in horses, such as osteoarthritis, tendinopathies, and desmopathies. This effectiveness stems from the high concentration of growth factors and anti-inflammatory cytokines that are released upon activation of this orthobiologic agent, whether activated endogenously or exogenously. Despite its growing popularity, there is a notable absence of instructional videos that demonstrate the techniques for obtaining PRP in horses. This study examines a double centrifugation tube method for obtain...
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...
Lobigs M, Pavy M, Hall RA, Lobigs P, Cooper P, Komiya T, Toriniwa H, Petrovsky N.Advax is a polysaccharide-based adjuvant that potently stimulates vaccine immunogenicity without the increased reactogenicity seen with other adjuvants. This study investigated the immunogenicity of a novel Advax-adjuvanted Vero cell culture candidate vaccine against Japanese encephalitis virus (JEV) in mice and horses. The results showed that, in mice, a two-immunization, low-dose (50 ng JEV antigen) regimen with adjuvanted vaccine produced solid neutralizing immunity comparable to that elicited with live ChimeriVax-JE immunization and superior to that elicited with tenfold higher doses of a ...
Cross AR, Higson FK, Jones OT, Harper AM, Segal AW.1. The absorption coefficient of human neutrophil plasma-membrane reduced-minus-oxidized cytochrome b-245 was determined [delta epsilon (mM; 559-540 nm) = 21.6 cm-1]. 2. Neutrophil polymorphonuclear leucocytes (neutrophils) were prepared from human, ox, horse and pig blood. In each case plasma-membrane fractions were found to contain low-potential cytochrome b. When membranes from horse neutrophils were incubated anaerobically with either NADH or NADPH the cytochrome b became reduced. Prior stimulation of the cells with phorbol myristate acetate did not increase the rate or extent of cytochrom...
Barberini DJ, Freitas NP, Magnoni MS, Maia L, Listoni AJ, Heckler MC, Sudano MJ, Golim MA, da Cruz Landim-Alvarenga F, Amorim RM.Studies with mesenchymal stem cells (MSCs) are increasing due to their immunomodulatory, anti-inflammatory and tissue regenerative properties. However, there is still no agreement about the best source of equine MSCs for a bank for allogeneic therapy. The aim of this study was to evaluate the cell culture and immunophenotypic characteristics and differentiation potential of equine MSCs from bone marrow (BM-MSCs), adipose tissue (AT-MSCs) and umbilical cord (UC-MSCs) under identical in vitro conditions, to compare these sources for research or an allogeneic therapy cell bank. Methods: The BM-MS...
Lewis NS, Daly JM, Russell CA, Horton DL, Skepner E, Bryant NA, Burke DF, Rash AS, Wood JL, Chambers TM, Fouchier RA, Mumford JA, Elton DM, Smith DJ.Equine influenza virus is a major respiratory pathogen in horses, and outbreaks of disease often lead to substantial disruption to and economic losses for equestrian industries. The hemagglutinin (HA) protein is of key importance in the control of equine influenza because HA is the primary target of the protective immune response and the main component of currently licensed influenza vaccines. However, the influenza virus HA protein changes over time, a process called antigenic drift, and vaccine strains must be updated to remain effective. Antigenic drift is assessed primarily by the hemagglu...
Salinovich O, Payne SL, Montelaro RC, Hussain KA, Issel CJ, Schnorr KL.Previous results from our laboratory have demonstrated that equine infectious anemia virus displays structural variations in its surface glycoproteins and RNA genome during passage and chronic infections in experimentally infected Shetland ponies (Montelaro et al., J. Biol. Chem. 259:10539-10544, 1984; Payne et al., J. Gen. Virol. 65:1395-1399, 1984). The present study was undertaken to obtain an antigenic and biochemical characterization of equine infectious anemia virus isolates recovered from an experimentally infected pony during sequential disease episodes, each separated by intervals of ...
Guest DJ, Smith MR, Allen WR.Autologous mesenchymal progenitor cells (MPCs) purified from bone marrow aspirates are being used in the treatment of superficial digital flexor tendon (SDFT) injuries in the horse with promising results. In this study the fate of autologous and allogeneic MPCs following injection into the SDFT was monitored by stable transfection of MPCs with green fluorescent protein (GFP). Small lesions were created manually in one forelimb SDFT of 2 horses and injected with autologous MPCs, allogeneic MPCs or bone marrow supernatant alone. Post mortem examinations performed after 10 or 34 days revealed GFP...
Pauvolid-Corrêa A, Campos Z, Juliano R, Velez J, Nogueira RM, Komar N.A recent study reported neutralizing antibodies to West Nile virus (WNV) in horses from four ranches of southern Pantanal. To extend that study, a serosurvey for WNV and 11 Brazilian flaviviruses was conducted with 760 equines, 238 sheep and 61 caimans from 17 local cattle ranches. Among the tested equines, 32 were collected from a ranch where a neurologic disorder outbreak had been recently reported. The sera were initially screened by using a blocking ELISA and then titrated by 90% plaque-reduction neutralization test (PRNT90) for 12 flaviviruses. Employing the criterion of 4-fold greater ti...
Möstl E, Messmann S, Bagu E, Robia C, Palme R.After 14C-labelled cortisol infusion in ponies and pigs, faecal samples were collected. Extraction of 0.5 g faeces with 5 ml 80-90% methanol yielded the highest radioactivity in the supernatant. Most of the metabolites were ether soluble. After high performance liquid chromatography (HPLC), the presence of immunoreactive metabolites was demonstrated by measuring each HPLC fraction using enzyme immunoassays for cortisol, corticosterone and 11-oxoaetiocholanolone. Only the assay for 11-oxoaetiocholanolone revealed peaks with co-eluting radioactivity. For biological validation of the test system,...
Bowen RA, Nemeth NM.West Nile virus emerged recently in North America as a serious human and animal pathogen. This review summarizes the use of experimental infections with West Nile virus in diverse vertebrate species that have been used to answer fundamental questions about the host response, pathogenesis of West Nile virus infection and virus evolution. Results: West Nile virus has an extremely broad vertebrate host range. Infection of common species of birds has defined those with high vs. low potential to serve as amplifying hosts for the virus. In general, mammals (primates, horses, companion animals) are d...
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...
Carrade Holt DD, Wood JA, Granick JL, Walker NJ, Clark KC, Borjesson DL.Mesenchymal stem cells (MSCs) are used in both human clinical trials and veterinary medicine for the treatment of inflammatory and immune-mediated diseases. MSCs modulate inflammation by decreasing the cells and products of the inflammatory response. Stimulated equine MSCs from bone marrow (BM), adipose tissue (AT), cord blood (CB), and umbilical cord tissue (CT) inhibit lymphocyte proliferation and decrease inflammatory cytokine production. We hypothesized that equine MSCs inhibit T cell proliferation through secreted mediators and that MSCs from different tissue sources decrease T cell proli...
Mehdizadeh Gohari I, Parreira VR, Nowell VJ, Nicholson VM, Oliphant K, Prescott JF.A role for type A Clostridium perfringens in acute hemorrhagic and necrotizing gastroenteritis in dogs and in necrotizing enterocolitis of neonatal foals has long been suspected but incompletely characterized. The supernatants of an isolate made from a dog and from a foal that died from these diseases were both found to be highly cytotoxic for an equine ovarian (EO) cell line. Partial genome sequencing of the canine isolate revealed three novel putative toxin genes encoding proteins related to the pore-forming Leukocidin/Hemolysin Superfamily; these were designated netE, netF, and netG. netE a...
Pirie RS.Recurrent airway obstruction is a widely recognised airway disorder, characterised by hypersensitivity-mediated neutrophilic airway inflammation and lower airway obstruction in a subpopulation of horses when exposed to suboptimal environments high in airborne organic dust. Over the past decade, numerous studies have further advanced our understanding of different aspects of the disease. These include clarification of the important inhaled airborne agents responsible for disease induction, improving our understanding of the underlying genetic basis of disease susceptibility and unveiling the fu...
Cheevers WP, McGuire TC.Equine infectious anemia (EIA) is a chronic, relapsing infectious disease of horses caused by a nononcogenic retrovirus. Virus persists in infected animals for life and can be reliably detected by serologic tests that measure levels of antibody to the major structural protein of the virus. Periodic virus replication in macrophages leads to an immunologically mediated acute disease characterized primarily by severe anemia. Recrudescence of acute EIA is the result of antigenic variation of the surface glycoprotein of EIA virus. The frequency and severity of clinical episodes of EIA decrease in m...
Bond S, Léguillette R, Richard EA, Couetil L, Lavoie JP, Martin JG, Pirie RS.The term "equine asthma" has been proposed as a unifying descriptor of inflammatory airway disease (IAD), recurrent airway obstruction (RAO), and summer pasture-associated obstructive airway disease. Whilst the term will increase comprehensibility for both the lay and scientific communities, its biologic relevance must be compared and contrasted to asthma in human medicine, recognizing the limited availability of peer-reviewed equine-derived data, which are largely restricted to clinical signs, measures of airway obstruction and inflammation and response to therapy. Such limitations constrain ...
von Bargen K, Haas A.The soil actinomycete Rhodococcus equi is a pulmonary pathogen of young horses and AIDS patients. As a facultative intracellular bacterium, R. equi survives and multiplies in macrophages and establishes its specific niche inside the host cell. Recent research into chromosomal virulence factors and into the role of virulence plasmids in infection and host tropism has presented novel aspects of R. equi infection biology and pathogenicity. This review will focus on new findings in R. equi biology, the trafficking of R. equi-containing vacuoles inside host cells, factors involved in virulence and ...
Radcliffe CH, Flaminio MJ, Fortier LA.Mesenchymal progenitor cells (MPCs) are often characterized using surface markers after expansion and treatment in culture. There are no studies directly comparing gene and protein markers in undifferentiated samples during the very early phases of culture. The goal of this study was to evaluate temporal gene and protein expression changes during establishment of equine MPC cultures. Bone marrow aspirate was obtained from 35 horses and processed by density gradient centrifugation. In freshly isolated bone marrow, mononuclear cells had variable expression of CD44, CD11a/CD18, CD90, and CD45RB c...
Brault AC, Powers AM, Chavez CL, Lopez RN, Cachón MF, Gutierrez LF, Kang W, Tesh RB, Shope RE, Weaver SC.Eastern equine encephalitis virus (EEEV), the sole species in the EEE antigenic complex, is divided into North and South American antigenic varieties based on hemagglutination inhibition tests. Here we describe serologic and phylogenetic analyses of representatives of these varieties, spanning the entire temporal and geographic range available. Nucleotide sequencing and phylogenetic analyses revealed additional genetic diversity within the South American variety; 3 major South/Central American lineages were identified including one represented by a single isolate from eastern Brazil, and 2 lin...
Cassano JM, Schnabel LV, Goodale MB, Fortier LA.Inflammatory licensed mesenchymal stem cells (MSCs) have the ability to promote functional tissue repair. This study specifically sought to understand how the recipient tissue environment reciprocally affects MSC function. Inflammatory polarized macrophages, modeling an injured tissue environment, were exposed to licensed MSCs, and the resultant effects of MSC immunomodulation and functionality of the MSC secretome on chondrocyte homeostasis were studied. Inflammatory licensed MSCs were generated through priming with either IFN-γ or polyinosinic:polycytidylic acid (poly I:C). Macrophages were...
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...
Munderloh UG, Madigan JE, Dumler JS, Goodman JL, Hayes SF, Barlough JE, Nelson CM, Kurtti TJ.The equine granulocytic ehrlichiosis agent, Ehrlichia equi, is closely related or identical to the human granulocytic ehrlichiosis (HGE) agent. Both are suspected of being transmitted by ticks. We have successfully isolated E. equi in a cell line, IDE8, derived from a putative vector, the tick Ixodes scapularis. Peripheral blood leukocytes from an experimentally infected horse were inoculated onto IDE8 monolayers. Cultures were incubated in a candle jar at 34 degrees C in tick cell culture medium with NaHCO3 and an organic buffer [3-(N-morpholino)-propanesulfonic acid] (MOPS). Within 2 weeks, ...
Takai S, Koike K, Ohbushi S, Izumi C, Tsubaki S.Antigens of Rhodococcus equi were analyzed by immunoblotting with naturally infected foal sera. Immunoblots of whole-cell antigen preparations of clinical isolates of R. equi revealed that major protein bands with molecular masses of 15 to 17 kDa were present in all clinical isolates tested and all isolates virulent for mice. In contrast, the 15- to 17-kDa antigens were not identified by immunoblotting in ATCC 6939, a type strain of R. equi that was avirulent for mice. Whole-cell antigens of 102 environmental isolates were investigated by immunoblotting and the mouse pathogenicity test. Twenty...
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...
Browning GF, Fitzgerald TA, Chalmers RM, Snodgrass DR.Equine rotavirus FI23 was shown to be prototypic of a novel G serotype, provisionally G14, by cross-neutralization and VP7 sequence determination. Although distinct, there are as few as six differing amino acid residues (92, 94, 96, 146, 147, and 221) in the VP7 antigenic regions of FI23 and G3 rotaviruses.
Shehu-Xhilaga M, Ablan S, Demirov DG, Chen C, Montelaro RC, Freed EO.The Gag proteins of a number of different retroviruses contain late or L domains that promote the release of virions from the plasma membrane. Three types of L domains have been identified to date: Pro-Thr-Ala-Pro (PTAP), Pro-Pro-X-Tyr, and Tyr-Pro-Asp-Leu. It has previously been demonstrated that overexpression of the N-terminal, E2-like domain of the endosomal sorting factor TSG101 (TSG-5') inhibits human immunodeficiency virus type 1 (HIV-1) release but does not affect the release of the PPPY-containing retrovirus murine leukemia virus (MLV), whereas overexpression of the C-terminal portion...
Blitvich BJ, Bowen RA, Marlenee NL, Hall RA, Bunning ML, Beaty BJ.We evaluated the ability of epitope-blocking enzyme-linked immunosorbent assays (ELISAs) to detect West Nile virus (WNV) antibodies in domestic mammals. Sera were collected from experimentally infected horses, cats, and pigs at regular intervals and screened in ELISAs and plaque reduction neutralization tests. The diagnostic efficacies of these techniques were similar.
Vannella KM, Moore BB.Idiopathic pulmonary fibrosis (IPF) remains exactly that. The disease originates from an unknown cause, and little is known about the mechanisms of pathogenesis. While the disease is likely multi-factorial, evidence is accumulating to implicate viruses as co-factors (either as initiating or exacerbating agents) of fibrotic lung disease. This review summarizes the available clinical and experimental observations that form the basis for the hypothesis that viral infections may augment fibrotic responses. We review the data suggesting a link between hepatitis C virus, adenovirus, human cytomegalo...
Payne SL, Fang FD, Liu CP, Dhruva BR, Rwambo P, Issel CJ, Montelaro RC.The extent and nature of genomic variation among nine antigenically distinct EIAV isolates recovered during sequential clinical episodes from two experimentally infected ponies were examined by restriction fragment analysis and nucleotide sequencing. Only minor variations in restriction enzyme patterns were observed among the viral genomes. In contrast, env gene sequences of four isolates from one pony revealed numerous clustered base substitutions. Divergence in env gene nucleotide and deduced amino acid sequences between pairs of virus isolates ranged from 0.62 to 3.4% env gene mutation rate...
