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.
Thomson K, Eskola K, Eklund M, Suominen K, Määttä M, Junnila J, Nykäsenoja S, Niinistö K, Grönthal T, Rantala M.Extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) are important causative agents for infections in humans and animals. At the Equine Veterinary Teaching Hospital of the University of Helsinki, the first infections caused by ESBL-E were observed at the end of 2011 leading to enhanced infection surveillance. Contact patients were screened for ESBL-E by culturing infection sites and rectal screening. This study was focused on describing the epidemiology and microbiological characteristics of ESBL-E from equine patients of the EVTH during 2011-2014, and analysing putative risk fac...
Steuer AE, Anderson HP, Shepherd T, Clark M, Scare JA, Gravatte HS, Nielsen MK.Horses are host to a plethora of parasites. Knowledge of the seasonality of parasite egg shedding and transmission is important for constructing parasite control programs. However, studies describing these patterns are sparse, and have largely been conducted only in the United Kingdom. This study evaluated strongylid egg shedding patterns and transmission dynamics of Strongylus vulgaris in naturally infected and untreated mares and foals through one calendar year in Kentucky, USA. The study also investigated the existence of a peri-parturient rise (PPR) in strongylid egg counts in foaling mare...
Moore T, Williams JM, Becerra-Rodriguez MA, Dunne M, Kammerer R, Dveksler G.Pregnancy-specific glycoproteins (PSGs) are members of the immunoglobulin superfamily and are closely related to the predominantly membrane-bound CEACAM proteins. PSGs are produced by placental trophoblasts and secreted into the maternal bloodstream at high levels where they may regulate maternal immune and vascular functions through receptor binding and modulation of cytokine and chemokine expression and activity. PSGs may have autocrine and paracrine functions in the placental bed, and PSGs can activate soluble and extracellular matrix bound TGF-β, with potentially diverse effects on multip...
Middlebrooks BT, Cowles B, Pusterla N.The objective of this study was to investigate the use of serum amyloid A (SAA) as an early indicator of subclinical inflammation in recently imported horses. Archived serum samples from 143 adult horses imported from Europe over 12 months were available for SAA testing. Based on clinical and hematological assessment performed shortly after arrival to a quarantine facility, the horses were characterized as healthy horses, horses with subclinical inflammation, and sick horses with and without hematological abnormalities. The majority of the horses (n = 109) were deemed healthy, 30 horses had ...
Verney M, Gautron M, Lemans C, Rincé A, Hans A, Hébert L.Trypanozoon infections in equids are caused by three parasite species in the Trypanozoon subgenus: Trypanosoma equiperdum, T. brucei and T. evansi. They are respectively responsible for infectious diseases dourine, nagana and surra. Due to the threat that Trypanozoon infection represents for international horse trading, accurate diagnostic tests are crucial. Current tests suffer from poor sensitivity and specificity, due in the first case to the transient presence of parasites in the blood and in the second, to antigenic cross-reactivity among Trypanozoon subspecies. This study was designed to...
Radcliffe RM, Bookbinder LC, Liu SY, Tomlinson JE, Cook VL, Hurcombe SDA, Divers TJ.Blood transfusion is a lifesaving treatment for horses with acute hemorrhage and other causes of anemia. Transfusions improve oxygen delivery to the tissues via increased blood volume and hemoglobin concentration. Certain aspects of equine blood transfusion are challenging, especially in the field situation, and practitioners may be unfamiliar or feel overwhelmed with the process. An understanding of the indications, materials, methods, and techniques as well as donor selection and possible complications will help practitioners successfully implement blood transfusion in clinical practice. Met...
Sharma D, Gupta S, Sethi K, Kumar S, Kumar R.Trypanosoma evansi, a hemoflagellate protozoan parasite, causes wasting disease called surra in wide range of animals. Although the organism has been reported from various parts of India, data generated from organized epidemiological study is still in infancy in majority states of India. In the present study, livestock of Himachal Pradesh, India, was targeted for epidemiological investigation of T. evansi infections. A total of 440 equines and 444 cattle serum samples were collected from four agro-climatic zones. Furthermore, serum samples of 280 buffaloes from three different agro-climatic zo...
Ohta M, Bannai H, Kambayashi Y, Tsujimura K, Tamura N, Iwamoto Y, Wakuno A, Yamayoshi S, Kawaoka Y, Nemoto M.Updating vaccine strains is important to control equine influenza (EI). Previously, we reported that a monovalent inactivated EI vaccine derived from a virus generated by reverse genetics (RG) elicited immunogenicity in horses. In the present study, we compared antibody responses to a bivalent inactivated EI vaccine generated by RG and a commercially available bivalent inactivated EI (CO) vaccine derived from wild-type equine influenza viruses in Thoroughbred horses. The CO vaccine contained A/equine/Ibaraki/1/2007 (Florida sub-lineage clade 1) and A/equine/Yokohama/aq13/2010 (Florida sub-line...
Wernery U, Chan E, Raghavan R, Teng JLL, Syriac G, Siu SY, Joseph M, Yeung ML, Jia L, Cai JP, Chiu TH, Lau SKP, Woo PCY.Glanders is a highly contagious and potentially serious disease caused by Burkholderia mallei, a Tier 1 select agent. In this study, we raised a monoclonal antibody (mAb) against the lipopolysaccharide (LPS) of B. mallei and developed a competitive enzyme-linked immunosorbent assay (cELISA) for B. mallei infection. Using the titrated optimal conditions of B. mallei-LPS (2 ng) for microtiter plate coating, sample serum dilution at 1:20 and 3.5 ng/μL anti-LPS mAb B5, the cutoff value of the cELISA was determined using serum samples from 136 glanders-free seronegative horses in Hong Kong. All ca...
Amat JAR, Patton V, Chauché C, Goldfarb D, Crispell J, Gu Q, Coburn AM, Gonzalez G, Mair D, Tong L, Martinez-Sobrido L, Marshall JF, Marchesi F....The mechanisms and consequences of genome evolution on viral fitness following host shifts are poorly understood. In addition, viral fitness -the ability of an organism to reproduce and survive- is multifactorial and thus difficult to quantify. Influenza A viruses (IAVs) circulate broadly among wild birds and have jumped into and become endemic in multiple mammalian hosts, including humans, pigs, dogs, seals, and horses. H3N8 equine influenza virus (EIV) is an endemic virus of horses that originated in birds and has been circulating uninterruptedly in equine populations since the early 1960s. ...
Rozario C, Martínez-Sobrido L, McSorley HJ, Chauché C.Influenza A viruses (IAVs) are important respiratory pathogens of horses and humans. Infected individuals develop typical respiratory disorders associated with the death of airway epithelial cells (AECs) in infected areas. Virulence and risk of secondary bacterial infections vary among IAV strains. The IAV non-structural proteins, NS1, PB1-F2, and PA-X are important virulence factors controlling AEC death and host immune responses to viral and bacterial infection. Polymorphism in these proteins impacts their function. Evidence from human and mouse studies indicates that upon IAV infection, the...
Schwartz EJ, Costris-Vas C, Smith SR.Equine infectious anemia virus (EIAV) is a lentivirus similar to HIV that infects horses. Clinical and experimental studies demonstrating immune control of EIAV infection hold promise for efforts to produce an HIV vaccine. Antibody infusions have been shown to block both wild-type and mutant virus infection, but the mutant sometimes escapes. Using these data, we develop a mathematical model that describes the interactions between antibodies and both wild-type and mutant virus populations, in the context of continual virus mutation. The aim of this work is to determine whether repeated vaccinat...
Lee OJ, Koch TG.Inflammation-associated disorders are significant causes of morbidity in horses. Equine single-donor mesenchymal stromal cells (sdMSCs) hold promise as cell-therapy candidates due to their secretory nonprogenitor functions. This has been demonstrated by mononuclear cell suppression assays (MSAs) showing that sdMSCs are blood mononuclear cell (BMC) suppressive in vitro. sdMSCs derived from umbilical cord blood are of clinical interest due to their ease of procurement, multipotency, and immunomodulatory ability. Due to the inherent donor-to-donor heterogeneity of MSCs, the development of robust ...
Liu CC, Hsiao YC, Chu LJ, Wang PJ, Liu CH, Hsieh WC, Yu JS., also known as Taiwanese cobra, is one of the most prevalent venomous snakes in Taiwan. Clinically, freeze-dried neurotoxic antivenom (FNAV) produced from horses by Taiwan Centers for Disease Control (CDC) has been the only approved treatment for envenoming for the last few decades. During antivenom production, large numbers of mice are used in the in vivo assay to determine whether the neutralization potency of hyperimmunized equines is satisfactory for large-scale harvesting. However, this in vivo assay is extremely laborious, expensive, and significantly impairs animal welfare. In the pre...
Birras J, White SJ, Jonsdottir S, Novotny EN, Ziegler A, Wilson AD, Frey R, Torsteinsdottir S, Alcocer M, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis in horses incited by salivary allergens from Culicoides spp. IBH does not occur in Iceland, as the causative agents are absent, however a high prevalence is seen in horses exported to Culicoides-rich environments. To study the natural course of sensitization to Culicoides allergens and identify the primary sensitizing allergen(s) in horses exported from Iceland utilizing a comprehensive panel of Culicoides recombinant (r-) allergens. IgE microarray profiling to 27 Culicoides r-allergens was conducted on 110 serological s...
Kamm JL, Riley CB, Parlane NA, Gee EK, McIlwraith CW.Mesenchymal stromal cells (MSCs) are believed to be hypoimmunogeneic with potential use for allogeneic administration. Bone marrow was harvested from Connemara (n = 1), Standardbred (n = 6), and Thoroughbred (n = 3) horses. MSCs were grouped by their level of expression of major histocompatibility factor II (MHC II). MSCs were then sub-grouped by those MSCs derived from universal blood donor horses. MSCs were isolated and cultured using media containing fetal bovine serum until adequate numbers were acquired. The MSCs were cultured in xenogen-free media for 48 h prior to use and d...
Kiemle J, Hindenberg S, Bauer N, Roecken M.Rapid, accurate detection of serum amyloid A (SAA) is needed in equine practice. We validated a patient-side point-of-care (POC) assay (Stablelab; Zoetis) compared to the turbidimetric immunoassays LZ-SAA (TIA-Hum) and VET-SAA (TIA-Vet; both Eiken Chemical). Analytical performance was assessed at 3 different concentration ranges and with interferences. Inter-method comparison using 49 equine serum samples revealed a significant difference between median SAA results ( < 0.0001), with the strongest bias between the POC and TIA-Vet (median 1,093 vs. 578 mg/L). The median SAA value obtain...
Ziegler A, Olzhausen J, Hamza E, Stojiljkovic A, Stoffel MH, Garbani M, Rhyner C, Marti E.Allergen-specific immunotherapy (AIT) constitutes the only curative approach for allergy treatment. There is need for improvement of AIT in veterinary medicine, such as in horses suffering from insect bite hypersensitivity, an IgE-mediated dermatitis to Culicoides. Dendritic cell (DC)-targeting represents an efficient method to increase antigen immunogenicity. It is studied primarily for its use in improvement of cancer therapy and vaccines, but may also be useful for improving AIT efficacy. Immunomodulators, like the Toll-like receptor 4 (TLR-4) agonist monophosphoryl lipid-A (MPLA) has been ...
Kahn SK, Cywes-Bentley C, Blodgett GP, Canaday NM, Turner-Garcia CE, Flores-Ahlschwede P, Metcalfe LL, Nevill M, Vinacur M, Sutter PJ, Meyer SC....Hyperimmune plasma raised against β-1→6-poly-N-acetyl glucosamine (PNAG HIP) mediates more opsonophagocytic killing of Rhodococcus equi (R equi) than does R equi hyperimmune plasma (RE HIP) in vitro. The relative efficacy of PNAG HIP and RE HIP to protect foals against R equi pneumonia, however, has not been evaluated. Objective: Transfusion with PNAG HIP will be superior to RE HIP in foals for protection against R equi pneumonia in a randomized, controlled, blinded clinical trial. Methods: Four hundred sixty Quarter Horse and Thoroughbred foals at 5 large breeding farms in the Un...
Antczak DF, Allen WRT.This chapter focuses on the early stages of placental development in horses and their relatives in the genus Equus and highlights unique features of equid reproductive biology. The equine placenta is classified as a noninvasive, epitheliochorial type. However, equids have evolved a minor component of invasive trophoblast, the chorionic girdle and endometrial cups, which links the equine placenta with the highly invasive hemochorial placentae of rodents and, particularly, with the primate placenta. Two types of fetus-to-mother signaling in equine pregnancy are mediated by the invasive equine tr...
Hay AN, Wagner B, Leeth CM, LeRoith T, Cecere TE, Lahmers KK, Andrews FM, Werre SR, Johnson AL, Clark CK, Pusterla N, Reed SM, Lindsay DS, Taylor S....Equine protozoal myeloencephalitis (EPM) is a debilitating neurologic disease affecting horses across the Americas. Gaps in understanding the inflammatory immune response in EPM-affected horses create difficulties with diagnosis and treatment, subsequently negatively impacting the prognosis of affected horses. The purpose of the current study was to evaluate circulating levels of the inflammatory immune marker soluble CD14 (sCD14), in horses with EPM (n = 7) and determine if they differed from healthy neurologically normal horses (n = 6). Paired sera and cerebrospinal fluid (CSF) samples were ...
Faber E, Tshilwane SI, Van Kleef M, Pretorius A.Expanding on our previous work, this study used transcriptome analysis of RNA sequences to investigate the various factors that contributed to either inducing apoptosis that resulted in cell death or promoting the survival of African horse sickness virus serotype 4 (AHSV4)-infected horse peripheral blood mononuclear cells (PBMC) after 24 h. Apoptosis is a host defense mechanism that prevents virus replication, accumulation and spread of progeny viruses. AHSV4-infected PBMC were killed via the intrinsic and the perforin/granzyme pathways of apoptosis during the attenuated AHSV4 (attAHSV4) in v...
Pakdemirli A, Çalışkan E, Hacıoğlu S, Danyer E, Kardoğan Ö, Kurt ZE, Yıldırım Ö, Taşkaya H, Ündar B, Sezgin Y, Ergin G, Ekici H....SARS-CoV-2 disease was announced as a pandemic by The World Health Organization in early 2020. It is still threatening the world population. Here, we aimed to produce hyperimmune sera that contain immunoglobulin G and F(ab')2 fragments sourced from horse antibodies as an urgent response to the pandemic. SARS-CoV-2 was produced and inactivated with three different methods [formaldehyde (FA), formaldehyde, and binary ethylene amine (FA + BEI), and heat treatment]. After in vitro inactivation control, immunogens were mixed with Freund’s adjuvant, thereafter horses (n: 2 for FA, 4 for FA + BEI, ...
Harman RM, Churchill KA, Jager MC, Van de Walle GR.Equid herpesvirus 1 (EHV-1) outbreaks occur when virus spreads from infected horses to in-contact horses, primarily via nasal shedding. This study evaluated the efficacy of factors secreted by equine peripheral blood derived mesenchymal stromal cells (PB-MSCs), collectively named the secretome, to inhibit the growth of EHV-1 in (i) 2D epithelial cell cultures (RK-13) in vitro, (ii) 3D equine nasal explants in vitro and (iii) an EHV-1 infection mouse model in vivo. The PB-MSC secretome was found to inhibit EHV-1 in RK-13 cells as well as in the epithelium of equine nasal explants. Although the ...
Orsini JA.The multiple topics summarized in this article and discussed in detail in this issue of VCNA are comprehensive and in-depth, exploring concepts and clinical experiences for state-of-the-art care of the equine foot. The research on the equine foot will translate to the clinical setting and with this the compassionate care of the horse.
Costa VMD, Cursino AE, Franco Luiz APM, Braz GF, Cavalcante PH, Souza CA, Simplício KMMG, Drumond BP, Lima MT, Teixeira BM, Kroon EG.Equine infectious anemia (EIA) is listed by the World Organization for Animal Health (OIE) as one of the equine diseases that must be notified. No effective treatment or vaccine is available. EIA control is based on segregation and euthanasia of positive equids. The disease is caused by the equine infectious anemia virus (EIAV), a member of the genus Lentivirus of the Retroviridae family. Despite the importance of this disease in equids, EIA has been poorly studied in donkeys (Equus asinus). We evaluate the sanitary conditions related to EIAV in donkeys from a shelter of abandoned animals capt...
Geiger T, Gerhards H, Wollanke B.Equine recurrent uveitis (ERU) is typically caused by chronic intraocular leptospiral infection in warm-blooded horses in central Europe. The most effective therapy for leptospiral-induced ERU is the surgical removal of diseased vitreous (vitrectomy). Since vitrectomy is a highly specialized and invasive surgery, the indication must be determined very carefully. In order to obtain evidence of intraocular leptospiral infection by laboratory diagnostics in questionable leptospiral ERU-cases, sampling of aqueous humor is required, because serum tests using microscopic agglutination test (MAT) are...
Leeth C, Adkins J, Hay A, Bogers S, Potter A, Witonsky S, Zhu J.Immunological studies in the horse are frequently hampered by lack of environmental control, complicated study design, and ethical concerns when performing high risk studies. The purpose of the current study was to investigate the utility of a xenograft model for studying acute equine immune responses. Immunocompromised non obese diabetic (NOD). sudden combined immunodeficiency (scid).gamma-/- (NSG) mice were engrafted with either equine peripheral blood lymphocytes (PBLs) or equine bone marrow to determine an optimal protocol for equine lymphocyte engraftment. We found that both PBL and bone ...
Scior T, Alexander C, Zaehringer U.There is literature evidence gathered throughout the last two decades reflecting unexpected species differences concerning the immune response to lipid IVa which provides the opportunity to gain more detailed insight by the molecular modeling approach described in this study. Lipid IVa is a tetra-acylated precursor of lipid A in the biosynthesis of lipopolysaccharide (LPS) in Gram-negative bacteria. Lipid A of the prototypic E. coli-type is a hexa-acylated structure that acts as an agonist in all tested mammalian species by innate immunorecognition via the Toll-like receptor 4 (TLR4)/myeloid d...
Zheng YH, Sentsui H, Nakaya T, Kono Y, Ikuta K.Equine infectious anemia virus (EIAV) is a good model for studying mechanisms generating escaped retrovirus variants. We previously sequenced the entire gp90-encoding region of 22 cDNA clones obtained from five antigenically distinct isolates (F1V to F5V) recovered during febrile episodes in horse 493 experimentally infected with the Japanese virulent EIAV strain V70. The results showed that the mutations occurred in the principal neutralizing domain (PND) by insertions/duplications. In this study, we further characterized the PND of virus isolates sequentially recovered during 22 febrile epis...
Kitai Y, Shoda M, Kondo T, Konishi E.West Nile virus (WNV) is now widely distributed worldwide, except in most areas of Asia where Japanese encephalitis virus (JEV) is distributed. Considering the movement and migration of reservoir birds, there is concern that WNV may be introduced in Asian countries. Although manuals and guidelines for serological tests have been created in Japan in preparedness for the introduction of WNV, differential diagnosis between WNV and JEV may be complicated by antigenic cross-reactivities between these flaviviruses. Here, we generated a monoclonal antibody specific for the nonstructural protein 1 (NS...
Payne S, Parekh B, Montelaro RC, Issel CJ.The unique periodic nature of equine infectious anaemia (EIA) is believed to result from the ability of the infecting virus. EIAV, to undergo relatively rapid antigenic variations which circumvent host immune responses resulting in distinct virus populations in sequential clinical episodes in the persistently infected horse. This model was examined by oligonucleotide mapping comparisons of the RNA genomes of selected isolates of EIAV. Variations in oligonucleotide maps could be reproducibly demonstrated (i) after adaptation of the laboratory strain of EIAV to replication in a pony, (ii) after ...
Peachey LE, Castro C, Molena RA, Jenkins TP, Griffin JL, Cantacessi C.A plethora of data points towards a role of the gastrointestinal (GI) microbiota of neonatal and young vertebrates in supporting the development and regulation of the host immune system. However, knowledge of the impact that infections by GI helminths exert on the developing microbiota of juvenile hosts is, thus far, limited. This study investigates, for the first time, the associations between acute infections by GI helminths and the faecal microbial and metabolic profiles of a cohort of equine youngstock, prior to and following treatment with parasiticides (ivermectin). We observed that high...
Mendoza L, Kaufman L, Standard PG.A practical, sensitive, and specific immunodiffusion test was developed for diagnosing and monitoring pythiosis in horses. Culture filtrates, a soluble cell mass, and trypsinized Pythium sp. antigens were evaluated against prepared rabbit anti-Pythium sp. serum and pythiosis horse case sera. The culture filtrate antigens demonstrated the greatest capacity for detecting precipitins and the greatest stability during storage. In contrast, the trypsinized antigens had the weakest capability for detecting multiple precipitins and the poorest stability. The 13 sera from horses with proven active pyt...
Cabañas R, López-Serrano MC, Carreira J, Ventas P, Polo F, Caballero MT, Contreras J, Barranco P, Moreno-Ancillo A.Different allergenic proteins have been involved in cross-reactivity among animals. Albumins seem to be cross-sensitizing allergenic components. The aim of this study was to assess the importance of albumin as a cross-reactive allergen in patients sensitized to cat, dog and horse. One hundred and seventeen patients sensitized to cat were tested for IgE reactivity using skin prick tests and RAST assays with cat, dog and horse hair/dander extracts and their purified albumin extracts. RAST-inhibition studies were carried out to assess cross-reactivity among cat, dog and horse and among their puri...
Tajima M, Nakajima H, Ito Y.Equine infectious anemia (EIA) virus was observed in thin sections of infected cultured horse leukocytes by electron microscopy. The virus particles had a spherical shape and were between 80 and 120 nm in diameter. Most of them contained an electron-dense nucleoid 40 to 60 nm in diameter. They were observed to form by a process of budding from the plasma membrane and appeared to have thin surface projections. The particles described were not detected in uninfected cultured cells, and their appearance could be prevented by adding EIA immune serum to the inoculum. The implications of these findi...
Thomson GR, Mumford JA, Campbell J, Griffiths L, Clapham P.An investigation was made of 3 serological tests (virus neutralization, complement fixation and indirect immunofluorescence), which are applicable to epidemiological studies of infections by Equid herpesvirus 1 (EHV-1). Sera from gnotobiotic foals inoculated intranasally with various strains of EHV-1 were unable in some cases to neutralize heterologous strains and these results were not consistent with the existence of clearly-defined subtypes of EHV-1, as previously proposed. The cross-reactions in complement-fixation tests paralleled those with neutralization but immunofluorescence tests wer...
Dennis SJ, Meyers AE, Guthrie AJ, Hitzeroth II, Rybicki EP.African horse sickness (AHS) is a debilitating and often fatal viral disease affecting horses in much of Africa, caused by the dsRNA orbivirus African horse sickness virus (AHSV). Vaccination remains the single most effective weapon in combatting AHS, as there is no treatment for the disease apart from good animal husbandry. However, the only commercially available vaccine is a live-attenuated version of the virus (LAV). The threat of outbreaks of the disease outside its endemic region and the fact that the LAV is not licensed for use elsewhere in the world, have spurred attempts to develop an...
Daly JM, Yates PJ, Newton JR, Park A, Henley W, Wood JL, Davis-Poynter N, Mumford JA.Two lineages of antigenically distinct equine influenza A H3N8 subtype viruses, American and European, co-circulate. Experiments were conducted in ponies to investigate the protection induced by vaccines containing virus from one lineage against challenge infection with homologous or heterologous virus. Regression analysis showed that vaccinated ponies with average pre-challenge single radial haemolysis (SRH) antibody levels (i.e. 45-190mm2) had a higher probability of becoming infected if they were vaccinated with virus heterologous to the challenge strain than if they were vaccinated with ho...
Chirnside ED, de Vries AA, Mumford JA, Rottier PJ.Complementary DNAs encoding ORFs 2 to 7 equine arteritis virus (EAV) have been cloned into the expression vector pGEX to produce glutathione-S-transferase fusion proteins. Recombinant proteins were affinity purified and screened in ELISA with equine sera to identify immunoreactive polypeptides. The large envelope glycoprotein (GL) was identified as the most reactive to EAV-positive equine sera and an immuno-dominant epitope was mapped between amino acids 55 and 98 by subcloning and expression. A fusion protein covering this region and a GL-specific synthetic peptide (residues 75 through 97) in...
Cheadle MA, Tanhauser SM, Dame JB, Sellon DC, Hines M, Ginn PE, MacKay RJ, Greiner EC.The nine-banded armadillo (Dasypus novemcinctus) is an intermediate host of at least three species of Sarcocystis, Sarcocystis dasypi, Sarcocystis diminuta, and an unidentified species; however, life cycles of these species have not been determined. Following feeding of armadillo muscles containing sarcocysts to the Virginia opossum (Didelphis virginiana), the opossums shed sporulated Sarcocystis sporocysts in their faeces. Mean dimensions for sporocysts were 11.0x7.5 microm and each contained four sporozoites and a residual body. Sporocysts were identified as Sarcocystis neurona using PCR and...
Beisel CE, Edwards JF, Dunn LL, Rice NR.Transcription of pathogenic equine infectious anemia virus (EIAV) in an acutely infected horse was examined by using the polymerase chain reaction and nucleotide sequencing. Four spliced transcripts were identified in liver tissue, in contrast to the multiplicity of alternatively spliced messages reported for in vitro-propagated human immunodeficiency virus, simian immunodeficiency virus, and, to a lesser extent, EIAV. Nucleotide sequence analysis demonstrated that three of these mRNAs encode known viral proteins: the envelope precursor, the product of the S2 open reading frame, and the regula...
Irvine KL, Hopkins LJ, Gangloff M, Bryant CE.TLR2 recognises bacterial lipopeptides and lipoteichoic acid, and forms heterodimers with TLR1 or TLR6. TLR2 is relatively well characterised in mice and humans, with published crystal structures of human TLR2/1/Pam3CSK4 and murine TLR2/6/Pam2CSK4. Equine TLR4 is activated by a different panel of ligands to human and murine TLR4, but less is known about species differences at TLR2. We therefore cloned equine TLR2, TLR1 and TLR6, which showed over 80% sequence identity with these receptors from other mammals, and performed a structure-function analysis. TLR2/1 and TLR2/6 from both horses and hu...
Abdelgawad A, Hermes R, Damiani A, Lamglait B, Czirják GÁ, East M, Aschenborn O, Wenker C, Kasem S, Osterrieder N, Greenwood AD.Equine herpesvirus type 1 (EHV-1) causes respiratory disorders and abortion in equids while EHV-1 regularly causes equine herpesvirus myeloencephalopathy (EHM), a stroke-like syndrome following endothelial cell infection in horses. Both EHV-1 and EHV-9 infections of non-definitive hosts often result in neuronal infection and high case fatality rates. Hence, EHV-1 and EHV-9 are somewhat unusual herpesviruses and lack strict host specificity, and the true extent of their host ranges have remained unclear. In order to determine the seroprevalence of EHV-1 and EHV-9, a sensitive and specific pepti...
Jarvis GE, Atkinson BT, Snell DC, Watson SP.1. Various platelet membrane glycoproteins have been proposed as receptors for collagen, in some cases as receptors for specific collagen types. In this study we have compared the ability of a range of collagen types to activate platelets. 2. Bovine collagen types I-V, native equine tendon collagen fibrils and collagen-related peptide (CRP) all induced platelet aggregation and shape change. 3. Responses were abolished in FcRgamma chain-deficient platelets, which also lack GPVI, indicating a critical dependence on the GPVI/FcRgamma chain complex. 4. Responses to all collagens were unaffected in...
Blanchard-Channell M, Moore PF, Stott JL.Two monoclonal antibodies (mAb), UC F6G-3 and UC F13C-5, were characterized as being specific for the apparent equine homologues of CD3 and CD5, respectively. Both antibodies exhibited characteristics of pan-T-lymphocyte markers based upon immunohistology and two-colour flow cytometry. UC F6G-3 precipitated a complex of proteins (up to seven) with molecular weights ranging from 18,000 to 42,000, similar to the human and murine CD3 complex. Upon further dissociation of the precipitated complex, two proteins were identified with molecular weights of 22,000 and 27,000. Immobilized UC F6G-3 was ef...
Bantle CM, Rocha SM, French CT, Phillips AT, Tran K, Olson KE, Bass TA, Aboellail T, Smeyne RJ, Tjalkens RB.Viral infection of the central nervous system (CNS) can cause lasting neurological decline in surviving patients and can present with symptoms resembling Parkinson's disease (PD). The mechanisms underlying postencephalitic parkinsonism remain unclear but are thought to involve increased innate inflammatory signaling in glial cells, resulting in persistent neuroinflammation. We therefore studied the role of glial cells in regulating neuropathology in postencephalitic parkinsonism by studying the involvement of astrocytes in loss of dopaminergic neurons and aggregation of α-synuclein protein fo...
Blumer R, Maurer-Gesek B, Gesslbauer B, Blumer M, Pechriggl E, Davis-López de Carrizosa MA, Horn AK, May PJ, Streicher J, de la Cruz RR, Pastor ÁM.To test whether palisade endings are a general feature of mammalian extraocular muscles (EOMs). Methods: Thirteen species, some frontal-eyed (human, monkey, cat, and ferret), and others lateral-eyed (pig, sheep, calf, horse, rabbit, rat, mouse, gerbil, and guinea pig) were analyzed. Palisade endings were labeled by using different combinations of immunofluorescence techniques. Three-dimensional reconstructions of immunolabeled palisade endings were done. Results: In all frontal-eyed species, palisade endings were a consistent feature in the rectus EOMs. Their total number was high and they exh...
Martin F, Höglund J, Bergström TF, Karlsson Lindsjö O, Tydén E.The aims of this study were to determine the species of Parascaris present in foals in Sweden and to establish whether anthelmintic resistance to pyrantel and fenbendazole is present on Swedish stud farms. Ascarid eggs collected from different regions in Sweden were karyotyped and were all identified as Parascaris univalens, characterized by one chromosomal pair. Faecal egg count reduction tests were performed on a total of 142 foals on 9 farms between September 2016 and May 2017. Healthy foals with at least 150 eggs per gram faeces (EPG) were included in the study and treated with oral pastes...
Brazil TJ, Dagleish MP, McGorum BC, Dixon PM, Haslett C, Chilvers ER.Neutrophil apoptosis and phagocytic clearance have been proposed as key determinants affecting the resolution of airway inflammation. Objective To determine the kinetics of neutrophil priming, recruitment, activation and subsequent clearance in a naturally occurring equine disease model of neutrophilic pulmonary inflammation. Results: A 5 h mouldy hay/straw challenge in hypersensitive horses induced transient pulmonary dysfunction lasting 4 days. At 24 h circulating neutrophils were primed and displayed delayed rates of spontaneous apoptosis in vitro. Neutrophil numbers in the airspaces peaked...
Kanai Y, van Rijn PA, Maris-Veldhuis M, Kaname Y, Athmaram TN, Roy P.African horse sickness (AHS) is an equine disease with a mortality of up to 90% for susceptible horses. The causative agent AHS virus (AHSV) is transmitted by species of Culicoides. AHSV serogroup within the genus Orbivirus of the Reoviridae family consists of nine serotypes that show no or very limited cross-neutralization. Of the seven structural proteins (VP1-VP7) of AHSV, VP2 is the serotype specific protein, and the major target for neutralizing antibodies. In this report, recombinant VP2 proteins of all nine serotypes were expressed individually by the baculovirus expression system and t...
Garton NJ, Gilleron M, Brando T, Dan HH, Giguère S, Puzo G, Prescott JF, Sutcliffe IC.Rhodococcus equi is a major cause of foal morbidity and mortality. We have investigated the presence of lipoglycan in this organism as closely related bacteria, notably Mycobacterium tuberculosis, produce lipoarabinomannans (LAM) that may play multiple roles as virulence determinants. The lipoglycan was structurally characterized by gas chromatography-mass spectrometry following permethylation, capillary electrophoresis after chemical degradation, and (1)H and (31)P and two-dimensional heteronuclear nuclear magnetic resonance studies. Key structural features of the lipoglycan are a linear alph...
van Maanen C, Bruin G, de Boer-Luijtze E, Smolders G, de Boer GF.The purpose of the study was twofold. First, using two groups of 22 foals each, we investigated the extent to which maternal antibodies interfere with the humoral response against equine influenza. The foals were born to mares that had been vaccinated twice yearly against influenza since 1982. Foals of group I were vaccinated three times at early ages (12, 16, and 32 weeks of age), and foals of group II were likewise vaccinated but a later ages (24, 28, and 44 weeks of age). After the first and second vaccinations, neither group showed an increase in antibodies that inhibit haemagglutination. ...
Jörg A, Pasquier JM, Klebanoff SJ.Eosinophil peroxidase (donor: hydrogen-peroxidase oxidoreductase, EC 1.11.1.7) was isolated in a highly purified form (415/280 nm ratio, 1.05) from horse peripheral blood eosinophil. Eosinophil peroxidase was extracted from intact eosinophils (98-100% purity) or isolated eosinophil granules with 0.05 M acetate buffer (pH 4.7)/0.18 M NaCl and purified by chromatography on Sephadex G-200 and carboxymethylcellulose. Final elution was with 0.05 M acetate buffer (pH 4.7)/ 1 M NaCl. Horse eosinophil peroxidase is a strongly basic protein with bacterial properties when combined with H2O2 and iodide, ...
Olomski F, Fettelschoss V, Jonsdottir S, Birkmann K, Thoms F, Marti E, Bachmann MF, Kündig TM, Fettelschoss-Gabriel A.Insect bite hypersensitivity (IBH) is the most common seasonal pruritic allergic dermatitis of horses occurring upon insect bites. In recent years, a major role for IL-31 in allergic pruritus of humans, monkeys, dogs, and mice was acknowledged. Here, we investigate the role of IL-31 in IBH of horses and developed a therapeutic vaccine against equine IL-31 (eIL-31). IL-31 levels were quantified in allergen-stimulated peripheral blood mononuclear cells (PBMCs) and skin punch biopsies of IBH lesions and healthy skin from IBH-affected and healthy horses. The vaccine consisted of eIL-31 covalently ...
Renshaw RW, Glaser AL, Van Campen H, Weiland F, Dubovi EJ.A virus that could not be identified as a previously known equine virus was isolated from the mononuclear cells of a horse. Electron microscopy revealed enveloped virions with nucleocapsid structures characteristic of viruses in the Paramyxoviridae family. The virus failed to hemabsorb chicken or guinea pig red blood cells and lacked neuraminidase activity. Two viral genes were isolated from a cDNA expression library. Multiple sequence alignments of one gene indicated an average identity of 45% as compared to Morbillivirus N protein sequences. A weaker relationship was found with Tupaia paramy...
