The immune response in horses involves a complex network of cells, tissues, and molecules that work together to protect the animal from pathogens and other harmful agents. This process includes both innate and adaptive immune mechanisms. Innate immunity provides the first line of defense and involves components such as physical barriers, phagocytic cells, and the complement system. Adaptive immunity, on the other hand, is characterized by the activation of lymphocytes and the production of antibodies, which provide a targeted response to specific antigens. Key components of the equine immune system include T cells, B cells, and various cytokines that facilitate communication between immune cells. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and implications of immune responses in equine health.
Michelotto PV, Muehlmann LA, Zanatta AL, Bieberbach EWR, Kryczyk M, Fernandes LC, Nishiyama A.This study investigated the putative roles of inflammation and platelet-activating factor (PAF) in exercise-induced pulmonary haemorrhage (EIPH). Two-year-old Thoroughbred colts (n=37) were exercised on a racetrack for 5months before commencement of the study. Each colt was then exercised at 15-16m/s over 800-1000m and broncho-alveolar lavage fluid (BALF) was collected 24h later. The colts were subsequently divided into two groups on the basis of BALF analysis; an EIPH-positive group (presence of haemosiderophages, n=23) and an EIPH-negative group (absence of haemosiderophages, n=14). BALF fro...
Brooks AC, Rickards KJ, Cunningham FM.Neutrophil activation, whilst a key component of host defence, must be tightly regulated in order to avoid an inappropriate cellular response. Annexin-1, which is present in large amounts in neutrophils, and its N-terminal peptides, reduce neutrophil accumulation but annexin peptides have also been shown to exhibit neutrophil activating properties. We have recently shown annexin-1 to be present in equine neutrophils and demonstrated that the annexin-1-derived peptide, Ac2-26, can both reduce superoxide production by these cells in response to other stimuli and directly induce free radical prod...
Pearson W, Fletcher RS, Kott LS.A biological extract of high-rosmarinic acid mint (HRAM) has previously demonstrated inhibitory effects on lipopolysaccharide (LPS)-induced prostaglandin E(2) (PGE(2)), nitric oxide (NO) and glycosaminoglycan (GAG) release in vitro. This study was undertaken to determine whether HRAM added to feed produces similar effects in horses challenged with intra-articular LPS. Eight horses received HRAM (0 or 28.1 ± 1.3 g/day; n = 4 per group) in their feed for 24 days in a blinded manner. On day 21, all horses received an intra-articular injection of LPS (0.3 ng) into their left or right intercarpal ...
Sun L, Adams AA, Betancourt A, Stewart JC, Liu C, Horohov DW.Interferon-gamma (IFNγ) plays an important role against viral and intracellular bacterial infections and its production is deficient in foals. Cellular proliferation provides an opportunity for de novo gene expression, though little is known about its role in regulating IFNγ expression in foals. While stimulation of foal peripheral blood mononuclear cells (PBMCs) with concanavalin A (ConA) increased the frequency of IFNγ(+) cells, the overall percentage of IFNγ(+) cells remained below that of adults. By contrast, the proliferative response of foal PBMC was significantly greater than that o...
Mealey RH, Kappmeyer LS, Ueti MW, Wagner B, Knowles DP.Theileria equi immune plasma was infused into young horses (foals) with severe combined immunodeficiency. Although all foals became infected following intravenous challenge with homologous T. equi merozoite stabilate, delayed time to peak parasitemia occurred. Protective effects were associated with a predominance of passively transferred merozoite-specific IgG3.
Secor EJ, Matychak MB, Felippe MJ.This study aimed to determine whether TNF-α is transferred to equine neonates via colostrum and the relationship between TNF-α and IgG concentrations in the equine neonate. Colostrum, presuckle and postsuckle foal serum samples were collected from healthy mares and their foals. Equine TNF-α ELISA and IgG SRID kits were used to determine the concentrations of TNF-α and IgG, respectively. Statistical analysis was performed using the Spearman rank correlation. TNF-α concentrations in all presuckle foal serum were below the limit of detection in 15/16 foals and increased in postsuckle foal se...
Goodyear A, Troyer R, Bielefeldt-Ohmann H, Dow S.The Gram-negative bacterium Burkholderia mallei causes rapidly fatal illness in equines and humans when contracted by inhalation and also has the potential to be used as a bioweapon. However, little is known regarding the early innate immune responses and signaling mechanisms required to generate protection from pneumonic B. mallei infection. We showed previously that monocyte chemoattractant protein 1 (MCP-1) was a critical chemokine required for protection from pneumonic B. mallei infection. We have now extended those studies to identify key Toll-like receptor (TLR) signaling pathways, effec...
Cauchard S, Bermúdez-Humarán LG, Blugeon S, Laugier C, Langella P, Cauchard J.Rhodococcus equi causes severe pneumonia in foals and has recently gained attention as a significant opportunistic pathogen in immunocompromised humans. However, no effective vaccine to prevent rhodococcosis is currently available. In this study, we have engineered the food-grade bacterium Lactococcus lactis to secrete the virulence-associated protein A from R. equi (LL-VapA). The immunogenic potential of LL-VapA strain was then evaluated after either intragastric or intranasal immunization in mice either alone or in combination with LL-Lep, a recombinant strain of L. lactis secreting biologic...
Go YY, Bailey E, Cook DG, Coleman SJ, Macleod JN, Chen KC, Timoney PJ, Balasuriya UB.Previously, we have shown that horses could be divided into susceptible and resistant groups based on an in vitro assay using dual-color flow cytometric analysis of CD3+ T cells infected with equine arteritis virus (EAV). Here, we demonstrate that the differences in in vitro susceptibility of equine CD3+ T lymphocytes to EAV infection have a genetic basis. To investigate the possible hereditary basis for this trait, we conducted a genome-wide association study (GWAS) to compare susceptible and resistant phenotypes. Testing of 267 DNA samples from four horse breeds that had a susceptible or a r...
Regan DP, Aarnio MC, Davis WS, Carmichael KP, Vandenplas ML, Lauderdale JD, Moore PA.Equine recurrent uveitis (ERU) is a spontaneous disease that is the most common cause of blindness in horses, affecting up to 15% of the horse population. Th17 cells are a major cell population driving the pathogenesis in several mouse models of autoimmune inflammation, including experimental autoimmune uveitis. The purpose of this study is to investigate the role a Th17 cell-mediated response plays in the pathogenesis of ERU. Methods: Banked, Davidson's-fixed equine globes histopathologically diagnosed with ERU (n = 7) were compared immunohistochemically with healthy control globes (n = 7). I...
Gildea S, Arkins S, Walsh C, Cullinane A.Many racing authorities, sales companies and equestrian bodies have mandatory vaccination policies for equine influenza (EI). The consequences of lack of vaccine efficacy include clinical disease, disruption to training programmes, the cancellation of equestrian events and the introduction of virus to susceptible populations. The correlation between antibody against the virus haemagglutinin and protection against influenza has been well established. The objective of this study was to compare the antibody responses of 66 unvaccinated Thoroughbred weanlings on four different stud farms, followin...
Declue AE, Johnson PJ, Day JL, Amorim JR, Honaker AR.Although the incidence of Gram-positive infection in horses is increasing, little is known about differences in inflammatory response between Gram-positive and Gram-negative organisms in this species. Equine blood was stimulated with components of both Gram-negative and Gram-positive organisms: lipopolysaccharide (LPS); lipoteichoic acid (LTA); peptidoglycan (PG); with combinations of LPS, LTA and PG; and with phosphate buffered saline (control). LPS, LTA and PG stimulated tumor necrosis factor (TNF) and interleukin (IL)-6 production but only LTA and PG stimulated IL-1β production from whole ...
Bourgeois MA, Denslow ND, Seino KS, Barber DS, Long MT.Gene expression associated with West Nile virus (WNV) infection was profiled in the central nervous system of horses. Pyrosequencing and library annotation was performed on pooled RNA from the CNS and lymphoid tissues on horses experimentally infected with WNV (vaccinated and naïve) and non-exposed controls. These sequences were used to create a custom microarray enriched for neurological and immunological sequences to quantitate gene expression in the thalamus and cerebrum of three experimentally infected groups of horses (naïve/WNV exposed, vaccinated/WNV exposed, and normal).From the sequ...
Bolfă PF, Leroux C, Pintea A, Andrei S, Cătoi C, Taulescu M, Tăbăran F, Spînu M.This study assesses the impact of equine infectious anaemia virus (EIAV) infection on the oxidant/antioxidant equilibrium of horses. Blood samples from 96 Romanian horses aged 1-25 years, were divided into different groups according to their EIAV-infection status, age, and time post-seroconversion. The effect of infection on oxidative stress was estimated by measuring enzymatic antioxidants (superoxide dismutase [SOD], glutathione peroxidase [GPx] and catalase), non-enzymatic antioxidants (uric acid and carotenoids), and lipid peroxidation (malondialdehyde [MDA]). Infection modified the oxidan...
Pietra M, Cinotti S, Ducci A, Giunti M, Peli A.During an 18 day test, we measured the cytokine mRNA expression (Interleukin-1beta [IL-1beta], Interleukin-8 [IL-8], Interferon-gamma [IFN-gamma], Tumor Necrosis Factor-alpha [TNF-alpha]) of cells from bronchoalveolar lavage fluid [BALF] in five horses previously diagnosed with RAO, before and during challenge exposure, and after the desensitization phase which involved dexamethasone treatment and environmental modification. Simultaneously, the same cytokine mRNA expression of cells from BALF in four asymptomatic RAO-affected horses maintained outdoors was analyzed. An evident respiratory dist...
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...
Oliveira-Filho JP, Badial PR, Cunha PH, Peiró JR, Araújo JP, Divers TJ, Winand NJ, Borges AS.Hepcidin has been found to be the key regulator of iron metabolism that leads to hypoferremia during inflammation. Recent work has shown that equine hepcidin is predominantly expressed in the liver of horses. In this study, hepcidin gene expression was determined in the liver and bone marrow of six healthy horses after iv infusion of Escherichia coli O55:B5 LPS. The IL-6 gene expression was also determined in liver and bone marrow samples. Clinical and laboratory evaluations were measured at multiple time points between 0 and 240 h post-LPS infusion (PI). Liver and bone marrow biopsies were ...
Dunkel B, Bolt DM, Smith RK, Cunningham FM.Platelet-rich plasma (PRP) is increasingly used for treatment of orthopaedic injuries. However, the effects of different stimuli on the release pattern of regenerative and proinflammatory factors from equine platelets are largely unknown and an optimal treatment protocol remains to be established. Objective: The aim of this study was to identify a stimulus that enhanced release of histopromotive factors (platelet-derived growth factor BB [PDGF] and transforming growth factor 1β[TGF]) without causing concurrent release of a proinflammatory mediator (CCL5). Methods: Washed platelets were prepar...
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...
Hainisch EK, Brandt S, Shafti-Keramat S, Van den Hoven R, Kirnbauer R.Infection with bovine papillomaviruses types 1 and 2 (BPV-1, BPV-2) can lead to the development of therapy-resistant skin tumours termed sarcoids and possibly other skin diseases in equids. Although sarcoids seriously compromise the welfare of affected animals and cause considerable economic losses, no prophylactic vaccine is available to prevent this common disease. In several animal species and man, immunisation with papillomavirus-like particles (VLP) has been shown to protect efficiently from papillomaviral infection. Objective: BPV-1 L1 VLPs may constitute a safe and highly immunogenic va...
Davies RS, Madigan JE, Hodzic E, Borjesson DL, Dumler JS.Anaplasma phagocytophilum is the zoonotic cause of granulocytic anaplasmosis. We hypothesized that immune response, specifically gamma interferon (IFN-γ), plays a role in disease severity. To test this, horses were infected and IFNG expression was pharmacologically downregulated using corticosteroids. Eight horses were infected with A. phagocytophilum; 4 received dexamethasone on days 4 to 8 of infection. Clinical signs, hematologic parameters, and transcription of cytokine/chemokine genes were compared among treated and untreated horses. Infection was quantitated by msp2 real-time PCR and mi...
Peroni JF, Borjesson DL.The recent interest in equine stem cell biology and the rapid increase in experimental data highlight the growing attention that this topic has been receiving over the past few years. Within the field of stem cell biology, the relevance of immunobiology is of particular intrigue. It appears that optimal and effective stem cell therapy for equine patients will require a thorough analysis of the immune properties of stem cells as well as their response to immune mediators. The main goal of this review is to discuss the biology of adult mesenchymal stem cells in the context of immunology.
Lin YZ, Shen RX, Zhu ZY, Deng XL, Cao XZ, Wang XF, Ma J, Jiang CG, Zhao LP, Lv XL, Shao YM, Zhou JH.The EIAV (equine infectious anemia virus) multi-species attenuated vaccine EIAV(DLV121) successfully prevented the spread of equine infectious anemia (EIA) in China in the 1970s and provided an excellent model for the study of protective immunity to lentiviruses. In this study, we compared immune responses induced by EIAV(DLV121) to immunity elicited by the virulent EIAV(LN40) strain and correlated immune responses to protection from infection. Horses were randomly grouped and inoculated with either EIAV(DLV121) (Vaccinees, Vac) or a sublethal dose of EIAV(LN40) (asymptomatic carriers, Car). C...
Racine J, Gerber V, Feutz MM, Riley CP, Adamec J, Swinburne JE, Couetil LL.Recurrent airway obstruction (RAO) is a severe chronic respiratory disease affecting horses worldwide, though mostly in the Northern hemisphere. Environmental as well as genetic factors strongly influence the course and prognosis of the disease. Research has been focused on characterization of immunologic factors contributing to inflammatory responses, on genetic linkage analysis, and, more recently, on proteomic analysis of airway secretions from affected horses. The goal of this study was to investigate the interactions between eight candidate genes previously identified in a genetic linkage...
Liu M, Bordin A, Liu T, Russell K, Cohen N.Focusing on the first 3 weeks of life, this study examined the mRNA transcript development of different Th-type cytokines in foals in response to Rhodococcus equi infection in vitro. Results demonstrated the significant up-regulation in expression of Th1-, Th2-, and Th17-type cytokines (IFN-γ, IL-4, IL-6, IL-8, IL-12p35, IL-12p40, IL-17, IL-23p19, and TNF-α) in R. equi infection of bronchial alveolar lavage (BAL) cells of 10-day-old foals. Consequently, signature cytokines of 3 Th cell types, IFN-γ (Th1), IL-4 (Th2), and IL-17 (Th17), were used to compare temporal response patterns of circu...
Leclere M, Lavoie-Lamoureux A, Lavoie JP.Animal models have been developed to investigate specific components of asthmatic airway inflammation, hyper-responsiveness or remodelling. However, all of these aspects are rarely observed in the same animal. Heaves is a naturally occurring disease of horses that combines these features. It is characterized by stable dust-induced inflammation, bronchospasm and remodelling. The evaluation of horses during well-controlled natural antigen exposure and avoidance in experimental settings allows the study of disease mechanisms in the asymptomatic and symptomatic stages, an approach rarely feasible ...
Daly K, Proudman CJ, Duncan SH, Flint HJ, Dyer J, Shirazi-Beechey SP.We aimed to determine the effects of variations in dietary composition on equine gut microbiota and their fermentation products, and proposed that dietary modifications profoundly affect microbial ecosystems and their metabolites. Bacterial communities within the large intestine of three groups of horses were compared using oligonucleotide-RNA hybridisation methodology. Each group consisting of six horses was maintained on (1) a grass-only diet, (2) a concentrate diet (i.e. supplemented with hydrolysable carbohydrates) and (3) a concentrate diet but horses were affected by simple colonic obstr...
Muehlmann LA, Michelotto PV, Nunes EA, Grando FC, da Silva FT, Nishiyama A.Phagocytosis exerted by alveolar macrophages and neutrophils is crucial in the clearance of exogenous particles deposited in the airways. Therefore, substances that activate these phagocytes in the airways can exert important effects on the particle clearance rate. PAF, particularly, was proved to be a potent activator of several immune cells and was shown to be present in the equine lower airways in specific conditions, such as after exercise. The present study aimed to investigate if PAF is able to increase the phagocytic capacity and the production of superoxide anion in equine alveolar mac...
Burbelo PD, Bren KE, Ching KH, Coleman A, Yang X, Kariu T, Iadarola MJ, Pal U.Infection with Borrelia burgdorferi is common in horses and ponies from the New England and mid-Atlantic regions of the United States. Here, we evaluated luciferase immunoprecipitation systems (LIPS) for profiling antibody responses against three different antigenic targets for the diagnosis of equine B. burgdorferi infection. LIPS testing of horse serum samples suspected of Lyme infection revealed that approximately 75% of the horse samples (114/159) were seropositive against the synthetic VOVO antigen, comprising repeated immunodominant C6 epitopes as well as OspC immunodominant epitopes. A ...
Jasiński T, Zdrojkowski Ł, Kautz E, Juszczuk-Kubiak E, Ferreira-Dias G, Domino M.Endometritis is an important issue decreasing mares' fertility. In the case of endometritis, both inflammatory cells infiltration and proinflammatory molecules production are regulated by various cellular and gene regulatory mechanisms, including the nuclear factor-κB (NF-κB)-dependent pathway. NF-κB-signalling pathway has been recently studied in the equine endometrium in the context of endometrosis. Thus, this study aimed to determine gene transcription of NF-κB subunits (RelA; NF-κB1; NF-κB2), proinflammatory molecules (MCP-1; IL-6) and hyaluronan synthases (HAS 1; HAS 2; HAS 3) in en...
Dennis VA, Klei TR, Miller MA, Chapman MR, McClure JR.Ten helminth-free pony foals divided into three groups were used in this study. Eight foals were each experimentally infected per os with 50 Strongylus vulgaris infective larvae weekly for 4 weeks, at which time one foal died of acute verminous arteritis. The remaining seven foals subsequently received 50 S. vulgaris infective larvae every 2 weeks for an additional 20 weeks. Four of the infected foals remained untreated (Group 1) and three of the infected foals were given ivermectin at 8, 16 and 24 weeks post initial infection (Group 2). Two foals served as controls (Group 3). Foals in Group 1...
Berghaus LJ, Cathcart J, Berghaus RD, Hart KA.The vitamin D receptor (VDR)-vitamin D axis modulates pulmonary immunity in people but its role in equine immunity is unknown. Bacterial pneumonia causes high morbidity/mortality in foals and alveolar macrophages (AMφ) are important for pulmonary defenses. Age-related variations in vitamin D-mediated function of AMφ might contribute to the foal's susceptibility to pneumonia. Our aim was to assess the impact of age on equine vitamin D metabolism and VDR expression in AMφ. AMφ and plasma was collected from healthy foals (2, 4 and 8 weeks old) and adult horses (once). AMφ VDR expression was ...
Brummer M, Hayes S, Adams AA, Horohov DW, Dawson KA, Lawrence LM.Selenium status has been reported to affect immune function across many different species. Yet few studies have focused on the effect of Se status on the equine immune system. This study examined the effect of Se supplementation on vaccination response and immune function in mature horses. Twenty-eight horses were blocked by age and sex and were randomly allocated to 1 of 4 dietary treatment groups: low Se (LS), adequate Se (AS), Se-yeast (SP), and sodium selenite (SS). For 35 wk, horses allocated to LS, SP, and SS received a low-Se diet (0.06 mg/kg DM) with the intention to lower Se stores, w...
Marr KA, Lees P, Cunningham FM.Activation of circulating neutrophils has been observed following challenge of horses with chronic obstructive pulmonary disease (COPD) and may facilitate the accumulation of these cells in the airways. In this study, no significant difference was observed between adherence to protein coated plastic of blood neutrophils from asymptomatic COPD-susceptible and normal horses stimulated by the mediators PAF, human recombinant (hr)IL-8 and hrC5a. Twenty-four hours after the start of a 7 h antigen challenge, adherence of unstimulated neutrophils from COPD-susceptible horses increased from 2.5 (0.5-4...
Klei TR, Torbert BJ, Chapman MR, Ochoa R.Nonimmune pony foals 9 to 12 mo of age were vaccinated with third-stage Strongylus vulgaris larvae (L3) irradiated with 70, 100, or 130 Kr of gamma radiation. Ponies receiving per os inoculations of L3 irradiated with 70 or 100 Kr were protected from the clinical disease and lesions associated with challenge infections of 4,300 L3, when compared to nonvaccinated controls. Similarly, the numbers of worms from the challenging population recovered from successfully vaccinated animals were significantly lower than from nonvaccinated controls. The degree of resistance that develops in individuals c...
Lomas HR, Robinson PA.Equine insect bite hypersensitivity (IBH), commonly known as sweet itch or summer eczema, is a frustrating recurrent skin disease in the equine industry involving an immune reaction to the bites of spp. midges. To investigate the impact of IBH in the field, an exploratory pilot study was conducted with equine stakeholders in one region of central England. Nine semi-structured, face-to-face interviews were conducted with horse owners and an equine veterinarian. The aim was to gain an understanding of experiences with IBH, and to gauge opinions on the value of the various management strategies ...
Troedsson MH, deMoraes MJ, Liu IK.The relationship between histologic lesions in endometrial biopsy specimens and susceptibility to chronic uterine infection (CUI) in mares was investigated. Mares were allotted to 4 groups on the basis of degree of endometrial lesions. Mares in group 1 (n = 6) had no pathologic changes, mares in group 2 (n = 5) had only mild pathologic changes, group-3 mares (n = 7) had moderate changes, and group-4 mares (n = 7) had severe inflammatory and fibrotic endometrial changes. Susceptibility to CUI was determined by the inflammatory response to intrauterine inoculation of 5 x 10(6) Streptococcus zooe...
Thorsteinsdóttir L, Jónsdóttir S, Stefánsdóttir SB, Andrésdóttir V, Wagner B, Marti E, Torsteinsdóttir S, Svansson V.Two types of gammaherpesviruses (γEHV) are known to infect horses, EHV-2 and EHV-5. Foals become infected early in life, probably via the upper respiratory tract, despite maternal antibodies. In this study, we analyzed samples from a herd of mares and their foals. The foals were followed from birth to 22 months of age and the dams during the first 6 months postpartum. Blood and nasal swab samples were taken regularly for evaluation of antibody responses, virus isolation and viral load by qPCR. EHV-2 was isolated on day 5, and EHV-5 on day 12, earlier than previously reported. γEHV specific a...
Foote CE, Love DN, Gilkerson JR, Rota J, Trevor-Jones P, Ruitenberg KM, Wellington JE, Whalley JM.The envelope glycoprotein D of equine herpesvirus 1 (EHV-1 gD) has been shown in laboratory animal models to elicit protective immune responses against EHV-1 challenge, and hence is a potential vaccine antigen. Here we report that intramuscular inoculation of EHV-1 gD produced by a recombinant baculovirus and formulated with the adjuvant Iscomatrix elicited virus-neutralizing antibody and gD-specific ELISA antibody in the serum of over 90% of adult mixed breed horses. The virus-neutralizing antibody responses to EHV-1 gD were similar to those observed after inoculation with a commercially avai...
Lemos KR, Marques LC, Aquino LP, Alessi AC, Zacarias RZ.This study aimed to characterize astrocytic and microglial response in the central nervous system (CNS) of equines experimentally infected with T. evansi. The experimental group comprised males and females with various degrees of crossbreeding, ages between four and seven years. The animals were inoculated intravenously with 10(6) trypomastigotes of T. evansi originally isolated from a naturally infected dog. All equines inoculated with T. evansi were observed until they presented symptoms of CNS disturbance, characterized by motor incoordination of the pelvic limbs, which occurred 67 days aft...
Kydd JH, Davis-Poynter NJ, Birch J, Hannant D, Minke J, Audonnet JC, Antczak DF, Ellis SA.Equine herpesvirus 1 (EHV-1) causes respiratory and neurological disease and abortion in horses. Animals with high frequencies of cytotoxic T lymphocytes (CTL) show reduced severity of respiratory disease and frequency of abortion, probably by CTL-mediated control of cell-associated viraemia. This study aimed to identify CTL epitopes restricted by selected major histocompatibility complex (MHC) class I alleles expressed in the equine leukocyte antigen (ELA) A3 haplotype. Effector CTL were induced from EHV-1-primed ponies and thoroughbreds with characterized MHC class I haplotypes and screened ...
Matthews AG, Imlah P, McPherson EA.The demonstration of a reagin-like antibody against Culicoides pulicaris extract in the serum of horses and ponies affected with recurrent seasonal dermatitis (sweet itch) is reported. This antibody can confer Prauznitz-Küstner (P-K) sensitivity on homologous skin for up to 5 days and, like human IgE, is thermolabile and susceptible to 2-mercaptoethanol reduction. It is eluted on diethylaminoethyl dextran-52 anion exchange chromatography independently of IgG, IgG(T) and IgM, and its elution characteristics indicate similarity in net molecular charge to human IgE. The P-K response observed in ...
Cook RF, Cook SJ, Bolin PS, Howe LJ, Zhou W, Montelaro RC, Issel CJ.In the context of DNA vaccines the native equine infectious anemia virus (EIAV)-envelope gene has proven to be an extremely weak immunogen in horses probably because the RNA transcripts are poorly expressed owing to an unusual codon-usage bias, the possession of multiple RNA splice sites and potential adenosine-rich RNA instability elements. To overcome these problems a synthetic version of sequences encoding the EIAV surface unit (SU) envelope glycoprotein was produced (SYNSU) in which the codon-usage bias was modified to conform to that of highly expressed horse and human genes. In transfect...
Brosnahan MM, Erb HN, Perkins GA, Divers TJ, Borges AS, Osterrieder N.Research in humans has demonstrated that high serum iron (sFe) concentration can predispose to infection, and many infections subsequently result in alterations of host sFe. A decrease in sFe concentration is an early and sensitive indicator of systemic inflammation caused by tissue necrosis, bacterial infections, or endotoxemia in horses. Serum iron parameters in acute equine herpesvirus type 1 (EHV-1) infection have not been evaluated previously. Objective: To document the sFe response to EHV-1 infection and to determine whether or not significant differences in sFe concentration exist betwe...
Abraham G, Brodde OE, Ungemach FR.In 12 healthy horses, the effects of the beta2-agonist clenbuterol and the glucocorticoid dexamethasone on the lymphocyte beta2-adrenoceptor density and affinity (determined by (-)-[125I]-iodocyanopindolol binding) as well as its responsiveness (assessed by lymphocyte cyclic AMP [cAMP] responses to 10 micromol/l (-)-isoprenaline) were studied. Clenbuterol treatment, 2 x 0.8 microg/kg/day i.v. for 12 days, decreased significantly ICYP binding sites by approximately 30-40%; concomitantly, lymphocyte cAMP response to (-)-isoprenaline was reduced. After withdrawal of clenbuterol, beta2-adrenocepto...
Schnabel CL, Babasyan S, Freer H, Wagner B.C-X-C motif ligand 10 (CXCL10) is a pro-inflammatory chemokine and has been extensively evaluated in people and mice. In horses, CXCL10 and its involvement in host immunity has rarely been analyzed due to the lack of specific antibodies. We generated a mAb specific for the equine chemokine CXCL10 using hybridoma technology. Antibody specificity was confirmed by intracellular staining and flow cytometric analysis of Chinese Hamster Ovary (CHO) cells expressing equine rCXCL10, while CHO cells expressing equine rCXCL9 were not detected. Native CXCL10 expression in PBMC from horses of different ag...
Olave CJ, Ivester KM, Couëtil LL, Franco-Marmolejo J, Mukhopadhyay A, Robinson JP, Park JH.To investigate the role of omega-3 polyunsaturated fatty acids (Ω-3)-derived proresolving lipid mediators (PRLM) in the resolution of mild airway inflammation in horses. Methods: 20 horses with mild airway inflammation. Methods: Horses previously eating hay were fed hay pellets (low Ω-3 content; n = 10) or haylage (high Ω-3 content; 9) for 6 weeks. Dust exposure was measured in the breathing zone with a real-time particulate monitor. Bronchoalveolar lavage (BAL) was performed at baseline, week 3, and week 6. The effect of PRLM on neutrophil apoptosis and efferocytosis was examined in vitro....
Dunkel B, Bolt DM, Smith RK, Cunningham FM.Platelet-rich plasma (PRP) is increasingly used for treatment of orthopaedic injuries. However, the effects of different stimuli on the release pattern of regenerative and proinflammatory factors from equine platelets are largely unknown and an optimal treatment protocol remains to be established. Objective: The aim of this study was to identify a stimulus that enhanced release of histopromotive factors (platelet-derived growth factor BB [PDGF] and transforming growth factor 1β[TGF]) without causing concurrent release of a proinflammatory mediator (CCL5). Methods: Washed platelets were prepar...
Baskerville A.Related to its potential vulnerability the respiratory tract has a very complex and effective defence apparatus. The interaction between these defence mechanisms and certain characteristics of aetiological agents results in a pattern in which initial infections by these agents tend to occur at specific sites in the tract. Infections in which the primary portal of entry is in the upper respiratory tract include Bordetella bronchiseptica and Haemophilus spp in pigs; Pasteurella spp in cattle, sheep, pigs; Mycoplasma spp in cattle, sheep, pigs and poultry; equine herpesvirus 1 in horses; infectio...
Nogradi N, Slovis NM, Gebhart CJ, Wolfsdorf KE, McCracken JL, Scoggin CF, Kass PH, Mapes SM, Toth B, Lundquist ML, Pusterla N.Equine proliferative enteropathy caused by Lawsonia intracellularis is an emerging disease with as yet unaddressed preventative measures. The hypothesis of this study was that vaccination will prevent clinical and sub-clinical disease. Weanling Thoroughbreds (n=202) from Central Kentucky were randomly assigned into two groups (vaccinated and non-vaccinated). Vaccinated foals received 30 mL of an avirulent, live L. intracellularis vaccine intra-rectally twice, 30 days apart. Foals were monitored for clinical disease, total solids and average weight gain until yearling age. There was an overall ...
Page AE, Loynachan AT, Bryant U, Stills HF, Adams AA, Gebhart CJ, Pusterla N, Horohov DW.Lawsonia intracellularis is the etiological agent of infectious intestinal hyperplasia for which several clinical diseases have been described including proliferative enteropathy (PE), intestinal adenomatosis, and ileitis. While initially recognized as the causative agent of PE in pigs, L. intracellularis is now viewed as an emerging cause of intestinal hyperplasia in a wide range of mammalian species, including horses. Equine proliferative enteropathy (EPE) has been reported worldwide though definitive diagnosis is difficult and the epidemiology of the disease remains poorly understood. Weanl...
Bertin FR, Ruffin-Taylor D, Stewart AJ.Systemic inflammation is a cause of insulin dysregulation in many species, but the insulin and glucose dynamics in adult horses diagnosed with systemic inflammatory response syndrome (SIRS) are poorly documented. Objective: In SIRS in horses, insulin and glucose dynamics will be altered and associated with survival. Methods: Adult horses diagnosed with SIRS admitted to a referral hospital. Methods: Prospective study enrolling horses diagnosed with SIRS in which serum insulin and glucose concentrations were measured. Horses were grouped by outcome (survival, hyperinsulinemia, and hyperglycemia)...
Marinkovic D, Aleksic-Kovacevic S, Plamenac P.Chronic obstructive pulmonary disease (COPD) is an inflammatory obstructive disease of the airways characterized with hypersensitivity of the airway tissues to various allergens, most commonly the fungi contained in the poor-quality hay and straw bedding-Saccharopolyspora rectivirgula, Aspergillus fumigatus, and Thermoactinomyces vulgaris. It is manifested clinically in middle-aged horses with recurrent episodes of dyspnea, chronic cough, and their reduced athletic and working capacity. Pulmonary emphysema and lack of pulmonary collapse are the most common gross lesion. Pathohistological findi...
Stokes A, Corteyn AH, Murray PK.A group of three horses was experimentally infected with equine herpesvirus type 1 (EHV-1) and showed clinical signs characterised by a biphasic febrile response, leucopenia and cell associated viraemia accompanied by virus shedding from the nasopharynx. A second exposure to the virus 18 days later resulted in the isolation of virus from the nasopharynx of one horse. This and a further group of three EHV-1 seropositive horses were subsequently infected with equine herpesvirus type 4 (EHV-4) 147 days after the initial EHV-1 infection and virus was shed from the nasopharynx in the absence of cli...
Bauquier JR, Tennent-Brown BS, Tudor E, Bailey SR.Polymyxin-B is used to treat equine systemic inflammation. Bacterial toxins other than lipopolysaccharide (LPS) contribute to systemic inflammation but the effects of polymyxin-B on these are poorly defined. Whole blood aliquots from six healthy horses diluted 1:1 with RPMI were incubated for 21 hr with 1 μg/ml of LPS, lipoteichoic acid (LTA) or peptidoglycan (PGN) in the presence of increasing concentrations of polymyxin-B (10-3000 μg/ml). A murine L929 fibroblast bioassay was used to measure TNF-α activity. Polymyxin-B significantly inhibited the effects of all three bacterial toxins. ...
Wilson AD.Horses are affected by a wide variety of arthropod ectoparasites, ranging from lice which spend their entire life on the host, through ticks which feed over a period of days, to numerous biting insects that only transiently visit the host to feed. The presence of ectoparasites elicits a number of host responses including innate inflammatory responses, adaptive immune reactions and altered behaviour; all of which can reduce the severity of the parasite burden. All of these different responses are linked through immune mechanisms mediated by mast cells and IgE antibodies which have an important ...
Hansen S, Baptiste KE, Fjeldborg J, Betancourt A, Horohov DW.An imbalance in various cytokine mRNA expression in bronchoalveolar lavage (BAL) and peripheral blood mononuclear cells (PBMC) in horses suffering from recurrent airway obstruction (RAO) has been demonstrated; however, the natural variation of cytokine expression in healthy horses has yet to be described. The objectives of this study were to: (1) identify age-related differences in the expression of pro-inflammatory cytokines in BAL and PBMC, (2) compare the expression of pro-inflammatory cytokines between BAL and PBMC, and (3) evaluate the relationship between BAL pro-inflammatory cytokine ex...
Shively MA, Banks KL, Greenlee A, Klevjer-Anderson P.Equine infectious anemia is a chronic disease of horses caused by a nononcogenic retrovirus. Studies were undertaken to determine the types of cells involved in the in vitro lymphoproliferative response to viral antigens and the dynamics of this reaction. It was observed that reactive lymphocytes were present at unpredictable times in the peripheral blood of infected horses. This reaction was shown to be specific for the interaction of equine infectious anemia virus and T lymphocytes. Enriched B-lymphocyte populations did not divide when exposed to equine infectious anemia virus. Macrophages w...
Nash DM, Paddison J, Davies Morel MCG, Barnea ER.Persistent mating-induced endometritis (PMIE) is a significant cause of mare infertility hence its treatment would advance the management of susceptible mares. Preimplantation factor (PIF) is secreted by viable embryos, including human, mouse and cattle, and is essential for maternal immune-tolerance without immune-suppression by modulating inflammation. This preliminary study aimed to test whether PIF exerts inflammatory-modulating properties upon equine endometrium challenged with Escherichia coli-derived lipopolysaccharide (LPS) using endometrial explant culture. Follicular (n = 3), lutea...
