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.
Alvarez I, Cipolini F, Wigdorovitz A, Trono K, Barrandeguy ME.The most used and reliable indicator of Equine infectious anemia virus (EIAV) infection is the detection of its specific antibodies in horse serum. In the present study, the performance of two commercial ELISA tests for the detection of EIAV antibodies as well as the potential advantages of their use as an EIAV infection screening tool were evaluated in 302 horse serum samples. Both ELISA assays showed 100% diagnostic sensitivity, and 92.3-94.3% diagnostic specificity. Discordant results were analyzed by immunoblot. The results showed that both ELISA tests are very efficient at detecting EIAV ...
Barton AJ, Prow NA, Hall RA, Kidd L, Bielefeldt-Ohmann H.This report summarises the findings from a case of naturally-occurring Murray Valley encephalitis in a 2-year-old filly presenting with acute onset of depression and weakness. Serum samples tested at the onset of clinical signs were negative for Hendra and Kunjin virus antibodies, but positive for Murray Valley encephalitis virus (MVEV) using IgM-capture ELISA (1 : 300 dilution). A virus neutralisation assay performed 4 weeks later confirmed a titre of 1 : 160. Sera collected in the weeks preceding neurological signs returned a negative titre for MVEV 2 weeks prior followed by a titre ...
Ortved K, Wagner B, Calcedo R, Wilson J, Schaefer D, Nixon A.Intraarticular (IA) administration of viral vectors expressing a therapeutic transgene is an attractive treatment modality for osteoarthritis (OA) as the joint can be treated as a contained unit. Humoral and cell-mediated immune responses in vivo can limit vector effectiveness. Transduction of articular tissues has been investigated; however, the immune response to IA vectors remains largely unknown. We hypothesized that IA rAAV2 and rAAV5 overexpressing insulin-like growth factor-I (IGF-I) would result in long-term IGF-I formation but would also induce neutralizing antibodies (NAb) and anti-c...
Sánchez-Matamoros A, Beck C, Kukielka D, Lecollinet S, Blaise-Boisseau S, Garnier A, Rueda P, Zientara S, Sánchez-Vizcaíno JM.African horse sickness (AHS) is a viral disease that causes high morbidity and mortality rates in susceptible Equidae and therefore significant economic losses. More rapid, sensitive and specific assays are required by diagnostic laboratories to support effective surveillance programmes. A novel microsphere-based immunoassay (Luminex assay) in which beads are coated with recombinant AHS virus (AHSV) structural protein 7 (VP7) has been developed for serological detection of antibodies against VP7 of any AHSV serotype. The performance of this assay was compared with that of a commercial enzyme-l...
Alghamdi AS, Madill S, Foster DN, Troedsson MH.When mares are inseminated repeatedly, protein molecules from the seminal plasma (SP) prevent sperm-neutrophil binding and reduced fertility. The molecule(s) responsible for sperm-neutrophil binding is not known and the identification of beneficial SP proteins is complicated by their large numbers and abundant variation. We examined several important aspects of sperm-neutrophil binding to ultimately facilitate the identification and isolation of the molecule(s) responsible. First, we raised anti-equine P-selectin antibodies to determine the involvement of this adhesion molecule in sperm-neutro...
Baig B, Mehta T, Khalid N, Chhabra L.We present the case of a 40-year-old man with rapidly deteriorating acute meningoencephalitis, finally diagnosed as eastern equine encephalitis (EEE). The course and timing in this patient are quite characteristic. EEE is an arthropod borneviral illness in which the mosquito serves as the vector. It is amongst the most severe of the arbovirus encephalitides and has a high mortality and morbidity. In nonfatal cases, residual neurological deficits are often severe and permanent. North American lineage of EEE is mainly found in the northeast especially along the coastal areas. EEE is primarily fo...
Espino-Solis GP, Quintero-Hernandez V, Olvera-Rodriguez A, Calderon-Amador J, Pedraza-Escalona M, Licea-Navarro A, Flores-Romo L, Possani LD.The αX I-domain of the horse integrin CD11c was successfully expressed in Escherichia coli, purified, biochemically characterized and used as immunogen to generate murine monoclonal antibodies against horse CD11c, which are not yet commercially available. One monoclonal antibody mAb-1C4 against the αX I-domain, is an IgG2a able to interact with the recombinant I-domain, showing an EC50=2.4ng according to ELISA assays. By western blot with horse PBMCs lysates the mAb-1C4 recognized a protein of 150kDa which corresponds well with the CD11c molecule. Using immunohistochemistry in horse lymph no...
Nielsen MK, Rubinson EF, Chambers TM, Horohov DW, Wagner B, Betancourt A, Reedy SE, Jacobsen S.Anthelmintics and vaccines are commonly given concurrently in routine equine management, but it is unknown to what extent an interaction between the two exists. Cyathostomins can modulate the local immune response by stimulating a type 2 helper T cell (Th2) response. In addition, anti-inflammatory effects of ivermectin have been found in rodent models. It is unknown whether these anti-inflammatory effects affect the acute phase response elicited by commonly used vaccines. This study evaluated how the acute phase inflammatory response, leukocyte expression of pro-inflammatory cytokines, and vac...
Niedźwiedź A, Jaworski Z, Kubiak K.The aim of this study was to investigate the levels of circulating immune complexes (CICs) and concentration of haptoglobin, fibrinogen and C-reactive protein in the serum of horses with recurrent airway obstruction and healthy controls. The study was conducted on a group of 14 adult Polish Konik horses, kept in uniform environmental and living conditions. Horses were divided into two groups: 7 horses were not affected by any respiratory problem (control group) and 7 horses had a history of recurrent airway obstruction (RAO) (study group). A clinical and laboratory evaluation, endoscopic exami...
Giannitti F, Diab S, Mete A, Stanton JB, Fielding L, Crossley B, Sverlow K, Fish S, Mapes S, Scott L, Pusterla N.Equine coronavirus (ECoV) is a Betacoronavirus recently associated clinically and epidemiologically with emerging outbreaks of pyrogenic, enteric, and/or neurologic disease in horses in the United States, Japan, and Europe. We describe the pathologic, immunohistochemical, ultrastructural, and molecular findings in 2 horses and 1 donkey that succumbed to natural infection with ECoV. One horse and the donkey (case Nos. 1, 3) had severe diffuse necrotizing enteritis with marked villous attenuation, epithelial cell necrosis at the tips of the villi, neutrophilic and fibrinous extravasation into th...
Mykkänen AK, Niku M, Ilves M, Koho NM.To characterize the expression of monocarboxylate transporters (MCTs) 1 and 4 and the ancillary protein CD147 in the intestinal tract of healthy equids and determine the cellular location of CD147 in the intestinal epithelium. Methods: 12 healthy horses and ponies slaughtered for meat production or euthanized for reasons unrelated to gastrointestinal tract disease. Methods: The entire gastrointestinal tract was removed from each equid within 45 minutes after slaughter or euthanasia. Tissue samples were obtained from the antimesenteric side of the duodenum, jejunum, ileum, middle part of the ce...
Calvo-Pinilla E, de la Poza F, Gubbins S, Mertens PP, Ortego J, Castillo-Olivares J.Previous studies show that a recombinant modified vaccinia Ankara (MVA) virus expressing VP2 of AHSV serotype 4 (MVA-VP2) induced virus neutralising antibodies in horses and protected interferon alpha receptor gene knock-out mice (IFNAR -/-) against challenge. Follow up experiments indicated that passive transfer of antiserum, from MVA-VP2 immune donors to recipient mice 1h before challenge, conferred complete clinical protection and significantly reduced viraemia. These studies have been extended to determine the protective effect of MVA-VP2 vaccine-induced antiserum, when administered 48h be...
Dupont S, De Spiegeleer A, Liu DJ, Lefère L, van Doorn DA, Hesta M.Commercial immunoglobulin E (IgE)-based tests are available for diagnosis of food allergies and are commonly used in equine practice. However, these tests have been proven unreliable as a screening method in man and other species, but not critically evaluated in equids. Therefore, a commercially available IgE-based test for horses was evaluated. Objective: To evaluate the consistency of the results obtained with a commercially available IgE-based test for food allergy diagnosis in ponies (Phase I) and to subject ponies to a provocation trial with the presumed allergens (Phase II). Methods: All...
Aguiar C, Theoret C, Smith O, Segura M, Lemire P, Smith LC.Induced pluripotent stem cells (iPSC) have brought immense hope to cellular therapy and regenerative medicine. However, the antigenicity of iPSC has not been well documented and remains a hurdle for clinical applications. Expression of major histocompatibility complex (MHC) molecules by human and murine iPSC is downregulated, making these cells potentially safe for transplantation. No such data are available for any large animal model. Objective: To measure expression of MHC molecules on equine iPSC (eiPSC) and describe their antigenicity using intradermal testing. The hypothesis was that allo...
Klier J, Lehmann B, Fuchs S, Reese S, Hirschmann A, Coester C, Winter G, Gehlen H.Recurrent airway obstruction (RAO), an asthma-like disease, is 1 of the most common allergic diseases in horses in the northern hemisphere. Hypersensitivity reactions to environmental antigens cause an allergic inflammatory response in the equine airways. Cytosine-phosphate-guanosine-oligodeoxynucleotides (CpG-ODN) are known to direct the immune system toward a Th1-pathway, and away from the pro-allergic Th2-line (Th2/Th1-shift). Gelatin nanoparticles (GNPs) are biocompatible and biodegradable immunological inert drug delivery systems that protect CpG-ODN against nuclease degeneration. Prelimi...
Uhl PB, Amann B, Hauck SM, Deeg CA.Retinal pigment epithelium (RPE) builds the outer blood-retinal barrier of the eye. Since one typical feature of the autoimmune disease, equine recurrent uveitis (ERU), is the breakdown of this barrier, we recently performed comparative analysis of healthy and uveitic RPE. We identified for the first time peripherin 2, which is responsible for visual perception and retina development, to be localized in RPE. The purpose of this study was therefore to validate our findings by characterizing the expression patterns of peripherin 2 in RPE and retina. We also investigated whether peripherin 2 expr...
Sanz MG, Oliveira AF, Loynachan A, Page A, Svansson V, Giguère S, Horohov DW.Rhodococcus equi (Rhodococcus hoagii/Prescottella equi) is a common cause of foal pneumonia, but its diagnosis remains a challenge for equine veterinarians. While the VapA-specific (virulence-associated protein A) immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) has low sensitivity and specificity for detecting pneumonic foals, little is known about VapA-specific IgG subclasses. Objective: To evaluate the performance of VapA-specific ELISA for IgG and its subclasses IgGa, IgGb and IgG(T) in the early diagnosis of pneumonia caused by R. equi. Methods: Assay validation follow...
Dunowska M, Gopakumar G, Perrott MR, Kendall AT, Waropastrakul S, Hartley CA, Carslake HB.Infection with equid herpesvirus 1 (EHV-1) may be asymptomatic, or may result in respiratory disease, abortion, neonatal death, or neurological disease. The aim of this study was to estimate the prevalence of EHV-1 infection, including differentiation between genotypes with aspartic acid (D) and asparagine (N) at position 752 of the DNA polymerase sequence, within a selected population of New Zealand horses. The second aim was to determine the predictive value of serology for detection of latently infected horses. Retropharyngeal lymph nodes (RLN) and trigeminal ganglia (TG) were dissected fro...
Chiocchetti R, Giancola F, Mazzoni M, Sorteni C, Romagnoli N, Pietra M.The lower esophageal sphincter (LES) is a specialized, thickened muscle region with a high resting tone mediated by myogenic and neurogenic mechanisms. During swallowing or belching, the LES undergoes strong inhibitory innervation. In the horse, the LES seems to be organized as a "one-way" structure, enabling only the oral-anal progression of food. We characterized the esophageal and gastric pericardial inhibitory and excitatory intramural neurons immunoreactive (IR) for the enzymes neuronal nitric oxide synthase (nNOS) and choline acetyltransferase. Large percentages of myenteric plexus (MP) ...
Iwaszko-Simonik A, Niedzwiedz A, Graczyk S, Slowikowska M, Pliszczak-Krol A.Recurrent airway obstruction (RAO) is an allergic disease of horses similar to human asthma, which is characterized by airway inflammation and activation of neutrophils, lymphocytes and platelets. Platelet activation and an increase in circulating platelet-leukocyte aggregates may lead to airway remodeling. The aim of this study was to investigate platelet status in RAO-affected horses based on the platelet morphology and platelet surface expression of CD41/61 and CD62P. Ten RAO-affected horses and ten healthy horses were included in this study. Blood samples were obtained to determine the pla...
Davis EG, Bello NM, Bryan AJ, Hankins K, Wilkerson M.Protection from infectious disease requires antigen-specific immunity. In foals, most vaccine protocols are delayed until 6 months to avoid maternal antibody interference. Susceptibility to disease may exist prior to administration of vaccination at age 4-6 months. Objective: The aim of this investigation was to characterise immune activation among healthy foals in response to a multivalent vaccine protocol and compare immune responses when foals were vaccinated at age either 90 or 180 days. Methods: Randomised block design. Methods: Twelve healthy foals with colostral transfer were blocked fo...
Bullone M, Lavoie JP.Animal models have been studied to unravel etiological, immunopathological, and genetic attributes leading to asthma. However, while experiments in which the disease is artificially induced have helped discovering biological and molecular pathways leading to allergic airway inflammation, their contribution to the understanding of the causality of the disease has been more limited. Horses naturally suffer from an asthma-like condition called "heaves" which presents sticking similarities with human asthma. It is characterized by reversible airway obstruction, airway neutrophilic inflammation, an...
Khatibzadeh SM, Gold CB, Keggan AE, Perkins GA, Glaser AL, Dubovi EJ, Wagner B.To compare antibody responses of horses naturally infected with West Nile virus (WNV) and those vaccinated against WNV, to identify whether vaccination interferes with the ability to diagnose WNV infection, and to determine the duration of antibody responses after vaccination. Methods: Sera from horses naturally infected with WNV (n = 10) and adult WNV-naïve horses before and after vaccination with a live canarypox virus-vectored vaccine (7) or a killed virus vaccine (8). Methods: An established WNV IgM capture ELISA was used to measure IgM responses. Newly developed capture ELISAs were used ...
Do Carmo GM, Da Silva AS, Klauck V, Pazinato R, Moura AB, Duarte T, Duarte MM, Bochi GV, Moresco RN, Stefani LM.Toxoplasmosis is an important parasitic disease affecting several species of mammals, but little is known about this disease in horses. This study aimed to investigate the levels of several immunological variables and markers of cell damage in the serum of seropositive horses for Toxoplasma gondii. Sera samples of adult horses from the Santa Catarina State, Brazil used on a previous study were divided into groups according to their antibody levels for T. gondii determined by immunofluorescence assay, i.e. 20 samples from seronegative horses (Group A - control), 20 samples from horses with tite...
Claessen C, Favoreel H, Ma G, Osterrieder N, De Schauwer C, Piepers S, Van de Walle GR.Equid herpesvirus 1 (EHV1) is an ubiquitous alphaherpesvirus that can cause respiratory disease, abortion and central nervous disorders. EHV1 is known to infect a variety of different cell types in vitro, but its tropism for cultured primary equine mesenchymal stem cells (MSC) has never been explored. We report that equine MSC were highly permissive for EHV1 and supported lytic replication of the virus in vitro. Interestingly, we observed that an infection of MSC with EHV1 resulted in a consistent downregulation of cell surface molecules CD29 (β1-integrin), CD105 (endoglin), major histocompat...
Ye C, Yan W, Xiang H, He H, Yang M, Ijaz M, Useh N, Hsieh CL, McDonough PL, McDonough SP, Mohamed H, Yang Z, Chang YF.Animal leptospirosis is one of the most common zoonotic diseases in the United States and around the world. In a previous study, we applied four recombinant antigens, rLipL21, rLoa22, rLipL32 and rLigACon4-8 of Leptospira interrogans (L. interrogans) for the serological diagnosis of equine leptospirosis (Ye et al, Serodiagnosis of equine leptospirosis by ELISA using four recombinant protein markers, Clin. Vaccine. Immunol. 21:478-483). In this study, the same four recombinant antigens were evaluated for their potential to diagnose canine leptospirosis by ELISA. A total of 305 canine sera that ...
Bielefeldt-Ohmann H, Prow NA, Wang W, Tan CS, Coyle M, Douma A, Hobson-Peters J, Kidd L, Hall RA, Petrovsky N.In 2011, following severe flooding in Eastern Australia, an unprecedented epidemic of equine encephalitis occurred in South-Eastern Australia, caused by Murray Valley encephalitis virus (MVEV) and a new variant strain of Kunjin virus, a subtype of West Nile virus (WNVKUN). This prompted us to assess whether a delta inulin-adjuvanted, inactivated cell culture-derived Japanese encephalitis virus (JEV) vaccine (JE-ADVAX™) could be used in horses, including pregnant mares and foals, to not only induce immunity to JEV, but also elicit cross-protective antibodies against MVEV and WNVKUN. Foals, 74...
Swegen A, Aitken RJ.Feral horses populate vast land areas and often induce significant ecological and economic damage throughout the landscape. Non-lethal population control methods are considered favourable in light of animal welfare, social and ethical considerations; however, no single effective, safe and species-specific contraceptive agent is currently available for use in free-ranging wild and feral horses. This review explores aspects of equine reproductive physiology that may provide avenues for the development of specific and long-lasting immunocontraceptive vaccines and some of the novel strategies that...
Janda J, Lehmann M, Luttmann W, Marti E.Interleukin-3 is a growth and differentiation factor for various hematopoietic cells. IL-3 also enhances stimulus-dependent release of mediators and cytokine production by mature basophils. Function of IL-3 has not been studied in horses because of lack of horse-specific reagents. Our aim was to produce recombinant equine IL-3 and test its effect on sulfidoleukotriene and cytokine production by equine peripheral blood leukocytes (PBL). Equine IL-3 was cloned, expressed in E. coli and purified. PBL of 19 healthy and 20 insect bite hypersensitivity (IBH)-affected horses were stimulated with Culi...
Sponseller BA, de Macedo MM, Clark SK, Gallup JM, Jones DE.Foals are particularly vulnerable to infection by Rhodococcus equi during the first 2 weeks of life whereas mature horses are not. While an innate immunodeficiency likely accounts for this clinically relevant vulnerability, the factors that contribute to infection by R. equi have not been fully elucidated. In this study, we demonstrate that cells of the monocyte lineage, including monocytes, macrophages, and dendritic cells, that have been activated with LPS and IFN-gamma, respond with a statistically significant, greater amount of cytokine mRNA production of IL-10, IL-12p35, and IL-12p40 than...
Adams AA, Sturgill TL, Breathnach CC, Chambers TM, Siger L, Minke JM, Horohov DW.Equine influenza virus is a leading cause of respiratory disease in the horse population; however, the susceptibility of old horses to EIV infection remains unknown. While advanced age in horses (>20 years) is associated with age-related changes in immune function, there are no specific recommendations regarding the vaccination of older horses even though a well-characterized effect of aging is a reduced antibody response to standard vaccination. Therefore, we evaluated the immunological and physiological response of aged horses to a live non-replicating canarypox-vectored EIV vaccine and s...
The proteins galectin-1 and Progesterone Induced Blocking Factor (PIBF) are present on human and murine trophoblast and are thought to influence both immunomodulation and trophoblast invasion. In equids, the invasive component of the placenta, the endometrial cups, stimulate maternal cell-mediated and humoral immune responses. It was therefore of interest to know if galectin-1 or PIBF could be immunolocalised to the invasive and/or non-invasive components of the equine placenta. Horse and mule (♀ horse X ♂ donkey) embryos and placental tissues between Days 12 and 124 of gestation were stai...
Uhl PB, Szober CM, Amann B, Alge-Priglinger C, Ueffing M, Hauck SM, Deeg CA.Retinal pigment epithelium (RPE) builds the outer blood-retinal barrier of the eye and plays an important role in pathogenesis of the sight threatening disease equine recurrent uveitis (ERU). ERU is a spontaneous autoimmune mediated inflammatory disease characterised by the breakdown of the outer blood-retinal barrier and an influx of autoaggressive T-cells into the inner eye. Therefore, identification of molecular mechanisms contributing to changed function of blood-retinal barrier in ERU is important for the understanding of pathophysiology. Cell surface proteins of RPE collected from health...
Flaminio MJ, Nydam DV, Marquis H, Matychak MB, Giguère S.Susceptibility of foals to Rhodococcus equi pneumonia is exclusive to the first few months of life. The objective of this study was to investigate the immediate immunologic response of foal and adult horse antigen-presenting cells (APCs) upon infection with R. equi. We measured the activation of the antigen-presenting major histocompatibility complex (MHC) class II molecule, costimulatory molecules CD40 and CD86, the cytokine interleukin-12 (IL-12), and the transcriptional factor interferon regulatory factor 1 (IRF-1) in monocyte-derived macrophages (mMOs) and dendritic cells (mDCs) of adult h...
Equine asthma is an inflammatory respiratory disorder, classified as mild-moderate (MEA) and severe (SEA). SEA is characterized by recurrent exacerbations, consisting of dyspnea, coughing and exercise intolerance; MEA causes poor performance, occasional cough and mucus hypersecretion. Although a precise pathogenesis is not completely understood, allergic mechanisms are considered an important pathophysiological feature of equine asthma. In equine medicine, intradermal testing (IDT) is effective in identifying hypersensitivity to specific allergens. However, to date, the studies about IDT in as...
Oaks JL, Ulibarri C, Crawford TB.Equine infectious anaemia virus (EIAV) infection of horses is characterized clinically by recurrent episodes of fever, thrombocytopenia and anaemia. In vivo, the only site of virus replication that has been previously demonstrated for EIAV is the tissue macrophage. In this study, in situ hybridization for EIAV was combined with immunohistochemistry for cell-type-specific markers to identify infected endothelial cells. EIAV-infected endothelial cells and macrophages were detected in horses infected with either virulent wild-type or with weakly virulent tissue culture-adapted strains of EIAV. Th...
Deeg CA.Equine recurrent uveitis (ERU) is a wide spread disease of the eye, which is the main cause for blindness in horses worldwide. Meanwhile, ERU is also accepted as the only reliable spontaneous model for human autoimmune uveitis. We identified and characterized novel autoantigens by analyzing the autoantibody-binding pattern from ERU cases to the retinal proteome. Cellular retinaldehyde-binding protein (CRALBP) and malate dehydrogenase (MDH) were detected as novel ERU autoantigens by this approach. B- and T-cell autoreactivity was detected to both autoantigens in ERU cases. The evaluation of the...
Kydd JH, Case R, Winton C, MacRae S, Sharp E, Ricketts SL, Rash N, Newton JR.Identification of risk factors which are associated with severe clinical signs can assist in the management of disease outbreaks and indicate future research areas. Pregnancy loss during late gestation in the mare compromises welfare, reduces fecundity and has financial implications for horse owners. This retrospective study focussed on the identification of risk factors associated with pregnancy loss among 46 Thoroughbred mares on a single British stud farm, with some but not all losses involving equid herpesvirus-1 (EHV-1) infection. In a sub-group of 30 mares, association between pregnancy ...
Romito M, Du Plessis DH, Viljoen GJ.The ability of a DNA vaccine to elicit an immune response in a horse was evaluated. The outer capsid protein VP2 of African horsesickness virus is known to elicit protective immunity in horses. Reverse transcribed DNA of the gene encoding VP2 was placed under the transcriptional control of the cytomegalovirus immediate-early enhancer/promoter and was injected on several occasions intramuscularly into a horse. Low antibody levels could be detected by ELISA. Antibodies directed against VP2 alone were shown by Western blot while low levels of neutralizing antibodies were detected by a 50% plaque ...
Takai S, Kawazu S, Tsubaki S.Humoral immune response to Rhodococcus equi in experimentally infected foals was studied with the enzyme-linked immunosorbent assay (ELISA) method. Class-specific antibodies were measured by ELISA in the sera of foals after intratracheal or oral inoculation with R. equi ATCC 6939 or T 48 and in the lung washings of a foal after intratracheal inoculation or of normal horses. After intratracheal or oral inoculation with R. equi, serum antibodies were first detected in immunoglobulin G (IgG) followed by IgM and IgA classes, but significant levels of IgM and IgA developed only in the foal infected...
Ficorilli N, Studdert MJ, Crabb BS.The nucleotide sequence of the glycoprotein G (gG) homologue of asinine herpesvirus 3 (AHV3), a respiratory alphaherpesvirus of donkeys, was determined. The AHV3 gG gene consists of 1233 base pairs (bp) and codes for a predicted protein of 411 amino acids. This is identical in size to the equine herpesvirus 1 (EHV1) gG gene and 6 amino acids longer than the equine herpesvirus 4 (EHV4) gG gene. The predicted amino acid sequence of AHV3 gG has characteristics of a class 1 membrane protein. The amino acid sequence of AHV3 gG shows 92% and 60% identity to EHV1 gG and EHV4 gG respectively. Two regi...
Lehmbecker A, Liebing J, Barthel Y, Habierski A, Cavalleri J, Puff C, Rademacher B, Lumpe S, Beineke A.Neurolymphomatosis is a rare manifestation of lymphoma and is characterized by neoplastic infiltration of the peripheral nervous system. The present report describes neoplastic infiltration of peripheral nerves in three horses with multicentric lymphoma. Immunohistochemistry revealed the presence of CD79a(+) lymphoblastic cells and well-differentiated CD3(+) T cells, characteristic of T-cell-rich B-cell lymphoma in all cases. Nerve infiltration by lymphoma is rare, but should be considered as a differential diagnosis for peripheral neuropathy in horses with lymphoma.
Freytag C, Seeger J, Siegemund T, Grosche J, Grosche A, Freeman DE, Schusser GF, Härtig W.The present study was performed on whole-mount preparations to investigate the chemical neuroanatomy of the equine myenteric plexus throughout its distribution in the intestinal wall. The objective was to quantify neurons of the myenteric plexus, especially the predominant cholinergic and nitrergic subpopulations. Furthermore, we investigated the distribution of vasoactive intestinal polypeptide and the calcium-binding protein calretinin. Samples from different defined areas of the small intestine and the flexura pelvina were taken from 15 adult horses. After fixation and preparation of the ti...
Rosin-Arbesfeld R, Rivlin M, Noiman S, Mashiah P, Yaniv A, Miki T, Tronick SR, Gazit A.Three cDNA clones representing structurally distinct transcripts were isolated from a cDNA library prepared from cells infected with equine infectious anemia virus (EIAV) by using a probe representing the S3 open reading frame, which is thought to encode Rev. One species, designated p2/2, contained four exons and was identical to a previously described polycistronic mRNA that encodes Tat. This transcript was predicted to also direct the synthesis of a truncated form of the transmembrane protein and a putative Rev protein whose N-terminal 29 amino acids, derived from env, are linked to S3 seque...
Reyna-Bello A, García FA, Rivera M, Sansó B, Aso PM.The standardization of ELISA for the detection of anti-Trypanosoma evansi antibodies in naturally and experimentally infected horses is described. Bayesian analysis was used to establish the cutoff between positive and negative sera. In order to determine the assessment of the ELISA test, the results obtained were compared with those from an IFA. A relative sensibility of 98.39%, a specificity of 95.12% and a predictive value of 96.83% were determined. The standardized technique was used to evaluate the antibody production against trypanosome in an experimentally infected equine, in which the ...
Katepalli MP, Adams AA, Lear TL, Horohov DW.Telomeres, specialized structures present at the ends of linear eukaryotic chromosomes, function to maintain chromosome stability and integrity. Telomeres shorten with each cell division eventually leading to replicative senescence, a process thought to be associated with age-related decline in immune function. We hypothesized that shortened PBMC telomere length is a factor contributing to immunosenescence of the aged horse. Telomere length was assessed in 19 horses ranging in age from 1 to 25 years. Mitogen-induced 3H-thymidine incorporation, total serum IgG, and pro-inflammatory cytokine exp...
Clegg PD, Burke RM, Coughlan AR, Riggs CM, Carter SD.The cellular production by resident articular cells and infiltrating inflammatory cells of the gelatinase matrix metalloproteinases (MMP) was investigated by tissue culture methods and analysis of cell supernatants by gelatin zymography. Peripheral blood neutrophils in short term culture produced MMP-9, as did peripheral blood monocytes in culture. Isolated articular chondrocytes in monolayer culture produced both MMP-2 and MMP-9, although articular cartilage maintained as explant culture produced MMP-2 alone. Synovial fibroblasts grown in monolayer culture produced MMP-2 alone, although synov...
Wyatt CR, Magnuson NS, Perryman LE.Six monoclonal antibodies, designated EqT2, EqT3, EqT6, EqT7, EqT12, and EqT13, which identify T lymphocyte antigens present at different stages of T cell maturation were used to examine T lymphocyte development in foals with severe combined immunodeficiency (SCID). Flow microfluorimetry demonstrated the presence of EqT12+ and EqT13+ prothymocytes and a few phenotypically mature EqT2+ and EqT3+ thymocytes within the thymic remnants of SCID foals. However, very few EqT6+ and EqT7+ resident cortical thymocytes were detected. The near absence of EqT6+ and EqT7+ cortical thymocytes was confirmed b...
Burk SV, Dangoudoubiyam S, Brewster-Barnes T, Bryant UK, Howe DK, Carter CN, Vanzant ES, Harmon RJ, Kazacos KR, Rossano MG.Currently, diagnosis of Parascaris equorum infection in equids is limited to patent infections. The goals of this study were to culture P. equorum larvae in vitro and identify excretory-secretory (ES) products for prepatent diagnostic testing. Parascaris equorum L2/L3 larvae were hatched and cultured for up to 3 weeks for ES product collection. Fifth stage (L5) P. equorum were also cultured for ES product collection. Examination of ES fractions by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and silver stain revealed L2/L3 products ranging from 12-94 kDa and L5 products...
van der Meide NM, Savelkoul HF, Meulenbroeks C, Ducro BJ, Tijhaar E.Culicoides spp. of the Obsoletus complex belong to the most important species of midge, involved in causing insect bite hypersensitivity (IBH) in horses in The Netherlands. The aim of the current study was to evaluate seven different Obsoletus complex-derived recombinant allergens (Cul o 1-Cul o 7) and to compare these with Obsoletus complex whole body extract (WBE) in an IgE ELISA, using sera of 194 clinically-confirmed cases of IBH and 175 unaffected horses. The highest test accuracy was obtained with WBE, followed by Cul o 2, 3 and 5. Two ELISAs with a combination of recombinant allergens, ...
Phillips JC, Lembcke LM, Noltenius CE, Newman SJ, Blackford JT, Grosenbaugh DA, Leard AT.To determine the tissue-restricted expression pattern of tyrosinase mRNA in canine and equine melanocytic tumors and relative tyrosinase and major histocompatibility complex (MHC) I mRNA expression in variants of melanocytic tumors. Methods: 39 canine and 8 equine tumor samples and 10 canine and 6 equine normal tissue samples. Methods: RNA was isolated from formalin-fixed, paraffin-embedded tissues. Real-time PCR assays were designed to amplify canine and equine tyrosinase, S18 ribosomal RNA, and major histocompatibility complex I transcripts. Relative expression was determined by use of S18 a...
Raza F, Ivanek R, Freer H, Reiche D, Rose H, Torsteinsdóttir S, Svansson V, Björnsdóttir S, Wagner B.Culicoides hypersensitivity (CH) is induced in horses by salivary allergens of Culicoides midges. In Iceland, the causal Culicoides species for CH are not present. Previous epidemiological data indicated that Icelandic horses are more susceptible to CH when they are exported from Iceland and first exposed to Culicoides at adult age. Horses born in countries where Culicoides is endemic, develop the disease less frequently. Here, we established a longitudinal allergy model to identify predictive and diagnostic serological biomarkers of CH. Results: Sixteen adult Icelandic horses from Iceland wer...
Keller LE, Tait Wojno ED, Begum L, Fortier LA.To gain insight into Treg interactions with synovial tissues in early OA, an equine tri-culture model of OA was used to test the hypothesis that Tregs, in the absence of T Helper 17 cells, are sufficient to resolve inflammation elicited by IL-1β. Unassigned: To model normal and OA joints, synoviocytes were co-cultured with chondrocytes in a transwell system and ± stimulated with IL-1β. Tregs were activated and enriched, then added to co-cultures, creating tri-cultures. At culture end, synoviocytes and chondrocytes were analyzed for gene expression, Treg Foxp3 expression was reexamined b...
Waller AS.Strangles, caused by the host adapted Lancefield group C bacterium Streptococcus equi sub-species equi (S. equi), is one of the oldest recognised infectious diseases of horses and continues to cause significant welfare and economic cost throughout the world. The ability of S. equi to establish sub-clinical persistent infections primarily in the guttural pouches of convalescent horses has been instrumental to its success. However, the implementation of simple control measures that permit the identification and treatment of persistently infected carriers can prevent further outbreaks of disease ...
McTaggart C, Yovich JV, Penhale J, Raidal SL.Flow cytometric assays were used to compare phagocytic and oxidative burst activity of neutrophils from healthy foals less than 7 days of age with the activity of cells from healthy adult horses. The phagocytosis of Staphylococcus aureus by foal neutrophils was less than that observed for adult neutrophils when autologous serum was used as the source of opsonins in the assay. The use of adult serum did not significantly improve the ability of foal neutrophils to attach bacteria. The oxidative burst activity of foal neutrophils was equivalent to that of adult cells. However, when serum or plasm...
Zayed M, Adair S, Dhar M.Synovial fluid contains cytokines, growth factors and resident mesenchymal stem cells (MSCs). The present study aimed to (1) determine the effects of autologous and allogeneic synovial fluid on viability, proliferation and chondrogenesis of equine bone marrow MSCs (BMMSCs) and (2) compare the immunomodulatory properties of equine synovial fluid MSCs (SFMSCs) and BMMSCs after stimulation with interferon gamma (INF-γ). To meet the first aim of the study, the proliferation and viability of MSCs were evaluated by MTS and calcein AM staining assays. To induce chondrogenesis, MSCs were cultured in ...
Prescott JF, Ogilvie TH, Markham RJ.A lymphocyte stimulation test using antigens of Corynebacterium equi was used to compare the response of peripheral blood lymphocytes from foals with C equi pneumonia with those of clinically normal foals and adult horses. The test clearly distinguished infected foals from normal foals when tested in animals less than or equal to 2 months old. After the 2nd month, stimulation response from individual normal foals sometimes exceed those from infected foals, but mean stimulation response to C equi antigens was significantly (P less than 0.025) greater in 3- to 5-month-old infected foals when com...
Sydor T, von Bargen K, Becken U, Spuerck S, Nicholson VM, Prescott JF, Haas A.Rhodococcus equi is a mucoid Gram-positive facultative intracellular pathogen which can cause severe bronchopneumonia in foals and AIDS patients. A polysaccharide capsule which gives R. equi a mucoid appearance has long been suspected to be a virulence factor. Here, we describe a transposome mutant in the gene fbpA of strain R. equi 103 causing absence of a capsular structure. FbpA is a chromosomal gene homologous to antigen 85 (Ag85) mycolyl chain transferase gene of Mycobacterium tuberculosis. The mutant multiplied normally in isolated macrophages, was able to establish the unusual R. equi-c...
Ramos-Vara JA, Ortiz-Santiago B, Segalès J, Dunstan RW.This report contains the clinical, histologic, immunohistochemical, and electron microscopic findings in two cases of equine cutaneous leishmaniasis. Nodular, sometimes crusty or ulcerated lesions were confined to the pinna and adjacent neck in both animals. The dermal inflammatory infiltrate was lymphohistiocytic in horse No. 1 and pyogranulomatous with formation of tuberculoid granulomas in horse No. 2. Numerous Leishmania organisms were found within macrophages in both animals. There was moderate to intense and specific reaction by immunoperoxidase using a polyclonal antiserum against Leish...
