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.
REBERS PA, HURWITZ E, HEIDELBERGER M.Rebers, Paul A. (Rutgers University, New Brunswick, N. J.), Esther Hurwitz, and Michael Heidelberger. Immunochemistry of pneumococcal types II, V, and VI. II. Inhibition tests in the type VI precipitating system. J. Bacteriol. 82:920-926. 1961.-As in other immune systems involving polysaccharides, rabbit antibodies but not those engendered in the horse were found sensitive to degradation of type VI pneumococcal (Pn) polysaccharide (SVI), and were readily inhibited by fragments of SVI. Large amounts, 30 to 111 mumoles, of most sugars gave up to 15% inhibition, while sugar and polyol phosphates ...
HORI J, AOKI K.Electrophoretic studies were made of normal horse and human serum albumins over the pH range 3.6–6.8 and at 25 °. The ionic strength of acetate or phosphate buffer used was 0.1, and the concentration of protein was 0.5% (g./100 ml.). Patterns were usually enantiographic and there were two (N and F1) or three (N, F1, and F2) boundaries in the pH range 3.6–5.2. The areas of the N and F1 boundaries changed continuously with pH, and the area of F2 was almost constant. The results were interpreted, in the same way as was previously done in the case of bovine serum albumin, by the isomerization...
HETRICK FM, YANCEY FS, HANSEN PA, BYRNE RJ. Four horses inoculated with EEE virus remained asymptomatic following injection but did develop measurable HI and neutralizing antibodies as a result of infection. HI antibodies were detectable earlier than neutralizing antibodies but the levels tended to drop more rapidly. 2. Of 14 horses and ponies having significant levels of neutralizing antibody, 5 to 9 had measurable HI antibody depending on number of units of antigen employed in the test. 3. Sera from 3 clinical cases of EEE were positive on the HI test while only one of these animals had a significant neutralizing antibody level.
Kalemkerian PB, Metz GE, Peral-García P, Lopez-Gappa J, Echeverría MG, Giovambattista G, Díaz S.We investigated the association of equine arteritis virus (EAV) infection and three short tandem repeat (STR) polymorphisms located within or in close proximity to equine lymphocyte antigen (ELA) region. We used a case-control design as a first approach before proceeding to select candidate genes. One hundred and sixty-five Silla Argentino horses were taken in 2002 from positive serological detections of EAV in Argentina, to determine whether STR genotypes were correlated to genetic susceptibility to EVA. Allele frequency distribution did not show significant differences between both groups (P...
Dagleish MP, Pemberton AD, McAleese SM, Thornton EM, Miller HR, Scudamore CL.Equine alpha-1-proteinase inhibitor (API) consists of three, occasionally four, serum glycoproteins. This study investigated the immunohistochemical localisation of equine API in paraformaldehyde fixed, paraffin embedded equine tissue samples of liver, lung, stomach, pancreas, jejunum and colon in five horses using affinity purified sheep polyclonal and protein A purified mouse monoclonal antibodies, whose specificities were verified by Western blotting. Exposing tissue sections to boiling citrate buffer greatly enhanced antigen recovery and improved immunostaining with both antibodies, result...
Nichani AK, Sharma RD, Sarup S.Efficacy of medium RPMI-1640 (supplied by Gibco USA, Centron and Hi-media) supplemented with horse, donkey, sheep and goat sera was evaluated for in vitro propagation of Theileria annulata (Hisar) infected bovine mononuclear cells. The results were compared with the growth rate in RPMI-1640 supplemented with foetal bovine serum (Gibco). RPMI-1640 (Gibco) proved to be the best medium for in vitro cultivation of the parasite infected cells. Foetal bovine serum could be easily, safely and reliably substituted with goat and sheep sera in the growth medium. Horse and donkey sera also gave comparabl...
Rhiner T, Fettelschoss V, Schoster A, Birkmann K, Fettelschoss-Gabriel A.Previously, virus-like particle (VLP)-based self-vaccinations targeting interleukin (IL)-5 or IL-31 have been suggested to treat equine insect bite hypersensitivity (IBH), a seasonal recurrent allergic dermatitis in horses. The IL-5-targeting equine vaccine significantly reduced blood eosinophil counts in horses, similar to human monoclonal antibodies targeting IL-5 or the IL-5 receptor alpha (IL-5Rα). Previous studies in humans have also reported an additional effect on reduction of basophil counts. The aim of the present study was to evaluate whether an equine anti-IL-5 vaccine affected blo...
Hoshiba H, Sinowatz F.Spermadhesins are proteins with various functions in sperm capacitation and zona pellucida binding. In this study the cellular localization of the spermadhesin AWN-1 has been examined in the equine male genital tract. Results obtained by immunohistochemical methods reveal that in the horse AWN-1 is synthesized in spermatogonia, in the rete testis, the ductus epididymidis and the seminal vesicles. These findings indicate that the cellular origin of spermadhesins is species-specific.
Marquardt J, Heymer J, Heinz H, Adolf GR, Deegen E.Recombinant equine interferon-beta 1 (reqIFN-beta 1) induces an antiviral state in blood mononuclear cells (BMC) of horses. Maximal protection against replication of vesicular stomatitis virus is achieved 6 hours after treatment with IFN in vitro and in vivo. Duration of the protective effect depends on the dose of IFN in vitro and in vivo. Availability of reqIFN-beta 1 in cultures of BMC for up to 48 hours does not prolong the antiviral state. The protective effect on BMC after treatment with IFN has similar duration in vivo and in vitro. Monitoring of the effect of IFN in vivo is, thus, simp...
Kudrimoti S, Machin J, Arojojoye AS, Awuah SG, Eisenberg R, Fenger C, Maylin G, Lehner AF, Tobin T.Based on structural similarities and equine administration experiments, Barbarin, 5-phenyl-2-oxazolidinethione from Brassicaceae plants, is a possible source of equine urinary identifications of aminorex, (R,S)-5-phenyl-4,5-dihydro-1,3-oxazol-2-amine, an amphetamine-related US Drug Enforcement Administration (DEA) controlled substance considered illegal in sport horses. We now report the synthesis and certification of d -barbarin to facilitate research on the relationship between plant barbarin and such aminorex identifications. D -barbarin synthesis commenced with production of d -2-oxo-2-phe...
Boussetta M, Chabchoub A, Ghram A, Jomaa I, Ghorbel A, Aouina T, Ben Amor H.Using the haemagglutination inhibition and immunodiffusion tests, a national serological survey was carried out to detect antibodies to equine influenza (EI) (A/equi/1/Prague 56 and A/equi/2/Miami 63) and equine infectious anaemia (EIA) in horse sera collected in northeastern Tunisia. 533 samples were analysed for EIA antibodies. All were negative. 13.6% of 433 equine sera tested for EI antibodies were positive. These results are discussed and compared with others obtained in Tunisia and bordering countries.
Tåmová B, Stumpa A, Zakopal J, Vĕzníková D, Mensík J.Equine influenza occurred in Czechoslovakia 14 years after the last epizootic in horses that had returned from abroad. Six strains A (Heq1Neq1) antigenically related to, but not identical with, strain A/eq/Praha/56 were isolated from 10 washings. Seroconversion was demonstrated with paired sera, but the antibody increase was more marked against the newly isolated strain.
Rabinovsky ED, Yang TJ.A tumor antigen (TA) associated with murine leukemia-lymphoma L5178Y cells has been identified by the enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) techniques. The antigen was present in both non-solubilized and 0.5% NP-40 solubilized membrane extracts. Rabbit anti-L5178Y lymphoma serum (RALS), extensively absorbed with normal mouse tissues, identified TA in extracts of L5178Y lymphoma and L5178Y leukemia cells grown in horse serum (L5178Y/HS), but not in extracts of L5178Y cells grown in fetal calf serum (L5178Y/FCS). Similarly, absorbed rabbit anti-L5178Y/HS...
Bocking T, Singh B.The lung is a complex organ, and its physiology and immunology are regulated by various immune molecules and cells. Lung surfactant, a mixture of phospholipids and proteins produced by the bronchiolar and type II alveolar epithelial cells, is one such important player in lung physiology. Compared to knowledge about the biology of the surfactant in rodents and humans, only limited data are available on the surfactant in the horse. Although there are data linking levels of surfactant proteins with respiratory disease in the horse, there are no data on the cellular localization of surfactant prot...
Sharma AK, Karthikeyan S, Sharma S, Yadav S, Srinivasan A, Singh TP.Lactoferrin (Lf), an iron binding glycoprotein found in the external secretions and neutrophilic leucocytes of mammals, is thought to be responsible for primary defence against microbial infection, mainly as a result of lactoferrin sequestration of iron required for microbial growth (Weinberg, 1978). Many other functions have been attributed to lactoferrin, including immunomodulation and cell growth regulation (Lbnnerdal & lyer, 1995). The lactoferrin has molecular mass of 80 kDa. The protein folds into two globular lobes, the N-lobe comprising the N-terminal half of the polypeptide chain ...
Vaske A, Gautier C, Winter J, Aurich C.We followed the hypothesis that equine neonates with reduced transfer of tumor necrosis factor-α (TNFα) are at increased risk of neonatal infection. We investigated TNFα concentrations in colostrum of healthy mares and blood of their neonates in a non-hospitalized population of Warmblood mares where delivery, neonatal adaptation and health was closely monitored by veterinarians. Concentration of TNFα and IgG was determined in colostrum respective milk and in neonatal blood collected immediately after delivery and 18 h thereafter in 97 foals that were assigned to groups failure of passive ...
Mattei DN, Harman RM, Van de Walle GR, Smith R, Grivel JC, Abdelalim EM, Vinardell T.Mesenchymal stromal cells (MSCs) have regenerative and immunomodulatory potential and may be used to treat injured tissues. Pregnancy has been associated with increased MSCs in the peripheral circulation in multiple species, but to date, there are no reports on this matter in horses. This study aimed to evaluate the effect of pregnancy on isolation efficiency and proliferation capacity of equine MSCs derived from the peripheral blood (PB) of mares. Venous blood samples were collected at the 11th month of gestation and 1 month after delivery from clinically healthy Arabian mares that presented ...
Wood JM, Baum HP, Bews JP, Wachsmuth ED, Heusser C, Hofbauer KG.In this study, the hypotensive efficacy of R-3-36-16, a monoclonal antibody against human kidney renin, was investigated during chronic administration to a primate. R-3-36-16 was given by continuous intraperitoneal infusion with osmotic minipumps to normotensive marmosets fed a low-sodium diet in doses of 30 or 300 micrograms/kg/day for 14 days. The lower dose had no effect on blood pressure (BP) or plasma renin activity (PRA). After two days of treatment, the higher dose reduced PRA by 57% and lowered BP by 13 +/- 7 mm Hg. Although the hypotensive response persisted after 14 days of treatment...
Rasmussen N, Karlsen P, Otten ND, Fjeldborg J, Hansen S.Bronchoalveolar lavage (BAL) cytology results from 1 lung might not be representative of both lungs. Objective: To determine whether the lung site sampled would influence the horse's BAL cytology profile, and if a pooled BAL sample would be superior with regard to BAL cytology diagnosis in a cohort of healthy and subclinical asthmatic warmblood horses. Methods: Fifty-nine horses in 2021 and 70 horses in 2022, the follow-up included 53 of the same in each year. Methods: A cross-sectional study with follow-up included BAL cytology samples from individual lungs and from pooled BAL samples. The BA...
Mullen KR, Felippe MJB.Equine common variable immunodeficiency (CVID) is a rare, late-onset, nonfamilial humoral deficiency characterized by B-cell depletion and/or dysfunction resulting in inadequate antibody production and predisposition to recurrent infections. Serum immunoglobulin concentration and peripheral blood lymphocyte immunophenotyping are required to diagnose and characterize CVID in horses. Early recognition of the disease by the equine practitioner is paramount to managing the quality of life for these patients, for whom specific treatment is not yet available and long-term prognosis remains poor. An ...
Bozorgmanesh R.Immune-mediated vasculopathies occur secondary to infection or another noninfectious stimulus. Potential triggers include heterologous antigens including viruses, injected proteins and drugs; or auto-antigens including immunoglobulins or other endogenous proteins. Although these conditions are rare in horses, immune-mediated vasculopathies can cause considerable morbidity, with variable clinical signs depending on severity and organ system affected. Examples include purpura hemorrhagica, systemic lupus erythematosus, drug-induced vasculitis, paraneoplastic vasculitis, and idiopathic immune-med...
Veiga IB, Affolter VK, Moore PF, Maia-Nussbaumer PJ, Gerber V, Unger L, Dettwiler M.This report describes a multicentric intermediate-size B-cell lymphoma with epitheliotropism in a Freiberger mare affecting multiple mucous membranes, skin and internal organs. The clonal neoplastic B-cell population was accompanied by numerous reactive polyclonal small T cells. Differential diagnoses for these unusual findings are discussed. 本报告描述了一种多中心性中等大小B细胞淋巴瘤, 其在弗雷伯格母马中具有驱上皮性, 影响多处粘膜、皮肤和内脏。克隆性肿瘤B细胞群伴有大量反应性多克隆小T细胞。就这些异常发现对鉴别诊...
Hart KA, Kimura S.Immunomodulators can stimulate, suppress, or regulate one or many aspects of the immune response. Use of a variety of immunostimulants, immunosuppressors, and anti-inflammatory drugs are described in horses, but the evidence supporting their efficacy is variable. Corticosteroids and nonsteroidal anti-inflammatory drugs are the best characterized immunomodulators in horses, but further study is needed to fully define their ideal dosing protocols and indications and to characterize the efficacy of other immunomodulators in equine medicine.
Guenther MC, Borowicz PP, Hirchert MR, Semanchik PL, Simons JL, Fridley J, White-Springer SH, Hammer CJ.The neonatal Fc receptor (FcRn) is the receptor responsible for bidirectional transport of immunoglobulin G (IgG) across cells, maintenance of IgG levels in serum, and assisting with antigen presentation. Unfortunately, little is known about FcRn in horses. Therefore, the objective of this study was to provide fundamental information regarding the location of FcRn in equine tissues. Tissues were collected from six horses of mixed breed, age, and sex immediately following euthanasia. Sampling locations included the respiratory tract, gastrointestinal tract (GIT), other visceral organs, cornea, ...
Höglund N, Rossi H, Javela HM, Oikari S, Nieminen P, Mustonen AM, Airas N, Kärjä V, Mykkänen A.Equine asthma (EA) is a chronic lower airway inflammation that leads to structural and functional changes. Hyaluronic acid (HA) has crucial functions in the extracellular matrix homeostasis and inflammatory mediator activity. HA concentration in the lungs increases in several human airway diseases. However, its associations with naturally occurring EA and airway remodelling have not been previously studied. Our aim was to investigate the association of equine neutrophilic airway inflammation (NAI) severity, airway remodelling, and HA concentration in horses with naturally occurring EA. We hypo...
Sobral GG, Neto OCG, Lima TC, Carneiro GF.Providing plasma with immunoglobulins is essential for the health of foals with failure of passive transfer of immunity. The use of lyophilized plasma (LP) offers a simple and affordable option in terms of transportation and storage. This study aimed to measure the concentrations of immunoglobulin G (IgG), total protein (TP), and total solids (TS) in fresh equine plasma before and after lyophilization. Plasma was collected from six healthy male horses. The samples underwent freeze-drying and were reconstituted in deionized water to their original volume. The concentrations of IgG in both fresh...
Shams F, Jokar M, Abdous A, Mohammadi P, Abbassioun A, Seuberlich T, Rahmanian V.Neospora spp. and Toxoplasma gondii are two closely related protozoan parasites that are widely distributed throughout the world. Horses can act as intermediate hosts for both parasites and can acquire disease. Blood samples were taken from 487 clinically healthy horses from 17 different mechanized stables in Tehran, the capital of Iran, during September and November of 2022. IFAT and ELISA were employed to detect antibodies directed against Neospora spp. and T. gondii. The anti-N. caninum antibodies were detected in 52 of the horses (10.67%) based on IFAT and in 86 of the 487 horses (17.65%) ...
Pimenta J, Prada J, Pires I, Cotovio M.Sarcoids and squamous cell carcinomas (SCCs) are the most concerning equine oncological diseases. Both tumors are challenging to manage due to their invasive behavior and high prevalence of recurrences. Furthermore, SCCs have a propensity to metastasize. Programed cell-death ligand 1 (PD-L1) has been one of the main therapeutic targets for immunotherapy in various human tumors. PD-L1 research in equine tumors is scarce and more efforts are necessary to understand the potential of this biomarker as a therapeutical target. Unassigned: Evaluate the immunohistochemical expression of PD-L1 in equin...
Ding W, Gong W, Liu H, Hu H, Shi L, Ren X, Cao Y, Zhang A, Shi X, Li Z, Bou T, Dugarjaviin M, Bai D.The growth and development of myofibers, as the fundamental units comprising muscle tissue, and their composition type are indeed among the most crucial factors influencing skeletal muscle types. Muscle fiber adaptation is closely associated with alterations in physiological conditions. Muscle fiber types undergo dynamic changes in fetus and adult horses. Our aim is to investigate the mechanisms influencing the differences in muscle fiber types between fetal and adult stages of Mongolian horses. The study investigated the distribution of muscle fiber types within longissimus dorsi muscle of fe...
Maeda M, Abe M, Aoshima K, Kobayashi A, Fukushi H, Kimura T.Equine herpesvirus-1 (EHV-1) causes respiratory diseases, abortion, and encephalomyelitis in horses. The EHV-1 immediate-early (IE) protein, essential for viral replication, is transactivated by the binding of a multiprotein complex including the open reading frame 12 (ORF12) and some host factors to the IE promoter region. Promoter-associated non-coding RNAs (pancRNAs), which are transcribed from bidirectional promoters, regulate the transcription of neighboring genes in mammals and pathogens. In this study, we identified a novel pancRNA transcribed from across the areas of the 5'-untranslate...
Botelho JHV, Pessoa GO, Caixeta ES, Sales G, de Oliveira KR, Nascimento Neto JDP, Ferreira RD, Palhão MP.This study aimed to evaluate the localised effects of intrauterine ozone therapy on endometrial recovery in mares with endometritis. Our investigation assessed changes in gene expression profiles of anti-inflammatory (IL-1RA and IL-10), proinflammatory (IL-R1B3i and TNFα) and pleiotropic (IL-6) cytokines, along with detailed histological measurements of epithelial and endometrial thickness and the glandular area ratio. Twenty mares were assigned to a 2 × 2 factorial design based on endometritis diagnosis and treatment (control or 42 μg/mL ozone insufflation), resulting in four groups: N...
Terpeluk ER, Schäfer J, Finkler-Schade C, Rauch E, Rohn K, Schuberth HJ.The quality of equine colostrum is typically defined by refractometry or the concentration of maternal antibodies. However, the activity of other equine colostral bioactive molecules has not yet been investigated. This study analyzed whether the administration of a fermentation product (SCFP) influences the biological activity of mare colostrum and whether the biological activity of colostrum has a lasting immunomodulating effect for foals. A total of fourteen pregnant mares received 20 g/day of a SCFP for a period of twelve weeks prior to the calculated date of birth (SCFP-group). Twelve pre...
