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.
Wormstrand A.An immunological gel-diffusion test for the diagnosis of pregnancy in the mare is described. 56 blood samples from 50 different mares were tested. Control tests were made both by the Ashheim-Zondek method and by clinical examination. The accuracy of the immunological method was 96.4 %. No false positive reactions were observed. It is recommended to draw the blood sample at approximately 45 days or more after the last service. The immunological method is simple, cheap and accurate and is recommended as a routine test for the diagnosis of pregnancy in mares.
Tumova B, Easterday BC.This study demonstrates relationships in envelope antigens of 4 human influenza A2 strains isolated during the period 1957-68 (including A2/Hong Kong/68), 2 strains of A/Equi-2/63 and 7 avian influenza viruses isolated in Europe, North America, and the Ukraine in the years 1960-67.Antigenic relationships among the strains were determined on the basis of haemagglutination-inhibition, virus-neutralization, strain-specific complement-fixation, and neuraminidase-inhibition tests.North American avian influenza strains, Turkey/California/64, Turkey/Massachusetts/65, Turkey/Wisconsin/66, Turkey/Ontar...
Lee CL, Zandrew F, Davidsohn I.One hundred infectious mononucleosis and the same number of non-infectious mononucleosis sera were studied to evaluate the sensitivity and specificity of horse erythrocytes in the diagnosis of infectious mononucleosis. Titres of horse agglutinins in infectious mononucleosis sera ranged from 28 to 7,168 with a geometric mean of 550, whereas the corresponding sheep agglutinin titres ranged from less than 7 to 3,584, with a geometric mean of 126. Horse agglutinin titres of non-infectious mononucleosis sera ranged from less than 7 to 896, with a geometric mean of 59. Infectious mononucleosis sera ...
Nasu T, Sueishi A, Morimoto M.We used immunohistochemical techniques to analyze the localization and distribution of the catecholamine-synthesizing enzyme tyrosine hydroxylase (TH) and the neuropeptides methionine-endephalin (M-Enk), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), calretinin (Cal), calcitonin gene-related peptide (CGRP), substance P (SP), and galanin (Gal) in the stellate ganglia of two species of domestic animal (cattle and horses). NPY, VIP and Gal immunoreactive neurons (both cell body and nerve fiber) were observed in the stellate ganglia of both animals. M-Enk and CGRP immunoreactive ne...
Chung CJ, Grimm AL, Wilson CL, Balasuriya UB, Chung G, Timoney PJ, Bandaranayaka-Mudiyanselage CB, Lee SS, McGuire TC.In an effort to improve a competitive blocking enzyme-linked immunosorbent assay (cELISA) for antibody detection to Equine arteritis virus (EAV), antigen purified by anion-exchange membrane chromatography capsule (AEC) was evaluated. Virus purification by the AEC method was rapid and easily scalable. A comparison was made between virus purified by the AEC method with that obtained by differential centrifugation based on the following: 1) the relative purity and quality of EAV glycoprotein 5 (GP5) containing the epitope defined by monoclonal antibody 17B7, and 2) the relative sensitivity of a c...
Crisman MV, Hodgson DR, Bayly WM, Liggitt HD.To determine whether road transport affected pulmonary phagocyte activity, 7 healthy Thoroughbred horses were shipped 1,160 kilometers over 36 hours. Fluid collected by bronchoalveolar lavage (BAL) 12 hours, and 7 and 14 days after transport was analyzed. Results were compared to those from the same horses pre-transport, and 7 non-transported control horses that had BAL performed at the same times as the transported horses. Of cells recovered with BAL the percentage of viable pulmonary alveolar macrophages (PAMs) declined from 90.0 +/- 0.9% pre-transport to 80.0 +/- 3.7% by 2 weeks post transp...
Ralston SL, Baile CA.The hypothesis that changes in blood glucose concentrations and(or) utilization rate affect feeding behavior in ponies was tested. Ponies (n = 4) were fasted for 4 h, then given iv injections of 50% glucose [.2 g glucose/BW.75 kg (low dose, LD) or 1.0 g glucose/BW.75 kg (high dose, HD)] or an equal volume of normal saline (HDS; LDS) 5 min before being allowed access to pelleted feed. Blood samples were drawn at regular intervals pre- and post-treatment and analyzed for plasma glucose (PG), immunoreactive insulin (IRI) and glucagon concentrations. All glucose-treated animals immediately ate mea...
Tesfaigzi Y.Exposure of airways to environmental toxins or allergens induces proliferation of epithelial cells. Depending on the type of exposure, existing and newly formed cells can differentiate into mucus-producing cells resulting in mucous cell metaplasia (MCM). During recovery, the epithelium reduces the number of epithelial cells to return to the original state. Understanding the mechanisms involved in this resolution could be useful in deleting mucous cells and, thereby, mucous secretions. We have found that metaplastic mucous cells induced by exposure to ozone, endotoxin, cigarette smoke or allerg...
Weiland G, Hasslinger MA, Mezger S, Pöllein W.In an investigation period over 8 months the natural course of infection was studied by means of coproscopic and serological methods in 27 mares and 29 foals. The examination of the stool showed in mares, before the beginning of the grazing season, an infection rate of 100% with small and a rate of 7.4% with large strongyles (Str. vulgaris). Serologically the ELISA showed in foals only a distinct increase of antibody activity with the somatic antigen. The mares retained the high IgG-values of activity, which were already found at the beginning of the investigations. Even though the agglutinati...
McDonald J, Gall R, Wiedenbach P, Bass VD, DeLeon B, Brockus C, Stobert D, Wie S, Prange CA, Yang JM.We investigated the use of particle concentration fluorescence immunoassay (PCFIA) as a technique for drug detection in racing horses. The test was constructed from an antiserum to a carboxyfentanyl-BSA conjugate and carboxyfentanyl linked to b-Phycoerythrin. Using these reagents and a PCFIA apparatus levels of fentanyl as low as 0.1 ng/ml could be detected by the assay. In addition, cross-reactivity studies on this assay showed that the anti-serum cross-reacted well with carfentanil, sufentanil and the methylated analogs of fentanyl. We therefore evaluated the ability of these agents to produ...
Herd RP, Kent JE.Serum protein responses were examined in 52 ponies divided into five groups and subjected to various control strategies that resulted in pasture infectivity ranging from 706 to 18,486 infective third stage, cyathostome and Trichostrongylus axei larvae per kilogram of herbage (L3/kg) by 17 September 1984. Major protein changes occurred only in young ponies (Groups 4 and 5) and were observed before exposure to maximum numbers of pasture larvae (Group 4; 10,210 L3/kg, Group 5: 10,042 L3/kg) on 17 September. It appeared that a primary infection of T axei was a greater stimulus to serum beta-globul...
Schmidt P, Meyer H, Hübert P, Hafner A, Andiel E, Grabner A, Dahme E.The detection of equine herpesvirus type 1 (EHV-1) in infected cell cultures, and in tissues taken at necropsy, by the in-situ hybridization technique is described. A 4.9 kb Bam HI fragment of EHV-1 vaccine strain RacH was used as a probe after labelling with [alpha-32P] thymidine 5'-triphosphate ([32P]TTP) or digoxigenin-deoxyuridine 5'-triphosphate (dUTP). Both probes specifically detected EHV-1 DNA in either cytospin or paraffin wax-embedded preparations of infected cells. The digoxigenin-labelled probe was further used to examine tissue sections of equine fetuses which had been aborted due...
Magnuson NS, Decker DM, Perryman LE.The effect of adenosine, deoxyadenosine, guanosine, and deoxyguanosine on the growth rate of fibroblasts derived from normal horses, horses heterozygous for the severe combined immunodeficiency (SCID) trait (heterozygotes), and horses with SCID was studied. All four purines were found to inhibit growth in a dose-dependent manner, but only adenosine and deoxyadenosine were inhibitory at concentrations of less than 100 microM. No statistical difference in sensitivity to adenosine was detected between normal and SCID fibroblasts. Fibroblasts from SCID horses were, however, more sensitive to the g...
Zhu ZY, Lin YZ, Wang YH, Zhao LP, Zhu YM, Zhou JH.To disclose the potential roles of humoral immune response in the EIAV vaccine-induced protective immunity. In this study, major parameters of humoral immunity be compared between horses inoculated with the EIAV vaccine strain and the pathogenic virulent strain. Methods: Experimental horses were randomly assigned into the group inoculated with the vaccine strain EIAV(DLV); (the vaccinated group) and the group inoculated with sub-morbigenous dose of virulent strain EIAV(Liao); (the inapparent infection group). Humoral immunity parameters, including binding endpoint titer and avidity index of an...
Black WD, Hartley CA, Ficorilli NP, Studdert MJ.Equine rhinitis B virus (ERBV), genus Erbovirus, is most closely related to the Cardiovirus genus in the family Picornaviridae. The structural proteins (VP1-4) of erboviruses are not well described, but are predicted by sequence to be 35, 29, 26 and 7 kDa. Methods for the purification of cardioviruses (polyethylene glycol, trypsin treatment) were used to characterise the structural proteins of ERBV1. Only one of the virus proteins detected was an expected molecular mass, and this 26 kDa protein was identified as VP3 by N-terminal amino acid sequencing. N-terminal sequencing of the 56 and a 29 ...
Broström H, Troye-Bomberg M, Perlmann P.To analyze in vitro lymphocyte-mediated immune responses of horses with sarcoids against allogeneic sarcoid cells containing endogenous retrovirus but not expressing major histocompatibility complex antigens. Methods: Lymphocyte-mediated immune reactions were assessed by means of proliferative responses in mixed lymphocyte tumor cell culture (MLTC) assay and lymphocyte-mediated cytotoxicity against various equine target cells. Methods: 12 horses with sarcoid tumors and 15 control horses. Methods: Blood lymphocytes were cocultured in MLTC with allogeneic sarcoid cells (Mc-1, BayMc-1), equine te...
Zizzadoro C, Caruso M, Putignano C, Crescenzo G, Ormas P, Belloli C.The effects of endotoxin on β-adrenergic-mediated relaxation were investigated in the equine digital artery (EDA). Possible involvement of cyclooxygenase-2 (COX-2) in endotoxin-induced effects and basal EDA β-adrenoceptor functionality was also evaluated. Endothelium-intact (e(+)) and/or -denuded (e(-)) EDA rings were incubated overnight with lipopolysaccharide (LPS), LPS+NS398 (selective COX-2 inhibitor) or NS398 alone. Vessel rings were then mounted in organ baths and relaxant responses to isoproterenol (ISOP) recorded on U44069-induced pre-contraction. Response to ISOP was further evaluat...
Hurley DJ, Berghaus LJ, Hurley KA, Moore JN.To evaluate effects of black walnut extract (BWE) on equine mononuclear cells and determine whether BWE has direct proinflammatory effects. Methods: Mononuclear cells separated from blood samples from 8 horses. Methods: Aqueous BWE was prepared and processed to eliminate contamination with particulates and microbes. A Limulus amoebocyte lysate assay was used to detect lipopolysaccharide (LPS) contamination in the BWE. Mononuclear cells were incubated in minimal essential medium with or without the addition of 0.6% to 10% (vol/vol) BWE. These mononuclear cells were assessed for viability, activ...
van Haeringen H.Investigations for the presence of antibodies to red blood cell antigens were carried out in equine colostrum and serum. Material from 181 mares without clinical disease was tested. The object was to obtain information on the number of mares producing antibodies capable of inducing haemolytic disease in newborn foals. Of the mares 2.8% was positive for haemolysins. These mares are expected to be a risk for haemolytic disease. In addition agglutinating antibodies were identified in 39.2 per cent of the mares examined. It is not known whether or not these antibodies constitute a hazard for the f...
Rush BR.Pharmacologic manipulation of pulmonary immunity plays an important role in primary and adjunct therapy for equine respiratory disease. Frequent exposure to respiratory viral pathogens, strenuous exercise, long distance transport, and inhalation of harmful substances destroy various aspects of the pulmonary defense system and predispose performance horses to development of infectious and noninfectious respiratory disease. Pulmonary immunity may be bolstered by nonspecific immunostimulants to combat primary or secondary immunodeficiency. State of the art technology improves active and passive-s...
Bannai H, Tsujimura K, Kondo T, Nemoto M, Yamanaka T, Sugiura T, Maeda K, Matsumura T.An immunoglobulin G (IgG) subclass response against equine herpesvirus type 1 (EHV-1) infection was investigated in horses that were naïve to EHV-1/4 and those that had previously been exposed to EHV-4. The IgG subclass response was determined by an ELISA using EHV-1-specific recombinant gG protein as an antigen. In most horses naïve to EHV-1/4, IgGa, IgGb, and IgG(T) were induced after experimental infection with EHV-1. In contrast, a subclass response dominated by IgGa and IgGb, with no apparent increase in IgG(T), was observed after EHV-1 infection in horses previously infected with EHV-4...
Karam B, Wilson WD, Chambers TM, Reedy S, Pusterla N.The use of a hemagglutination inhibition (HI) assay to assess humoral immune response to equine influenza virus (EIV) vaccines from various manufacturers administered to previously immunized adult horses was investigated. Subjects were allocated into one of 3 groups and vaccinated with various commercially available vaccines. Groups were subdivided into subjects that received 1 dose of a particular vaccine and those that received a second dose, 30 d later. Serum was collected at various times to assess antibody responses to contemporary EIV Florida sub-lineage strains. Statistical significance...
Mollerach-Gobbi B, Retegui LA, Peña C.The immunochemical behavior of several fragments of equine growth hormone (eGH) was examined using competitive binding assays with antibodies (Abs) to eGH obtained from different sources. Antigenicity was detected within the sequences 5-72 and 73-123 by rabbit Abs to eGH and by three mouse monoclonal antibodies (MAbs) produced by using bovine growth hormone as immunogen, but showing heteroclitic properties towards eGH. The polyclonal Abs to eGH also recognized as immunoreactive two smaller peptides corresponding to the amino acid residues 52-72 and 110-123. By contrast, the heteroclitic Abs to...
Lipscomb DL, Boudreaux MK, Paxton R, Spano J, Welles EG, Schumacher J.To establish the existence of platelet-derived proteins in equine plasma, with the future goal of developing an assay for the detection of in vivo platelet activation. Methods: 5 mature healthy horses. Methods: Platelet-rich plasma and platelet-poor plasma were prepared from anticoagulated blood. Platelets were separated from plasma proteins by gel filtration, then activated with 0.5 microM platelet-activating factor. Protease inhibitors were added, and the released platelet proteins were harvested. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was performed on the released platele...
Espino-Solis GP, Calderon-Amador J, Calderon-Aranda ES, Licea AF, Donis-Maturano L, Flores-Romo L, Possani LD.A three-dimensional model of the alphaX I-domain of the horse integrin CD11c from dendritic cells provided information for selecting two segments of the primary structure for peptide synthesis. Peptide 1 contains 20 amino acids and peptide 2 has 17 amino acid residues. The first spans from position Thr229 to Arg248 of an alpha-helix segment of the structure, whereas peptide 2 goes from Asp158 to Phe174 and corresponds to an exposed segment of the loop considered to be the metal ion-dependent adhesion site. Murine polyclonal antisera against both peptides were generated and assayed in periphera...
Aggarwal N, Holmes MA.Despite the importance of IgG Fc receptors in the regulation of various immunological mechanisms, these receptors have not been well characterised in the domesticated animals including equines. This paper describes the production of two monoclonal antibodies (CVS 59 and CVS 61) that recognise equine IgG Fc receptors. Fusions were conducted using BALB/c mice hyperimmunised with equine peripheral blood mononuclear cells. Hybridoma supernatants were screened on the basis of their ability to inhibit the rosetting of equine antibody coated sheep erythrocytes with equine peripheral blood mononuclear...
Baker JM, Stidworthy M, Gull T, Novak J, Miller JM, Antczak DF.Serological and cellular assays and molecular techniques were used to define features of the major histocompatibility complex (MHC) of the donkey With this information in hand, immune recognition of MHC determinants within and between donkeys and horses was compared. An antibody-mediated, complement-dependent, microcytotoxicity assay using a variety of antisera to donkey histocompatibility antigens, including those induced as a result of intraspecies or interspecies pregnancy in horse mares and jenny donkeys, delineated five donkey leukocyte antigen (DoLA) specificities. Antisera raised across...
Johnson JU, Oxender WD, Berkhoff HA.Effect of estrogen (E2) and progesterone (P4) on uterine antibacterial activity and immunoglobulin concentrations in mares was studied. In 2 in vitro experiments, 6 mixed-breed mares were ovariectomized, and uterine fluid and blood serum were analyzed. Antibacterial assay methods were used to determine inhibitory effects on Streptococcus zooepidemicus of uterine fluid samples collected on days 3, 5, and 8, and serum obtained on day 8 of treatment. Single radial immunodiffusion methods were used to quantify amounts of IgA and IgG in uterine fluid and serum on days 3, 5, 8, and 14 of treatment. ...
Bell K, Arthur H, Breen M.Eleven apparent mutations of the equine plasma transferrin and esterase gene (10 in TF and one in ES) were found in an analysis of approximately 240,000 thoroughbred horses. Eight of the transferrin mutations produced variants not previously recognized in horses. In the two remaining transferrin mutations and the esterase mutation, reduced plasma concentrations of the proteins were demonstrated by immunological techniques and together with the family data indicated the existence of 'null' alleles.
Bakst M, Hadick S, Proudman J, Maruyama K.This study was conducted to determine the crossreactivity of antisera to human prolactin (PRL), adrenocorticotropic hormone (ACTH), and growth hormone (GH) to turkey pituicytes. In addition, crossreactivities of the above antisera and antiserum to turkey GH to pituicytes of turkey, cat, rabbit, horse, owl monkey, and human were evaluated. Results of the immunocytochemical localizations showed that with one exception antisera to human hormones were positive for each species tested. Turkey pituicytes failed to crossreact with antiserum to human GH. Likewise, antiserum to turkey GH failed to cros...
Asmundsson T, Gunnarsson E, Johannesson T.Blood samples were taken from 18 healthy horses (Group A), 15 horses clinically diagnosed to have "haysickness" ("farmer's lung") (Group B), 10 closely related horses (Group C) and 14 inbred horses (Group D). Precipitins in sera were measured by double gel diffusion test against Micropolyspora faeni, Thermoactinomyces vulgaris, Aspergillus fumigatus, Alternaria, Penicillium and Rhizopus species. In Group A, all the horses were precipitin negative except one with a faint reaction to Rhizopus species. In Group B all had precipitin against M faeni. One horse also had precipitins against Rhizopus ...
Tajima M, Fujinaga T, Okamoto Y, Otomo K, Koike T.The relationship between the optimum concentration of mitogen which induces lymphocyte blastogenic response and the receptor occupancy by mitogen was investigated. The receptor occupancies which induced maximal blastogenic activity in equine, bovine and canine peripheral blood lymphocytes (PBL) were 31.1 per cent, 26.5 per cent and 38.4 per cent with phytohaemagglutinin-P, and 48.2 per cent, 17.9 per cent and 24.5 per cent with concanavalin A, respectively. The data clearly show that each animal species had its own optimum concentration of mitogen for stimulation of PBL. Optimum concentration ...
Dhawedkar RG, Jain NC, Mount ME, Bowling AT, Vegad JL.An enzyme-linked immunosorbent assay (ELISA) was standardised and applied for the detection of antiplatelet and antineutrophil antibodies using a heterologous system consisting of equine platelets or neutrophils and antisera raised in rabbits. The standardised technique consisted of using Immulon type 3 plate, 1 per cent gelatine as a blocking solution, poly-L-lysine buffer as a coating solution, unfixed antigen, 90 microliters test serum, horseradish peroxidase conjugated antibody and o-phenylenediamine dihydrochloride as a substrate. The number of unfixed platelets or neutrophils required fo...
