The immune system in horses is a complex network of cells, tissues, and organs that work together to protect the body from pathogens, such as bacteria, viruses, and parasites. This system includes both innate and adaptive immune responses, which function to identify and eliminate foreign invaders. The innate immune response provides an immediate, non-specific defense, while the adaptive immune response involves a more targeted and long-lasting protection through the production of antibodies. Key components of the equine immune system include white blood cells, such as lymphocytes and macrophages, as well as various signaling molecules like cytokines. This page compiles peer-reviewed research studies and scholarly articles that explore the structure, function, and regulation of the immune system in horses, with an emphasis on understanding its role in maintaining equine health and its response to diseases.
James K, Pullar DM, Morton JB, Dalton RG, Nolan B, Woodruff MF.Methods are described for the intravenous administration of equine antilymphocytic globulin (ALG) to renal transplant recipients. The development of circulating antibodies to the equine IgG has been investigated using primary and secondary immunological procedures. The need for primary immunoassay procedures to assess both the immune response and induction of tolerance to equine IgG in ALG treated patients is extensively discussed.
Nansen P, Riising HJ.The metabolism of immunoglobulin classes has been closely examined in several animal species. Although the horse has received much attention in experimental and applied immunology there seems to be little information available on immunoglobulin kinetics in this species. The present report describes the metabolism of equine IgG in 4 healthy, normoimmunoglobulinaemic horses, in 1 horse with hyperimmunoglobulinaemia and in 1 horse with relatively low immunoglobulin levels.
Schmidt NJ, Melnick JL, Wenner HA, Ho HH, Burkhardt MA.Immune horse sera to 42 enterovirus immunotypes were pooled according to the Lim Benyesh-Melnick and the "intersecting serum" schemes. Each serum was diluted in the pools to contain 50 antibody units. After it was established that the pools correctly neutralized prototype virus strains, they were evaluated in tests against 273 enterovirus field strains representing most of the viral types included in the pools. With test virus doses of 10-100 TCD(50), most of the poliovirus and coxsackievirus field strains were correctly identified in both schemes, but a number of the echoviruses were neutrali...
Montgomery PC, Bello AC, Rockey JH.N-terminal tetrapeptides from heavy chains of equine γGab- and γT-globulins, and of human γG and γA myeloma proteins and a γM macroglobulin, have been studied. The equine and human heavy chains lacked free α-amino-terminal groups. After mild alkaline hydrolysis, glutamic acid was identified as the terminal amino acid by reaction with dimethylaminonaphthalenesulfonyl chloride, tentatively identifying pyrrolid-2-one-5-carboxylic acid (PCA) as the unreactive terminal residue of each heavy chain. Peptides lacking a free α-amino group were isolated from subtilisin and pronase digests of the ...
Tajima M, Nakajima H, Ito Y.Equine infectious anemia (EIA) virus was observed in thin sections of infected cultured horse leukocytes by electron microscopy. The virus particles had a spherical shape and were between 80 and 120 nm in diameter. Most of them contained an electron-dense nucleoid 40 to 60 nm in diameter. They were observed to form by a process of budding from the plasma membrane and appeared to have thin surface projections. The particles described were not detected in uninfected cultured cells, and their appearance could be prevented by adding EIA immune serum to the inoculum. The implications of these findi...
Kasel JA, Couch RB.The recognition of an antigenic relationship between the haemagglutinins of A/Equi-2 and A2/Hong Kong/68 viruses led to experimental studies in man and horses with these virus types.Human volunteers were inoculated with A/Equi-2/Miami/63 virus and virus shedding ensued in all subjects. The most common clinical response was a febrile illness indistinguishable from naturally occurring human influenza. After administration of A2/Hong Kong/68 virus to 10 ponies there was virus shedding from 9 and a febrile response in 6.When the human subjects previously inoculated with equine virus were challenge...
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...
Hampil B, Melnick JL.This paper summarizes the results of the second part of co-operative studies undertaken by the WHO International Reference Centre for Enteroviruses and a number of WHO Regional Virus Reference Centres, WHO Virus Collaborating Laboratories and other laboratories in a comprehensive testing programme of enterovirus equine antisera. The studies were designed to appraise the specificity of immune serum prepared in horses against 16 representative prototype enteroviruses (polioviruses 2 and 3, coxsackieviruses A7, B1, B2, B4, B5 and B6 and echoviruses 1, 2, 3, 5, 7, 9, 12 and 17). Tests for neutrali...
Domańska D, Trela M, Pawliński B, Podeszewski B, Domino M.The somatic cell count in milk (SCC) and electrical conductivity of milk (ECM) are indicators of the health status of the mammary gland. Among somatic cells, mainly polymorphonuclear neutrophils (PMN), macrophages (MAC), and lymphocytes (LYM) are rated. This study aimed to determine the SCC, PMN, MAC, LYM, ECM, and bacteriological index (BII) in milk collected from mares with (CM) and without (NCM) clinical symptoms of mastitis concerning mares with (SM) and without (NSM) subclinical mastitis. Milk samples were collected from 27 mares divided into NCM (n = 12) and CM (n = 15) groups. In sample...
Gilger BC, Salmon JH, Wilkie DA, Cruysberg LP, Kim J, Hayat M, Kim H, Kim S, Yuan P, Lee SS, Harrington SM, Murray PR, Edelhauser HF, Csaky KG....To determine the feasibility, safety, and effectiveness of an episcleral or deep scleral lamellar sustained release cyclosporine (CsA) device in a naturally occurring animal model of uveitis. Methods: A two-compartment perfusion chamber was used to assess in vitro human and equine scleral permeability of fluorescein, dexamethasone-fluorescein, or CsA. A biodegradable, matrix-reservoir CsA implant was designed, and release rates of CsA were determined in vitro. Tissue CsA levels were measured in eyes with the implant. Horses with equine recurrent uveitis (ERU) received episcleral or deep sclera...
Ryu SH, Koo HC, Lee YW, Park YH, Lee CW.Infectious upper respiratory disease (IURD) of Thoroughbred racehorses has been a frequent problem (29.6% of incidence) at the Seoul Race Park (Korea). Risk factors for IURD include the season with a high transfer rate (summer and fall), the stabling period (≤ 3 months), and age (2 to 3 years old), suggesting that the movement and new environment may have depressed the immune system of the horses and decreased their ability to respond properly to pathogens. The bacterial strains (n = 98) isolated from IURD horses included Pseudomonas spp., Escherichia coli, Staphylococcus spp., Streptococcus...
Dubin A, Potempa J, Turyna B.Horse blood leucocyte cytosol exhibits a broad inhibitory activity against serine proteinases. The purified inhibitor was exposed to investigated enzymes (trypsin, chymotrypsin, elastases and serine proteinase from S. aureus) for variable time and the products were analyzed by gradient polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate. The molar ratio I:E, association rate constants k on and inhibition constants Ki for the enzymes and inhibitor were determined. The examined elastases form stable, stoichiometric complexes with the inhibitor (Ki less than 10(-10) M), ...
McKibbin LS, Cheng RS.This study showed that subcutaneous injection of a solution of D-amino acids produced effective analgesia in horses. It is postulated that systemic D-phenylalanine and D-leucine may become one of the safe, effective and nonaddictive drugs for acute and chronic pain treatment. These D-amino acids cause analgesia by presumably preserving brain endorphins. They may bind reversibly to enkephalinases and prevent enzymatic degradation of enkephalins.
Pellegrini A, Hägeli G, Fretz D, von Fellenberg R.An electrophoretic procedure for the qualitative and quantitative assay of protein protease inhibitors is reported. This assay is particularly suited for investigations of crude biological materials when specific antisera are not available. The supporting medium consists of agarose into which denatured fibrinogen is incorporated as the substrate for proteases. The processing then is divided into two steps: (1) electrophoretic resolution of the inhibitor containing material and (2) detection of the inhibitor bands through their protease inhibiting activity. The inhibitor position is thus made v...
Slater J, Hannant D.The identification of some of the adaptive immune responses to infection with equine viruses has been the first step toward rational immunoprophylactic design. Sufficient knowledge of infection-induced immunity and informed estimates of the requirements for long-term immunity for EIV have now been obtained. Thus, the future for inactivated EIV vaccines is promising now that new adjuvants have been applied to induce cellular immunity and safe methods have been designed to stimulate virus-neutralizing (VN) antibody at mucosal surfaces. Adenoviruses induce circulating VN antibody, the presence of...
Esser AF, Tarnuzzer RW, Tomlinson S, Tatar LD, Stanley KK.Lack of hemolytic activity of horse serum is an inherent property of horse C9. To understand the molecular reasons for this deficiency we have cloned C9 cDNA from a horse liver cDNA library and have sequenced the cDNA yielding the complete coding sequence for horse C9. Purification of C9 from horse plasma and microsequencing established the N-terminus of the mature protein and verified that the correct horse C9 cDNA clone had been isolated. The deduced amino acid sequence corresponds to a mature protein of 526 amino acids that is 77% identical to human C9. It has the same domain structure as h...
Hamza E, Torsteinsdottir S, Eydal M, Frey CF, Mirkovitch J, Brcic M, Wagner B, Wilson AD, Jungi TW, Marti E.Insect bite hypersensitivity (IBH) is an IgE-mediated dermatitis of horses caused by bites of Culicoides spp. IBH does not occur in Iceland where Culicoides are absent. However, following importation into continental Europe where Culicoides are present, >or=50% of Icelandic horses (1st generation) develop IBH but
Lee GKC, Kang H, Beeler-Marfisi J, Sears W, Lillie BN, Bienzle D.Salivary scavenger and agglutinin (SALSA) is a secreted protein with various immunomodulatory roles. In humans, the protein agglutinates and inactivates microorganisms, and inhibits the release of pro-inflammatory cytokines. Saliva, which is rich in SALSA, accelerates bacterial phagocytosis, but SALSA's contribution is unclear. In horses, the functions of SALSA in inflammation remain undetermined, so they were investigated through phagocytosis and cytokine assays. Equine SALSA was purified from duodenal tissue, which contains abundant SALSA. To assess phagocytosis, fluorescently-labelled bacte...
Degroote RL, Hauck SM, Treutlein G, Amann B, Fröhlich KJ, Kremmer E, Merl J, Stangassinger M, Ueffing M, Deeg CA.Autoimmune uveitis is characterized by crossing of blood-retinal barrier (BRB) by autoaggressive immune cells. Equine recurrent uveitis (ERU) is a valuable spontaneous model for autoimmune uveitis and analyses of differentially expressed proteins in ERU unraveled changed protein clusters in target tissues and immune system. Healthy eyes are devoid of leukocytes. In ERU, however, leukocytes enter the inner eye and subsequently destroy it. Molecular mechanisms enabling cell migration through BRB still remain elusive. Previously, we detected decreased talin 1 expression in blood-derived granulocy...
Parrilla Hernández S, Franck T, Munaut C, Feyereisen É, Piret J, Farnir F, Reigner F, Barrière P, Deleuze S.Myeloperoxidase (MPO), as a marker of neutrophil activation, has been associated with equine endometritis. However, in absence of inflammation, MPO is constantly detected in the uterine lumen of estrous mares. The aim of this study was to characterize MPO in the uterus of mares under physiological conditions as a first step to better understand the role of this enzyme in equine reproduction. Total and active MPO concentrations were determined, by ELISA and SIEFED assay, respectively, in low-volume lavages from mares in estrus ( = 26), diestrus ( = 18) and anestrus ( = 8) in absence of endometr...
Sedgwick AD, Lees P, Dawson J, May SA.The migration of leucocytes to sites of acute and chronic inflammation is an event of central importance to the maintenance of inflammatory processes; extravascular leucocytes are responsible for generating chemical mediators of inflammation and the phagocytosis of particulate matter. They may also be involved in the conversion of acute to chronic inflammatory lesions. Leucocytes are attracted to sites of tissue injury by a range of chemoattractants. This paper describes the development of a method for separating on Percoll gradients purified populations of equine polymorphonuclear and mononuc...
Milam SB, Mackay RJ, Skelley LA.Secretion of tumor necrosis factor (TNF) by equine mammary exudate macrophages (MEM phi) exposed to bacterial lipopolysaccharide (LPS) was dose-dependent and was maximal (216.5 +/- 51.9 U/ml) at 100 micrograms LPS/ml, the highest concentration tested. All concentrations of dexamethasone tested (10(-8) to 10(-4) M) significantly (P less than or equal to 0.05) inhibited TNF production by MEM phi when the agent was added 1 hour before LPS. Pretreatment with pentoxifylline at concentrations greater than 3 micrograms/ml also significantly (P less than or equal to 0.05) reduced secretion of TNF by M...
Leise BS, Yin C, Pettigrew A, Belknap JK.Further knowledge of equine keratinocyte physiology and keratinocyte response to various stimuli is important in developing a better understanding of disease states involving the epidermis. Objective: To assess the inflammatory cytokine response of cultured equine keratinocytes to various pathogen-associated molecular pattern molecules (PAMPs) from both Gram-negative and positive bacteria likely to be present in equine sepsis. Methods: Keratinocytes were isolated from skin of 2 horses and primary cultures performed. Keratinocytes were harvested for RNA extraction after exposure to lipopolysacc...
Perryman LE, McGuire TC.Between January 1973 and September 1979, 2,092 horses and ponies were evaluated for immunologic disorders. A total of 418 abnormalities were detected in 416 (20%) of the animals tested. Disorders encountered were failure or partial failure of colostral immunoglobulin transfer from mare to foal (228 cases), combined immunodeficiency (159 cases), selective immunoglobulin M deficiency (19 cases), agammaglobulinemia (3 cases), transient hypogammaglobulinemia (2 cases), and lymphosarcoma (7 cases). Four conclusions were drawn from the study. (1) Immunologic abnormalities occur commonly in horses an...
McDonald J, Gall R, Wiedenbach P, Bass VD, DeLeon B, Brockus C, Stobert D, Wie S, Prange CA, Ozog FJ.A one step enzyme-linked immunosorbent assay (ELISA) test for morphine was evaluated as part of a panel of pre- and post-race tests for narcotic analgesics in racing horses. This ELISA test is very sensitive to morphine with an I-50 for morphine of about 400 pg/ml. The test is also rapid, and ten samples, a normal pre-race complement, can be analyzed in about thirty minutes. The test can be read with an inexpensive spectrophotometer, or even by eye. The test readily detects the presence of morphine or its metabolites in equine blood for up to six hours after administration of sub-therapeutic d...
Balena V, Pradhan SS, Bera BC, Anand T, Sansanwal R, Khetmalis R, Madhwal A, Bernela M, Supriya K, Pavulraj S, Tripathi BN, Virmani N.Equid alphaherpesvirus 1 (EHV-1) infection causes significant health problems in equines. The EHV-1 infection leads to abortion storm in mares, respiratory disease and myeloencephalopathy. Despite the wide use of vaccines, the outbreaks of EHV-1 infections keep occurring globally, suggesting the need for the development of improved vaccines. Gene deletion attenuated mutant viruses could be a good candidate for the development of modified live vaccines. Here, we report the generation of mutant EHV-1 by deleting virulence (glycoprotein E & internal repeat 6; IR6) and immune evasive (pUL43 &a...
Morris DD, Henry MM, Moore JN, Fischer K.In laboratory animals, the incorporation of alpha linolenic acid or other n-3 series fatty acids into the diet results in marked changes in cell membrane composition as well as arachidonic acid metabolism. The purpose of the present study was to determine whether endotoxin-induced thromboxane A2 (TxA2) and/or prostacyclin (PGI2) production by equine peritoneal macrophages was altered by feeding horses a diet containing 8% linseed oil as a source of alpha linolenic acid for 8 weeks. Peritoneal macrophages were cultured in vitro in the presence of endotoxin (LPS) (0.5-500 ng/ml) or calcium ionop...
Bertram TA.Differences in neutrophil morphology between various species of domestic animals are evident when morphometric techniques are used. Morphometric analysis can be coupled with functional assays of degranulation to demonstrate changes in granule volume after neutrophil activation (Bertram and Jensen, 1984). Morphometric and functional analysis of the neutrophil can also be used to evaluate the response of neutrophils to infectious agents (Coignoul et al., 1984a). Comparison of these assays between animal species may provide insight into the susceptibility of animals to various microbial pathogens...
Blue HB, Blue MG, Kenney RM, Merritt TL.Forty uterine fluid samples were obtained from 4 mares classified as resistant to uterine bacterial infection. The uterus of each mare was flushed with 50 ml of saline solution during estrus and diestrus of successive estrous cycles. Bacteria or fungi were isolated from 4 samples, and 7 additional samples were obtained from a mare with active intrauterine infection. Fluid volumes obtained during estrus (means = 40.3 +/- 11 ml) tended to be greater than those recovered during diestrus (means = 36.8 +/- 7.9 ml), but the difference was not significant. Concentrations and yields of protein in reco...
Piccione G, Rizzo M, Arfuso F, Giannetto C, Di Pietro S, Bazzano M, Quartuccio M.During early post-partum period both neonatal foals and peripartum mares are most susceptible to diseases. The aim of this study was to establish physiologic modifications of leukogram during the first month after foaling in mares and their newborn foals. To this end blood samples were collected from nine mares and nine foals (T0-T10), every three days from the 1st day until the 30th day after foaling. Samples were analysed for white blood cell (WBC) count and differential leucocyte counts. Two-way repeated measure analysis of variance (ANOVA) showed, in postpartum mares WBC showed significant...
Bougrine SI, Fihri OF, Fehri MM.A Western immunoblotting procedure has been developed for the detection of African horse sickness virus (AHSV) protein-specific antibody responses. This assay readily identifies antibodies specific for at least 4 distinct, AHSV proteins, including VP5, NS1, NS2 and NS3/NS3a. By using the AHSV non-structural proteins as 'markers', the Western blotting procedure could be employed to provide a reliable means of discriminating between animals vaccinated with a purified, inactivated AHSV vaccine and those either naturally infected or vaccinated with a live, attenuated AHSV vaccine.
Guelfi JF, Kraouchi DE.Chemotaxis and superoxide anion production of neutrophils in healthy horses were investigated before and 8 h after, a single injection of dexamethasone at a dose of 0.045 mg/kg. Chemotaxis was studied by the technique of migration under agarose and superoxyde production was measured by ferricytochrome c reduction. Superoxide anion production was not changed, but the chemotactic index, with zymosan activated horse serum, was increased. The FMLP chemoattractant effect, at 10(-4) M, was slightly enhanced.
Gupta SK.Mammalian zona pellucida (ZP) is composed of three to four glycoproteins, which plays an important role during fertilization. Mutations in the genes encoding zona proteins are reported in women with empty follicle syndrome, degenerated oocytes and those with an abnormal or no ZP further emphasizing their relevance during fertility. Immunization with either native or recombinant ZP glycoproteins/proteins leads to curtailment of fertility in various animal species. Observed infertility is frequently associated with ovarian pathology characterized by follicular atresia and degenerative changes in...
Lopez BS, Hurley DJ, Giancola S, Giguère S, Hart KA.Immunological and endocrine immaturity in foals increases foal morbidity and mortality from bacterial sepsis. Dendritic cells (DC) are critical in activating the adaptive immune response, but foal DC are phenotypically and functionally different than those of adult horses. Age-related variations in availability of some soluble plasma factors, such as hormones, might govern some age-related differences in DC function. Effects of exposure to plasma factors on equine DC phenotype and function have not been described. We hypothesized that exposure to plasma from foals or adult horses would differe...
Rółkowski R, Worowski K, Skrzydlewski Z.Antiheparin activity of plasma of different species of vertebrates depends to a large extent on contents of low density lipoproteins (LDL). High antiheparin activity of the blood plasma of chicken and human corresponds to high contents of LDL and low antiheparin activity of the blood plasma of horse, cow, sheep, dog and pig corresponds to decreased contents of these proteins. Differences in the contents of fibrinogen, acid alfa1-glycoproteins, globulins, alkaline proteins and antithrombin III activity have smaller influence on antiheparin activity in the blood plasma of the examined animals.
Bossut DF, Leshin LS, Stromberg MW, Malven PV.Electro-acupuncture (EA) treatment of horses to induce cutaneous analgesia also increased plasma concentrations of beta-endorphin (beta-EP) and cortisol. The magnitude of these increases did not relate consistently to the degree of EA-induced analgesia. Respiration and heart rates were also markedly increased during EA treatment. Intact female horses had higher packed cell volume and plasma beta-EP as well as lower plasma total protein than castrated male horses. Plasma cortisol, heart rate, and respiration rate did not differ significantly between sexes. None of the parameters measured before...
Janda J, Plattet P, Torsteinsdottir S, Jonsdottir S, Zurbriggen A, Marti E.Allergic horses react to innocuous environmental substances by activation of Th2 cells and production of allergen-specific IgE antibodies. The mechanisms leading to Th2 differentiation are not well understood. In humans and mice, epithelial cell-derived thymic stromal lymphopoietin (TSLP) plays a central role in this process. Little is known about equine TSLP (eqTSLP) and its role in allergic diseases and our current knowledge is limited to the assessment of TSLP mRNA expression. In order to be able to study eqTSLP at the protein level, the aim of the present study was to produce recombinant e...
Kettler MK, Weil MR, Mascotti K, Perryman LE.A group of diseases termed combined immunodeficiency (CID) results in a severe form of immunodeficiency. While CID in humans has two genetics bases, in Arabian it is inherited in an autosomal recessive manner. Kettler et al. (1989) determined that uric acid was significantly (p 0.05) between carrier and non-carrier horse's serum levels of hypoxanthine or xanthine. These data, combined with our previous ones suggest that an enzymatic lesion in the purine salvage pathway may occur at the urate oxidase step. ZUSAMMENFASSUNG: Serum-Hypoxanthin- und -Xanthin-Spiegel in Pferden mit Heterozygotie fÃ...
