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.
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...
Curran JA, Argyle DJ, Cox P, Onions DE, Nicolson L.Interferon gamma, a cytokine produced by T-lymphocytes and natural killer cells, plays a central role in the modulation of the immune response, and its antiviral and antitumourigenic properties have made it a potential candidate for use in immunoprophylactic and therapeutic regimes. We have cloned the equine IFN gamma cDNA to facilitate production of this cytokine for clinical evaluation in the horse. The predicted equine IFN gamma amino acid sequence is 67% identical to that of the human equivalent and 78% to the bovine equivalent.
Schrenzel MD, Watson JL, Ferrick DA.Genes encoding the horse (Equus caballus) T-cell receptor beta chain (TCRB) were cloned and characterized. Of 33 cDNA clones isolated from the mesenteric lymph node, 30 had functionally rearranged gene segments, and three contained germline sequences. Sixteen unique variable segments (TCRBV), 14 joining genes (TCRBJ), and two constant region genes (TCRBC) were identified. Horse TCRBV were grouped into nine families based on similarity to human sequences. TCRBV2 and TCRBV12 were the most commonly represented horse families. Analysis of predicted protein structure revealed the presence of conser...
Timoney JF, Mukhtar MM.The group C streptococci are the most commonly isolated bacteria from disease states in the horse. Important virulence factors of S. equi and S. zooepidemicus are the hyaluronic acid capsule and the antiphagocytic fibrillar M protein located on the surface of the cell wall and extending into and through the capsule. The hyaluronic acid capsule is non-antigenic and so is not involved in protective immunity. The M protein, a superantigen, elicits very strong B and T cell responses that may result in protective immunity mediated by opsonic antibodies in plasma and by locally synthesized IgG and I...
McCulloch J, Williamson SA, Powis SJ, Edington N.It has been suggested that EHV-1 infection may perturb immune responsiveness in the natural equine host. The mechanism underlying this phenomenon is not clear, but disturbances of circulating leucocyte populations could contribute. In order to objectively assess the nature of the haematological changes provoked by EHV-1 infection, two groups of conventionally-maintained Welsh mountain ponies were challenge-infected intra-nasally with the Ab4 isolate of EHV-1. These groups were controlled by similarly-sized groups of non-infected ponies. All data generated was subjected to rigorous statistical ...
Troedsson MH, Liu IK, Thurmond M.In vitro phagocytosis and chemotaxis of uterine and blood-derived polymorphonuclear neutrophils (PMNs) were compared in mares with different resistance to chronic uterine infection (CUI). Both the primary in vitro function of PMNs and the role of uterine environmental factors on PMN function were investigated. The uteri of mares susceptible to (n = 6) and resistant to CUI (n = 5) were inoculated with 5 x 10(6) Streptococcus zooepidemicus when the mares were in estrus. Uterine secretions in addition to uterine and blood-derived PMNs were sampled at 5 and 24 h later. During a subsequent estrus, ...
Boschwitz JS, Timoney JF.A rapid method for purifying equine C3 which yields milligram quantities of pure C3 is described. Protein from equine plasma was selectively precipitated with polyethylene glycol, and the C3 was purified by anionic and cationic exchange HPLC. The yield from this procedure was 12%. The purified C3 was composed of an alpha chain (118 kD) and a beta chain (68 kD) linked by at least one disulfide bond, and it had an isoelectric point of 4.7. Amino acid analysis indicated a strong conservation of amino acid usage between equine and human C3. The N-terminal sequences of the alpha and beta chains wer...
Art T, Lekeux P.This study was conducted in order to assess whether exercise- and training-induced cardio-respiratory adjustments are modified during the 10-day period which follows a booster vaccination with an oily adjuvanted inactivated vaccine against influenza and equine herpesvirus-1 (Equiffa). Nine healthy vaccinated thoroughbred horses were used. Six were revaccinated and three were kept as control. All the horses completed a standardised exercise test (SET) that was repeated 4 times, i.e. 10 (SET1) and 2 (SET2) days before revaccination, and 2 (SET3) and 10 (SET4) days after revaccination. During the...
Robinson JA, Allen GK, Green EM, Garner HE, Loch WE, Walsh DM.Serum interleukin-6 (IL-6) concentration was measured in 11 colostrum-fed (CF) and 8 colostrum-deprived (CD) 2- to 3-day-old foals after foals were infused with lipopolysaccharide (LPS; Escherichia coli O55:B5 endotoxin, 0.5 microgram/kg of body weight in sterile saline [0.9% NaCl] solution). Four CF and 2 CD foals were given saline solution alone. Serum IL-6 concentration was estimated by use of an in vitro proliferative bioassay, using the IL-6 dependent B.13.29 clone 9 cells. Interleukin-6 concentration increased in all LPS-infused foals, and geometric mean serum IL-6 concentration was sign...
Prescott JF, Hoffman AM.This article summarizes recent advances in understanding of the epidemiology, pathogenesis, clinical and laboratory diagnosis, immunology, treatment, and control of Rhodococcus equi infections in foals. Our understanding of these aspects currently is sufficient to ensure control of this problem on affected farms and in infected foals. More information, however, is needed on factors predisposing foals to R. equi pneumonia, in particular, the nature of the naturally occurring cellular immunodeficiency in foals of 2 to 4 months of age, which also predisposes them to severe respiratory infection w...
Scudamore CL, Pemberton A, Watson ED, Miller HR.Studies have demonstrated that as a result of proteolytic inactivation or complex formation (with neutrophil elastase), human alpha-1-proteinase inhibitor (API) becomes a potent chemoattractant for human neutrophils. The present study aimed to investigate the in vitro chemotactic response of equine neutrophils to an equivalent complex of equine API and neutrophil elastase. No evidence of neutrophil migration was observed towards purified complex derived from equine neutrophil elastase and the Spi 1 isoform of equine API, or to crude mixtures of porcine pancreatic elastase and unseparated equin...
Evans MJ, Kitson NE, Livesey JH, Donald RA.Perifused equine anterior pituitary cells were used to investigate the effect of cortisol on the ACTH response to pulses of corticotrophin-releasing hormone (CRH; 0.01 nmol/l) and arginine vasopressin (AVP; 100 nmol/l), given for 5 min every 30 min for 690 min and ACTH measured in 5-min fractions. At the fourth pulse of secretagogue (0 min), a constant perifusion with cortisol began (0 nmol/l (control), 100, 200, 500, 5000 and 50,000 nmol/l) and continued until the ninth pulse (150 min). For each pulse of secretagogue, the amount of ACTH (pmol) secreted in response to each pulse (ACTH response...
Coyne CP, Fenwick BW, Iandola J, Williams D, Griffith G.Objectives of this investigation were to extract and isolate protein fractions inhibitory to the cytotoxic properties of tumor necrosis factor-alpha (TNF-alpha). In this context, mixed populations of WBC were harvested from equine blood and were stimulated with a combination of a synthetic chemotactic peptide and a calcium ionophore. Several methods were subsequently applied for the initial preparation of cell-free crude protein extracts, including fractional precipitation with gradient concentrations of ammonium sulfate and preparative-scale isoelectric focusing. In addition, protein fraction...
Madison JB, Ziemer EL.Purified streptococcal M protein was injected into one intercarpal joint in three horses hyperimmunised with Streptococcus equi M protein vaccine. The contralateral joints were injected with pH adjusted polyionic solution. All antigen-injected joints developed a severe suppurative synovitis (mean synovial fluid nucleated cell count = 102,200 x 10(6) cells litre-1). Eosinophils were found in the synovial fluid and in synovial membrane biopsy specimens of two of the horses. Immune complexes were not demonstrated in the synovial membrane. Two horses are described that developed synovial fluid eos...
Lunn DP.Monoclonal antibody technology has allowed the recognition and study of numerous leucocyte antigens in man and laboratory animals for over a decade. Numerous advances in the understanding of immune responses and immunopathology have resulted. In recent years equine researchers have started to develop similar reagents, which now offer a powerful tool to investigators of equine immunology and disease.
Tewari D, Gibson JS, Slater JD, O'Neill T, Hannant D, Allen GP, Field HJ.EHV-1 was inoculated into specific pathogen-free (SPF) foals in order to study uncomplicated primary responses. Infection resulted in a strong serological response recognizing EHV-1-specific antigens; this contrasts with a previous publication where a weak response was recorded in SPF animals. Antibodies to EHV-1 were readily detected by four techniques (virus neutralization, complement fixation, Western blots and immune precipitation), yet there was comparatively little cross-reaction to EHV-4 target antigen. Re-inoculation with the same virus strain stimulated antibodies to EHV-1 but no addi...
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.
Fitzpatrick JL, Bailey M, Harbour DA, Stokes CR.Adult ponies which were fed ovalbumin (OVA) daily for 2 weeks had significantly greater serum anti-OVA IgG (P = 0.001) and antigen specific lymphocyte responses (P = 0.031) after intramuscular injection with OVA given with saponin than control ponies which had not been fed the antigen. This suggests that, despite the lack of evidence of B- or T-cell activation in peripheral blood during the period of OVA feeding, the animals were primed for an active secondary immune response. Adult ponies were challenged with equine rotavirus, strain H-2, but no statistically significant differences were foun...
Moore RM, Schneider RK, Kowalski J, Bramlage LR, Mecklenburg LM, Kohn CW.Bacterial culture and susceptibility results were analysed from 233 horses with septic arthritis/tenosynovitis or osteomyelitis that developed after fracture repair. Antibiotics were deemed highly effective, effective or ineffective if > or = 85%, 70-84.9% or < 70% of the isolates were susceptible respectively. In total, 424 bacterial types were isolated; 386 were aerobic or facultative and 38 were anaerobic. Enterobacteriaceae (28.8%) were the most common bacterial group isolated, followed by non-beta-haemolytic streptococci (13.0%), coagulase-positive staphylococci (11.8%), beta-haemol...
McConnico RS, Roberts MC, Tompkins M.A 5-year-old female American Quarter Horse was determined to have immune-mediated hemolytic anemia after detection of a positive response to a direct Coombs' test. Penicillin-induced immune-mediated hemolytic anemia was confirmed via a direct antiglobulin test, using penicillin-coated RBC. The horse was clinically improved and the anemia resolved in response to supportive care and discontinuation of penicillin treatment. Penicillin should be considered a possible cause of immune-mediated hemolytic anemia in horses.
Weiss DJ, Geor RJ, Burris SM, Smith CM.Pentoxifylline has been reported to improve peripheral vascular circulation by altering the flow properties of blood. To determine if the hemorrheological effects of pentoxifylline were mediated by alterations in neutrophil function and/or flow properties, we evaluated the drug's effects on equine neutrophils in vitro. Pentoxifylline, at a concentration of 1 x 10(-1) M, but not at concentrations of 1 x 10(-6) M to 1 x 10(-2) M, markedly suppressed neutrophil superoxide production, zymosan phagocytosis and adherence to nylon wool. Pentoxifylline failed to improve neutrophil filterability throug...
Chong YC, Duffus WP.Four foals were raised under specific pathogen free (SPF) conditions. At 3 to 4 months of age, SPF foals and 1 other non-SPF foal were intranasally inoculated with equine herpes virus type 1 (EHV-1). Clinical signs included depression, fever, inappetence and intermittent coughing. Clinical recovery was complete by seven days but high titres of virus were detected in nasal mucus for at least 10 days after inoculation. Clinical illness was less severe in the non-SPF foal. Interferon was detected in the nasal mucus of all foals from 2 days post infection (dpi), persisting until 8 or 10 dpi. ELISA...
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...
Singh RK, Kooreman KM, Babbs CF, Fessler JF, Salaris SC, Pham J.The scavenging of superoxide radicals by endogenous and therapeutically administered superoxide dismutases may prevent superoxide-mediated oxidative stress leading to lipid peroxidation, membrane lysis, and cell death in a wide variety of normal and pathologic states. Simple inorganic manganous salts such as MnCl2 also have superoxide dismutase-like activity and are extremely inexpensive, compared with enzymatic superoxide dismutase preparations. In this study, we explored the use of Mn salts as antioxidant drugs. We used the percentage of inhibition of nitroblue tetrazolium reduction by super...
Muirhead FS.Equine infectious disease remains a constant and important threat to the health of domesticated horses. Vaccination plays a critical role in protecting against such disease, but at the present time the efficacy of some equine vaccination strategies is in doubt. The best strategy for resolving these concerns is an improved knowledge of the immunologic basis of successful vaccination, combined with the appropriate integration of effective vaccines into well-designed disease control policies.
Mendoza L, Villalobos J, Calleja CE, Solis A.Two vaccines to treat phythiosis insidiosi in horses were evaluated in 71 Costa Rican horses between 1982 to 1988. One vaccine used a cell-mass (CMV) as antigen and the other a soluble concentrated antigen (SCAV). Both vaccines cured horses infected with Pythium insidiosum (p value approximately 14%). The age of lesions prior to vaccination was important in the response of the horses to immunotherapy. All horses with lesions 0.5 months or less in duration were cured regardless of the vaccine used. Horses with lesions two or more months old did not respond to either vaccine. The age of the hors...
Laviada MD, BabÃn M, Dominguez J, Sánchez-VizcaÃno JM.A sandwich enzyme-linked immunsorbent assay (ELISA) for rapid detection of African horsesickness virus (AHSV) in infected spleens or cell culture supernatant was developed. This method uses two monoclonal antibodies (MAbs) which recognize two non-overlapping epitopes of the major core protein (VP7) to coat the solid phase, and one labeled with biotin as second antibody. This ELISA was evaluated for its ability to detect AHSV in infected spleens resulting in a sensitivity of 97.4% and a specificity of 100% compared with virus isolation in cell culture, and can be used for the detection of the n...
Henry MM, Moore JN, Fischer JK.Because certain inflammatory processes are dependent on the fatty acid composition of the cellular membrane, dietary manipulations that replace omega-6 fatty acids with omega-3 fatty acids may modify inflammatory responses. We investigated the effect of supplemental dietary linseed oil, containing the omega-3 fatty acid, alpha-linolenic acid, on in vivo responses of horses to endotoxin. One group of horses (n = 6) was fed a control pelleted ration (0% linseed oil), and another group of horses (n = 6) was fed an 8% linseed oil pelleted ration. After 8 weeks of consuming these rations, all horse...
Sano Y, Matsuda K, Okamoto M, Takehana K, Hirayama K, Taniyama H.Antigen-presenting cells (APCs) in the uveal tract participate in ocular immunity including immune homeostasis and the pathogenesis of uveitis. In horses, although uveitis is the most common ocular disorder, little is known about ocular immunity, such as the distribution of APCs. In this study, we investigated the distribution of CD163-positive and MHC II-positive cells in the normal equine uveal tract using an immunofluorescence technique. Eleven eyes from 10 Thoroughbred horses aged 1 to 24 years old were used. Indirect immunofluorescence was performed using the primary antibodies CD163, MHC...
Mitlehner W, Mitlehner HC.A horse allergic rider completed 60 riding lessons on Curly Horses within six months. This rider has become clinically tolerant to normal horse breeds within this time. This case may indicate that riding and brushing ABCR Curly Horses after 60 riding hours facilitates tolerance induction. Our data indicate that this could be a valid alternative to the common recommendation to strictly avoid horse riding. Eine pferdeallergische Reiterin erhielt 60 Reitstunden auf „Curly Horses“ innerhalb von 6 Monaten. Die Reiterin tolerierte die Allergenexposition mit Pferden anderer Rassen innerhalb diese...
Chong YC, Duffus WP, Hannant D.Peripheral blood mononuclear cells (PBMC) from an adult horse and from foals demonstrated natural killer (NK)-type cytotoxicity against a range of xenogeneic and allogeneic cell targets. The human tumour cell line, Chang liver was consistently the most susceptible. Chang liver, rabbit kidney (RK-13), equine sarcoid (ES) and embryonic equine kidney (EEK) cells were more susceptible when presented to horse PBMC than monolayer cultures. Embryonic equine lung (EEL) and murine YAC-1 cells conversely, were more susceptible in a trypsinized state. Horse PBMC demonstrated higher levels of NK-type acti...
Heyneman RA.The subcellular distribution of the superoxide-forming enzyme in horse polymorphonuclear leukocytes was investigated. After activation of the cells with sodium oleate, a relatively stable and NAD(P)H-dependent oxygen consumption and superoxide production was found in association with the plasma membranes. The pH dependence displayed an optimum near neutrality. The apparent Km values were 38 x 10(-6) mol/l for NADPH and 1,560 x 10(-6) mol/l for NADH, suggesting that NADPH is the physiological donor. The rates of oxygen uptake, O2- production, and NADP consumption were consistent with the stoich...
Strzemienski PJ, Dyer RM, Kenney RM.Neutrophils isolated from jugular blood of ovariectomized mares were studied for the effect of estradiol and progesterone on bactericidal activity against Staphylococcus aureus. In experiment 1, neutrophils obtained from 4 mares were tested for bactericidal activity by adding estradiol (43 pg/ml) or progesterone (6.4 ng/ml) to the bactericidal assay. In experiment 2, 3 of the 4 ovariectomized mares were given 2 mg of estradiol, IM, daily for 3 days. Eighteen days after the initial estradiol injection, mares were given 300 mg of progesterone, IM, for 6 days. Neutrophils from these mares were te...
Blanchard DB, Leid RW.Bovine and equine factor D were purified to apparent homogeneity as evidenced by a single protein staining band on 7.5-17.5% SDS-PAGE slab gels under both reducing and non-reducing conditions. An apparent mol. wt of 15,000 for bovine D and 22,500 for equine D were noted after SDS-PAGE gel analysis of both reduced and non-reduced preparations. A single polypeptide chain for both proteins was evidenced by the lack of any change in the electrophoretic mobility under each of these conditions. The bovine and equine D were enriched 3347- and 9447-fold, with a 20 and 29% yield of hemolytic activity, ...
Sun L, Adams AA, Betancourt A, Stewart JC, Liu C, Horohov DW.Interferon-gamma (IFNγ) plays an important role against viral and intracellular bacterial infections and its production is deficient in foals. Cellular proliferation provides an opportunity for de novo gene expression, though little is known about its role in regulating IFNγ expression in foals. While stimulation of foal peripheral blood mononuclear cells (PBMCs) with concanavalin A (ConA) increased the frequency of IFNγ(+) cells, the overall percentage of IFNγ(+) cells remained below that of adults. By contrast, the proliferative response of foal PBMC was significantly greater than that o...
Szabó MP, Castagnolli KC, Santana DA, de Castro MB, Romano MA.Since host immune reaction to ticks interferes with tick-borne pathogen transmission, it is important to recognize naturally occurring tick-host immune relationships to better understand the epidemiology of such infectious diseases. Amblyomma cajennense is an important tick-borne disease vector in the Neotropical region and horses maintain it in domestic environments. In the present work intradermal testing of A. cajennense tick exposed horses and donkeys using crude tick antigens was used to evaluate the type of hypersensitivity induced by infestations. Animals sensitized by A. cajennense inf...
Wells PW, McBeath DG, Eyre P, Hanna CJ.This article attempts to relate some of the more recently accepted concepts of immunology to an understanding of the mechanisms of immunity in the horse. The cellular mechanisms involved in the immune response are outlined, with an indication of their likely role in humoral and cell-mediated immunity. In describing the humoral immune response, the structure and function of the different equine immunoglobulins are reviewed. The significance of humoral and cell-mediated immune responses are considered in relation to actively and passively acquired immunity.
Hashimoto Y, Ohki H, Sato F, Yanaihara N, Iwanaga T.Chromogranin A (CgA) is an acidic glycoprotein that is co-stored with hormones or neurotransmitters in granular components of endocrine cells and neurons, and released together with them in response to adequate stimulation. In addition to acting as a packaging protein, CgA functions as a precursor molecule that yields several bioactive peptides by proteolytic cleavage. The purpose of this study is to elucidate how different the processing of CgA is among endocrine tissues by immunostaining using multiple region-specific antisera, and to evaluate the availability of region-specific antisera. Wh...
Behrens NE, Gershwin LJ.Hypersensitivity reactions, such as hives or fatal anaphylactic shock, in response to vaccination constitute a health hazard for horses that develop allergies to vaccine components. In such horses vaccination with viral vaccines stimulates an IgE response to non-target antigens. Viral vaccines share contaminating non-target proteins, such as bovine serum albumin (BSA); these antigens can stimulate IgE production with each exposure. We hypothesized that the addition of a CpG oligodeoxynucleotide (ODN) administered in conjunction with a West Nile virus vaccine would decrease the IgE response; th...
Brainard BM, Epstein KL, LoBato DN, Kwon S, Darien BJ, Hurley DJ, Moore JN.Inflammation-induced P-selectin (CD62P) expression on platelets and endothelial cells facilitates interactions among platelets and polymorphonuclear leukocytes (PMN), and can also promote coagulation. The effects of clopidogrel and aspirin (ASA) on equine platelet CD62P expression were investigated. Six horses were treated in a cross-over design with clopidogrel (2mg/kg PO q 24) or ASA (5mg/kg PO q 24h) for 5 days. Platelets collected at 24, 72, 96, 120, and 168 h after the initiation of therapy were stimulated using 0.1 μg/mL thrombin, followed by flow cytometric analysis using anti-CD41/61 ...
Simonin EM, Wagner B.IgE-binding monocytes are a rare peripheral immune cell type involved in the allergic response through binding of IgE on their surface. IgE-binding monocytes are present in both healthy and allergic individuals. We performed RNA sequencing to ask how the function of IgE-binding monocytes differs in the context of allergy. Using a large animal model of allergy, equine Culicoides hypersensitivity, we compared the transcriptome of IgE-binding monocytes in allergic and non-allergic horses at two seasonal timepoints: (i) when allergic animals were clinical healthy, in the winter "Remission Phase", ...
Tortschanoff M, Aurich C, Rosengarten R, Spergser J.Mycoplasma equigenitalium and Mycoplasma subdolum have been associated with infertility, endometritis, vulvitis and abortions in mares, and with reduced fertility and balanoposthitis in stallions. Despite their role in equine genital disorder, determinants of virulence and pathogenesis as well as factors provoking specific host immune responses have not been identified, so far. To establish the major immunogenic components of Mycoplasma (M.) equigenitalium and M. subdolum, antigen profiles of their type strains as well as 30 clinical isolates were compared by SDS-PAGE and immunoblot analysis u...
Weiser G, Kohn C, Vachon A.Immune-mediated hemolytic anemia was diagnosed in two horses on the basis of regenerative anemia, increased erythrocyte fragility in hypotonic saline, autoagglutination, and a positive direct antiglobulin (Coomb's) test. During steroid therapy partial resolution of the anemia was indicated by rising packed cell volume, macrocytosis, and bone marrow erythroid hyperplasia. Using erythrocyte volume distribution histograms (erythrograms), the regenerative response was characterized by analysis of macrocytic and normocytic erythrocyte subpopulations. In both horses, a gradual net increase of about ...
Osborne AC, Carter SD, May SA, Bennett D.An investigation was made into the possible contribution of autoimmune mechanisms to equine arthropathies. Serum and synovial fluid (SF) immune complexes and anti-collagen Type II antibodies were measured, by ELISA, in groups of horses with naturally occurring osteoarthritis (OA), osteochondritis dissecans (OCD), bone fracture, traumatised joints, synovitis, infected joints and non-diseased (control) joints. Significantly raised anti-collagen Type II antibodies were found in osteoarthritic (P < 0.02) and traumatised joint synovial fluids (P < 0.01) compared with the control, where ten of...
Tong T, Bai Y, Liu G, Wang Q, Zhang W, Xiao Y, Xu S, Liu N, Yang T, Wu D.IL-18 is a cytokine originally discovered as an important modulator of immune responses and subsequently shown to be pleiotropic. In this report, we expressed the recombinant equine mature interleukin-18 (rEMIL-18) in E. coli and purified it by nickel affinity gel column chromatography. Purified rEMIL-18 had biological activity commensurate with recombinant human IL-18, as determined by its synergistic effect with recombinant human IL-12 (rhIL-12) on the induction of IFN-gamma gene expression in equine peripheral blood mononuclear cells (PBMC). Following intraperitoneal (i.p.) immunization of ...
Liu IK, Pascoe DR, Chang LW, Zee YC.Serum antibody concentrations against influenza A-equi-1 virus and A-equi-2 virus were measured in a group of 18 foals from birth to 4 months of age. More than 50% of the foals were seronegative to A-equi-1 virus infection by 4 weeks of age, with titers of less than or equal to 1:16. For A-equi-2 virus, more than 50% of the foals were seronegative by 2 weeks of age, with titers of less than or equal to 1:8. Passively derived antibodies against influenza A-equi-1 virus and A-equi-2 virus in foals obtained from recently vaccinated mares and from mares not vaccinated within 6 months before foalin...
Easton-Jones CA, Estell KE, Magdesian KG.Information concerning clinical presentation, conditions associated with immune-mediated haemolytic anaemia (IMHA) and thrombocytopenia (IMTP) and outcome in equids is lacking. Previous case reports suggest that immune-mediated disease and neoplasia are associated. Objective: Characterise the clinical presentation, clinicopathologic data, underlying conditions, treatment and outcome of IMHA and IMTP cases in equids. We hypothesise that IMHA with concurrent thrombocytopenia occurs more often than IMHA or IMTP alone, and that neoplasia is commonly associated with these immune diseases and cases ...
Smith R, Chaffin MK, Cohen ND, Martens RJ.To characterize changes in lymphocyte subsets over time in foals from birth to 18 weeks of age, accounting for differences among individuals, and to determine the effect of overnight storage of blood samples on foal lymphocyte subset concentrations. Methods: 8 healthy Quarter Horse foals from birth to 18 weeks of age. Methods: Blood samples were collected longitudinally from birth to 18 weeks of age and a CBC performed on each sample. The samples were stained for lymphocyte markers, either immediately or after overnight storage and analyzed by flow cytometry. Results: Total leukocytes, total l...
Berlin S, Wallstabe S, Scheuch E, Oswald S, Hasan M, Wegner D, Grube M, Venner M, Ullrich A, Siegmund W.Standard treatment of foals with severe abscessing lung infection caused by Rhodococcus equi using rifampicin and a macrolide antibiotic can be compromised by extensive inhibition and/or induction of drug metabolising enzymes (e.g. CYP3A4) and transport proteins (e.g. P-glycoprotein), as has been shown for rifampicin and clarithromycin. The combination of rifampicin with the new, poorly metabolised gamithromycin, a long-acting analogue of azithromycin and tulathromycin with lower pharmacokinetic interaction potential, might be a suitable alternative. Objective: To evaluate the pharmacokinetic ...
Lunn DP, Schram BR, Vagnoni KE, Schobert CS, Horohov DW, Ginther OJ.Lymphokine activated killing (LAK) is an example of natural cytotoxicity, and as such is a critical means of defense against diseases such as viral infection and neoplasia. Despite this important role, the specific molecular interactions involved in LAK or other forms of natural cytotoxicity are only partially understood. In some species, cells capable of mediating natural cytotoxicity express the CD8 molecule, although no specific role has been demonstrated for CD8 in non-MHC restricted cytotoxicity. In this study the role of the EqCD8 equine homolog of CD8 in LAK cell activity was examined. ...
Yilma T, Perryman LE, McGuire TC.The results of a study on the induction of IFN-alpha, IFN-beta, and IFN-gamma in normal and SCID foals showed a deficiency of IFN-gamma but not IFN-beta in SCID foals. The ability of SCID mononuclear cells to produce IFN-alpha in response to poly I:C but not to NDV may indicate a partial deficiency of IFN-alpha in SCID foals. The deficiency of IFN-gamma and presence of IFN-beta in SCID foals supports the classification of IFN-gamma and IFN-beta as immune and nonimmune interferons, respectively. Furthermore, the deficiency of IFN-gamma in SCID foals may in part explain the high susceptibility t...
Rashmir-Raven AM, Coyne CP, Fenwick BW, Gaughan EM, Andrews GA, DeBowes RM.The ability of polysulfated glycosaminoglycans (PSGAG) to inhibit the complement cascade was evaluated. The role of complement in inflammation and infection has been well documented. Inhibition of the complement cascade by PSGAG could explain why intra-articularly administered PSGAG diminish diarthrodial joint inflammation and potentiate septic arthritis in horses. Hemolytic complement testing was performed to evaluate the effect of PSGAG on the equine classical and alternate pathways of complement, using rabbit erythrocytes as the target cells. Concentration of PSGAG between 0.2 mg/ml and 0.6...
AbdelKhalek A, Ostafe R, Olave C, HogenEsch H, Turner JW.Immunization with porcine zona pellucida (PZP) proteins is being used successfully to induce infertility in wildlife including horses. However, widespread adoption of this method to control the growth of horse populations requires further refinement in order to induce long-term infertility, reduce the frequency and severity of injection site reactions, and make the vaccines easier to administer. The next generation of PZP-based vaccines will likely be a controlled-release formulation with different adjuvants from the Freund's adjuvants used in existing vaccines. We evaluated the response of eq...
Fraser RS, Arroyo LG, Meyer A, Lillie BN.Collagenous lectins are a family of soluble pattern recognition receptors that play an important role in innate immune resistance to infectious disease. Through recognition of carbohydrate motifs on the surface of pathogens, some collagenous lectins can activate the lectin pathway of complement, providing an effective means of host defense. Genetic polymorphisms in collagenous lectins have been shown in several species to predispose animals to a variety of infectious diseases. Infectious diseases are an important cause of morbidity in horses, however little is known regarding the role of equin...
Istanbullugil FR, Risvanli A, Salikov R, Bayraktar M, Kadiraliyeva N, Zhunushova A, Yilmaz O, Yuksel BF, Turanli M, Uz M, Asinbekovic MI.Immune compatibility between mare and foal is one of the important topics of reproductive immunology. At this point, although there are many studies on antibodies, there are not many publications on the relationship between the cytokine levels of mare, foal and milk and the effects of milk composition on this relationship. Here we investigate the relationship between Th1/Th2 cytokine balance and milk composition in Kyrgyz mares and foals. Samples were taken soon after the foal was born and on days 5, 10 and 20 after birth. Th1 (IFN-γ, IL-2, TNF-α) and Th2 (IL-4, IL-5, IL-10) cytokine levels ...
Kumar J, Chaudhury A, Yadav SC.Trypanosomosis (Surra) is an economically important disease caused by Trypanosoma evansi which is an extracellular parasite present in the plasma, tissues and other body fluids of a wide range of hosts including domesticated animals. Currently, serological reports are based on detection of antibodies by ELISA using whole cell lysate (WCL) antigen, which has a limitation of persistence of anti-trypanosomal antibodies after successful treatment of the disease. Moreover, it has some ethical issues also like requirement of mice for in vivo maintenance of parasite for preparing the antigen. Therefo...
