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.
Kono Y.The antigenic structure of 16 viruses isolated from four horses which were inoculated with a clone of equine infectious anemia (EIA) virus was compared by the neutralization test. The antigenic structure of viruses isolated after development of neutralizing antibody differed from virus to virus. Back mutation of the antigenic structure was also demonstrated by serial passage of the virus in horses. These results suggest that EIA virus is subject to multidirectional antigenic variation. The possibility that the variants originated in the heterologous virus population in the inoculum seems to be...
Hussain KA, Issel CJ, Schnorr KL, Rwambo PM, West M, Montelaro RC.Monoclonal antibodies (MCAbs) were used to dissect the antigenic sites of the surface glycoproteins of the prototype cell-adapted Wyoming strain of equine infectious anemia virus (EIAV). Serologic reactivities of these MCAbs were determined by ELISA, additive ELISA, competitive ELISA, and Western blot assays. The results indicated that antigenic reactivity of gp90 was localized on at least four distinct epitopes, two of which were important in neutralization. Our studies also revealed that these epitopes were localized on overlapping antigenic sites on gp90. On the other hand, only two distinc...
Jones I, Madej A.Microtitre plates were coated with antiserum against oestradiol-17 beta-6-(O-carboxymethyl)-oxime bovine serum albumin raised in sheep. The plasma samples (0.2-1.0 ml) were extracted with peroxide-free diethyl ether prepared daily by treatment with Al2O3. The enzyme conjugate was prepared by coupling oestradiol-17 beta-6-(O-carboxymethyl)-oxime to horse-radish peroxidase. The conjugate was chromatographed on a Sephadex G-25 column. The standard curve ranged from 0.37 to 18.40 fmol/well of oestradiol-17 beta. The amount of oestradiol-17 beta causing a 50% reduction of maximum binding was 4.4 fm...
Bowling AT, Ewalt-Evans R.Family data are presented for a new allele (Aabdg) in the A system of horse erythrocyte alloantigens which includes factors Aa and Ab traditionally thought to be products of allelic genes. Evidence for incorrect assignment of the codominant factor Ae in the presence of Ab and Ac and the absence of Aa is discussed.
Wyatt CR, Magnuson NS, Perryman LE.Six monoclonal antibodies, designated EqT2, EqT3, EqT6, EqT7, EqT12, and EqT13, which identify T lymphocyte antigens present at different stages of T cell maturation were used to examine T lymphocyte development in foals with severe combined immunodeficiency (SCID). Flow microfluorimetry demonstrated the presence of EqT12+ and EqT13+ prothymocytes and a few phenotypically mature EqT2+ and EqT3+ thymocytes within the thymic remnants of SCID foals. However, very few EqT6+ and EqT7+ resident cortical thymocytes were detected. The near absence of EqT6+ and EqT7+ cortical thymocytes was confirmed b...
Riggs MW.Currently recognized equine immune deficiency disorders include failure of passive colostral immunoglobulin transfer, combined immunodeficiency, selective IgM deficiency, transient hypogammaglobulinemia, and agammaglobulinemia. Additional equine immune deficiency disorders probably exist. Immune deficiency should be suspected in any horse experiencing persistent or recurrent infections that are not responsive to conventional therapy.
Winston S, Fiscus S, Hesterberg L, Matsushita T, Mildbrand M, Porter J, Teramoto Y.The development of three separate rapid ELISAs for detecting antibodies in host serum to three different viruses is described. These include: 1. A direct antigen assay using enzyme labelled anti-canine Ig for detecting antibodies to canine parvovirus, 2. A competitive ELISA using a feline infectious peritonitis virus-specific monoclonal antibody labelled with enzyme, and 3. A competitive ELISA using an equine infectious anemia virus-specific monoclonal antibody and enzyme labelled antigen, p. 26. The utility and benefits of each of the three approaches is emphasized.
Perryman LE, Bue CM, Magnuson NS, Mottironi VD, Ochs HS, Wyatt CR.Thirty-eight foals with combined immunodeficiency (CID) received transplanted fetal liver cells, fetal liver and thymus cells, histocompatible bone marrow cells, or equine lymphocyte antigen (ELA) haploidentical bone marrow cells in an attempt to reconstitute their deficient immune systems. Engraftment was infrequent, partial, and unpredictable when fetal cells were employed. Three of five CID foals receiving ELA haploidentical bone marrow cells demonstrated partial reconstitution, but engraftment was only temporary. Administration of histocompatible bone marrow cells resulted in rapid, full a...
Seide RK, Jacobs RM, Dobblestein TN, Kehoe JM.A novel myeloma paraprotein has been isolated from a horse with a lymphoid tumor. The protein was a euglobulin and consequently was readily isolated from serum in pure form and high yield by simple dilution in distilled water. The purified intact protein had a molecular weight of 150,000 and was composed of heavy and light chains, both of which had blocked amino-termini and were thus not susceptible to amino-terminal sequence analysis. The amino acid compositions of these respective chains corresponded to those of comparable chains from immunoglobulins of other species. Peptide maps of parapro...
Payne SL, Fang FD, Liu CP, Dhruva BR, Rwambo P, Issel CJ, Montelaro RC.The extent and nature of genomic variation among nine antigenically distinct EIAV isolates recovered during sequential clinical episodes from two experimentally infected ponies were examined by restriction fragment analysis and nucleotide sequencing. Only minor variations in restriction enzyme patterns were observed among the viral genomes. In contrast, env gene sequences of four isolates from one pony revealed numerous clustered base substitutions. Divergence in env gene nucleotide and deduced amino acid sequences between pairs of virus isolates ranged from 0.62 to 3.4% env gene mutation rate...
Houle JJ, Hoffmann EM.A passive hemolysis assay system was developed which permitted comparisons of the hemolytic activities of complement (C) from six species. This system employs a single antigen and an antiserum raised in one species. Thus, variations resulting from different target antigens and those inherent in using antibodies (of different affinities and isotypes) raised in a variety of species were minimized. Of the erythrocytes (E) examined, those from horses and guinea pigs were most susceptible to lysis, and either would be suitable, as a tentative choice, for measuring C activity of a previously unstudi...
Nishita T, Matsushita H, Kai M.The location of carbonic anhydrase III (CA-III) in frozen sections of biopsies of Thoroughbred horse skeletal muscle was studied. Fibre types were determined by ATP-ase and succinate dehydrogenase staining. CA-III isozyme was detected using a peroxidase conjugated anti-CA-III antibody. CA-III was found to be localised in slow twitch oxidative fibres (ST), but was also present in fast twitch oxidative (FTH) fibres in small amounts. Fast twitch glycolytic (FT) fibres were stained lightly compared with control sections. The concentrations of CA-III in muscle and liver were 70 micrograms/mg protei...
Fu ZF, Denby L, Lien DH, Robinson AJ.An indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies against equine herpesvirus type 2 (EHV-2) in equine sera. The optimal conditions of antigen concentration, and serum and conjugate dilutions were established by chequerboard titrations. When the standard ELISA test was used for titration of test sera, it was found to give titres approximately 1500 times higher than those obtained in the virus neutralization (VN) test, and a correlation coefficient of 0.815 was obtained between these two tests on 42 equine sera. All the positive serum samples by ...
Morris DD, Whitlock RH.Equine antiserum to core lipopolysaccharide (LPS) was evaluated in a double-blind prospective study for therapeutic benefit in suspected septicemia in neonatal foals. Forty foals younger than 7 days of age were included in the study by satisfaction of clinical and laboratory criteria, suggestive of gram-negative septicemia. Twenty-two foals were treated with core LPS antiserum (plasma produced from horses which were hyperimmunized with rough gram-negative mutant bacterin) and 18 foals received "nonimmune" plasma (from horses prior to immunization against core LPS). All foals received antimicro...
Clegg JB.A new member (theta 1, or psi alpha) of the alpha-globin gene family has recently been identified in a number of species. In higher primates the theta 1 gene has all the structural features apparently necessary for expression, and it appears to have long been under strong selective constraints which suggests that it could still be, or recently have been, a functional gene. No corresponding 'globin' has yet been identified, however. In some other species, galago and rabbit for example, the theta 1 and psi alpha genes have accumulated enough inactivating mutations for them to be considered genui...
Matthews SM, Joysey VC.Fifteen equine leucocyte antigens were defined by absorption and titration analysis of alloantisera obtained by natural sensitisation through pregnancy and by planned experimental immunisation. Definitive sera were tested on the cells of 90 unrelated horses and members of eight equine families. The family data suggested that 13 specificities were coded by a single locus (first locus) and one specificity (Eq 14) was coded by a second linked locus. The remaining specificity (Eq 7) was controlled by a third locus unlinked to the first or second loci. Tests on the cells of unrelated horses showed ...
Watson ED, Stokes CR, Bourne FJ.The influence of arachidonic acid metabolites on migration of equine neutrophils under agarose was investigated. Leukotriene B4 (LTB4) was chemotactic at concentrations between 0.1 and 1000 ng ml-1 and prostaglandin E2 (PGE2) at 1 and 10 ng ml-1 but not at higher or lower concentrations. Prostaglandin F2 alpha (PGF2 alpha) was not chemotactic for equine neutrophils at any concentration. Random migration was significantly inhibited (P less than 0.05) by suspension of neutrophils in LTB4 (0.1 to 1000 ng ml-1) and PGF2 alpha (0.1 ng ml-1) but not at high concentrations. There was a significant po...
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...
Mair TS, Batten EH, Stokes CR, Bourne FJ.The distribution of mucosa-associated lymphoid tissue along the equine respiratory tract was surveyed in light microscopical sections. Intra-epithelial lymphocytes and similar cells scattered in the lamina propria were identified in all sites from the nasal vestibule to bronchioles of 2 to 4 mm diameter. Isolated lymphoid patches, occasionally with nodules, were common in bronchioles, but the density of this bronchiole-associated lymphoid tissue (BRALT) varied between individual horses. Bronchus-associated lymphoid tissue (BALT) was infrequently encountered. In the upper respiratory tract, nod...
Watson ED, Stokes CR, Bourne FJ.Both random and directional migration of blood neutrophils from 9 mares susceptible to persistent endometritis were significantly less (p less than 0.05) than neutrophils from 8 resistant mares. Serum from susceptible mares had significantly more (p less than 0.01) chemotactic activity than serum from resistant mares. Although phagocytosis of yeast blastospores by blood neutrophils from 4 resistant and 3 susceptible mares was similar, uterine neutrophils from susceptible mares were significantly worse (p less than 0.01) at phagocytosis than uterine neutrophils from resistant mares. Uterine was...
Cooper HM, Jemmerson R, Hunt DF, Griffin PR, Yates JR, Shabanowitz J, Zhu NZ, Paterson Y.Comparative binding studies with peptide fragments of the whole antigen, or with evolutionarily related intact proteins with varying degrees of sequence homology, have been used extensively to map antigenic sites on proteins to the resolution of single amino acid residues. These methods are limited, however, since high affinity antibodies will often not react with peptides and evolutionarily related proteins are available for only a few antigens. In this study we use site-directed chemical modification of horse cytochrome c to identify residues involved in the binding sites of four monoclonal ...
Woolcock JB, Mutimer MD, Bowles PM.Normal horses of all ages regularly show evidence of having responded immunologically to R. equi, thus adding serological support to epidemiological evidence that this organism is a normal intestinal inhabitant. More animals from "diseased" farms show a stronger antibody response when compared with foals from "healthy" farms. Various serological tests have been used to detect evidence of infection and to relate antibody level to severity of disease. Anti-R. equi IgG antibody levels, as measured by ELISA, are raised significantly during natural infection. Clinical severity of pneumonia can be c...
Hietala SK, Ardans AA.The interaction of Rhodococcus equi with alveolar macrophages from adult horses, foals experimentally exposed to R. equi (sensitized foals) and non-exposed foals was studied using in vitro bactericidal assays, cytochemical staining and transmission electron microscopy. It was demonstrated that R. equi is a facultative intracellular parasite, able to survive and multiply within the alveolar macrophages of the host by interfering with phagosome-lysosome fusion. Opsonization of R. equi with antibody against capsular components was associated with increased phagosome-lysosome fusion and significan...
Takai S, Kawazu S, Tsubaki S.Humoral immune response to Rhodococcus equi in experimentally infected foals was studied with the enzyme-linked immunosorbent assay (ELISA) method. Class-specific antibodies were measured by ELISA in the sera of foals after intratracheal or oral inoculation with R. equi ATCC 6939 or T 48 and in the lung washings of a foal after intratracheal inoculation or of normal horses. After intratracheal or oral inoculation with R. equi, serum antibodies were first detected in immunoglobulin G (IgG) followed by IgM and IgA classes, but significant levels of IgM and IgA developed only in the foal infected...
Martens RJ, Martens JG, Renshaw HW, Hietala SK.The opsonic capacity of serum containing R. equi-specific antibody was compared with antibody-deficient sera using luminol-dependent chemilumenscence (LDCL) and bactericidal assays. These assays incorporated peripheral blood polymorphonuclear neutrophilic leukocytes (PMNL) exposed to R. equi opsonized with neonatal equine pre-colostral serum (control) or serum from foals with R. equi infections (principal). All sera were complement inactivated at 56 degrees C for 30 min. Bacteria were obtained from the lung of a foal with R. equi pneumonia. Neutrophils were obtained from one adult horse for LD...
Drummer HE, Reynolds A, Studdert MJ, MacPherson CM, Crabb BS.Sera from 33 Australian thoroughbred mares were tested during an outbreak of equine herpesvirus 1 (EHV1) abortion with an enzyme-linked immunosorbant assay (ELISA) for the presence of EHV1-specific antibodies. The ELISA used a recombinant EHV1 antigen derived from glycoprotein G (gG) and distinguished antibodies to EHV1 from those of the antigenically related and widespread herpesvirus EHV4. Sera were obtained from most of the mares on three occasions, three, 13 and 67 days after the first abortion. Mares which were negative in the ELISA were kept separate from mares which were positive. A sec...
Mykkänen AK, Niku M, Ilves M, Koho NM.To characterize the expression of monocarboxylate transporters (MCTs) 1 and 4 and the ancillary protein CD147 in the intestinal tract of healthy equids and determine the cellular location of CD147 in the intestinal epithelium. Methods: 12 healthy horses and ponies slaughtered for meat production or euthanized for reasons unrelated to gastrointestinal tract disease. Methods: The entire gastrointestinal tract was removed from each equid within 45 minutes after slaughter or euthanasia. Tissue samples were obtained from the antimesenteric side of the duodenum, jejunum, ileum, middle part of the ce...
Stefanetti V, Pascucci L, Wilsher S, Cappelli K, Capomaccio S, Reale L, Passamonti F, Coletti M, Crociati M, Monaci M, Marenzoni ML.Endogenous retroviruses (ERVs) are proviral phases of exogenous retroviruses, which have coevolved with vertebrate genomes for millions of years. The conservation of ERV genes throughout evolution suggests their beneficial effects on their hosts' survival. An example of such positive selection is demonstrated by the syncytin gene, which encodes a protein with affinity for various mammalian placentas that is involved in the formation of syncytiotrophoblasts. Although the horse has an epitheliochorial placenta, in which the fetal trophoblasts are simply apposed to the intact uterine epithelium, ...
Kakoi H, Kikuchi M, Ishige T, Nagata SI, Hirosawa Y, Tanaka S, Kishinami T.Erythrocyte alloantigen frequencies of draft horses in Japan were investigated to assess blood donor suitability for transfusion. Here, 148 Japanese draft, 69 Percheron, and 65 Breton horses were blood-typed and subjected to an indirect antiglobulin test. Regarding the major immunogenic factors, the rates of Aa- and Qa-negative horses ranged from 0.35 to 0.49 and from 0.82 to 1.00, respectively. The rate of alloantibody-positive horses ranged from 0.12 to 0.35. Although the prevalence of alloantibodies in these horses was higher than that expected naturally, the rates of Aa- and Qa-negative ho...
Mair TS, Stokes CR, Bourne FJ.An indirect immunoperoxidase technique was used to demonstrate both free immunoglobulin and immunoglobulin-containing plasma cells of IgG, IgA, and IgM classes in the mucosa of the equine respiratory tract. IgA-producing plasma cells predominated in the upper airways, whereas IgG-producing cells predominated in the lower respiratory tract. IgM-secreting cells were uncommon, but present in their highest numbers in the nasopharynx. Plasma cells specific for all of the immunoglobulin classes were identified in the surface epithelium, lamina propria connective tissue, glandular tissue and organise...
Ungar-Waron H, Braverman Y, Gluckman A, Trainin Z.Summer seasonal recurrent dermatitis (SSRD) or "sweet itch" is a seasonally occurring allergic dermatitis of horses provoked by biting midges. The allergic skin reactions have been attributed to allergens present in various Culicoides species. C. imicola is the suspected etiological agent of SSRD in Israel. Whole body extracts of this midge induced hypersensitivity reactions upon injection into susceptible horses and in this study attempts were made to define components of C. imicola which have immunogenic and allergenic properties. Immunogenic potency was evaluated by raising antisera to whol...
Allen MJ, Jemmerson R, Nall BT.Refolding of surface epitopes on horse cytochrome c has been measured by monoclonal antibody binding. Two antibodies were used to probe re-formation of native-like surface structure: one antibody (2B5) binds to native cytochrome c near a type II turn (residue 44) while the other (5F8) binds to a different epitope on the opposite face of the protein near the amino terminus of an alpha-helical segment (residue 60). The results show that within the first approximately 100 ms of refolding all of the unfolded protein collapses to native-like folding intermediates that contain both antibody binding ...
Salco R, Bowers J, Hernandez V, Barnum S, Pusterla N.This study aimed to determine if the administration of a modified live equine influenza virus vaccine (FluAvert) to foals would positively impact their health and reduce colonization of their upper airways with equine herpesviruses (EHV) during the weaning period. A single dose of FluAvert was given to 20 healthy foals 7 days prior to being weaned; 20 healthy foals served as unvaccinated controls. Nasal secretions and blood were collected before vaccination, the day of weaning, and weekly thereafter for 3 weeks. Nasal secretions were tested by quantitative polymerase chain reaction (qPCR) for ...
Andersen S, Fogh J.During a 5 months' period from January to May 1981 faecal samples of 176 donkeys from 59 herds all over the country were examined at the Institute of internal medicine, The Royal Veterinary and Agricultural University, Copenhagen. In addition, the investigation also included 106 horses from 30 of the donkey herds and 34 horses hospitalized with symptoms of dyspnoea and chronic coughing. In all, 87.5% of the donkeys were shown to excrete D. arnfieldi larvae, often in very high numbers, and the larval excretion was the only symptom of lungworm infection. There was no significant correlation betw...
Rossano MG, Schott HC, Kaneene JB, Murphy AJ, Kruttlin EA, Hines MT, Sellon DC, Patterson JS, Elsheikha HM, Dubey JP, Mansfield LS.To determine whether daily administration of pyrantel tartrate can prevent infection in horses experimentally challenged with Sarcocystis neurona. Methods: 24 mixed-breed specific-pathogen-free weanling horses, 10 adult horses, 1 opossum, and 6 mice. Methods: Sarcocystis neurona-naïve weanling horses were randomly allocated to 2 groups. Group A received pyrantel tartrate at the labeled dose, and group B received a nonmedicated pellet. Both groups were orally inoculated with 100 sporocysts/d for 28 days, 500 sporocysts/d for 28 days, and 1000 sporocysts/d for 56 days. Blood samples were collec...
Keating DL, Lehman JS, Burk SV.Identification of factors associated with parasite infestation in horses could reduce frequency of anthelmintic administration and slow development of anthelmintic resistance. The study aim was to evaluate management factors, equine characteristics, and equine salivary cortisol concentrations for association with strongyle-type egg shedding levels. As immunocompromised horses appear to be more susceptible to parasite infestation, it was hypothesized that salivary cortisol concentration could be associated with parasite egg shedding. Saliva and fecal samples were collected from 200 horses acros...
Rossano MG, Schott HC, Murphy AJ, Kaneene JB, Sellon DC, Hines MT, Hochstatter T, Bell JA, Mansfield LS.Equine protozoal myeloencephalitis (EPM) is a serious neurological disease of horses in Americans. Most cases are attributed to infection of the central nervous system with Sarcocystis neurona. Parasitemia has not been demonstrated in immunocompetent horses, but has been documented in one immunocompromised foal. The objective of this study was to isolate viable S. neurona from the blood of immunocompetent horses. Horses used in this study received orally administered S. neurona sporocysts (strain SN 37-R) daily for 112 days at the following doses: 100/day for 28 days, followed by 500/day for 2...
Yamaguchi K, Sawada T, Yamane S, Haga S, Ikeda K, Igata-Yi R, Yoshiki K, Matsuoka M, Okabe H, Horii Y, Nawa Y, Waltrip RW, Carbone KM.Borna disease virus (BDV) is a neurotropic pathogen that infects a wide variety of vertebrates. We have developed a new electrochemiluminescence immunoassay (ECLIA) for the detection of antibodies to BDV, using three synthetic peptides corresponding to the amino acid residues 3-20 and 338-358 of p40 and 59-79 of p24 peptide of BDV. Using the ECLIA, we examined serum samples for the presence of anti-BDV antibodies in 20 rats (experimentally BDV-infected and uninfected) and 38 horses (13 US horses, experimentally infected and uninfected, and 25 Japanese horses, feral and domestic). The ECLIA, pe...
Fernandes I, Lima EX, Takehara HA, Moura-da-Silva AM, Tanjoni I, Gutiérrez JM.Horse IgG isotypes and cross-neutralization of two snake antivenoms produced in Brazil and Costa Rica. Toxicon 000-000. This work compared the specificity, ELISA titers and IgG subclass content of the polyvalent antivenom (anti-Bothrops asper, Crotalus durissus durissus and Lachesis muta stenophrys) of Instituto Clodomiro Picado (Costa Rica) and the bothropic antivenom (anti-Bothrops jararaca, B. jararacussu, B. moojeni, B. neuwiedi and B. alternatus) of Instituto Butantan (Brazil). The role of IgG(T) and IgGa subclasses in neutralization of some venom toxic activities and the cross neutraliza...
Leblanc MM, Pritchard EL.The effects of bovine colostrum, absorption of equine colostral immunoglobulins and age on phagocytic and serum opsonizing activity of nine clinically healthy foals were examined. Cells and serum were collected prior to suckling and at 7, 14 and 28 days of age. Seven foals had serum IgG concentrations greater than 600 mg/dl whereas two foals had less than 350 mg of IgG/dl. Phagocytic and serum opsonic activity of eight clinically ill foals with less than 400 mg of IgG/dl of serum were also examined before and after plasma transfusion. Phagocytic and serum opsonizing activities were evaluated b...
Pazinato FM, Curcio BDR, Varela Junior AS, Corcini CD, Wendt CG, Moreira F, Schmit RA, Nogueira CEW.Placental tissues from humans, rodents, and farm animal contain leptin and its receptor. Expression of leptin has already been described in horses, although there is no description about immunolocalization of leptin and its receptor. The aim of the present study was to investigate the presence and distribution of leptin and ObR-b in the equine placenta at term by immunofluorescence staining, and the changes on plasma leptin concentrations during late gestation. The present study involved eight Criollo-type mares carrying healthy pregnancies. Blood samples were collected during the third trimes...
Yager JA, Foster SF, Zink MC, Prescott JF, Lumsden JH.Polymorphonuclear leukocytes from adult horses were separated from whole blood, using a 2-step Percoll gradient, and were tested for bactericidal function against Corynebacterium equi. Staphylococcus aureus, an organism against which equine neutrophils have proved efficacy, was a positive control. The percentage of uptake after a 15-minute preincubation of the neutrophils and bacteria in the presence of normal horse serum was also calculated. The results indicated that equine neutrophils effectively phagocytosed and killed C equi and S aureus. The percentage of uptake for S aureus (95% +/- 3%)...
Lowden S, Heath T.In the horse ileum, lacteals in the villi are continuous with prelymphatic intercellular channels and a plexus of lymphatic sinuses in the lamina propria that encircle the domes of the follicle/dome structures and proprial follicles. These sinuses may act as the major entry site for many of the lymphocytes migrating from gut-associated lymphoid tissue via the lymphatic system. Vessels from this plexus penetrate the muscularis mucosae and lymph flows into lymphatic vessels within the interfollicular tissue between the follicles of both follicle/dome structures and lymphoglandular complexes (LGC...
Hu WG, Alvi AZ, Fulton RE, Suresh MR, Nagata LP.A recombinant gene encoding a single-chain variable fragment (scFv) antibody against Venezuelan equine encephalitis virus (VEE) was cloned into a prokaryotic T7 RNA polymerase-regulated expression vector. A streptavidin-binding peptide gene fused to a 6His tag was attached downstream to the scFv gene. The recombinant fusion protein was expressed in bacteria as inclusion bodies that were subsequently solubilized with 8 M urea and renatured by an arginine system. Purification of the fusion protein was achieved by immobilized metal affinity chromatography. Enzyme-linked immunosorbent assay (ELISA...
Naef A, Damerau B, Keller HU.The relationship between the short transient intracellular increase in cAMP levels on the one hand and chemotaxis or crawling movements on the other hand was investigated using human and equine granulocytes. C5ades arg, f-met-leu-phe, human serum albumin and immunoglobulin were used as stimulating agents. There was no strict correlation between the induction of crawling movements or of chemokinesis in general and the generation of the cAMP peak. But there was so far a strict parallelism between the occurrence of the chemotactic response and the cAMP peak. However, the magnitude of the peak was...
Nunn FG, Pirie RS, McGorum B, Wernery U, Poxton IR.There is much evidence to suggest that group III Clostridium botulinum (types C and D) are involved in the aetiology of equine grass sickness (EGS). Antibodies have been detected previously in the blood and high levels associated with resistance to disease. Specific mucosal antibodies in the gastrointestinal (GI) tract are likely to be important in protection, and this study was performed to ascertain if such antibodies could be detected and if their levels were related to disease state. Objective: To develop a method for quantifying IgA antibodies to C. botulinum types C and D in the GI tract...
Harrington JR, Wilkerson CP, Brake CN, Cohen ND.The innate immune system plays a critical role in protecting neonates against infections early in life and Toll-like receptors (TLRs) are key components of innate immune recognition of pathogens. This study examined the effects of age and stimulation with a TLR 7/8 agonist (R848) on TLR8 mRNA expression by foal neutrophils during the first month of life. We also examined the effects of R848 stimulation on mRNA expression of interleukin (IL)-6 and IL-8 at 1 and 14 days of life. We observed that TLR8 mRNA was constitutively expressed (P<0.05) at all ages examined, and its expression did not c...
Bailey M, Martin SC, Lloyd S.Immunologic and hematologic responses were examined in 4 ponies with experimentally induced Strongylus vulgaris infection and in 5 helminth-free ponies. Two ponies were inoculated with 200 larvae and 2 were inoculated with 700 larvae of S vulgaris and then were reinoculated with the same numbers of larvae 34 weeks later. Initial response of the ponies inoculated with S vulgaris was S vulgaris antigen-induced lymphocyte response that developed 1.5 to 3 weeks after inoculation and did not persist. Development of antigen-reactive lymphocytes was followed sequentially by a biphasic complement-fixi...
Rusek J, Klumplerova M, Molinkova D, Sedlinska M, Dusek L, Muzik J, Putnova L, Vrtkova I, Celer V, Horin P.Individual variation in immune responses to herpesviruses was observed in various species. Here, associations between polymorphic molecular markers and life-long anti-EHV-1/4 antibody immune responses were analyzed in a model EHV-infected population of the Old Kladruber horses. Two-dimensional analysis including overall mean titers and titer dynamics expressed by differences between spring and autumn titers allowed identification of low-responders. 50 randomly selected microsatellites and nine single nucleotide polymorphisms in nine immunity-related candidate genes were genotyped. Due to diffe...
Marr KA, Lees P, Cunningham FM.Adherence to vascular endothelium and extracellular matrix proteins is a pre-requisite for neutrophil accumulation at sites of inflammation. In this study, equine neutrophil adherence to fibronectin and autologous serum-coated plastic in response to PAF, hrIL-8, hrC5a and PMA has been measured. In addition, the mechanisms involved have been investigated using monoclonal antibodies (MoAbs) against the beta2 integrin CD18. PAF and hrC5a caused similar, concentration dependent, increases in adherence to fibronectin- and serum-coated plastic (maximum responses 19 +/- 4% and 19 +/- 3% for PAF and 1...
Kurotaki T, Narayama K, Oyamada T, Yoshikawa H, Yoshikawa T.An immunohistochemical study was carried out on the kinetics of Langerhans cells (LCs) at various pathological stages of "Kasen". Skin lesions of "Kasen" that were collected by biopsy from May to October were classified histopathologically into three stages: initial (Group I, 31 cases), developing (Group II, 50 cases) and regressing (Group III, 13 cases). LCs showed a positive reaction with anti-equine thymocytes (EqT6) monoclonal antibody (MoAb) and anti-major histocompatibility complex (MHC) class II MoAb by immunohistochemical staining. The anti-EqT6 MoAb was intensely positive along the cy...
Harkiss GD, Brown DL, Smith DJ, Nagington J.Circulating immune complexes were isolated from the sera of cardiac allograft recipients by bovine conglutinin/anti-conglutinin co-precipitation, or by gel filtration and protein A-Sepharose affinity chromatography. The antibody moieties within these isolated immune complexes were tested for specificity against heterologous anti-thymocyte globulins by solid phase radioimmunoassay, and bacterial and viral antigens by indirect immunofluorescence. The results showed that in addition to possessing specific anti-equine anti-thymocyte globulin antibodies, immune complexes also contained cross-reacti...
Srivastava SK, Barnum DA.The ability of either formalin-treated or heat-inactivated whole Streptococcus equi cell vaccines or partially purified M-protein of S. equi to give rise to protective antibody levels was studied in Standardbred foals by serological means. Two commercial preparations, i.e. a beta-propiolactone killed whole S. equi cell bacterin and a cell-free extract of S. equi cells were included in the study. The mean passive hemagglutination antibody titers (10 X log2) in sera of foals given either four doses of formalin-treated whole cell vaccine or an initial dose of formalin-treated followed by three do...
Jungeblut CW.1. A flocculation reaction has been described which occurs between alcoholic extracts of pneumococci and antipneumococcus serum. 2. The reaction appears to be species-specific. It is not strictly type-specific, as slight or moderate cross-reactions occurred between Type I serums and Type II and Type III extracts. 3. The flocculating power of the serum from five horses undergoing immunization with pneumococcus, Type I, did not develop to any extent before the end of the 4th or 5th month. 4. In the case of two of these horses in which it was possible to carry out parallel tests on a larger numbe...
Koets AP.The function of eCG in equine pregnancy is far from clear but it has become evident that eCG has little or no FSH activity in the horse and is therefore probably not responsible for the secondary ovulations. eCG does have luteotrophic activity and it could play a role in the resurgence of the primary corpus luteum (1,7,44). Some evidence exists that the receptor population on the equine gonads is heterogenous in a way that makes it possible to distinguish eCG from eLH, resulting in different post-receptor effects (7). There is also evidence that eCG itself is heterogenous, both in glycosylatio...
