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.
Winder NC, Pellegrini A, von Fellenberg R.Using a peroxidase anti-peroxidase technique alpha-1-protease inhibitor (alpha-1-PI) was identified in normal equine hepatocytes in formalin-fixed liver sections, and in airway secretions and macrophages in formalin-fixed lung sections of horses with chronic small airway disease and chronic bronchointerstitial pneumonia. In addition, it was identified occasionally in macrophages in bronchoalveolar lavage samples from clinically healthy horses and from horses with chronic small airway disease. Equine peripheral blood leucocytes and formalin-fixed lung sections with normal histology were negativ...
Kolmakova MV, Kuskova ZR, Ratner GM, Laptakova LM.Horse serum albumin has been shown to meet the requirements to protein preparations for microanalysis and thus to be suitable for use in kits of reagents for the radioimmunological determination of insulin and myoglobin, for the determination of tick-borne encephalitis virus antigen by the method of the enzyme immunoassay and for the stabilization of proteins in the hemagglutination test and the hemagglutination inhibition test.
Meredith DM, Stocks JM, Whittaker GR, Halliburton IW, Snowden BW, Killington RA.Equine herpesvirus types 1 and 4 (EHV-1 and EHV-4) labelled with [14C]glucosamine were purified from infected cell culture medium and profiles of their structural proteins were obtained that enabled identification of the major glycoproteins. Nine glycosylated polypeptides were identified for each virus. Preparations of the purified viruses each contained a glycoprotein which was linked by disulphide bonds, as determined by diagonal gel electrophoresis under reducing/non-reducing conditions. High Mr forms of this glycoprotein were detected for EHV-1 when the sample was not heated. The EHV-1 pro...
Saikku A, Koskinen E, Sandholm M.The glutaraldehyde coagulation test was adapted to foal serum to determine adequacy of the colostral-intestinal transfusion of IgG. The test is performed simply by mixing one volume of reagent with 10 volumes of serum and observing the coagulation time. The required glutaraldehyde concentration was established for various threshold levels of IgG as determined by radial immunodiffusion. The analysis consisted of 140 serum samples from foals. Sera with low IgG levels require high glutaraldehyde concentrations and vice versa. The 4 g/l threshold generally accepted for IgG adequacy, was achieved a...
Ricci G, Del Boccio G, Pennelli A, Aceto A, Whitehead EP, Federici G.Glutathione transferase (EC 2.5.1.18) from horse erythrocytes has been purified and some molecular and kinetic properties have been investigated. It appears to be a dimeric protein composed of subunits of about 23 kDa, indistinguishable either in sodium dodecyl sulfate or in urea electrophoresis. Amino acid composition, substrate specificities, sensitivity to inhibitors, CD spectra, and immunological studies provide evidence that the horse enzyme is related to the pi class transferases. This enzyme has only two reactive thiol groups/dimer whose integrity appears to be essential for the activit...
Heath TJ, Perkins NR.The pathways through which lymph flows from terminal afferent lymphatics to the lymph sinuses, and from the sinuses to initial efferent lymphatics, were studied in horse lymph nodes by using Microfil casts and electron microscopy. Terminal afferent lymphatics are continuous with the subcapsular sinus through oval holes, about 3 microns wide, along their length, and through larger openings near their end. Other terminal afferents penetrate into the node within trabeculae and are supported by processes across the lumen. They connect with trabecular and medullary sinuses through oval or round hol...
Lavoie JP, Spensley MS, Smith BP, Mihalyi J.Colostral volume and IgG and IgM concentrations were determined in 6 multiparous mares at foaling and them every 2 hours from 16 to 20 hours after parturition. Serum IgG and IgM concentrations at foaling also were determined in each mare. The rate of mammary secretion was 292 +/- 26 ml/h (range, 202 to 389 ml/h), and the colostral volume was 5.1 +/- 0.5 L (range, 3.2 to 7.0 L). The colostral IgG and IgM contents were 440 +/- 106 g (range, 199 to 855 g) and 3.1 +/- 0.9 g (range, 0.7 g to 7.1 g), respectively. There was no significant correlation between serum and initial colostral IgG and IgM c...
Linke RP, Trautwein G.Tumorous amyloid deposits in the nasal mucosa of two horses differed from generalized AA-amyloidosis with respect to clinical features, organ distribution, and resistance to KMnO4 treatment. Using a panel of antibodies directed against different human amyloid fibril proteins and employing the peroxidase-anti-peroxidase (PAP) technique, we showed the described equine amyloid to be A lambda-type, as demonstrated by immunohistochemical cross-reactivity. Consequently, we identified a second amyloid class in horses and showed that immunoglobulin light-chain-derived amyloid may also be present in an...
Brostroöm H, Paulie S, Perlmann P.To characterise the expression of surface antigens on equine sarcoid cells compared to normal equine fibroblasts, immune sera were produced in rabbits against transformed cells of a virus-containing sarcoid cell line (Mc-1) and normal dermal fibroblasts, respectively. The specificities of the sera were analysed by antibody-dependent cellular cytotoxicity against 51Cr-labelled target cells using human lymphocytes as effector cells. Anti-Mc-1 antiserum induced strong cytotoxicity against transformed cells of two sarcoid cell lines (Mc-1 and Bay Mc-1), whereas the cytotoxicity against transformed...
Passaniti A, Roth TF.Ferritin was purified from chicken liver by two different methods: gel filtration on controlled-pore glass beads, and immunoaffinity chromatography employing a chicken ferritin-specific monoclonal antibody that did not cross-react with horse spleen ferritin. This antibody recognizes intact ferritin and an oligomeric 240 kDa form of the molecule after protein transfer to nitrocellulose, but not the 22 kDa chicken ferritin subunit. Chicken liver ferritin purified by these methods exhibited reduced migration on non-denaturing polyacrylamide gels compared with horse spleen ferritin. These results ...
Satoh K, Nakao T, Nagai F, Kano I, Nakagawa A, Ushiyama K, Urayama O, Hara Y, Nakao M.Monoclonal antibodies against horse kidney outer medulla (Na+ + K+)-ATPase were prepared. One of these antibodies (M45-80), was identified as an IgM, recognized the alpha subunit of the enzyme. M45-80 had the following effects on horse kidney (Na+ + K+)-ATPase: (1) it inhibited the enzyme activity by 50% in 140 mM Na+ and by 80% in 8.3 mM Na+; (2) it increased the Na+ concentration necessary for half-maximal activation (K0.5 for Na+) from 12.0 to 57.6 mM, but did not affect K0.5 for K+; (3) it slightly increased the K+-dependent p-nitrophenylphosphatase (K-pNPPase) activity; (4) it inhibited p...
Mendoza L, Marin G.Antigens and rabbit-antisera from holotypes of Pythium insidiosum and P. destruens were prepared to elucidate their antigenic relationship. The antigens and rabbit-antisera of P. insidiosum as well as P. destruens used as a reference system showed that both shared three precipitin bands in common. The antigen and rabbit-antisera of P. destruens and P. insidiosum used as a reference system against other strains isolated from humans and animals with pythiosis, also showed three precipitin bands in common. When we used sera taken from horses with proven pythiosis against antigens of P. insidiosum...
Rossmanith W, Horvath E.After electrophoretic separation in SDS-PAGE structural proteins of the virus of Equine Infectious Anemia (EIA) were easily blotted by the semi-dry-blotting method onto nitrocellulose filters. Strips of these filters were used for antibody demonstration, and positive reactions thereof were intensified by a biotin-avidin-peroxidase system. Sensitivity of this system was so high as to allow readable interpretation of bands up to the dilution of 1:6,400 of a strongly positive serum. Frequently this procedure allowed to make a firm diagnostic Western-Blot diagnosis on far weaker equine sera. Inter...
Furuoka H, Ito H, Hamada M, Suwa T, Satoh H, Itakura C.The endocrine cell components in the pancreatic islets of the following 4 pancreatic regions of the horse were investigated by immunohistochemical methods: lobus pancreatis sinister (left lobe); lobus pancreatis dexter (right lobe); and 2 regions of Corpus pancreatis (body), the duodenal lobe which lies along the cranial duodenal flexure and descending duodenum, and the intermediate lobe which is situated around the portal vein. The islets in the left and intermediate lobes contained a central mass of glucagon cells surrounded by insulin cells, a few somatostatin cells and sporadic pancreatic ...
Whalley JM, Robertson GR, Scott NA, Hudson GC, Bell CW, Woodworth LM.A gene in equine herpesvirus 1 (EHV-1; equine abortion virus) equivalent to the gB glycoprotein gene of herpes simplex virus (HSV) has been identified by DNA hybridization and nucleotide sequencing. A 4.3 kbp EHV-1 PstI-ClaI sequence (0.40 to 0.43 map units) contained an open reading frame flanked by appropriate control elements and was capable of encoding a polypeptide of 980 amino acids. This had 50 to 60% identity over a 617 amino acid conserved region with the gB gene products of HSV and three other alphaherpesviruses, and 20 to 30% identity with those of human cytomegalovirus and Epstein-...
Saudek V, Williams RJ, Ramponi G.The solution structure of acylphosphatase determined by proton nuclear magnetic resonance spectroscopy is described. The results allow us to discuss the fold of the protein (101 amino acids), to correlate the exposure and the mobility of the backbone with the antigenicity, and to locate the active site.
Crucière C, Guillemin MC, Roseto A, Wirbel A, Plateau E.Monoclonal antibodies (Mo Abs) were prepared against influenza/A/equine/Prague/1/56 (H7N7) and influenza/A/equine/Miami/1/63 (H3N8) reference strains of equine influenza virus. These monoclonals were tested against the 2 reference strains, 8 field strains of equine influenza virus, 3 human influenza viruses possessing the H3 hemagglutinin, and one virus of human origin possessing the H1 hemagglutinin. Two antibodies were obtained in one fusion against the Prague/1/56 strain and reacted only with this strain. Four anti/A/equine/Miami/1/63 Mo Abs were obtained in one fusion. They differentiated ...
Matsushita T, Hesterberg LK, Porter JP, Smith BJ, Newman LE.Two diagnostic tests are approved for detecting antibody to equine infectious anemia virus: the agar-gel immunodiffusion (AGID) test and the competitive enzyme-linked immunosorbent assay (ELISA). A total of 420 sera from National Veterinary Services Laboratories check sets were tested with the AGID and competitive ELISA. A 100% correlation was obtained. The AGID and competitive ELISA were further used to test difficult samples with low levels of equine infectious anemia antibody (weak positives). A third test (Western blot) was also used with these weak positive samples to resolve any discorda...
Nishita T, Matsushita H.Sections of equine thymus were examined for the presence of carbonic anhydrase (CA) isozymes by an immunohistochemical method. Carbonic anhydrase III, a major enzyme of skeletal muscle, was localized in some of the epithelial-reticular cells of the equine thymus. This finding suggests the presence of a new type of cell in the thymic cortex. The concentration of CA-III in the thymus was 17 micrograms/g wet tissue. CA-I and CA-II were not found in equine thymus.
Valpotić I, Kastelan M, Rudolf M, Gerencer M, Jukić B, Basić I.The percentage of T and B lymphocytes in the peripheral blood of horses chronically infected with equine infectious anaemia (EIA) virus was determined and the results were compared with the percentage of these cells in healthy uninfected horses. Cells with membrane receptors for sheep erythrocytes (T and active T lymphocytes) were determined by E and A rosette techniques, while cells with receptors for the C3b component of complement and those with receptors for mouse erythrocytes (B lymphocytes), were determined by the EAC rosette method. The percentage of Fe positive cells was assayed by the...
Park CA, Hines HC, Threlfall WR.Equine lymphocyte antigen (ELA) gene frequencies were estimated for pacing and trotting Standardbred mares residing on a breeding farm in central Ohio. The ELA gene frequencies for Ohio Standardbreds did not differ significantly from the ELA gene frequencies of Kentucky Standardbreds, determined by Bailey (1983). No significant differences were found in the distribution of ELA class I antigens in horses with lower overall fertility or a history of abortion on the investigated breeding farm. Likewise, no significant association was observed when the ELA types of both the mare and the stallion t...
Cornick JL, Brumbaugh GW.An eight-year-old Thoroughbred gelding with dermatographic urticaria is presented. Forelimb edema and generalized urticaria were the presenting clinical signs. All hematologic and serum biochemical values were normal. Immunologic and histologic evaluation failed to reveal specific abnormalities. During hospitalization, an urticarial response to mechanical pressure (dermatographism) was identified. Clinical responses to corticosteroid and antihistaminic (H1) therapy were equivocal. The condition resolved in five weeks and an etiology was not discovered. A discussion of the pathogenesis, diagnos...
dos Santos MC, D'Império Lima MR, Furtado GC, Colletto GM, Kipnis TL, Dias da Silva W.Pooled horse plasma containing antibodies against Crotalus durissus terrificus whole venom were digested with pepsin at an enzyme-substrate ratio of 8:1, pH 3.1, for 40 min and the F(ab')2M fragments purified by adding 8.7% caprylic acid (pH 5.0). For comparison, F(ab')2B purified by precipitation with ammonium sulphate and uncleaved IgG purified with caprylic acid were also prepared. Fab' fragments were obtained by reduction and alkylation of F(ab')2B. The anti-whole C.d. terrificus venom titers, determined by Dot-Blot were 12,800 (IgG), 6400 [F(ab')2B], 4800 [F(ab')2M] and 3200 (Fab'B). Immu...
Antczak DF, Allen WR.There is little evidence for maternal immunological recognition of pregnancy in most species with the striking exception of the members of the genus Equus. Almost all mares make strong cytotoxic antibody responses to paternally inherited fetal antigens by Day 60 of gestation. Most of these responses are directed against antigens of the Major Histocompatibility Complex (MHC), which constitutes the primary immunogenetic barrier to successful organ transplantation. The source of fetal MHC antigens in the pregnant mare appears to be the specialized trophoblast cells of the chorionic girdle region ...
Jönsson L, Beck-Friis J, Renström LH, Nikkilä T, Thebo P, Sundquist B.Ten aborted foals, diagnosed as infected with Equine Herpes Virus 1 (EHV-1) on histopathological criteria, were examined for the presence of EHV-1 using immunohistology as the investigative instrument. The primary reagent was an antiserum specific for viral envelope glycoproteins. Immunohistology localised EHV-1 to areas of liver necrosis and to the cytoplasm of infected Kupffer cells and hepatocytes. Cytoplasmic immunolabelling was also prominent in reticular cells of the red pulp of the spleen and in intact and degenerated bronchiolar epithelium. Cytoplasmic immunolabelling was seen in morph...
Melrose PA, Knigge KM.The present study describes the topography of immunoreactive (ir) oxytocin (OXY) and vasopressin (AVP) neurons in the forebrain of Equus caballus and the coexistence of ir proopiomelanocortin (POMC)-derived peptides in the same cells. These data are compared to those for other mammalian species and the possible significance of species variations is considered. As expected, magnocellular neurons of the equine hypothalamus, which contain ir OXY or AVP, have prominent discernible projections to the neurohypophysis. Further, as in other mammalian species, the field of ir OXY perikarya generally ex...
Antal A, Szabó I, Vajda G, Antal VD, Polner A, Totth B, Szollár I, Stipkovits L.Clinical, microbiological, haematological, and immunological investigations were carried out in mares and their foals of 2 studs. A considerable number of foals fell ill with pneumonia, the mortality rate was high. Mycoplasmas were mostly isolated from nasal swabs and from the lungs. The isolation rate of bacteria was lower. Serum IgG concentration was reduced in the diseased or dead foals compared to that of healthy animals, the data stress in importance of IgG in the development of respiratory diseases also in foals.
Murray MJ, Doran RE, Pfeiffer CJ, Tyler DE, Moore JN, Sriranganathan N.Isolated segments of left dorsal colon and a side-to-side colocolostomy (between the left ventral colon and left dorsal colon) were surgically created in 6 adult ponies. Four segments, each separated by an empty segment, were inoculated (20 ml) with 1 of the following 4 solutions: phosphate buffered saline solution (PBSS)/1% polyethylene glycol (PEG); purified cholera toxin in PBSS/1% PEG (5 micrograms cholera toxin/ml of PBSS/1% PEG); lyophilized Salmonella typhimurium UCD 1755 culture lysate, reconstituted in PBSS/1% PEG; and viable S typhimurium UCD 1755 (10(8) organisms/ml of PBSS/1% PEG)....
Soulé C, Boulard C, Levieux D, Barnouin J, Plateau E.Three, four, and one horses were respectively infected with 100, 1,000, and 5,000 metacercariae of Fasciola hepatica. Six of them were reinfected 38 weeks later with 1,000 metacercariae each. Specific antibodies assayed by counter-electrophoresis, passive hemagglutination and ELISA tests appeared three to six weeks post-infection and peaked 10 to 17 weeks post-infection. Horses infected by 1,000 metacercariae and more showed 17.6% of positive samples by counter-electrophoresis, 49.2% by ELISA, and 75.6% by passive hemagglutination. Plasma glutamate dehydrogenase and gamma-glutamyltransferase l...
Brown JE, Corstvet RE, Stratton LG.Two experiments incorporating 13 mares were conducted for the purpose of producing and monitoring intrauterine infection with Klebsiella pneumoniae. In the pilot study, the infection was produced with strains of K pneumoniae type 68 and type 10 isolated from the genital tract of stallions with a history of breeding problems. In the principal study, K pneumoniae type 68 was used to produce the infection. Tampons and guarded culture swabs were used to obtain uterine samples in the pilot study. In comparing the efficacies of isolation of K pneumoniae with the tampons and isolation with standard g...
Trenholme HN, Sakai DM, Berghaus LJ, Hanafi AL, Knych HK, Ryan CA, McHale B, Banovic F, Quandt JE, Barletta M, Reed RA. To evaluate changes in immunological parameters following subcutaneous (SC) and intramuscular (IM) administration of meperidine in horses through quantitative analysis of plasma tryptase, histamine, and IgE levels. Six adult horses were enrolled in a prospective randomized crossover design. Horses were administered one treatment per day, with a seven day washout period: (a) meperidine 1 mg/kg IM, saline 6 mL SC; (b) saline 6 mL IM, meperidine 1 mg/kg SC; (c) saline 6 mL SC, saline 6 mL IM. Blood samples were obtained for plasmatic histamine (baseline, 5, 10, 15, 30, and 60 min) via LC-MS/MS ...
Reid CJ, Thompson L, Donnelly S, Deaton CM, Marlin DJ, Carrington SD, Irwin JA.Recurrent airway obstruction (RAO) is a chronic inflammatory condition in equine lung, which may share a common immunological basis with human asthma, in which dysregulated Th2 responses occur. Mammals express chitinases and chitinase-like proteins, two of which are active enzymes, chitotriosidase and acidic mammalian chitinase (AMCase). Both enzymes are upregulated in a range of inflammatory conditions, including asthma. We investigated the activity of chitinase in bronchoalveolar lavage fluid from horses with and without RAO in response to organic dust challenges. No significant differences ...
Wijnker JJ, Bull S, Van Dijk P, Veenman JN, Rutten VP, Klein WR, Fink-Gremmels J.The detrimental effects of the pro-inflammatory cytokine TNF-alpha during equine acute abdominal disease are well known. Its pivotal role in many human diseases has led to various in-depth studies regarding its release mechanism, in particular by TNF-alpha converting enzyme (TACE). In this study we investigated the inhibitory effect of a TACE-inhibitor on cytokine release (TNF-alpha, IL-1alpha and IL-6) in three different cell models, including U937 cells, a recently established equine macrophage cell line, known as eCAS, and primary equine PBMC. The aim was to show the similarity of TNF-alpha...
Tada M, Kobashigawa Y, Mizuguchi M, Miura K, Kouno T, Kumaki Y, Demura M, Nitta K, Kawano K.Equine lysozyme is a calcium-binding lysozyme and an evolutional intermediate between non-calcium binding c-type lysozyme and alpha-lactalbumin. We constructed a chimeric protein by substituting the fluctuating loop of bovine alpha-lactalbumin with the D-helix of equine lysozyme. The substitution affects the protection factors not only in the fluctuating loop but also in the antiparallel beta-sheet, the A- and B-helices, and the loop between the B-helix and the beta-sheet. Amide protons in these regions of the chimera are more protected from exchange than are those of bovine alpha-lactalbumin....
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...
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...
Sanada Y, Noda H, Nagahata H.A fluorometric assay was applied to evaluate blastogenesis of equine lymphocytes. Optimal culture conditions were as follows; concentrations of phytohaemagglutinin-P (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were 1 microgram/ml, 40 micrograms/ml and 10 micrograms/ml, respectively, when 5 X 10(5) lymphocytes were incubated with culture medium containing 20% pooled horse serum (PHS) for 120 hours. The relative mean stimulation index of healthy non-pregnant mares were 5.107 +/- 0.323 (M +/- SE) with PHA, 4.019 +/- 0.183 with Con A and 3.610 +/- 0.131 with PWM. Sequentially the blas...
Peterson C, Driskell E, Wilkie D, Premanandan C, Hamor R.Expression of the 70-kDa heat-shock protein (HSP70) has been demonstrated in normal canine corneal epithelium, and inducible expression has been suggested to facilitate wound resolution through organized migration, proliferation, and adhesion of the corneal epithelial cells. Diminished expression of HSP70 may therefore contribute to prolonged healing in the pathologic cornea of other companion animal species, including the horse. Methods: Normal and pathologic equine cornea was evaluated to determine whether the expression of HSP70 is correlated with appropriate corneal epithelial wound healin...
Wassall DA, Gregory RJ, Phipps LP.The detection of antibodies against Trypanosoma equiperdum in 689 equid sera was compared by enzyme-linked immunosorbent assay (ELISA), the complement fixation test (CFT) and an indirect immunofluorescent test (IIF). CFT was the least sensitive technique, susceptible to anti-complementary factors and the most technically demanding. IIF was more sensitive, but was only suitable for testing limited numbers of samples. In this study, ELISA was the most sensitive test, the least labour intensive and lends itself to a considerable degree of automation. It is suggested that ELISA would be relatively...
Melrose PA, Knigge KM.The present study describes the topography of immunoreactive (ir) oxytocin (OXY) and vasopressin (AVP) neurons in the forebrain of Equus caballus and the coexistence of ir proopiomelanocortin (POMC)-derived peptides in the same cells. These data are compared to those for other mammalian species and the possible significance of species variations is considered. As expected, magnocellular neurons of the equine hypothalamus, which contain ir OXY or AVP, have prominent discernible projections to the neurohypophysis. Further, as in other mammalian species, the field of ir OXY perikarya generally ex...
Madelin TM, Clarke AF, Mair TS.Sera from 54 two- to three-year-old Thoroughbred horses from an English racing stable were examined for precipitins to antigen extracts prepared from 18 species of moulds (fungi and thermophilic actinomycetes) isolated from the same stable. Twenty-seven horses exhibited serum precipitins to one or more antigens; sixteen of the mould antigens elicited positive reactions in sera from one or more horses. Significantly more precipitins occurred in sera of those horses stabled in a barn than among those stabled in individual boxes. This indicated a possible association between type of housing, leve...
Hassall L, Rigsby P, Stickings P.The International Standard for Diphtheria Antitoxin Equine is essential for the standardisation of assays used to determine the potency of therapeutic diphtheria antitoxin products produced from equine serum. This paper describes the production and characterization of the 2nd International Standard for Diphtheria Antitoxin Equine and its calibration in International Units. Calibration was performed by toxin neutralization test in vivo and in vitro (Vero cell assay), and potency was expressed relative to the 1st International Standard to ensure continuity of the International Unit. The candidat...
Levanti B, Hannestad J, Esteban I, Ciriaco E, Germanà G, Vega JA.The neurotrophins are a family of growth factors that act on responsive cells through specific high-affinity signal-transducing receptors called Trk (A, B, and C) proteins. The neurotrophin receptor proteins are widely distributed in both nervous and nonnervous tissues, including the lymphoid organs. The expression of these receptor proteins by a cell population is an indication of responsiveness to the respective binding neurotrophin. The present study investigated the presence and cellular localization of high-affinity neurotrophin receptor proteins in equine and bovine Peyer's patches. Peye...
Archambault D, Laganière G, St-Laurent G.The genetic variation in equine arteritis virus (EAV) nonstructural (NS) protein-encoding open reading frames (ORF) 3 and 4 genes was investigated. Nucleotide and deduced amino acid sequences from seven different EAV isolates (one European, one American and five Canadian isolates) and the Arvac vaccine strain were compared with those of the Bucyrus reference strain. ORF 3 nucleotide and amino acid sequence identities amongst these isolates (including the Arvac vaccine strain) and the Bucyrus reference strain ranged from 85.6 to 98.8%, and 85.3 to 98.2%, respectively, whereas ORF 4 nucleotide a...
Xu J, Lasry JB, Svaren J, Wagner B, Darien BJ.P-selectin glycoprotein ligand-1 (PSGL-1, CD162) is a dimeric, mucin-like, transmembrane glycoprotein constitutively expressed on leukocytes. A high baseline level of P-selectin expression in circulating equine platelets suggests a primed state toward inflammation and thrombosis via P-selectin/PSGL-1 adhesion. To investigate the potential role of equine P-selectin in these events, we first identified the cDNA sequence of equine PSGL-1 (ePSGL-1) using degenerate PCR and RACE-PCR and then compared the predicted sequence with that of human PSGL-1 (hPSGL-1). ePSGL-1 protein subunit is predicted to...
El-Hage C, Hartley C, Savage C, Watson J, Gilkerson J, Paillot R.During Australia's first and only outbreak of equine influenza (EI), which was restricted to two northeastern states, horses were strategically vaccinated with a recombinant canarypox-vectored vaccine (rCP-EIV; ProteqFlu™, Merial P/L). The vaccine encoded for haemagglutinin (HA) belonging to two equine influenza viruses (EIVs), including an American and Eurasian lineage subtype that predated the EIV responsible for the outbreak (A/equine/Sydney/07). Racehorses in Victoria (a southern state that remained free of EI) were vaccinated prophylactically. Although the vaccine encoded for (HA) belon...
Kong XG, Pang H, Sugiura T, Sentsui H, Onodera T, Matsumoto Y, Akashi H.Equine infectious anemia virus (EIAV) core proteins were obtained from a baculovirus expression system. Recombinant baculoviruses (rBVs) highly expressed the Gag precursor and p26 antigens in an rBV-infected Sf21 cell culture supernatant. Enzyme-linked immunosorbent assay (ELISA) and agar gel immunodiffusion (AGID) were conducted using the expressed proteins to detect antibodies from experimentally infected horses. The expressed antigens showed low background levels, high specificity and sensitivity in ELISA and AGID. The results of the serological tests using the expressed antigens were ident...
Kahn SK, Cywes-Bentley C, Blodgett GP, Canaday NM, Turner-Garcia CE, Vinacur M, Cortez-Ramirez SC, Sutter PJ, Meyer SC, Bordin AI, Vlock DR, Pier GB....The efficacy of transfusion with hyperimmune plasma (HIP) for preventing pneumonia caused by Rhodococcus equi remains ill-defined. Quarter Horse foals at 2 large breeding farms were randomly assigned to be transfused with 2 L of HIP from adult donors hyperimmunized either with R. equi (RE HIP) or a conjugate vaccine eliciting antibody to the surface polysaccharide β-1→6-poly-N-acetyl glucosamine (PNAG HIP) within 24 hours of birth. Antibody activities against PNAG and the rhodococcal virulence-associated protein A (VapA), and to deposition of complement component 1q (C՛1q) onto PNAG were d...
McAleese SM, Brown JK, Macrae AI, Mackellar A, Huntley JF, Miller HR.The high-affinity receptor for IgE (FcepsilonRI) plays a central role in IgE-mediated allergic reactions. Cross-linking of FcepsilonRI by IgE-antigen complexes results in the activation of mast cells and basophils and is thought to contribute to the immunopathology of Heaves, a chronic obstructive pulmonary disease of horses. Recombinant protein corresponding to the extra-cellular portion of the FcepsilonRI alpha subunit, cloned and sequenced previously, was expressed using both mammalian cells and insect cells. The yield of expressed protein was considerably greater using insect cells and the...
Murakami K, Sentsui H, Shibahara T, Yokoyama T.Three horses were experimentally infected with equine infectious anemia virus (EIAV). All horses were febrile after inoculation with EIAV and then developed chronic symptoms with intermittent fever. The febrile period was characterized by a rise in body temperature with reduced PBL and erythrocyte counts. Flow cytometric analysis showed that the reduced number of lymphocytes was due to significant decreases in CD4+ and CD8+ T cells in the absence of any change in B cell number. At the end of the febrile period the body temperature began to recover and numbers of CD4+ and CD8+ T cells showed a ...
Becht JL, Page EH, Morter RL, Boon GD, Thacker HL.A series of modified (field) tests were compared to a crossmatch between mare and foal for their reliability in predicting neonatal isoerythrolysis (NI) in eight foals born to experimentally alloimmunized mares. In the field tests, mare's serum, plasma and colostrum were combined with foal erythrocytes washed by a modified procedure to determine which combination was the best predictor of impending NI. A consistent grading system for agglutination and hemolysis was employed. The field tests using mare's plasma demonstrated less agglutination and hemolysis than tests where serum was employed. I...
Capistrano da Silva E, Gibson DJ, Jeong S, Zimmerman KL, Smith-Fleming KM, Martins BDC.Matrix metalloproteinases (MMPs)-2 and -9 are present in corneal ulcers, and an imbalance between MMPs and tissue inhibitors of metalloproteinases (TIMPs) leads to further corneal degradation. Amniotic membrane homogenate (AMH) has proteolytic properties beneficial for corneal healing, but it is unknown whether AMH possesses TIMPs or effectively inhibits MMP-2 and MMP-9 activity. Objective: To determine if bovine and equine AMH reduce in vitro MMP-2 and MMP-9 activities associated with the presence of TIMPs. Methods: Undiluted and diluted twofold series (0-fold to 16-fold dilutions) of equine ...
Derksen FJ, Slocombe RF, Gray PR, Robinson NE.The lungs of sensitized horses were exposed to aerosolized ovalbumin. Some horses (n = 4) were given ovalbumin in 1 lung only, whereas in others (n = 7), ovalbumin or vehicle were inoculated in the cranial, ventral, and caudal regions of the caudal lung lobe. Horses were exercised 5 hours after ovalbumin exposure. Immediately before exercise, endoscopy failed to reveal any abnormality. After exercise, endoscopic examination of horses subjected to unilateral ovalbumin exposure revealed extensive blood in airways leading to the exposed lung in all horses. Blood was not observed in the airways le...
De Martin I, Theoret CL.To describe immunolocalization of TGF-beta receptors (RI and RII) in normal equine skin and in thoracic or limb wounds, healing normally or with exuberant granulation tissue (EGT). Methods: Group A: six wounds on one metacarpus and one midthoracic area. Group B: six wounds on both metacarpi, one of which was bandaged to stimulate EGT. Immunohistochemistry was used to detect RI and RII expression in wound margins. Methods: Eight horses, randomly assigned to one of two study groups. Methods: Neutralizing polyclonal anti-rabbit RI and RII antibodies were used to detect spatial expression of RI an...
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. ...
Horsington J, Hartley CA, Gilkerson JR.Respiratory infections are a major burden in the performance horse industry. Equine rhinitis B virus (ERBV) has been isolated from horses displaying clinical respiratory disease, and ERBV-neutralizing antibodies have been detected in 50-80% of horses in reported surveys. Current ERBV isolation and detection methods may underestimate the number of ERBV-positive animals and do not identify multiple serotype infections. The aim of the current study was to develop a serotyping ERBV antibody-detection enzyme-linked immunosorbent assay (ELISA) and examine the seroprevalence of ERBV in a group of Aus...
Warko G, Bostedt H.The aim of this study was to determine the course of the IgG concentration in blood serum of neonatal foals. A comparison of blood serum IgG concentration of the mares showed IgG values of 3356 +/- 671 mg/dl up to a maximum of 3579 +/- 766 mg/dl (means +/- s). In accordance with Eisenhauer (1981) and in contrast to Jeffcott (1974) no significant change of the IgG level in the blood serum of the mares could be observed during the test period. However, the IgG concentration in the colostrum of meanG = 11776 mg/dl during birth decreased considerably 96 hours later with meanG = 135 mg/dl. At birth...
Liu C, Cook SJ, Craigo JK, Cook FR, Issel CJ, Montelaro RC, Horohov DW.Unlike other lentiviruses, EIAV replication can be controlled in most infected horses leading to an inapparent carrier state free of overt clinical signs which lasts for many years. While the resolution of the initial infection is correlated with the appearance of virus specific cellular immune responses, the precise immune mechanisms responsible for control of the infection are not yet identified. Since the virus undergoes rapid mutation following infection, the immune response must also adapt to meet this challenge. We hypothesize that this adaptation involves peptide-specific recognition sh...
Morris DD, Harmon BG, Moore JN.A study was performed to determine whether equine antiserum to core lipopolysaccharide (LPS) would enhance phagocytosis of smooth gram-negative (GN) organisms by equine macrophages. Five healthy adult horses (group A) were immunized with a bacterin prepared from the J-5 mutant of Escherichia coli 0111:B4 and Salmonella minnesota R595 to produce antibodies to core LPS. Five horses (group B) served as nonimmunized controls and were given physiologic saline solution instead of the rough mutant bacterin. Serum antibody titers to core LPS and to smooth E coli 0111:B4 were determined by indirect ELI...
