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.
Martínez-Torrecuadrada JL, Díaz-Laviada M, Roy P, Sánchez C, Vela C, Sánchez-Vizcaíno JM, Casal JI.Fifteen horses were experimentally infected with African horse sickness virus (AHSV) serotype 4. To learn more about the time course of production and specificity of AHSV-specific antibodies, sera were analyzed by immunoblot analysis. Only animals that survived for more than 9 days were able to develop a humoral immune response detectable by immunoblotting. The earliest serological markers corresponded mainly to VP5, VP6, and NS2 and to a lesser extent to VP3, NS1, and NS3. Neutralizing antibodies to VP2 were not detected by immunoblotting, suggesting that they are mostly conformation dependen...
Catena C, Asprea L, Carta S, Tortora G, Conti D, Parasacchi P, Righi E.We have investigated and compared DNA damage and cell killing induced in human and equine lymphocytes after in vitro X-irradiation. Our data show that the cytogenetic and the lethality effects are both greater in equine lymphocytes, but that the difference is wider for lethality. The ratios between doses inducing the same effect are 1.3, 1.7 and 9.4 for the number of binucleated cells with micronuclei, micronucleus frequency in binucleated cells and DNA synthesis inhibition, respectively. The very different radiosensitivity observed for the two mammalian species encourages us to use their lymp...
Chesters PM, Steele M, Purewal A, Edington N.A 2.6 kb cDNA species has been isolated from a cDNA library prepared from interferon-alpha stimulated equine peripheral blood leucocytes and the nucleotide sequence determined. The cDNA has a single open reading frame potentially encoding a 660 amino acid polypeptide showing a high degree of homology with known mammalian Mx proteins, including the possession of three consensus GTP-binding motifs. The protein has a calculated pI = 6.1 and in accordance with proposed nomenclature we have designated it equine MxA.
Kochanowska IE, Kuropatwa M, Szewczuk A.It was noted that human and horse sera as well as human heart and skeletal muscle homogenates or extracts distinctly decrease immunoassays of purified myoglobins. The assays of homogenate and extract myoglobins could be many times increased by precipitation certain proteins with concentrated ammonium sulfate or sodium chloride. Also in homogenates and extracts incubated for several days increased assays of myoglobins were noted. The obtained results indicate that both myoglobins occur in complex with other tissue component(s).
Studer U, Marti E, Stornetta D, Lazary S, Gerber H.20 sarcoid-affected horses from a practice in the northern Jura were used in this experiment. The mean age of the 20 horses was 3.9 years at the time of the first observation of sarcoid tumors. On the average, 4.4 tumours were noted per horse. 10 of the horses were treated in a double-blind study with an unspecific immunostimulant (Baypamun P), 10 others received a placebo. One single tumour only was treated per horse. The injections were given under and around the sarcoid. In eight out of the 20 horses all tumours regressed totally or for more than 50% of their initial size. Five of these had...
Schultheiss PC, Collins JK, Hotaling SF.Equine herpesvirus-1 (EHV-1) infection in a few widely scattered neurons and astrocytes plus endothelial cells in brain and spinal cord of two horses with naturally occurring paralytic disease was demonstrated by use of an immunoperoxidase technique. These horses were euthanatized less than 48 hours after the onset of clinical signs. No staining for EHV-1 was demonstrated in brain or spinal cord of three horses that had a longer duration of clinical disease or in two uninfected horses.
Parma AE, Sanz ME, Lucchesi PM, Mazzonelli J, Petruccelli MA.A protein epitope which is involved in an antigenic relationship between equine ocular tissues and Leptospira interrogans was detected in homogenates of the bacterium. The antigenic determinant was harboured on a peptide structure which was shown to be sensitive to the action of denaturing and reducing agents by means of Western blotting. The outer surface of the leptospires appeared to be free of this epitope as was proved by dot-blot and electron microscopic studies.
Lisiecki P, Sobiś-Glinkowska M, Mikucki J.Under iron-restricted conditions staphylococcal strains could utilize in vitro several animals body iron sources in form of bovine haemoglobin, hemin, lactoferrin and transferrin, ovotransferrin, horse myoglobin ferritin and cytochrome C. Spectrum of utilized iron sources was not dependent on species affiliation and kind of siderophores system. Strains isolated from clinical materials utilized largest spectrum of animal iron body sources.
Magnarelli LA, Flavell RA, Padula SJ, Anderson JF, Fikrig E.Serum samples from dogs and equids suspected of having canine or equine borreliosis, respectively, were analyzed in polyvalent enzyme-linked immunosorbent assays (ELISAs) with whole-cell or recombinant antigens of Borrelia burgdorferi sensu stricto. Purified preparations of recombinant antigens included outer surface protein A (OspA), OspB, OspC, OspE, OspF, and p41-G (a fragment of flagellin). Of the 36 dog sera that reacted positively to whole-cell antigen, 32 (88.9%) contained antibodies to one or more recombinant antigens. Reactivities to OspF (88.9% positive) and p41-G (75% positive) were...
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...
Tyler-McGowan CM, Hodgson JL, Hodgson DR.To determine the regional incidence and effectiveness of treatment of failure of passive transfer (FPT) in foals. Methods: A study of disease incidence. Methods: Eighty-eight foals and 57 mares from four studs in the practice area of the Rural Veterinary Centre were tested. Methods: Foals were tested for their serum IgG and total serum protein (TSP) concentration within the first 72 hours of life. Colostrum was collected from mares and specific gravity determined. FPT and partial failure of passive transfer (PFPT) of immunoglobulins was diagnosed when serum IgG concentrations were < 4 g/L and ...
Schrenzel MD, King DP, McKnight ML, Ferrick DA.Horse (Equus caballus) immunoglobulin mu chain-encoding (IgM) variable, joining, and constant gene segments were cloned and characterized. Nucleotide sequence analyses of 15 cDNA clones from a mesenteric lymph node library identified 7 unique variable gene segments, 5 separate joining segments, and a single constant region. Based on comparison with human sequences, horse variable segments could be grouped into either family 1 of immunoglobulin (Ig) clan I or family 4 of Ig clan II subclan IV. All horse sequences had a relatively conserved 16 base pair (bp) segment in framework 3 which was reco...
Sugahara Y, Matsumura T, Kono Y, Honda E, Kida H, Okazaki K.Heparin extensively inhibited infection of MDBK cells by equine herpesvirus 1 (EHV-1) strains adapted to bovine cells or hamsters, while the reagent merely reduced infectivity of strains passaged only in equine cells. The gC of two strains adapted to non-equine cells seemed to have higher affinity for heparin, although the reagent bound to both the gC and gB of all strains tested. Amino acid substitutions of the gC of the EHV-1 strains adapted to non-equine cells converged on the hydrophilic regions, amino acid residues 92 to 175, resulting in the glycoprotein becoming more cationic. These res...
Proudman CJ, Holmes MA, Sheoran AS, Edwards SE, Trees AJ.The equine intestinal cestode Anoplocephala perfoliata has been the subject of recent epidemiological and immunological studies because of its suspected association with intestinal disease in the horse. We have previously shown that the IgG(T) subtype antibody response to the 12/13 kDa component of the parasite excretory/secretory (E/S) antigen is positively correlated with parasite intensity. In this study, we utilize that correlation to examine the changes in natural infection intensity with age. Infection intensity based on IgG(T) responses showed a triphasic age-dependency pattern with pea...
Adeyefa CA, McCauley JW, Tomori O.The complete amino acid sequences of the hemagglutinin (HA) glycoprotein of three equine-2 influenza viruses from tropical Africa are presented in comparison with that of a well characterized European equine-2 virus (Suffolk/89) and a consensus sequence from the database. The sequences of the tropical African viruses were deduced from the complete nucleotide sequences of their HA genes reported earlier. Mutational changes in the nucleotide sequences resulted in amino acid changes in the HA which led to the introduction of a new asparagine-linked (N-linked) glycosylation site in two viruses. Th...
Wang LF, Gould AR, Selleck PW.Full-length cDNA clones coding for the matrix (M) and fusion (F) proteins of equine morbillivirus (EMV) were isolated by RT-PCR, and expressed in Escherichia coli using two different expression systems. Western blot analysis indicated that the M and F proteins, expressed either by itself or as fusion proteins with glutathione S-transferase (GST), were insoluble and degraded after expression. Analysis of the degradation pattern of recombinant M protein suggested that the N-terminus of the matrix protein might be more stable and antigenic than the C-terminal region. Therefore a third system was ...
Gregoire C, Rosinski-Chupin I, Rabillon J, Alzari PM, David B, Dandeu JP.The gene encoding the major horse allergen, designated Equus caballus allergen 1 (Equ c1), was cloned from total cDNA of sublingual salivary glands by reverse transcription-polymerase chain reaction using synthetic degenerate oligonucleotides deduced from N-terminal and internal peptide sequences of the glycosylated hair dandruff protein. A recombinant form of the protein, with a polyhistidine tail, was expressed in Escherichia coli and purified by immobilized metal affinity chromatography. The recombinant protein is able to induce a passive cutaneous anaphylaxis reaction in rat, and it behave...
Sheoran AS, Holmes MA.Equine IgG possesses four well-defined subisotypes, designated IgGa, IgGb, IgGc and IgG(T) on the basis of their increasing anodal mobility in electrophoresis. However, the preparation of IgGa and IgGb reference proteins has not previously been reported. Certain bacterial cell wall proteins, termed protein A and protein G, have been used for purification of IgG subisotypes from the serum of domestic animals which, combined with other techniques utilising differences in the physico-chemical properties of the proteins, has allowed the purification of Ig isotypes. This paper describes purificatio...
Bilzer T, Grabner A, Stitz L.Tissues from nine horses and one donkey suffering from natural Borna disease were investigated. Clinically, all animals demonstrated progressive reduced mentation and aggravating gait disturbances. During the clinical course anorexia and progressive loss of proprioception were observed. Cranial nerve failure was accompanied by signs of pharyngeal paralysis, sialorrhea, bruxism, and by blindness. Virologically, infectious virus was detected in the brain of all animals investigated but was not found regularly in all areas of the brain. However, in all cases, infectivity was found in the thalamus...
Madden CR, Shih DS.Sequential passage of the tissue culture-adapted prototype strain of EIAV in fetal donkey dermal (FDD) cell cultures generated a virus stock which exhibits cytopathic effects in FDD cell cultures. In this study, the effects of the long terminal repeat (LTR) region on virus replication and cytopathogenicity were examined. The FDD-adapted virus LTR was found to contain a number of base pair mutations and a large insertion within the U3 region in comparison with the previously characterized LTR, lambda12. Transient gene expression studies showed that basal promoter activity, in FDD cell cultures,...
Arun SS, Breuer W, Hermanns W.Five species of domestic animals were examined immunohistochemically and the light-chain ratios of the immunoglobulins produced by plasma cells analysed. Forty dogs, 11 cats, 10 horses, 11 cattle and 14 pigs were tested using the sequential indirect immunoperoxidase and immunophosphatase methods. Tissues from the tonsils, spleen and cervical lymph nodes were analysed. It could be seen that the lambda/kappa ratio in dogs, cats, horses and cattle is largely dominated by the lambda chains (lambda/kappa ratio in dogs: 91/9%, in cats; 92/8%; in horses: 96/4%; in cattle: 91/9%). A more or less balan...
Ramos-Vara JA, Ortiz-Santiago B, Segalès J, Dunstan RW.This report contains the clinical, histologic, immunohistochemical, and electron microscopic findings in two cases of equine cutaneous leishmaniasis. Nodular, sometimes crusty or ulcerated lesions were confined to the pinna and adjacent neck in both animals. The dermal inflammatory infiltrate was lymphohistiocytic in horse No. 1 and pyogranulomatous with formation of tuberculoid granulomas in horse No. 2. Numerous Leishmania organisms were found within macrophages in both animals. There was moderate to intense and specific reaction by immunoperoxidase using a polyclonal antiserum against Leish...
Watson ED, Thomson SR.Aromatase P-450 (P-450arom) is a crucial regulatory enzyme that is necessary for conversion of androgens to oestrogens. Corpora lutea and follicles were obtained from the ovaries of cyclic mares and from mares at day 20 and days 40-70 of pregnancy. The presence of P-450arom within specific cell types was investigated by immunostaining to determine potential sites of oestrogen synthesis. Immunoreactivity for P-450arom was confined to the granulosa layer of non-atretic follicles > 5 mm in diameter and to corpora lutea at all stages of the oestrous cycle and during pregnancy. These findings co...
Murray MJ, Eichorn ES, Dubovi EJ, Ley WB, Cavey DM.Whole blood and serum were collected from foals to determine the prevalence of Equine herpesvirus type 2 (EHV 2) infection in foals, age at which infection can first be identified and serological responses to infection. Equine herpesvirus type 2 was isolated from peripheral blood mononuclear cells (PBMC) from 68 of 69 foals, 1-8-months-old, sampled once. Virus isolation was performed twice at intervals of 2-7 months on PBMCs from 33 foals and EHV2 was isolated on both occasions in all but one foal (negative, then positive). Regression analysis of log2-transformed reciprocal serum EHV2 virus ne...
Hiemstra PS, Maassen RJ, Stolk J, Heinzel-Wieland R, Steffens GJ, Dijkman JH.Antileukoprotease (ALP), or secretory leukocyte proteinase inhibitor, is an endogenous inhibitor of serine proteinases that is present in various external secretions. ALP, one of the major inhibitors of serine proteinases present in the human lung, is a potent reversible inhibitor of elastase and, to a lesser extent, of cathepsin G. In equine neutrophils, an antimicrobial polypeptide that has some of the characteristics of ALP has been identified (M. A. Couto, S. S. L. Harwig, J. S. Cullor, J. P. Hughes, and R. I. Lehrer, Infect. Immun. 60:5042-5047, 1992). This report, together with the catio...
Kato H, Youn HY, Ohashi T, Watari T, Goitsuka R, Tsujimoto H, Hasegawa A.Using lipopolysaccharide (LPS)-stimulated equine peripheral blood mononuclear cell (PBMC) cDNA as a template, we performed polymerase chain reaction (PCR) amplification with equine interleukin-1 beta (IL-1 beta) specific primers. Electrophoresis of the PCR product on agarose gel revealed an additional smaller fragment that hybridized with an equine IL-1 beta cDNA probe. Sequencing of this fragment demonstrated that it was shorter than normal equine IL-1 beta cDNA by 162 nucleotides, which corresponded to exon 5 of the human and murine IL-1 beta genes. The deletion of 162 nucleotides did not re...
Horohov DW, Keadle TL, Pourciau SS, Littlefield-Chabaud MA, Kamerling SG, Keowen ML, French DD, Melrose PA.Intense exercise affects various parameters of the immune system. The overall effect of exercise on immune function is dependent upon the physical condition of the subject, the intensity and duration of the exercise period, and the immune parameter assessed. Unconditioned horses subjected to a single bout of intensive exercise exhibit multiple alterations in immune function, including an augmentation of lymphokine activated killer (LAK) cell function. This increase in LAK cell activity is not due to an increase in circulating LAK precursors. While peripheral blood mononuclear cells from exerci...
Zhang P, Sun Y, Tan C, Ling M, Li X, Wang W, Cong Y.To prevent and control H3N8 subtype equine influenza, we prepared virus-like particles (VLPs) comprising the HA, NA and M1 proteins of H3N8 equine influenza virus (EIV) through the insect cell-baculovirus expression system. The results of Western blot and hemagglutination analyses demonstrated that the constructed VLPs comprising HA, NA and M1 proteins have good hemagglutination activity. Immunoelectron microscope revealed that the VLPs share similar morphology and structure with natural virus particles. The hyperimmune serum from horses immunized with the VLPs were injected into mice by means...
Watson ED, Thomson SR.Aromatase P-450 (P-450arom) is a crucial regulatory enzyme that is necessary for conversion of androgens to oestrogens. Corpora lutea and follicles were obtained from the ovaries of cyclic mares and from mares at day 20 and days 40-70 of pregnancy. The presence of P-450arom within specific cell types was investigated by immunostaining to determine potential sites of oestrogen synthesis. Immunoreactivity for P-450arom was confined to the granulosa layer of non-atretic follicles > 5 mm in diameter and to corpora lutea at all stages of the oestrous cycle and during pregnancy. These findings co...
Silva A, Wagner B, McKenzie HC, Desrochers AM, Furr MO.The objectives of this study were to (1) evaluate the effects of equine soluble CD14 (sCD14) and monoclonal antibodies (mAb) to equine CD14 on lipopolysaccharide-induced tumor necrosis factor α (TNF-α) secretion from equine peripheral blood mononuclear cells (PBMC); and to (2) determine serum concentrations of sCD14 in a population of horses with gastrointestinal diseases or other illnesses likely to result in endotoxemia. Equine PBMC isolated from 10 healthy horses were incubated with Escherichia coli LPS plus CD14 mAb or sCD14 and assayed for TNF-α activity. Pre-incubation with CD14 mAb d...
Pauwels FE, Wigley SJ, Munday JS, Roe WD.A 13-year-old Thoroughbred mare was presented with a history of mild colic over 3 days. This colic had acutely exacerbated and was unresponsive to analgesic treatment, and was referred to Massey University Veterinary Teaching Hospital. Results: On examination the heart rate was 100 beats per minute, and mucous membranes were pale and tacky. A large mass was detected on transrectal palpation in the caudal abdomen to the left of midline. Explorative laparotomy revealed severe haemoperitoneum and several masses that were associated with the reproductive tract. The mare was then subject to euthana...
Fenwick BW, Schore CE, Osburn BI.Equine, caprine, ovine, canine and feline peripheral blood lymphocytes were evaluated in a short term dose-response study for their in vitro blastogenic responsiveness to human recombinant interleukin-2(125) (HrIL-2(125] alone or in combination with phytohemagglutinin-P, concanavalin-A, and pokeweed mitogen. HrIL-2(125) induced lymphocyte proliferation in all of the animals tested. The magnitude of the proliferative response varied among the species of animal tested. In all cases the proliferative response was dependent on the concentration of HrIL-2(125). HrIL-2(125) at a minimum concentratio...
Allen GK, Campbell-Beggs C, Robinson JA, Johnson PJ, Green EM.Six, clinically healthy horses, of mixed age and sex, were infused via a jugular venous catheter with 100 ml of pyrogenfree sterile saline (PFSS; 0.9% NaCl). Animals were infused with Escherichia coli O55:B5 endotoxin (total dose = 50 ng/kg bwt), 24 (LPS-1) and 48 h (LPS-2) after PFSS infusion. Blood was collected before, and every 15 min after, each infusion for the first 8 h and then every 2 h for the following 14 h. Clinical responses (rectal temperature, heart rate, respiration rate and blood pressure) were determined before and every 4 h after each infusion for 20 h. Geometric mean anti-e...
Stark G, Schneider B, Gemeiner M.Zinc concentration has been shown to have a potent immunomodulatory capacity, particularly influencing T helper cell organisation and cytokine secretion. Culicoides hypersensitivity (CHS) in horses resembles the early and late phase of type I hypersensitive reactions in man, characterised by a shift from T helper cell subtype 1 to T helper cell subtype 2 cytokine profile. In this pilot study, zinc and copper levels were measured in the plasma of 48 CHS-affected and 56 healthy Icelandic horses age 4-25 years (mean approximately 11 years) kept on 7 farms. Affected horses were divided into 3 grou...
Tosi I, Bureau F, Farnir F, Denoix JM, Lekeux P, Art T.Cytosine-phosphate-guanosine (CpG-ODN) has been described as a potent immunostimulatory agent in different species. No study reported the effect of a P-class CpG when administered systemically in healthy horses. The aim of this study was to evaluate the tolerance and the effect of an intramuscularly administered P-class CpG-ODN on hematology and on plasma cytokines (IFN-α, IL-10, TNF-α, IFN-γ) in 8 healthy horses. Intra-muscular CpG-ODN or placebo (PBS) was administered twice at a 7 days-interval. Groups were inversed after 2 months of washout period. A physical examination, complete bloo...
Klomkleaw W, Kasashima Y, Fuller GA, Kobayashi A, Yoshihara T, Oikawa MA, Izumisawa Y, Yamaguchi M.An anatomical study of horse lumbrical muscle (Lm) was carried out by light and electron microscopy in combination with immunochemical and cytochemical methods. Paraffin sections were subjected to haematoxylin and eosin (H & E) and Masson's trichrome staining for morphometric analysis. Paraffin sections were also used for immunostaining by anti-PGP 9.5 for reaction with nerve-protein associated-structures, anti-heat-shock protein 70 (hsp 70) for detection of gene expression changes, anti-fast myosin for the determination of muscle fibre types, and for detection of apoptotic gene expression...
Yamamoto M, Nakagawa K, Fujiwara K, Shimizu A, Ikeguchi M, Ikeguchi M.Equine β-lactoglobulin (ELG) assumes non-native helices during refolding and in partially folded states. Previously, circular dichroism (CD) combined with site-directed mutagenesis identified helical regions in the acid- and cold-denatured states of ELG. It is also known that a fragment of ELG, CHIBL (residues 88-142), has a structure similar to that of the cold-denatured state. For the study reported herein, the structure of a shorter fragment, CHIBLΔF (residues 97-142), was investigated by CD and nuclear magnetic resonance spectroscopy. The secondary chemical shifts clearly showed that non...
Yao Q, Ma J, Wang X, Guo M, Li Y, Wang X.Tetherin (BST-2) is an important host restriction factor that can inhibit the release of a diverse array of enveloped viruses from infected cells. Conversely, to facilitate their release and spread, many viruses have evolved various strategies to overcome the antiviral effect of tetherin in a species-specific manner. During the development of an attenuated equine infectious anemia virus (EIAV) vaccine in our laboratory, we found that serial passage of a field-isolated virulent EIAV strains in horse and donkey as well as the cultivated donkey cells, produces several typical EIAV strains, includ...
Wilkins PA, Dewan-Mix S.The efficacy intravenous plasma to transfer passive immunity to clinically healthy colostrum-deprived and clinically ill foals with failure of passive transfer was investigated. Efficacy of transfer was evaluated by the elevation of serum IgG per gram of IgG administered as a function of body weight. Colostrum deprived healthy foals had a significantly greater increase in serum IgG than did clinically ill foals with failure of passive transfer. Knowledge of the IgG content of plasma to be administered and the health status of a foal with failure of passive transfer should allow more accurate p...
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...
Ulrich R, Eydner M, Grün A, Haydn J, Baumgärtner W.This report describes the macroscopic, histologic, immunohistologic and ultrastructural characteristics ofa biphasic malignant mesothelioma in the peritoneal and pleural cavity of a 13-year-old Icelandic pony mare, which exhibited recurrent ascites clinically. Immunohistology was performed employing multiple monoclonal antibodies against cytokeratins (CK) and vimentin. The ultrastructural examination included the quantitative evaluation of the length to diameter ratio of the microvilli. Post mortem examination revealed a severe ascites and hydrothorax. The serosal surfaces of the peritoneum an...
MacHarg MA, Bottoms GD, Carter GK, Johnson MA.Adrenocortical function was assessed in horses given multiple IM doses of dexamethasone to determine the duration of adrenocortical suppression and insufficiency caused by 2 commonly used dosages of dexamethasone (0.044 and 0.088 mg/kg of body weight). Dexamethasone was administered at 5-day intervals for a total of 6 injections. Daily blood samples were collected. The plasma was frozen and later assayed for cortisol. An ACTH response test was determined 2 days before the first injection of dexamethasone and again 8 days after the last dexamethasone injection. Maximum suppression of plasma cor...
Acland HM, Allen PZ, Kenney RM.After contagious equine metritis bacteria were inoculated into the uterus of mares, genital tract tissues were examined for presence of the organism by bacteriologic cultural technique and an indirect immunofluorescent staining technique. Up to 14 days after mares were inoculated, the organism was frequently in the lumen of the uterus and in the cervix and, less frequently, in the vagina, vestibule, clitoral fossa, clitoral sinus, and uterine tubes. After 21 to 116 days, the organism was occasionally found on the ovarian surface, in the uterine tubes, uterus, cervix, and vagina and more freque...
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)....
Troedsson MH, Liu IK, Thurmond M.The validity of measuring concentrations of immunoglobulins in undiluted uterine secretions was established. The concentrations of IgG, IgA, and cleavage factor C3 of the complement system in uterine secretions were compared in mares with different resistance to chronic uterine infection (CUI). The uteri of mares susceptible (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 were sampled, and sampling was immediately followed by a uterine lavage at 5 and 24 h after bacterial inoculation. During a sub...
Liccardi G, Dente B, Senna G, De Martino M, D'Amato L, D'Amato G.It has been well established that occupational exposure to horses increases the risk of allergic sensitization to horse hair, on the contrary very few data have been published in individuals without direct contact with horses. We describe two cases of severe respiratory symptoms triggered by a single direct exposure in two patients with only 4-5 previous short contacts with horses during the entire their life, since they live in urban area of Naples. Cutaneous and serological diagnostic tests showed significant sensitization to horse dander other than some common inhalant allergens. Our report...
Rivolta AA, Pittman DC, Kappes AJ, Stancil RK, Kogan C, Sanz MG.The efficacy of Rhodococcus equi-specific hyperimmune plasma (HIP) is usually evaluated in vitro. Anticoagulants (AC) used for plasma collection can negatively impact bacterial replication but their effect on R. equi growth has not been evaluated. The aim of this study was to establish the effect that AC routinely used in veterinary medicine (ACD, KEDTA, Li Heparin, and Na Citrate) have on in vitro R. equi growth. To assess this, in vitro assays commonly used to test HIP efficacy (direct effect on microorganism and macrophage infection), were performed using each AC and non-treated bacteria. R...
Kuttler KL, Goff WL, Gipson CA, Blackburn BO.Both the complement-fixation test (CFT) and the indirect fluorescent antibody test (IFAT) were conducted on weekly serum samples from nine Arab geldings for 28 days before and 256 days after their exposure to Babesia equi of European origin. On an average the IFAT became positive 8 days before the CFT and showed higher relative serum titer increases. Both test procedures successfully detected infection and neither showed an appreciable drop in titer during this time frame, with the exception of the CFT, which showed a transient drop immediately following treatment with imidocarb. A test conduc...
Davis SL, Graf M, Morrison CA, Hall TR, Swift PJ.The chemical nature and variations in serum concentrations of growth hormone binding protein (GHBP) from humans, rabbits, and rodents have been reported. To date little is known about the GHBP of domestic animals. Therefore, we initiated these studies to determine whether a serum GHBP was present in domestic animals and to purify the binding protein (BP) from serum of selected species. Using a dextran-coated charcoal separation assay, specific growth hormone (GH) binding was demonstrated in ovine, bovine, chicken, human, goose, porcine, and equine serum (listed in sequence from lowest to highe...
Tarr MJ, Olsen RG, Krakowka GS, Cockerell GL, Gabel AA.Erythrocyte rosette (ER) formation of equine peripheral blood lymphocytes (PBL) was characterized. Guinea pig and, to a lesser extent, human erythrocytes formed ER; cat, cow, dog, hamster, mouse, rat, and sheep erythrocytes showed negligible rosetting properties. Conditions of the assay were varied to determine which procedure allowed the largest percentage of rosette formation. The PBL from 20 normal horses were then assayed, averaging 38 +/- 2% ER. To characterize the erythrocyte receptor as being on T or B cells, equine thymocytes from 6 foals were assayed; the thymocytes formed an average ...
Verney M, Gautron M, Lemans C, Rincé A, Hans A, Hébert L.Trypanozoon infections in equids are caused by three parasite species in the Trypanozoon subgenus: Trypanosoma equiperdum, T. brucei and T. evansi. They are respectively responsible for infectious diseases dourine, nagana and surra. Due to the threat that Trypanozoon infection represents for international horse trading, accurate diagnostic tests are crucial. Current tests suffer from poor sensitivity and specificity, due in the first case to the transient presence of parasites in the blood and in the second, to antigenic cross-reactivity among Trypanozoon subspecies. This study was designed to...
Neubauer A, Meindl A, Osterrieder N.The equine herpesvirus 1 (EHV-1) modified live vaccine strain RacH is apathogenic for both laboratory animals and the natural host. The apathogenicity of RacH was caused by serial passages of the virus in heterologous cells. When compared to the virulent parental strain RacL11 several changes in the RacH genome occurred. Previous results have shown that the loss of the IR6 gene correlated with the loss of virulence. Additional important mutations were observed within the US2 gene which is directly adjacent to the IR6 gene and within the glycoprotein B (gB) gene. To answer the question whether ...
Iddagoda J, Gunasekara P, Handunnetti S, Jeewandara C, Karunatilake C, Malavige GN, de Silva R, Dasanayake D.It is clinically important to identify allergens in Artocarpus heterophyllus (jackfruit), Moringa oleifera (moringa), Trianthema portulacastrum (horse purslane) and Syzygium samarangense (rose apple). This study included 7 patients who developed anaphylaxis to jackfruit (1), moringa (2), horse purslane (3) and rose apple (1). We sought to determine allergens in the edible ripening stages of jackfruit (tender, mature, and ripened jackfruit) and seeds, edible parts of moringa (seeds, seedpod, flesh inside seedpod, and leaves), horse purslane leaves and ripened rose apple fruit. The persistence o...
Townsend J, Sneddon CL, Tortonese DJ.The intrapituitary mechanisms regulating gonadotrophin secretion in the horse remain unclear. Here, we examined seasonal and gonadal effects on the gonadotroph and lactotroph populations of male horses with the aim of defining a possible morphological basis for the differential release of gonadotrophins. Pituitaries were collected from: (i) gonadal-intact horses in the breeding season (GBS); (ii) orchidectomized horses in the breeding season (OBS); and (iii) orchidectomized horses in the nonbreeding season (ONBS). Immunohistochemistry was performed using antibodies to the luteinizing hormone (...
Raidal SL, McTaggart C, Penhale J.To quantify absorption of colostral IgG by healthy neonatal foals and to test the hypothesis that delayed ingestion of macromolecules prolongs the duration of intestinal permeability to immunoglobulins (Ig) in newborn foals. Methods: Thirteen mixed breed foals. Methods: Foals were randomly assigned to two treatment groups, which were fed either a glucose-electrolyte solution or a commercial milk replacer for 12 h after birth, before being fed a known amount of colostral IgG. A control group was fed a known amount of colostral IgG from birth. The efficiency of IgG absorption was calculated foll...
Bailey SR, Elliott J.Endotoxin has been implicated in the pathophysiology of acute laminitis. The aim of this study was to examine the direct effects of endotoxin on isolated equine digital blood vessels. Equine digital veins (EDV), incubated in Krebs-Henseleit solution containing lipopolysaccharide (LPS) (1 microg/ml) became hyporesponsive to 5-HT after 16 h. Cycloheximide and ibuprofen blocked this effect of LPS and increased the maximum response obtained to 5-HT when compared to control vessels. L-nitroarginine methyl ester (L-NAME) reversed the hyporesponsiveness caused by LPS. Vessels maintained in culture me...
Mendoza E, Bubis J, Pérez-Rojas Y, Montilla AJ, Spencer LM, Bustamante F, Martínez JC.Previously, we have identified a protein in Trypanosoma equiperdum that possesses homology with the regulatory (R) subunits of the mammalian cAMP-dependent protein kinase (PKA). The recombinant T. equiperdum PKA R-like protein was expressed in bacteria and purified to homogeneity. Mice polyclonal antibodies were raised against the recombinant R-like protein to serologically evaluate its humoral immune response. High titers of specific sera antibodies were obtained against the parasite R-like protein by indirect enzyme-linked immunosorbent assay (ELISA), and immunoblots revealed that this prote...
