Topic:Immunology
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.
Laboratory methods of equine pregnancy diagnosis. Rectal examination is a reliable method of diagnosing pregnancy in the mare. Also, test kits are available for the simple quick detection of pregnant mare serum gonadotrophin. Nevertheless there is a considerable demand by practitioners for an independent laboratory service in equine pregnancy diagnosis, particularly during the gestational phase when placental gonadotrophin is concentrated in the blood. An initial attempt to provide a service by means of the agar gel diffusion test was disappointing and alternatives were sought. The primary requirements for an ideal alternative technique were ...
Electron-microscopic study of the development of an equine adenovirus in cultured fetal equine kidney cells. Sequential changes induced by an equine adenovirus in cultured fetal equine kidney cells were studied by electron microscopy. The first morphological change was the appearance of type I inclusions. These inclusions developed to type II inclusions which appeared as ring forms. Type III inclusions were formed within the central part of type II inclusions and finally filled up most of the nuclear space. As the infection proceeded, type IV inclusions which appeared as dense dark-staining spheres were formed at the center of the type III inclusions and also inside the cytoplasm. These dark-staining...
Immunoglobulin G subclass [IgG and IgG(T)] interaction with the P26 group specific antigen of equine infectious anemia virus: immunodiffusion and complement-fixation reactions. Isolated equine immunoglobulin (Ig)G(T) antibodies to equine infectious anemia virus P26 antigen did not precipitate with antigen when the ratio of antibody to antigen was high. However, at lower ratios of antibody to antigen precipitation occurred. In addition, complement-fixation by IgG and P26 antigen was inhibited by high concentrations of IgG(T). The unusual reaction pattern noted with IgG(T) antibodies was still detectable by the immunodiffusion test for equine infectious anemia virus. In situations of nonprecipitability by IgG(T), the adjacent positive control line was inhibited, and th...
RNA-dependent DNA polymerase associated with equine infectious anemia virus. Equine infectious anemia (EIAV) is shown to have an associated RNA-instructed DNA polymerase similar in its cofactor requirements and reaction conditions to the RNA tumor virus DNA polymerases. Demonstrating this DNA polymerase activity requires a critical concentration of a nonionic detergent, all four deoxyribonucleoside triphosphates, and a divalent metal ion. The reaction is sensitive to RNase, and a substantial fraction of the FNA synthesized is complementary to viral RNA. The detection of a complex of tritium-labeled polymerase product DNA-template RNA, which sedimented at 60S to 70S, pr...
[Long-term therapy using horse anti-dog lymphocyte globulin without sensitization against horse protein]. Eight mongrel dogs received a standard daily i.v. infusion of 20 mg/kg b.w. deaggregated horse-anti-dog-lymphocyte-globulin (ALG) and additional prednisolone (1 mg/kg b.w. daily i.v.) over a maximum period of 82 days following pretreatment with deaggregated normal horse IgG. No sensitization against horse protein was observed during therapy of afterwards as proved by lack of humoral antibodies against horse antigens, maintained lymphopenia, good compatibility, longterm prolongation of xenogeneic skin graft survival (85.6+/-20.6 days, n=8' untreated controls 12.5+/-1.3 days, n=4) and longterm s...
The activity of purine salvage pathway enzymes in murine and horse models of congenital and acquired dysimmunity. Previous studies of human congenital immunodeficiency states and in vitro observations of lymphocyte response to mitogens have implicated two purine salvage pathway enzymes, andenosine deaminase (ADA) and nucleoside phosphorylase (NP), as critical in the normal maturation and/or function of the immune system. Based on this information, ADA and NP activities were examined in a variety of congenital and acquired animal models of dysimmunity. The animals studied herein included: congenitally athymic (nude) mice; congenitally asplenic mice; congenitally athymic-asplenic mice; motheaten mice; New Z...
IgM antibody–I. Heterogeneity of the component chains of equine anti-lactose antibody. The heterogeneity of the IgM response has been studied with anti-lactose antibody purified from the sera of seven horses. The IgM antibody was induced with a bacterial vaccine and the sera were obtained during a one-year period of immunization. L and H chain preparations were derived from separate bleedings of each horse and examined by analytical isoelectric focusing. All of the L chain preparations were complex and similar and, under optimum conditions, exhibited about 45 bands. Their similarity included almost identical concentration distributions over the entire pH gradient. Isoelectric ba...
Corynebacterium equi enteritis in foals. Corynebacterium equi is a pathogen associated with respiratory disease in the foal. This paper discusses two cases of Corynebacterium equi infection, one acute and one chronic, in which the major damage was intestinal. Necrosis of Peyer's patches was the only lesion seen in the small intestine of both foals. The foal with acute disease had distinct green-tan focal necrosis and thickened mucosa of the large intestine. In the foal with chronic disease, the mucosa of the large intestine was thickened, rugose, and mottled red-tan. Histologically, the predominant lesions were villous atrophy, mucos...
Equine antibody to bovine serum induced by several equine vaccines as a source of extraneous precipitin lines in the agar gel immunodiffusion test for equine infectious anemia. Precipitin lines not associated with equine infectious anemia (EIA) were observed in routine agar gel immunodiffusion (AGID) testing for the infection. The serums which produced these lines were obtained from horses which had been given multiple vaccinations with commercially available cell culture-origin equine virus vaccines as part of a comprehensive herd health program. The lines formed against cell culture-derived, but not spleen-derived EIA viral antigens. Investigation revealed that bovine serum proteins in the vaccines induced precipitating antibodies which reacted with bovine serum pr...
Selective immunoglobulin M deficiency in foals. Selective immunoglobulin M deficiency was diagnosed in 5 foals, on the basis of reduced serum immunoglobulin M concentrations (more than 2 standard deviations below the normal mean). All 5 foals had clinical signs or lesions involving the respiratory tract. Lkebsiella sp was isolated from joint fluids, bronchial lymph nodes, or tracheal washings from the 3 foals in which such samples were available for microbiologic evaluation.
Reaction of bovine and equine growth hormones with tetranitromethane. Bovine and equine growth hormones were chemically modified with tetranitromethane, at pH 7.4 during 5 h and at pH 8.0 in the presence of 8 M urea during 1 h. a) Both hormones have very similar but not identical reactivities. b) The nitration of the reactive tyrosines and tryptophan residues at pH 7.4 produces no detectable changes in their immunological or somatotrophic activities. C) The nitration of all tyrosine residues in both hormones gives rise to a complete loss of somatographic activity with no alteration of the immunological activity.
Purification and characterization of equine herpesvirus-induced DNA. Infection of cells with equine herpesvirus type 1 (EHV-1) or type 3 (EHV-3) resulted in the induction of a DNA polymerase activity distinguishable from host cell DNA polymerases by its high salt requirement for maximal activity. By column chromatography on DEAE-cellulose, DNA-cellulose, phosphocellulose, and hydroxyapatite, the EHV-1-induced polymerase was purified 500-fold with 1–2% recovery of total activity from the nuclei of infected hamster livers. The final enzyme preparation was homogeneous as judged by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels. Calculations based ...
Recent advances in equine reproduction. Mares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova accumulate in the oviducts of unserved mares. During pregnancy, corpora lutea accumulate; all regress together at mid pregnancy. Plasma progesterone levels rise and oestrogen levels fall towards the end of pregnancy. Methods are available for early termination of pregnancy and for induction of parturition. Pregnancy can be diagnosed efficiently by rectal examination, and by immunological assay of pregnant mare serum gonadotrophin. Service at the foal heat is associated with an increased prevalence of early...
In vitro cytotoxicity of serum and peripheral blood leukocytes for equine herpesvirus type 1-infected target cells. The immune response in horses following experimental infection with equine herpesvirus type 1 (EHV-1) was assessed by measuring cytotoxicity for EHV-1-infected target cells. A technique was developed, using [125I]5-iodo-2'-deoxyuridine ([125I]IUDR)-labeled equine fetal kidney cells infected with EHV-1 as the target cells. It was shown that peripheral blood leukocytes from a recovered horse were capable of lysing target cells, as measured by the loss of radio-active label. Following the experimental infection of specific-pathogen-free ponies with EHV-1, cytotoxicity was obtained with fresh auto...
Labeling of antilactose antibody. Affinity labeling studies with anticarbohydrate antibodies have been very limited. In earlier studies, diazoniumphenyl glycosides were employed as affinity labeling reagents for rabbit and equine anti-p-azophenyl-β-lactoside and p-azophenyl- β-galactoside antibodies. Although these antibodies were heterogeneous, it was possible to identify the labeled residues in the heavy or light chains since the modified residues had characteristic absorption spectra. With the discovery of bacterial cell walls of Streptococcus groups A and C induced antipolysaccharide antibodies of restricted heterogeneit...
Human lymphocyte subpopulations: rosette formation with sheep, human and horse red blood cells. Rosette formation between human lymphocytes and horse red blood cells could be promoted by a low pH medium, overnight incubation and a temperature of 4 degrees C. The percent of sheep, horse and human rosette-forming cells in the peripheral blood were 71.7 +/- 1.8, 30.5 +/- 2.8 and 28.3 +/- 3.4 respectively. However, their percentages in thymuses were 97.1 +/- 1.1, 91.4 +/- 2.4 and 89.0 +/- 3.4. Using preparations of isolated subpopulations, it was observed that the horse and human red cell rosette-forming cells were probably also "early" sheep red cell rosette-forming cells. Rosette formation...
Lyophilized combination pools of enterovirus equine antisera: preparation and test procedures for the identification of field strains of 19 group A coxsackievirus serotypes. This paper describes the preparation of seven combination pools of equine antisera, designated J though P, for identification of 19 coxsackievirus A immunotypes. Each pool is composed of 4 to 6 antisera; the serotypes included are A1-6, 8, 10-15, and 17-22. These pools, unlike the previously prepared A-H enterovirus pools, were lyophilized from volumes of 0.5 ml dispensed into 5-ml vials, and when rehydrated with 5 ml of diluent provide 50-antibody-unit material ready for use in identification tests without further dilution. Procedures for using the antiserum pools are given, and guidance is p...
Combined immunodeficiency in foals in Arabian breeding: evaluation of mode of inheritance and estimation of prevalence of affected foals and carrier mares and stallions. Combined immunodeficiency (CID), a defect in both B- and T-lymphocytes, was found to occur in 2.3% of 257 foals of Arabian breeding. All affected foals died by 5 months of age. The belief that CID is transmitted as an autosomal recessive genetic defect was supported by results from matings of dams and sires that had previously produced affected foals. Based on a prevalence of 2.3%, the proportion of carriers of the CID trait among the adult population surveyed was estimated to be 25.7%. Recent descriptions of other immunologic defects in foals emphasized the need for careful differential diagn...
Identification of the PR prealbumin proteins in horse serum. The Pr protein, which is one of the major equine acidic prealbumins and which consists of a large number of phenotypes, has been studied with regard to its chemical identity. Serum samples of known Pr phenotype which had been treated with varying amounts of bovine trypsin were subjected to starch gel electrophoresis at pH 4.8. When a certain amount of trypsin was used, the Pr protein was markedly affected, whereas the other acidic prealbumins retained their normal electrophoreitic pattern. Extracts from three different regions of the acidic prealbumin field were tested by the casein precipitat...
Serological relationships between rotaviruses from different species as studied by complement fixation and neutralization. Human, piglet, mouse, foal, lamb, calf and rabbit rotaviruses all infected, but could not readily be subcultured in LLC MK2 cells. Cells infected with mouse and calf rotaviruses reacted by indirect immunofluorescence (FA) with convalescent serum from children, piglets, mice, foals, lambs, calves or rabbits, taken after rotavirus infection. Human, calf, piglet, mouse and foal rotaviruses reacted with human, calf, mouse, foal and lamb convalescent serum by complement fixation (CF). It was not possible to distinguish between different rotaviruses by CF or FA. Neutralization tests, however, detect...
[Influenza vaccination: which vaccine (author’s transl)]. A comparative study of the literature of the past ten years showed that vaccination of horses and ponies against influenza is best done using adjuvant-containing vaccines. Comparable results may probably be obtained by twice inoculating an aquenous vaccine. There are no drawbacks to the use of aluminium-hydroxide as an adjuvant when mineral oil is used as an adjuvant, the first and second vaccinations do not present any problems.
The husbandry and veterinary care of wild horses in captivity. A short account of the natural history of the wild Equidae is given as a background to their management in captivity. In general the approach to their husbandry and veterinary care is similar to that for the domestic horse. A mixture of etorphine and acepromazine has been found to be the most effective for handling and conventional methods of anaesthesia can be safely superimposed on these if required. The data collected at Whipsnade on the haematology and biochemistry of these species is summarised in tabular form and an analysis is included of the post-mortem examinations of 105 equine carca...