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.
Persistence in nature of influenza virus A/eq/Praha/56 (Heq1Neq1). Equine influenza occurred in Czechoslovakia 14 years after the last epizootic in horses that had returned from abroad. Six strains A (Heq1Neq1) antigenically related to, but not identical with, strain A/eq/Praha/56 were isolated from 10 washings. Seroconversion was demonstrated with paired sera, but the antibody increase was more marked against the newly isolated strain.
Topographic antigenic determinants on cytochrome c. Immunoadsorbent separation of the rabbit antibody populations directed against horse cytochrome. Seven populations of site-specific antibodies were isolated from each of three sera of rabbits immunized against glutaraldehyde-polymerized horse cytochrome c. The antibodies were separated using an immunoadsorption scheme which employed the following cytochromes c: horse, beef, guanaco, rabbit, mouse testicular, pigeon, and the cyanogen-bromide cleaved fragment of the rabbit protein containing residues 1 to 65. The monovalent, antigen-binding fragments of the antibodies (Fab') gave 1:1 stoichiometries with native horse cytochrome c in fluorescence quenching assays. Cross-reactivities with het...
Dynamic changes of horse serum T-globulin immunization with snake venoms, tetanus and diphtheria toxoids. In course of immunizing horses with snake venoms, tetanus and diphtheria toxoids, a new serum component, T-globulin, was formed and migrated between the beta- and gamma-globulins. The T-globulin content was parallel with the antibody titre after the middle course of immunization. There were many components in snake antivenin and T-globulin was composed of most of those components. The components of diphtheria T-globulin were the same as those of crude antitoxin and tetanus T-globulin except one precipitin.
Viruses isolated from Culicoides midges in South Africa during unsuccessful attempts to isolate bovine ephemeral fever virus. Five viruses, unrelated to bovine ephemeral fever virus (BEFV), were isolated from Culicoides biting-midges collected during the summer months of the years 1968-69 and 1969-70 near a cattle herd in which cases of BEF occurred and at an open horse stable at Onderstepoort. These viruses were investigated by means of serological, electron-microscopical and physicochemical tests. It was established that 2 isolates, Cul. 1/69 and Cul. 2/69, were related to each other and belonged to the Palyam subgroup of the genus Orbivirus, that isolate Cul. 3/69 belonged to the equine encephalosis subgroup of th...
Evaluation of an indirect fluorescent antibody test to diagnose Babesia equi infection in horses. An indirect fluorescent antibody (IFA) test for the diagnosis of Babesia equi infections was evaluated. Antigen prepared by conventional methods was of high quality in one instance and of lesser quality in a second when possible autofluorescence of the horse blood caused inconvenience in reading tests. Tests on 14 horses shown by parasitological means to be either infected (9) or uninfected (5) produced reactions at dilutions of 1/270 to 1/7290 for infected and at 1/10 to 1/90 for uninfected animals. The accuracy of the test was further demonstrated during investigations of 701 horses in 3 sta...
Cell-mediated immunity in horses with sarcoid tumors against sarcoid cells in vitro. Cell-mediated immunity in horses with sarcoid tumor against sarcoid antigens was studied in vitro by means of mixed lymphocyte tumor cell culture assay and lymphocyte-mediated cytotoxicity of 52Cr-labeled target cells. When Mc-1 sarcoid cells were used as stimulatory cells for peripheral blood lymphocytes in the mixed lymphocyte tumor cell assay, a clear difference in the kinetics of the generated lymphocytic proliferative response could be detected between sarcoid and control horses. With sarcoid horses, their proliferative maximum was reached 3 days earlier than that of the control horses, a...
The effects of sodium cromoglycate on antigen inhalation challenge in two horses affected with chronic obstructive pulmonary disease (COPD). 80 mg sodium cromoglycate (SCG) was administered by inhalation to two COPD-affected animals known to have respiratory hypersensitivity to Micropolyspora faeni. SCG treatment 20-30 minutes prior to inhalation challenge with M. faeni prevented exacerbation of respiratory disease, usually seen 4-8 hours after challenge. duration of protection against antigen challenge after a single SCG treatment was 4-5 days. The duration of protection was not prolonged by reducing the frequency of antigen challenge. Multiple antigen challenge, using M. faeni and Aspergillus fumigatus, shortened the protective p...
A study of Klebsiella pneumoniae infection in the uterus of the mare. 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...
Evaluation of functional thymic hormones in Arabian horses with severe combined immunodeficiency. Arabian horses with severe combined immunodeficiency disease (SCID) were evaluated for thymic hormone activities using thymic extracts and sera. Extracts prepared from thymus of SCID horses were able to increase the number of spleen cells responding to sheep red blood cells in irradiated, bone marrow-reconstituted mice. In addition, ultrafiltrates prepared from sera of these immunodeficient horses, which contained material with molecular weight of less than 50,000 Daltons could (a) induce a population of human bone marrow precursor cells to differentiate into cells bearing SRBC receptors and f...
Identification of alpha1-lipoproteins in crossed immunoelectrophoresis. Evans Blue dye binds selectively, but with different avidities, to five major antigens in human serum. The anodic mobility of the antigen-dye complexes is greater than that of the antigens alone in crossed immunoelectrophoresis, which is of practical value for identification. We used this characteristic to show that in some human sera there is a population of alpha1-lipoprotein molecules that migrates electrophoretically in the beta-lipoprotein region, where in conventional zone electrophoresis it could be mistaken for beta-lipoprotein. We also demonstrate that horses, unlike rabbits, rarely m...
Cellular and humoral immune response of foals to vaccination with Corynebacterium equi. Transformation of peripheral blood lymphocytes from pony foals vaccinated and subsequently infected with Corynebacterium equi was studied. Three foals were vaccinated on two occasions using a formalinized C. equi vaccine with aluminum hydroxide as an adjuvant. Three nonvaccinated foals served as controls. Foals were challenged intratracheally with 9 x 10(9) C. equi six weeks after the initial vaccination. Foals survived this infection for one to two weeks. Significant lymphocyte transformation in response to C. equi antigens was detected in two vaccinated foals at the third week after initial ...
Isolation and partial characterization of prolactin from equine pituitary gland (hypophysis). Highly purified equine prolactin was prepared from equine pituitary glands (hypophysis) by serial extractions with water at pH 5.5, 0.1 M (NH4)2SO4 at pH 4.0, and 0.25 M (NH4)2SO4 at pH 5.5 to remove other hormones, and then finally with 70% ethanol at pH 9.3 to 10.0 to extract prolactin. Preliminary purification of the extract involved salting out other substances with 0.1% NaCl at pH 9.0. Prolactin was precipitated out by adding three times the volume of 95% ethanol at 4 C. This prolactin preparation had a biological potency of 24 IU/mg. Further purification by isoelectric focusing on a pH g...
Isolation and characterization of antibodies to Clostridium perfringens epsilon toxin from hyperimmune horse serum. Antibodies against epsilon toxin were isolated from hyperimmune horse serum by affinity chromatography. Purified epsilon prototoxin covalently bound to Affigel 202 was used as immunosorbent, and antibodies were eluted with 6.0 M guanidine chloride. In a single run 80 mg of antibody could be recovered from a 20 microliter column of immunosorbent. The antibody was shown to belong to the IgG(T) class of immunoglobulins.
Agammaglobulinemia in a horse. Immunologic deficiency was suspected in an 18-month-old Standardbred horse with persistent fever, multifocal bacterial infection, and neutropenia with a large number of immature neutrophils. Serum protein electrophoresis revealed marked depression of the gamma-globulin fraction (0.2 g/100 ml). Immunologic testing and histologic examination of lymphoid tissues identified the immune deficit as agammaglobulinemia. Serum concentrations of immunoglobulin (Ig)G and IgG(T) were initially low and declined with time; IgM and IgA were not detectable. The horse failed to produce antibodies when inoculate...
The presence of precipitating antibodies in the sera of horses with chronic obstructive pulmonary disease (COPD). The sera of horses affected and not affected with chronic obstructive pulmonary disease (COPD) were examined for precipitins to Micropolyspora faeni and Aspergillus fumigatus. Precipitins to both antigens were not restricted to COPD cases but occurred more frequently in animals affected with COPD. Many animals without detectable precipitins responded clinically to inhalation challenge with these antigens.
Identification and characterisation of the major antiproteases in equine serum and an investigation of their role in the onset of chronic obstructive pulmonary disease (COPD). Three major antiprotease components in equine serum were identified and characterised. These were the acidic prealbumin Pr, the homologue of human alpha-1 antitrypsin and 2 protease binding proteins, the acidic prealbumin Xc and alpha-2 macroglobulin, both capable of inhibiting the proteolytic activity of trypsin, but with only limited inhibitory effect on its esterolytic activity. The possible role of these serum antiproteases in the onset of chronic obstructive pulmonary disease (COPD), analogous to the hereditary dysproteinaemia of alpha-1 antitrypsin in man, was investigated. There was no ...
Purification of the subunit Clq from the first component of equine complement. Initial separation and concentration of Clq from fresh, normal equine serum was accomplished by precipitation in 0.02 M acetate buffer, pH 5.5, at 4 degrees for 24 h. The re-dissolved precipitate was clarified by centrifugation at 80,000 g for 1 h and then dialysed against Tris-HCl buffer (0.05 M, pH 8.0) containing 10-3 M EDTA. The clarified dialysate remained biologically active at 5 degrees for at least 4 weeks. Biological activity of equine Clq was determined by assay of its ability to agglutinate sensitized sheep erythrocytes (EA). Following ammonium sulphate fractionation, Sepharose 4B g...
In vitro of adenosine on lymphocytes and erythrocytes from horses with combined immunodeficiency. The effect of adenosine on the mitogenic response of peripheral blood lymphocytes (PBL) and on the nucleotide pools of erythrocytes from normal horses, horses heterozygous for the combined immunodeficiency (CID) trait (carriers), and foals with CID was studied. When PBL from normal, carrier, and CID horses were stimulated by phytohemagglutinin (PHA), concanavalin A, or pokeweed mitogen, [3H]thymidine uptake was inhibited by adenosine (0.1 microM) to 1.0 mM) in a dose-dependent manner. Adenosine (100 microM) mediated inhibition of [3H]thymidine uptake was prevented in both normal and carrier ho...
Linkage of loci controlling alloantigens on red blood cells and lymphocytes in the horse. A system of equine lymphocyte alloantigens designated ELA, is identified, and it is shown that the locus or loci controlling these markers must be closely linked to the locus controlling markers in the A system of horse blood groups. Among 29 offspring in two stallion families there was evidence for one recombinant. Lod scores for linkage between the A and ELA loci in the two families were 3.61 and 3.33, respectively, for theta equal to 0.