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.
Immunity and the level of neutralization antibodies in foals and mares vaccinated with a modified live-virus rhinopneumonitis vaccine. Foals (farms 1 and 2) and mares (farms 1 and 3) vaccinated with a commercially available rhinopneumonitis vaccine were tested for the level of antibodies and for protection against the natural infection. The serum-neutralization (SN) antibody titers against equine herpesvirus type 1 were 1:8 or less in the majority of foals and 1:16 or higher in about 10%. The level of the nasal secretory antibody in the foals (farm 2) was less than 1:4. The vaccinated foals did not show any apparent respiratory tract infection for about 6 months and then an epizootic of respiratory tract disease appeared on f...
Evaluation in donkeys on an inactivated Venezuelan equine encephalitis vaccine.
Summary
Seven donkeys were immunized with a Venezuelan equine encephalitis virus vaccine which had been prepared by inactivation of the virus with formalin and Tween-80-Tri(n-butyl)phosphate and addition of saponin. Fourteen days later they, and four non-vaccinated controls, each received 50,000 suckling mouse intraperitoneal LD50 units of challenge virus. None of the seven immunized donkeys demonstrated signs of clinical illness or viremia. Of the four non-vaccinated controls, all became ill and one died. These results suggest that more extensive experiments might well be carried out on ...
Histological development of the thymic and intestinal lymphoid tissue of the horse. The basic components of the immune system, and the defence mechanisms in the gastrointestinal tract, are briefly reviewed. Histological studies in 84 equine foetuses showed that lymphoid cells begin populating the thymic primordium at 11-12 weeks, the mesenteric lymph nodes at 13 weeks, the spleen at 25 weeks and the intestinal lamina propria at 13-14 weeks' gestation. Lymphocytes were seen in the intestinal epithelium very early in gestation. Histological signs of response to antigenic stimulation were seen in five foetuses, indicating that the horse is likely to be capable of mounting an imm...
Surface receptors on neutrophils and monocytes from immunodeficient and normal horses. Surface receptors on peripheral blood neutrophils and monocytes from normal and immunodeficient horses have been studied. Sheep erythrocytes (SRBC) coated with IgG, IgM, and complement but not IgG(T), readily bound to normal equine monocytes and neutrophils. More than 4000 molecules of IgG were required to sensitize each SRBC for adherence to monocytes, and more than 12,000 molecules were required for adherence to neutrophils. Young horses with a severe combined immunodeficiency had an almost total absence of lymphocytes, but normal numbers of monocytes and neutrophils. The number of receptors...
Antimicrobial therapy in horses. Little has been written about the use of antibiotics in the horse. This article is based on personal experiences related to equine clinical medicine and literature review and certainly does not represent all the possible therapeutic regimens that can he employed in the horse. There are two concepts that this article will emphasize. First and most importantly, when an infective process is suspected in a patient, cul-tures and sensitivities are the most important determinations to be made prior to antibiotic therapy. Whether in the treatment of a single case or in the treatment of a herd problem...
Rapid diagnosis of Venezuelan equine encephalomyelitis by fluorescence microscopy. Goat Venezuelan equine encephalomyelitis (VEE) antiserum and normal serum were conjugated and evaluated for staining sensitivity and specificity. Cross-staining with either eastern or western equine encephalomyelitis virus-infected cells did not occur. The baby hamster kidney (BHK-21) cell line when combined with highly specific VEE conjugate detected 100 medium suckling mouse intracerebral lethal doses (suckling mouse LD-50/IC) of the 1B subtype of VEE virus per milliliter of equine tissue suspension. Conjugated goat antiserum was assayed for sensitivity for detection of VEE virus-infected eq...
A microprecipitation test for rapid detection and identification of Venezuelan, eastern and western equine encephalomyelitis viruses. The development of a new diagnostic procedure for the identification of Venezvelan, eastern and western equine encephalomyelitis (VEE, EEE, WEE) viruses is described. The procedure utilizes virus precipitation with reference fluorescein-conjugated gamma globulin, followed by cellulose acetate electrophoresis. Clinical specimens containing varying concentrations of virus yielded, in primary duck embryo cell culture, sufficient virus for detection within 22 to 44 hours. Identification of VEE, EEE and WEE virus in specimens was accomplished by microprecipitation within this time. In contrast to c...
[An immunologic study of hyaluronidase of different animal origin]. Studied was the antigenic relatedness of hyaluronidase contained in the semen of breeder animals of homologic and heterologic species. The experiments were carried out by means of the immunodiffusion and the immunoelectrophoretic methods. The results obtained showed that the seminal hyaluronidase of bulls, rams and bucks is antigenically related, and that of stallions, boars and rabbits does not exhibit antigenic relatedness. Stallion semen is closely related antigenically with the above-mentioned three animal species' semen as manifested by two precipitation bands, but these are not identical...
[Contribution to the antigenic study of influenza viruses in animals. I.–Neuraminidase of the equine influenza viruses (author’s transl)]. From the Revised Nomenclature of WHO, the fowl influenza virus A/Duck/Ukraine/63 (Hav7 Neq2) has the same neuraminidase as the equine virus A/equi 2/Miami/63 (Heq2 Neq2); the A/Chicken Germany "N"/49 virus has the same neuraminidase as the equine virus A/equi 1/Prague/56. A comparative study of the antigenic specificities confirms that the Neq2 neuraminidases are closely connected, whatever their animal origin, and that the fowl strain Hav7 Neq2 can be used for the titration of anti Neq2 antibodies in the serums of animals immunized with the equine virus Heq2 Neq2. The Neqi neuraminidases of v...
The sensitizing properties of anti-mouse anti-thymocyte horse serum. The authors have compared the anaphylaxis due to active and passive sensitization of mice. In the case of active sensitizing, anti-mouse anti-thymocyte horse serum (ATS), and/or normal horse serum (NHS), whereas in the case of passive sensitizing, plasma, peripheral leukocytes, spleen cells and thymocytes of sensitized animals were used. Provocation of shock was carried out by intravenous administration of ATS or NHS. Irreversible anaphylaxis occurred in a significantly higher rate in the case of ATS than NHS sensitivity, produced either actively, or passively. Differences have been found also...
[Systemic cutaneous and subcutaneous amyloidosis in the horse]. A 9-year-old horse had numerous firm, painless nodules of the skin and subcutis. Moderately vascular granulation tissue with numerous uni- or multinuclear reticuloendothelial cells was in the nodules and the regional lymph nodes but not in the viscera. By using special stains and electron microscopy, widespread amyloid deposits, mainly in the cytoplasm of reticuloendothelial cells, were identified. Amyloid was probably produced within the reticuloendothelial cells, then expelled from the dying cell and deposited in the intercellular space.
Studies on equine immunoglobulins. IV. Immunoglobulins of the donkey. Donkey IgGa was isolated in purified form from normal and immune donkey sera by column chromatography on DEAE-cellulose. Isolated donkey IgGa and mixtures of (IgGa+IgGb) were used as antigens to prepare rabbit reagents specific for equine IgGa or IgGb. Antibodies present in sera obtained from a single donkey at various times during the course of hyperimmunization with BSA were isolated by immuno-adsorption. The class or subclass of immunoglobulins present among isolated, donkey anti-BSA antibodies was determined by use of specific rabbit anti-equine immunoglobulin reagents. The homologues of h...
The application of polyvalent horse immune sera for electroimmunodiffusion methods. Horse immune sera do not give satisfactory results in immunochemical techniques based on electrophoresis of antigens through antibody-containing agarose gel. As the majority of precipitating horse antibodies belongs to the beta globulins, they migrate in the gel during electrophoresis. After enzymatic treatment the pepsin fragments work well in all electroimmunodiffusion methods.
Hypogammaglobulinemia predisposing to infection in foals. Measurement of serum immunoglobulins in 46 foals less than 2 weeks old revealed 9 foals with hypogammaglobulinemia. The hypogammaglobulinemia was attributed to failure in transfer of immunoglobulins from dam to foal via colostrum. Three of the affected foals did not nurse at all, or only slightly, and 2 of these died of infections within a few days after birth, whereas the 3rd foal did not grow as well as normal foals. Six of the affected foals nursed in an apparently normal manner, and 5 of these had nonfatal respiratory infections between 2 and 5 weeks of age. Analysis of serum samples from ...
Equine anti-hapten antibody. IX. IgM anti-lactose antibodies. The immune response to a bacterial vaccine of Streptococcus faecalis (strain N) was characterized in all of the seven horses studied by the sustained production of about 90% IgM anti-lactose antibody over a period of 44 weeks with maximum values of the total antibody ranging from 4 mg/ml of serum to 12 mg/ml of serum. With respect to the binding of a lactose-containing ligand the association constants of the antibodies purified from sera obtained between 5 and 44 weeks fell in the range of 1 times 10-5 M-1 to 2 times 10-5 M-1. Not only was there no significant indication of maturation of a-fin...
[Contribution to the antigenic study of influenza viruses in animals. II.–Antibodies, antineuraminidase in horse: conditions of apparition and importance (author’s transl)]. In the first part of this paper the conditions for a specific titration of antibodies against the neuraminidase (N) of each of the two horse virus subtypes are defined. The antigens used are: the H72Neq 1 recombining agent to measure the anti Neq1 antibodies and the A/Duck/Ukraine/63 strain for the anti Neq2 antibodies. The immunity response to neuraminidase appears after the natural disease; this response is studied in two foci, one due to a virus belonging to the A equi I subtype (Loire 73 strain), the other to a virus of the A equi 2 subtype (SHN 73 strain). The kinetics of apparition of an...
Double diffusion in gel tests with Paul-Bunnell antibodies of infectious mononucleosis sera. Double diffusion tests in gel were employed for studies of reactions between infectious mononucleosis sera and extracts of bovine, sheep and equine erythrocyte stromata. The extracts were obtained by ultrasonication of stromata prepared from trypsin-digested erythrocytes. The reaction with bovine stroma extract was composed, in many instances, of two lines. A single line was observed in reactions with sheep and equine stroma extracts. This line merged into a reaction of partial or complete identy with one of the lines formed with bovine stroma extract. Evidence was obtained that some infectioo...