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.
A comparison of horse, cow, and sheep blood in NYC medium: effect on recovery of N. gonorrhoeae and urogenital mycoplasmas. NYC medium supplemented with cow blood (NYC-C) and sheep blood (NYC-S) were tested for the growth of N. gonorrhoeae and urogenital mycoplasma in comparison with standard NYC medium which contains horse blood. In situations where horse blood is not available, cow blood could be substituted in NYC standard medium, whereas the use of sheep blood was found unsuitable.
Separation of mononuclear leukocytes and polymorphonuclear leukocytes from equine blood. The present study describes a two step technique for the separation of mononuclear leukocytes or mononuclear and polymorphonuclear leukocytes from whole equine blood. First, the leukocyte rich plasma was obtained by sedimentation of erythrocytes in the undiluted blood. Subsequently, separation of the different populations of white blood cells was performed by centrifugation with different gradients overlaid with the leukocyte rich plasma. The optimal separation of the mononuclear cells was obtained by the centrifugation of the leukocyte rich plasma overlaying the gradient containing 24 parts o...
[FAB immunoglobulin fragments. I. The comparative characteristics of the serological and virus-neutralizing properties of a gamma globulin against tick-borne encephalitis and of the FAB fragments isolated from it]. A comparative study was made of the serological properties and virus-neutralizing activity of antiencephalitis gamma-globulin and Fab-fragments isolated from it by gel-filtration. Horse immunoglobulins against the autumno-summer tick-borne encephalitis virus could be disintegrated with the aid of papaine to monovalent Fab-fragments which (according to the complement fixation reaction, the test of suppression of the complement fixation, and the HAIT) retained the serological activity whose level was compared with that of the serological activity of gamma-globulin. Fab-fragments possessed a mark...
Detection of immunologically active zones in equine growth hormone. Peptide fragments, obtained from equine growth hormone by cyanogen bromide cleavage and further chemical treatment, were isolated and identified. Their immunological reactivities were tested by hemagglutination and complement fixation methods using rabbit antisera against native hormone. Antigenic determinants were detected in the fragments comprising amino acid sequences 5-72 and 73-123, this last one being predominant. Fragment 124-178 had very low reactivity. Nitration of peptide 73-123 did not modify its immunological properties,but oxidation diminished them. Comparison of the antigenicity...
Observations on the transmission, immunology, clinical signs and chemotherapy of dourine (Trypanosoma equiperdum infection) in horses, with special reference to cerebro-spinal fluid. This paper is a record of observations on the transmission and clinical signs of dourine in naturally infected cases of known duration, and of temporal and quantitative aspects of the immune response in blood and cerebro-spinal fluid. Included in the record are observations on the presence of Trypanosoma equiperdum parasites in these body fluids and methods for their detection. There is evidence that the occurrence of nervous symptoms and lesions in infected horses is associated with the presence of Trypanosoma equiperdum parasites in cerebro-spinal fluid. The suitability of cerebro-spinal flu...
An anaemic state in a horse associated with a cold-acting antibody. Auto-immune, haemolytic anacmias (AHA) of man (Dacie, Citation1963) and domestiicated animals (Schalm, Citation1965; Farrelly et al., Citation1966; Lapras and Oudar, Citation1971) are classified either as idiopathic or secondary to an underlying disease process (Pirofsky, Citation1969). In both categories antibodies active against the indivual's own erythrocytes are formed. These auto-antibodies are of two types being either warm or cold-acting. Warm-acting antibodies are most effective at 37°C, belong to the IgG class of immunoglobulins, and are incomplete in that, generally, they do not cau...
Equine herpesviruses. 6. Sequential infection of horses with types 2, 3 and 1. The immunological and virological status of 3 foals in respect of equine herpesviruses (EHV) was established and the foals were sequentially infected with EHV2, EHV3 and EHV1. Following experimental infection with EHV2, no clinical signs of disease were observed in any foal. The inoculation of EHV3 into the genital tract resulted in lesions of the mucous membrane and perineal skin that were considered typical of equine coital exanthema. Following intransal inoculation of EHV3 extensive ulceration and pustule formation on the nasal mucosa was observed by day 5 accompanied at day 7 by a profuse,...
Immunity to equine herpesvirus type 1 (rhinopneumonitis): in vitro lymphocyte response. Twenty-two ponies were examined for serum-neutralizing (SN) antibody to equine herpesvirus type 1 and for in vitro lymphocyte transformation in the presence of viral antigen. Six ponies had undetectable levels of neutralizing antibody (titer less than 1:2) and had lymphocytes which did not respond in culture with viral antigen (stimulation index less than 2.0). Four ponies which had SN antibody to equine herpesvirus type 1 did not manifest lymphocyte transformation in vitro. The 12 remaining seropositive ponies had lymphocyte transformation with viral antigen in vitro (stimulation indexes from...
Serological detection of equid herpesvirus 1 infections of the respiratory tract. An investigation was made of 3 serological tests (virus neutralization, complement fixation and indirect immunofluorescence), which are applicable to epidemiological studies of infections by Equid herpesvirus 1 (EHV-1). Sera from gnotobiotic foals inoculated intranasally with various strains of EHV-1 were unable in some cases to neutralize heterologous strains and these results were not consistent with the existence of clearly-defined subtypes of EHV-1, as previously proposed. The cross-reactions in complement-fixation tests paralleled those with neutralization but immunofluorescence tests wer...
The ultrastructure of the cell types in the endocrine pancreas of the horse. The islets of Langerhans of the equine pancreas were examined with the electron microscope after immersion or perfusion fixation. Five cell types could be distinguished after fixation by either technique: 1. A-cells, situated at the center of the islets, 2. B-cells, containing mostly "pale granules" and constituting the principal cell type of the periphery of the islets, 3. D-cells, also located mainly at the periphery of the islets, 4. G-cells, found at the edge of the islets and in the exocrine pancreas, and 5. S-cells, (small granule cells), which are relatively few in number and occur only...
Chemical mediators of anaphylaxis (histamine, 5-HT, and SRS-A) released from horse lung and leukocytes in vitro. Horses were sensitized to bovine plasma in Freund's complete adjuvant. Leukocytes, separated from venous blood, yielded histamine upon incubation with bovine plasma. Ioslated lung fragments incubated with bovine plasma liberated histamine and 5-HT, but not SRS-A. Pulmonary veins obtained from the same animals contracted to histamine, 5-HT and to antigen (Schultz-Dale reaction). Histamine and 5-HT probably contribute to immediate-type hypersensitivity in horses whereas the role of SRS-A is not proved.
Evaluation of adenosine deaminase and other purine salvage pathway enzymes in horses with combined immunodeficiency. Foals with combined immunodeficiency had normal levels of purine salvage pathway enzymes, including adenosine deaminase, nucleoside phosphorylase, and xanthine oxidase.
Substrate specificity and modifications of the active centre of elastase-like neutral proteinases from horse blood leucocytes. Two proteinases (2A and 2B) purified from the granular fraction of horse blood leucocytes degrade casein (Km values 12.8 and 6mg/ml respectively) with maximum activity at pH 7.4 and in the presence of 2m-urea. Urea-denatured haemoglobin, fibrinogen, albumin and resorcin/fuchsin-stained elastin are digested at a slower rate. The enzymes hydrolyse synthetic substrates of elastase, N-benzyloxycarbonyl-L-alanine 4-nitrophenyl ester (Km 0.114 and 0.178 mM) and N-acetyl-tri-L-alanine methyl ester (Km 5.55 and 0.98 mM), but they do not hydrolyse synthetic substrates of trypsin, chymotrypsin and throm...
Characterization of human, bovine, and horse antithrombin III. A comparison of the physical-chemical properties of human, bovine, and horse antithrombin III has been made. These three plasma proteins are strong inhibitors of bovine factor Xa and form a 1:1 molar complex with this coagulation enzyme. Human, bovine, and horse antithrombin III are glycoproteins containing hexose, hexosamine, and neuraminic acid. The total carbohydrate was 9, 12, and 16% for human, bovine, and horse antithrombin III, respectively. These proteins have a similar amino acid composition, although some monor variations were noted. Each antithrombin III is composed of a single poly...
Chemical modification as a probe of the topography and reactivity of horse-spleen apoferritin. In apoferritin, but not in ferritin, 1.0 +/- 0.1 cysteine residue per subunit can be modified. In ferritin 3.3 +/- 0.3 lysine residues and 7.1 +/- 0.7 carboxyl groups per subunit can be modified, whilst the corresponding values for apoferritin are 4.4 +/- 0.4 lysine residues and 11.0 +/- 0.4 carboxyl groups per subunit. Modification of lysine residues which maleic anhydride and carboxyl groups with glycineamide in apoferritin which has been dissociated and denatured in guanidine hydrochloride leads to the introduction of 9.1 +/- 0.5 maleyl groups per subunit and 22.0 +/- 0.9 glycineamide resid...
Purification, characterization, and quantitation of the antigen employed in the immunodiffusion test for diagnosis of equine infectious anemia. Equine infectious anemia (EIA) antigen extracted from the spleen of horses infected with EIA virus was purified by pH treatment, (NH4)2SO4 fractionation and affinity chromatography. The homogeneity of the antigen was indicated by sedimentation rate and sedimentation equilibrium experiments. A S20,w of 0.51 was determined and a molecular weight of 7600 was calculated from sedimentation equilibrium analysis. The amino acid composition of the pure antigen indicated the antigen is an acidic protein. Employing radical immunodiffusion (RID) and pure antigen a method for quantitating antigen content ...
Isolation and partial characterization of three major allergens of horse hair and dandruff. Three major allergens of horse hair and dandruff have been isolated. The fractionation procedures involved various combinations, described in detail, of ethanol precipitation below --5degreesC, cation- and anion-exchange chromatography, and gel filtration. UV absorption, quantitative immunoelectrophoresis and RAST inhibition were used to monitor the separations. Protein impurities constituted less than 5% in all cases. The molecular weights of the isolated proteins were 1.9 X 10(4), 5.1 X 10(4) and 3.1 X 10(4) daltons, respectively. The pIs were determined as 4.1, 3.8 and 3.9, respectively. Th...
Preparation and immunosuppressive potency of equine anti-human thymocyte membrane IgG. Anti-human thymocyte cell membrane antibody prepared by hyperimmunization of the horse produced an antiserum capable of prolonging skin allografts in the rhesus monkey for an average of 26 days. Lymphocyte depletion was present in paracortical areas of mesenteric lymph nodes of these animals after 28 days of treatment; the intravenous administration was tolerated without ill effects. Immunofluorescent studies identified both broad specificity antibodies reacting with numerous human cell types as well as thymus-dependent (T) cell antibodies reactive with human thymocytes and peripheral T-cells....