Topic:Antigen
Antigens are substances that can induce an immune response in horses, typically by being recognized as foreign by the immune system. These substances can include proteins, polysaccharides, or lipids, and are often components of pathogens such as bacteria, viruses, or parasites. In horses, antigens are essential for the activation of both the innate and adaptive immune responses, leading to the production of antibodies and the activation of immune cells. The study of antigens in equines encompasses understanding their structure, the mechanisms by which they are recognized by the immune system, and their role in vaccine development. This page compiles peer-reviewed research studies and scholarly articles that explore the identification, characterization, and immunological impact of antigens in equine health and disease.
[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...
A comparison of antigenic structure and phage pattern with biochemical properties of staphylococcus aureus strains isolated from horses. Out of 70 S. aurew strains isolated from the anterior nares of horses, 48 (69 per cent)
belonged to the E biotype. Approximately one third of these isolates were typed with factor
sera, the 6 (35 per cent) that were typable showing 5 different patterns. All strains but one
were non-typable with the basic sets of phages for typing human and bovine staphylococci
even at RTD x 100. Without any exception the equine staphylococci of the E biotype
contained polysaccharide Aa. Sixteen biochemically different strains belonged to the biotype A, B or C. A number of different serological patterns an...
Equine infectious anemia virus from infected horse serum. Equine infectious anemia virus was purified from infected horse serum samples. Electron microscope observation on negatively stained preparations of purified virus showed roughly spherical particles sized between 100 and 200 nm in diameter. In disrupted particles, an envelope was visible but no internal structure could be resolved. Since the purified virus fraction had a strong antigenic activity to antiserum in immunodiffusion reaction, these particles are thought to be the causative virus of equine infectious anemia.
Purification and antigenicity of an M-like protein of Streptococcus equi. A cell wall component of Streptococcus equi analogous to the M protein of group A streptococci has been identified and purified. A highly purified product has been obtained from cells by hot acid extraction, followed by acid precipitation, ammonium sulfate fractionation, and column chromatography. This product reacts with S. equi antiserum. The existence of this fraction in S. equi has been confirmed by the failure of trypsin-treated cells and their extracts to remove the long-chaining capacity of S. equi antiserum. The antigenicity of this M-like protein when incorporated in adjuvant has been...
Detection of tumor-specific antigens in an equine sarcoid cell line. Indirect immunofluorescence and lymphocyte cytotoxicity experiments demonstrated the presence of a tumor-specific antigen(s) on the surface of cells from an equine sarcoid cell line (Mc1). Autologous serum (taken from the horse from which the Mc1 cells were derived) and sera from three other sarcoid-bearing horses revealed a similar membrane immunofluorescence when reacted with Mc1 cells, indicating the existence of cross-reacting antibodies. Results of serum colony inhibition experiments indicate that these antibodies are not cytotoxic. Incubation of Mc1 cells with autologous lymphocytes resu...
Equine herpesviruses: antigenic relationships and deoxyribonucleic acid densities. Equine herpesviruses with a deoxyribonucleic acid density of 1.716 to 1.717 g/cm(3) were compared with one another by the plaque-reduction test and by the rate of development of cytopathic effect as indicated by plaque size in rabbit kidney cultures. Of the 19 isolates studied, the 9 which had already been tentatively labeled equine abortion viruses were serologically similar to one another; each of them grew more quickly than did any of the other 10 isolates although the mean plaque sizes formed a series of gradations with no clear hiatus which would permit the unequivocal delineation of the ...
Extraction of equine infectious anemia immunodiffusion antigen with the aid of the chaotropic agent, thiocyanate. Immunodiffusion antigen from spleens of horses infected with equine infectious anemia virus was prepared by methods employing freeze-thaw cycles and thiocyanate treatment. Thiocyanate (0.5 M) permitted the recovery of the greatest amount of antigen. Furthermore, it was most effective for recovery of immunodiffusion antigen from spleens which yielded unsatisfactory concentrations of antigen by the conventional freeze-thaw or water-extraction methods. The reactivity of the antigen did not appear to be affected by this chemical treatment.
Equine infectious anemia: activity of liquid antigen extracts in the agar-gel immunodiffusion and complement-fixation tests. Twenty-nine lots of acetone-ether extracted liquid antigen were prepared from the pulp of 11 spleens collected from horses at the acute phase of experimental infection. The lots prepared from the highly reactive pulp resulted in general in a liquid antigen of greater activity than those extracted from weakly reactive pulps. Some variations in activity between lots of antigen prepared from the same spleen were also observed. No matter what the results, given a wide enough variation, all results were reproducible. The procedure permitted production of a greater number of antigen test doses from ...
Identification and quantitation of equine serum and secretory immunoglobulin A. Immunoglobulin A (IgA) was demonstrated in equine serum and secretions. This immunoglobulin had a molecular weight extending from 150,000 to 700,000 and reacted with specific antihuman alpha-chain antiserum. Antigenic determinants specific for secretory IgA were demonstrated and found to be absent on serum IgA. Antigen binding activity was detected in IgA from tears. Purified IgA was antigenically distinct from equine IgG, IgM, IgG(T), and aggregating immunoglobulin. Quantitative studies demonstrated that IgA was the predominant immunoglobulin in tears and milk but not in colostrum. The electr...
Demonstration of antigenic identity between purified equine infectious anemia virus and an antigen extracted from infected horse spleen. Antigenic relationship between purified equine infectious anemia (EIA) virus and spleen-derived antigen from EIA-infected horses was examined by immunodiffusion. Identical antigenicity of these two antigens has been proven because precipitation lines formed between the two antigens and EIA antiserum connected with each other. The results indicate that the antigenic substance derived from infected spleen is a component of EIA virus.
Detection of African horsesickness viral antigens in tissues by immunofluorescence. The fluorescent antibody reaction was studied in tissues of ponies infected with African horsesickness virus (AHSV). Lung, spleen, lymph node, liver, skeletal muscle, intestine, stomach, nerve ganglion and kidney were sectioned and stained by the direct fluorescent antibody technique (FA). Fluorescence was demonstrated only in the spleen and could be inhibited by using unconjugated antiserum.
Detection of chlamydial antibodies in animal sera by double diffusion in gel. Postinoculation sera collected from pigeons, turkeys, guinea pigs, sheep, a calf, a rabbit, and a horse experimentally infected with various strains of Chlamydia psittaci yielded a high incidence of positive reactions when tested by double diffusion in gel. Antigen was a deoxycholate extract of SA-2 strain of C. trachomatis. Good correlation was obtained with results of complement fixation tests, whereas double diffusion in gel was less sensitive. Immunoelectrophoresis of the antigen revealed presence of two antigens in the extract.
Equine infectious anemia: preparation of a liquid antigen extract for the agar-gel immunodiffusion and complement-fixation tests. An agar-gel immunodiffusion test recommended for the diagnosis of equine infectious anemia was evaluated. Our preliminary observations confirmed those of Coggins concerning the mechanism of the test and the results obtained. Furthermore, emphasis was put on the difficulties encountered in the production of spleen antigens with an optimum amount of reactivity. Acetone-ether extraction procedures for the preparation of a liquid antigen extract are described. This type of antigen was reactive in the complement-fixation test in 1:8 or greater dilution and it is proposed to use the complement-fixat...
Tolerance to sheep red cells: breakage with thymocytes and horse red cells. Mice rendered tolerant to sheep red cells and then given normal thymocytes, made no antibody when immunized with these cells. When immunized with horse red blood cells, however, they made significant amounts of noncross-reacting antibody to sheep red blood cells. This suggests that antibody-making precursor cells (B cells) which are nontolerant but nonactivatable by specific antigen, may exist in tolerant hosts.
Antigenic variation of equine (Heq2Neq2) influenzavirus. Influenza equine (Heq2Neq2) strains isolated during the course of epizootics observed in Guanabara (Rio de Janeiro) and São Paulo, Brazil, in July-October 1969 were shown to differ antigenically from earlier strains of the same subtype (A/equine/Miami/1/63 (Heq2Neq2)). The difference could be clearly demonstrated in haemagglutination inhibition tests performed with postinfection horse or ferret sera but not with hyperimmune rooster sera. Antibody responses of diseased horses were higher and more frequent against current isolates than against strain equine/Miami/1/63. Some animals also showed ...