Complement fixation is an immunological reaction involving the binding of complement proteins to antibodies that have attached to specific antigens. In horses, this process is part of the innate immune response, contributing to the identification and elimination of pathogens. The complement system consists of a series of proteins that, when activated, enhance the ability of antibodies and phagocytic cells to clear microbes and damaged cells. This system also promotes inflammation and attacks the pathogen's cell membrane. The complement fixation test is a diagnostic tool used to detect the presence of specific antigens or antibodies in equine serum by observing the consumption of complement proteins. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, regulation, and diagnostic applications of complement fixation in equine immunology.
Equine recurrent uveitis serves as a spontaneous model for human autoimmune uveitis. Unpredictable relapses and ongoing inflammation in the eyes of diseased horses as well as in humans lead to destruction of the retina and finally result in blindness. However, the molecular mechanisms leading to inflammation and retinal degeneration are not well understood. An initial screening for differentially regulated proteins in sera of uveitic cases compared to healthy controls revealed an increase of the alternative pathway complement component factor B in ERU cases. To determine the activation status ...
Goto H, Yamamoto Y, Ohta C, Shirahata T, Higuchi T, Ohishi H.A total of 305 horse sera collected in the Hidaka district of Hokkaido in the years 1988-90 were tested for the presence of hemagglutination-inhibition (HI) antibodies to A/equine/Newmarket/1/77 (H7N7), A/equine/Tokyo/2/71 (H3N8) and A/equine/Kentucky/1/81 (H3N8, Kentucky) strains of equine influenza (EI) virus. Antibodies to the 3 strains were detected in hardly of the 45 sera from 2-years-old horses which were collected before vaccination. Many of the 51 horses, after vaccination with inactivated EI virus, had HI antibodies to the 3 strains in 37 to 88 per cent. However, the number of positi...
Baba SS, Akinyele HA, Olaleye OD.The occurrence of antibodies against the African horse sickness virus was investigated in 246 domestic animals (horses, donkeys, camels, dogs) in various regions of Nigeria by means of the complement-fixing rate. 34% of the sera tested were positive: 75% in donkeys, 68% in horses, 19% in camels, and 9% in dogs. Among the horses, those of 6 to 15 years of age had higher than average prevalence rates than the other age groups. Stallions from the northern regions had higher prevalence rates than mares generally and stallions from other regions. These findings are important for the epidemiology of...
Camp CJ, Leid HW.Extracts of Onchocerca cervicalis, an equine parasite, were incubated with radiolabeled equine neutrophils and neutrophil migration was assessed for factors derived from the parasite itself or for host-derived factors after incubation of these same parasite extracts with equine serum. No stimulus for cell migration was observed in saline extracts of adult worms, uterine microfilariae, or skin microfilariae at any dosage tested. However, after incubation of saline extracts with fresh normal equine sera a marked stimulus for neutrophil migration was observed. Ablation of this biologic activity w...
Troedsson MH, Lee CS, Franklin RD, Crabo BG.The effect of seminal plasma on polymorphonuclear neutrophil (PMN) chemotaxis, PMN phagocytosis and complement-induced cytolysis was determined using blood plasma pooled from four horses and seminal plasma pooled from two stallions. To investigate chemotaxis, complement in blood plasma was activated with E. coli lipopolysaccharide in the presence of 0-50% seminal plasma diluted with a standardized volume of McCoy's medium and placed in a chemotactic chamber. Chemotaxis of blood derived equine PMNs toward the chemoattractants was determined after incubation at 37 degrees C for 45 min. To invest...
Metenier L, Grosclaude J, Meriaux JC.The chief application of blood typing in domestic animals is in the verification of parentage. However, the acquisition of good standardized reagents in sufficient quantity remains an obstacle for the development of this work. The production of monoclonal antibodies directed against blood group determinants offers an attractive means of improving both the quality and quantity of serological reagents, and could facilitate the definition of new specificities. Fusions between a mouse myeloma line and splenocytes from mice immunized with horse red cells have resulted in four hybridomas producing a...
Tatarov G, Martinov S, Panova M.It was established that the complement binding reaction (CBR) is a suitable and very fast method for horse rhino-pneumonitis diagnostics. Cell cultural virus produced in cell cultures of pig kidneys was used as antigen. The antigen lots tested have no anticomplementary properties. Highest complement binding activity was evident in the non-diluted antigen, which discovered specific antibodies in immune serums. The CBR specificity was tested by the aid of homologous and heterologous serums and antigens. The titers of complement binding antibodies in the serums of 255 horses recovered from the di...
Cohen ND, Hughes EV, Bayne C, Morris ERA, Bray JM, Landrock KK, Gonzales DM, Baker RM, Klein RL, Liu W, Legere RM, Wehmeyer SG, Bordin AI....Evaluate the immunogenicity of a vaccine targeting the S protein (Ssee) of Streptococcus equi subsp equi and determine antibody activity against Ssee in horses with strangles. Methods: The study was designed as a prospective experiment using 20 university-owned Quarter Horses and a cross-sectional serosurvey of 78 privately owned horses with strangles. Horses were immunized IM with 0 (n = 4), 200 (n = 8), or 400 (n = 8) μg of recombinant Ssee at weeks 0, 4, and 12. Serum and nasal secretions were collected at weeks 0, 4, 6, 12, 16, and 28 and tested by ELISA for immunoglobulin (Ig)-G against ...
Cohen ND, Hughes EV, Bayne C, Morris ERA, Bray JM, Landrock KK, Gonzales DM, Baker RM, Klein RL, Liu W, Legere RM, Wehmeyer SG, Bordin AI....Evaluate the immunogenicity of a vaccine targeting the S protein (Ssee) of Streptococcus equi subsp equi and determine antibody activity against Ssee in horses with strangles. Methods: The study was designed as a prospective experiment using 20 university-owned Quarter Horses and a cross-sectional serosurvey of 78 privately owned horses with strangles. Horses were immunized IM with 0 (n = 4), 200 (n = 8), or 400 (n = 8) μg of recombinant Ssee at weeks 0, 4, and 12. Serum and nasal secretions were collected at weeks 0, 4, 6, 12, 16, and 28 and tested by ELISA for immunoglobulin (Ig)-G against ...
Enkhtuul B, Khurtsbaatar O, Lkham B, Agiimaa T, Unenbat J, Buyanbadrakh B, Ninjbulgan S, Liushiqi B, Suzuki Y, Kimura T, Batbaatar V.Glanders, a zoonotic disease caused by , has re-emerged in Mongolia after decades of control. We conducted nationwide serosurveillance from 2021 to 2024 to assess the prevalence and geographic distribution of glanders. Using random 3-stage cluster sampling, we collected 3,001 horse serum samples from 332 herds. Those herds were in 46 soums (administrative districts equivalent to counties) in 13 provinces and in 3 districts in Ulaanbaatar. Sera were tested using the complement fixation test, and positive results were confirmed by immunoblotting and ELISA. Overall seroprevalence was 1.03% (95% C...
