Analysis of C3 and C4 in Ovine Plasma

Abstract

The distributions of plasma concentrations of complement proteins C3 and C4 were studied in sample populations of merino and Suffolk sheep. No differences between the breeds or the sexes were observed. The distribution for ovine C4 was polymodal and very disperse relative to that for C3. It was found, however, that C3 concentrations were elevated in specimens from 20 merino sheep bred as high responders to a Trichostrongylus vaccine. Significantly decreased plasma C4 concentrations were observed in representatives of both merino and merino X Border Leicester cross-bred sheep affected with congenital progressive ovine muscular dystrophy. Agarose gel electrophoretic variants of ovine C3 were not detected. Evidence for electrophoretic variants of ovine C4 in agarose gels was found although individual allotypes could not be reliably identified. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) did not reveal size heterogeneity for the α and β chains of immunoprecipitated ovine C3. Analysis of reduced immunoprecipitated ovine C4 by SDS-PAGE revealed considerable size heterogeneity in the α chain consistent with isotypic and/or allotypic variability. The data presented strongly suggest the presence of two C4 loci in sheep, each of which exhibits polymorphism.

The effect of ovine peripheral blood mononuclear cells on Haemonchus contortus larval death in vitro

“…As STC have been documented to develop an early response and therefore early recognition, differences between parasite susceptible and parasite resistant breeds could also be linked to differences in complement proteins. When plasma concentration of complement proteins C3 and C4 were measured in a population of Suffolk sheep compared to merino sheep, it was found that C3 concentrations were elevated in merino sheep, where C4 was significantly reduced (Groth et al, 1987). Additionally, when analyzed using immunoprecipitation, differences were observed in protein size, suggesting multiple loci and polymorphisms between sheep (Groth et al, 1987) which can be attributed to observed differences in circulating complement.…”

“…When plasma concentration of complement proteins C3 and C4 were measured in a population of Suffolk sheep compared to merino sheep, it was found that C3 concentrations were elevated in merino sheep, where C4 was significantly reduced (Groth et al, 1987). Additionally, when analyzed using immunoprecipitation, differences were observed in protein size, suggesting multiple loci and polymorphisms between sheep (Groth et al, 1987) which can be attributed to observed differences in circulating complement. Taken together, deficiencies in SUF complement activation or polymorphisms in complement proteins may account for observed differences in larval ATP when L 3 are cultured with SUF-derived PBMC and serum.…”