The novel cuticular collagen Ovcol-1 of Onchocerca volvulus is preferentially recognized by immunoglobulin G3 from putatively immune individuals

The concentration and affinity to concanavalin A (ConA) of plasma alpha 1-acid glycoprotein (AGP) and AGP levels in extracts of liver tissues were investigated in specific-pathogen-free chickens infected with the highly virulent HPS-2 strain or virulent reference GBF-1 strain of infectious bursal disease virus. The plasma AGP value in uninfected control 3- to 7-wk-old chickens was 161.8 +/- 25.8 micrograms/ml (mean +/- SD), and ConA-unreactive and ConA-reactive AGP comprised 47% and 63% of total AGP. Increases in AGP levels in plasma and liver extracts were observed in both the HPS-2 and the GBF-1 groups, although albumin levels decreased. The plasma AGP values were higher in the HPS-2 group than in the GBF-1 group through the experimental period. In the HPS-2 group, ConA-reactive AGP reached levels 6.8-fold greater than control values and comprised 80% of total AGP at 4 days post-inoculation. In the lipopolysaccharide group, a great increase in ConA-reactive AGP was observed.