Two serum glycoproteins in chickens inoculated with a transplantable Marek's disease cell line and preparation of monoclonal antibodies against the glycoproteins.

Abstract

In the sera from chickens inoculated with a transplantable Marek's disease (MD) lymphoblastoid cell line, MDCC-MSB1-41C, five peaks (I, II, III, IV and V) were separated by chromatofocusing in a gradient of pH 5-6. Peaks I, II, III and IV were not exactly detectable in normal chicken serum. The contents of two peaks (I and II) correlated to tumor size. Subsequently, Peaks I and II were each purified by Cellulofine gel filtration and six monoclonal antibodies to the purified materials were prepared by somatic cell hybridization. Polyacrylamide gel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS) revealed that Peaks I and II were each a glycoprotein of the same molecular weight, approximately 105, 000 (105K) daltons, with different isoeltctric points. All monoclonal antibodies obtained cross-reacted equally with either Peak I and Peak II by enzyme-linked immunosorbent assay. By immunoblotting analysis using one (P5-13) of these antibodies, when the same samples from normal and MSB1-41C-transplanted chickens and the purified Peaks I and II were each subjected to SDS-PAGE and blotted on a sheet of nitrocellulose, a single band reacted with P5-13 was formed at a position corresponding with 105K dalton in the respective samples and the density of each band correlated to tumor size. These results suggest that the cross-reactive 105K molecules may increase when chickens develop tumors.