An unusually high-titer human anti-Epstein Barr virus (EBV) serum and its use in the study of EBV-specific proteins synthesized in vitro and in vivo

Abstract

Sera from a patient with a chronic Epstein Barr virus (EBV) infection contained unusually high anti-EBV antibody titers (1:2560 to 1:10,240 for EA(D) and 1:5,120 to 1:40,960 for VCA). One of these serum samples was shown by immunoprecipitation to recognize at least 11 EBV-specific proteins from virus producer cells labeled in vivo and 10 EBV-specific proteins from in vitro translations of producer cell mRNA. Six of the in vivo labeled proteins (135,000, 89,000, 50,000 to 55,000 doublet, 46,000, and 34,000 daltons) are "early" by their resistance to phosphonoacetic acid, and five (350,000, 220,000, 160,000, 140,000, and 85,000 daltons) are "late" membrane and capsid proteins. The EBV-specific proteins immunoprecipitated from in vitro translations had molecular masses of 150,000, 140,000, 115,000, 52,000, 50,000, 45,000, 34,000, 29,000, 17,000, and 15,000. Subcellular fractionation studies of cells labeled in vivo revealed that the 135,000-dalton protein and part of the 50,000 to 55,000 dalton protein doublet were found in both the nuclear and the cytoplasmic fractions, and thus are good candidates to be components of the EA(D) diffuse-type immunofluorescence observed with many EA-positive sera.