Reactivity of Paul-Bunnell type heterophile antibody in sera from infectious mononucleosis patients with the surface of lymphoid cells carrying Epstein-Barr virus genomes.

The possible presence of Paul-Bunnell (PB) antigen on Epstein-Barr virus (EBV)-transformed lymphocytes were investigated. Of 23 EBV genome-positive lymphoblastoid cell lines tested all but one absorbed PB type antibody from the serum of an infectious mononucleosis patient. The one EBV-negative B cell line tested did not absorb the heterophile antibody. PB antibody, purified by an immunoadsorbent procedure using beef cell antigen, reacted with the EBV producer P3HR-1 cell line in an indirect membrane immunofluorescence test and was shown to be IgM antibody. Titers of heterophile agglutinin and reactivity with the cell surface were reduced to the same degree by absorption with beef cell antigen but not with guinea pig kidney antigen. PB antibody was distinct from IgM antibody against the EBV-determined membrane antigen, since the latter was not absorbed by beef cell antigen. PB antibody was also reactive with other EBV-positive B cell lines (QIMR-WIL, NC-37, and Raji) which were free of surface IgM. No reaction occurred with the nonproducer P3HR-1 line, a null cell line, and two T cell lines. The results suggest the presence of PB antigen on most EBV-transformed B lymphocytes, and its appearance in each of the transformed lymphocytes of patients with acute infectious mononucleosis.