Detection localization of Epstein-Barr virus-associated early antigens in single cells by autoradiography using 125I-labeled antibodies. (With 1 color plate).

A characteristic feature of virus-transformed cells is the expression of virus-specific antigens usually detectable by immunological or radioimmune procedures. We report here an autoradiographic method for the detection and localization of such antigens in individual cells which combines the cellular specificity and radiolabeling sensitivity of the above procedures. As a test system we have studied the reaction between virus antigen in some Epstein-Barr virus (EBV) DNA-containing cell lines and anti-virus antibody specificities in certain human sera. EBV DNA-containing cell lines express an EBV-determined nuclear antigen (EBNA) and some lines also express the EBV-associated antigens, early antigen (EA) and virus capsid antigen (VCA), in a minority of cells in the population. By employing appropriate 125I-IgG-labeled human sera, we clearly show that EA can be detected without difficulty in cell lines known to spontaneously express this antigen. Moreover, the specificity and sensitivity of the present method is such that low levels of EA cand be detected at cellular concentrations which remain undetectable by conventional immunofluorescence.