A Positive Correlation between the Precursor Frequency of Cytotoxic Lymphocytes to Autologous Epstein-Barr Virus-Transformed B Cells and Antibody Titer Level against Epstein-Barr Virus-Associated Nuclear Antigen in Healthy Seropositive Individuals

A limiting dilution analysis was established to determine the precursor frequency (PF)of cytotoxic lymphocytes against autologous B cells transformed with the Epstein-Barr virus (EBV). This method was found to detect mainly self-restricted T-cell activity and little non-self-restricted cytotoxicity. The mean PF in 21 healthy EBV-seropositive persons was 1.4×10-3 (range: 0.03×10-3 to 8.7×10-3) for peripheral blood mononuclear cells, whereas 4 samples of mononuclear cells obtained from umbilical cord blood had PFs below 0.007×10-3. A positive correlation was observed between the PF and serum antibody titers against EBV-associated nuclear antigen among the seropositive persons.