The EBNA-3B deletion variant was evident prior to CTL infusion and persisted after CTL infusion, while virus with wild-type EBNA-3B was eliminated by CTL infusion.

(A) Primers spanning the EBNA-3B deletion were used to amplify viral DNA from patient and donor peripheral blood drawn before transplantation; from patient blood drawn prior to CTL infusion and 1, 2, and 3 weeks after CTL infusion; from the pre- and post-CTL tumor lines; and from the donor LCL. (B) Wild-type EBNA-3B was detected pre-BMT and pre-CTL but disappeared after CTL infusion. Primers from within the EBNA-3B deletion that could amplify only wild-type EBNA-3B DNA were used in an attempt to avoid competitive effects from the deletion template. The amplification products were run on a 2% agarose gel, Southern blotted, and probed with an EBNA-3B probe. The limitations of the sequence did not allow good PCR primers to be designed; nevertheless, faint wild-type EBNA-3B bands were seen in the donor LCL, donor and recipient mononuclear cells before BMT, and in recipient mononuclear cells pre-CTL infusion but not after. Wild-type EBNA-3B was also detectable in the pre-CTL tumor line and to a lesser degree in the post-CTL tumor line.