Epstein Barr virus (EBV)-carrying cells of a chronic lymphocytic leukemia (CLL) subpopulation express EBNA1 and LMPs but not EBNA2 in vivo.

ABSTRACT

We have previously described an exceptional CLL patient, P.G., whose leukemic cell population contained a small fraction of Epstein-Barr virus (EBV)-carrying cells. These cells grow directly into permanent cell lines in vitro. Using RT-PCR analysis, we now show that the in vivo EBV-carrying CLL cells expressed EBNAI, LMPI, LMP2a and 2b, but not EBNA2, in 4 of 4 blood samples obtained during the last 3 years of the patient's life. Our data also show that the CLL cells used a promoter in the F/Q, but not the W or C, region. This is consistent with the fact that CLL cells resemble resting lymphocytes rather than immunoblasts. Expression of LMP1 and LMP2b differs from the exclusive EBNAI and LMP2a expression of normal resting B cells, however, and corresponds to the state defined as latency II. This form of latency was until now detected only in EBV-carrying non-B cells in vivo. Our data show that a B-cell subtype can also show this expression pattern in vivo.