SEATTLE--DNA from the recently discovered Kaposi's sarcoma-associated
herpesvirus (KSHV) has been isolated in KS lesions as well as
some AIDS-related lymphomas, and the new research suggests that
foscarnet (Foscavir) may effectively inhibit the virus. Enrique.
A. Mesri, PhD, of the Department of Medicine, Cornell University
Medical College, reported the findings at the American Society
of Hematology (ASH) meeting.
Dr. Mesri and his colleagues at Cornell and Memorial Sloan-Kettering
found a DNA fragment from KSHV in a high percentage of both AIDS-related
and non-AIDS-related Kaposi's sarcoma lesions. The DNA fragment
was also found in cells from AIDS-related body cavity-based B-cell
The KSHV+ DNA found in BC-1 cells (a cell line established from
an AIDS-BCBL patient and the first cell line known to stably carry
KSHV-DNA) was protected from DNAse degradation, possibly, the
researchers concluded, by being inside a viral capsid.
They also found that KSHV shared DNA homology with Epstein-Barr
virus and herpesvirus-Saimiri, both lympho-trophic herpesviruses,
Dr. Mesri said.
Further studies found that the KSHV+ viral particles were infective
and could transmit KSHV-DNA to human CD19+ B lymphocytes in culture.
This in vitro infection could be blocked by the viral DNA-polymerase
inhibitor foscarnet, as well as by ultraviolet irradiation, indicating
that transmission and persistence of KSHV-DNA is dependent on
a biologically active replicating virus.
Dr. Mesri and his colleagues plan to pursue the potential of foscarnet,
currently approved by the FDA for the treatment of CMV retinitis,
as a treatment for Kaposi's sarcoma and AIDS-related body cavity-based