Adenoviruses infection of CLL cells induces cytotoxicity. Primary CLL cells from 7 patients were infected with Ad5dl309 or heat-inactivated Ad5dl309 (mock-infected). At the indicated times, cell viability was determined by cell counting and trypan blue staining and compared with the viability of uninfected and mock-infected cells. (A) The degree of cytotoxicity seen 4 days after infection of primary CLL with Ad5dl309. (B) The degree of cytotoxicity seen 20 days after infection of primary CLL with Ad5dl309. In both figures, control refers to uninfected cells and mock refers to cells infected with heat-inactivated virus.