Enhanced parainfluenza I (6/94) virus detection in latently infected human brain cell cultures by treatment with cytochalasin D and dimethyl sulfoxide.

The ability of cytochalasin D (CD) and dimethyl sulfoxide (DMSO) to enhance parainfluenza I (6/94) virus replication was studied in various cell culture systems. Treatment of CV1 cells with CD (1 microgram/ml) dissolved in DMSO prior to primary 6/94 virus exposure at 10(0)--10(5) multiplicities of infection did not substantially enhance virus replication. However, there was a transient increase in cell associated virus one day after infection of DMSO-treated cultures. CD treatment of cultures of human brain cells latently infected with 6/94 virus (LIHB cells) did not enhance 6/94 virus detection. Cocultivation of CV1 cells with CD-treated LIHB cell cultures, and cocultivation of LIHB cell cultures with CD-treated CV1 cells, resulted in the production of both cell-associated and cell-free 6/94 virus three and five days after cocultivation. No virus was detected after similar cocultivation of untreated LIHB cell cultures with untreated CV1 cells. The usefulness of CD-DMSO treatment in the rescue of virus from 6/94 LIHB cell cultures appears limited to a cocultivation system. The use of these techniques to enhance virus rescue from human tissues suspected of harboring latent viral genomes is discussed.