GENERATION OF INFECTIOUS RETROVIRUS AEROSOL THROUGH MEDICAL LASER IRRADIATION

A novel model system was used to investigate the spread of infectious particles and live cells through the application of lasers commonly us ed in clinical medicine. Supernatants from a cell line producing recom binant retroviruses carrying a marker gene (neoR) were exposed to Er:Y AG-laser beams. Aerosols were collected from various sites and distanc es from the point of laser impact and were analyzed by reverse transcr iption-polymerase chain reaction (RT-PCR) for neoR. In addition, a sus ceptible indicator cell line was used to investigate the presence of i nfectious virions in collected aerosols. To test the possibility of di ssemination of viable cells, a cell line was laser irradiated, and the generated aerosols were analyzed for the presence of viable cells. Th e viral marker gene neoR could be detected in 16% (distance: 5.0-6.3 c m) to 59% (0.5-1.6 cm) of wells adjacent to the point of laser impact. The presence of infectious viruses in laser vapors conferring G418 re sistance could be detected in 3% (distance 5.0-6.3 cm) to 20% (distanc e: 0.5-1.6 cm) of wells containing susceptible cells, and subsequent P CR analysis of isolated resistant clones revealed the presence of neoR -RNA and -DNA. Viable cells were detected in 40% (distance 0.7-3.6 cm) to 3% (distance 10.7-11.8 cm) of wells adjacent to the point of laser impact. These results demonstrate that laser vapors can contain infec tious viruses, viral genes, or viable cells and may promote the spread of infections or tumor cell dissemination. (C) 1998 Wiley-Liss, Inc.