Detection of influenza virus induced DNA damage by Comet assay

Influenza virus A2/HK/68 is known to be a biological mutagen and teratogen, Reports are available implicating influenza virus as a causative agent of chromosomal aberrations in cells in culture and also in circulating leukocy tes of humans, Also, an increased incidence of abortions, prenatal mortalit y and congenital abnormalities during the periods of epidemics has also bee n reported. In view of these reports, it would be worthwhile to screen pers ons especially pregnant women exposed to influenza virus for possible DNA d amage, The present study reports the use of Comet assay to measure influenz a virus induced DNA damage. We have carried out in vitro infection experime nts using human leukocytes, Our results clearly indicate that influenza vir us A2/HK/68 induces DNA damage in leukocytes right from 2-h post-infection. Maximum damage was observed at 24-h post-infection, However, at 48-h post- infection, a slight decrease was observed which can be attributed to the DN A repair occurring in the cells, Thereafter, irreparable damage was noticed . Cell viability results have shown lack of cytotoxicity till 72-h post-inf ection. However, significant cytotoxicity was observed only at 96-h post-in fection. The occurrence of DNA damage without cell death may result in chro mosomal aberrations or mutations. Therefore, it is most advisable to get sc reened for the possible DNA damage especially persons frequently infected w ith influenza and pregnant women, (C) 1999 Elsevier Science B.V. All rights reserved.