[Different sensitivity to acid reaction of the AIDS virus and virus-producing cells: clinical conclusions]

Sensitivity of the cell-free human immundeficiency virus type 1 (HIV-1) and its producer cells was Studied in acidic media between pH 7.4 and 4.9 vitro. The cytopathic effect, reverse transcriptase activity and p24 antigen production by survived viruses were monitored in indicator cell cultures. It was established that, the cell-free HIV-1 particles are very sensitive to acidity. Between pH 7.4 and 6.0 they loose infectivity gradually, but this process is irreversible under pH 6.0 and subsequent neutralization cannot restore lost infectivity. However, viability, of virus producer cells is hardly affected between pH 7.4 and 4.9, but their ability to release infectious particles is lost gradually, similarly to the case of cell-free viruses. Neutralization of the media after treatment results in gradual restoration of releasing infectious viruses. These data explain that, cell-free HIV-1 looses infectivity in the acidic vagina or does on the skin, but infectivity is preserved in the blood, semen, rectum and breast milk being neutral or slightly alcalic. Virus carrier or producer lymphocytes by any route of infection can survive such protective mechanism of the body.