Protective activity of tetracycline analogs against the cytopathic effect of the human immunodeficiency viruses in CEM cells.

Tetracycline analogs were evaluated for anti-HIV activity in CEM cells; minocycline and doxycycline were the most active of these in inhibiting the virus-induced cytopathic effect between 7 and 14 days post-infection. The active concentrations (0.3-1.5 micrograms/ml) were devoid of toxicity in uninfected cultures. Virus production, however, was not inhibited, indicating a dissociation between protection against cell death and suppression of virus growth. These protected cells could be maintained in culture for 6-7 weeks, even in the absence of the compounds. After that period, virus production ceased and cells could then be cultivated for several months without loss of viability or reappearance of virus production. As HIV stocks produced in the presence of tetracycline analogs were unable to induce cell death, we suggest that the cytopathogenicity of HIV may be due in some cases to the presence of tetracycline-sensitive contaminating microorganisms.