HIV-induced cytopathology and viral load in a pentamidine-treated lymphocytic cell line

Preincubation of CD4 lymphocytes with pentamidine isethionate at a concentration of 1.5 mg/L then removal from incubation medium prior to addition of HIV-1, or incubation of cells with the drug and virus simultaneously, increased HIV-1 DNA load but reduced p24 antigen release. The number of syncytia generated was not affected by the presence of pentamidine. The extent of balloon degeneration of cells was greater, however, although this was not associated with a discernable increase in cellular necrosis or reduction in cell viability. This suggests that drug-treatment resulted in an increased load of intracytoplasmic (but not necessarily integrated) forms of HIV- 1; this may explain the lower levels of antigen produced and also the balloon degeneration of treated cells, a phenomenon previously observed with other retroviruses.