Replication at the level of reverse transcription of HIV-1SF2 strain in Th1 and Th2 cells.

It has been reported that Th2 cells better support replication of T-tropic HIV-1 strain than Th1 cells. We investigated at the level of reverse transcription the replication of T-tropic HIV-1SF2 strain in Th1 and Th2 cells. To determine the presence of the early (RU5), intermediate (gag) and full-length (LTR/gag) product of reverse transcription of virus RNA in Th1 and Th2 cells, we employed the PCR technique. Our results revealed that the early (RU5) product of reverse transcription was detectable 30 min after infection in Th2 cells and 1 h after infection in Th1 cells. The product of reverse transcription corresponding to the gag region of HIV-1 was detected in Th2 cells 2 h after infection, whereas the same fragment of viral DNA in Th1 cells was observed 4 h later. The full-length viral DNA was seen in Th2 cells 6 h after infection but the same time course was not detected in the Th1 cells. We also observed that higher efficiency of reverse transcription of viral RNA correlated with better replication of HIV-1SF2 in Th2 than Th1 cells. The higher concentration of p24 HIV-1 antigen in culture medium than cytoplasm of Th1 and Th2 cells confirmed the lack of restriction at the budding step of HIV-1SF2 replication in Th1 and Th2 cells. Our observation may confirm the suggestion that Th0/Th2 cell orientation supports at the reverse transcriptional level the replication of T-tropic HIV-1 strains, which accelerates the onset of AIDS symptoms.