Detection of human T-lymphotropic virus type I (HTLV-I) infection during coculture of HTLV-I infected and uninfected cells using inverse long PCR

Abstract

Objective: Identifying the new integration of human T-lymphotropic virus type I (HTLV-I) proviral genome into initially uninfected cells after cocultivation with HTLV-I infected cells is important for clarifying the process of infection. We examined the usefulness of inverse long polymerase chain reaction (IL-PCR) for this purpose.

Methods: An experimental system using IL-PCR was applied to detect the transmission of HTLV-I between irradiated HTLV-I infected cells (HUT102) and uninfected targed cells (MOLT4, K562) after short-term and long-term coculturing.

Results: In every coculture experiment with irradiated HTLV-I infected cells and uninfected cells, the new integration of HTLV-I was easily identified by IL-PCR. Oligoclonal proliferation of HTLV-I-positive cells was shown among MOLT4 cells even 4 months after the cocultivation; however, no evidence of viral replication was observed by indirect immunofluorescence assay or reverse transcription-PCR. We also used IL-PCR to assess the inhibitory effects of azidothymidine, anti-gp46, anti-vascular cell adhesion molecule-1 and anti-heat shock cognate protein 70 (HSC70) monoclonal antibody. Integration of HTLV-I provirus was inhibited in all of these cases except for anti-HSC70.

Conclusion: This experimental method enabled the detection of cell-to-cell transmission of HTLV-I directly and was useful for studying the mechanisms of cell-associated HTLV-I infection.