CD4 T cells as targets for the cytotoxic T lymphocyte assay: A study of enhancers of HIV-1 infection in the target cell preparation.

Abstract

My objective was to establish the conditions necessary to measure cytotoxic T lymphocyte (CTL) activity. The approach was to clone peripheral blood mononuclear cells (PBMC) from HIV-1$\sp+$ asymptomatic patients to obtain CD8$\sp+$ clones and test these cells against autologous CD4$\sp+$ T lymphoblasts. I also tested the following enhancers of viral infectivity: DEAE-Dextran (DD), Polybrene and Tumor Necrosis Factor-Alpha (TNF$\alpha$) in normal T cells and HUT-78 cells and found that DD greatly increases infection when used as pretreatment and during infection at 10 $\mu$g/ml. Polybrene (2.5-5 $\mu$g/ml) also increases infection when used as pretreatment and during infection but not as much as DD. It proved to be less toxic than DD and would be useful when a slow, less acute infection is desired. The effect of TNF $\alpha$ at 5 ng/ml was not noticeable in normal T cells the first few days after the infection but the infection increased six or seven days later. TNF$\alpha$ did not have any significant effect on the HUT-78 cell line. The improved infection protocol with the use of enhancers will be useful in the production and maintenance of high titer virus stocks in the laboratory and in the infection of sensitive target cells for CTL assays. (Abstract shortened by UMI.)