Production of leukocyte migration inhibition factor (LIF) and migration stimulation factor (MStF) by CD4+ and CD8+ human lymphocytes subsets and T-cell clones.

The production of the lymphokines leukocyte migration inhibition factor (LIF) and migration stimulation factor (MStF) at the level of CD4+ and CD8+ human lymphocyte subsets was investigated. In a first series of experiments, anti-CD4 and anti-CD8 monoclonal antibodies capable of inhibiting the activation by concanavalin-A (Con-A) of the respective T-cell subset were used. It was observed that when CD8+ cell activation was blocked, LIF was always produced after Con-A activation. When CD4+ cell activation was blocked, MStF was produced in five out of nine experiments (no activity in the other four). The addition of N-acetyl-D-glucosamine to block LIF in supernatants of anti-CD8 treated cells was unable to show evidence of masked MStF activity. In a second series of experiments, T-cell clones were established from continuous growing T-lymphocyte cell lines developed from cultures of Con-A activated normal human leukocyte cultures. The phenotype of 22 clones was determined and their ability to produce LIF or MStF investigated. Four clones produced MStF after Con-A activation and all of them were CD3+, CD4-, CD8+. Three clones produced LIF after Con-A activation and all of them were CD3+, CD4+, CD8-. We conclude that LIF is produced by CD4+ cells and MStF by CD8+ cells.