Migration inhibition factor secreting human T-cell lines reactive to PPD: a study of their antigen specificity, MHC restriction and the use of Epstein-Barr virus-transformed B-cell lines as requirement for antigen-presenting cells.

Two PPD-reactive T-cell lines and two clones derived from them have been characterized. The lines were maintained for a period of 10-12 weeks in I1-2 containing medium. The clones were derived from the uncloned lines by the limiting dilution method and maintained in culture for 12 weeks. The cloning efficiency was 1%. Both the cloned and the uncloned lines were highly reactive to tuberculin in a proliferation assay and produced migration inhibition factors following antigenic stimulation. Both these functions were dependent on the addition of antigen-presenting cells and genetically regulated by Class II molecules of the MHC. Each uncloned line and the clones derived from them were restricted by just one of the DR alleles of the autologous host. An analysis of cell types involved in antigen presentation showed that macrophages and Epstein-Barr virus-transformed B-cell lines induced both proliferation and MIF secretion in the T-cell lines and clones cultured with PPD. Phenotypic studies indicate that the cells are Sheep E+, OKT4+, OKT8- and HLA-DR+.