T cell subsets and their limphokines

The general biological properties of T cell related lymphokines are reviewed here. In particular the stimulatory function of IL-3 on a subset of T cells isolated from the peripheral blood of a normal individual was demonstrated. These cells were CD4 and CD8 negative and expressed the alpha/beta T cell receptor instead of the expected gamma/delta heterodimer. Previously IL-3 has been described to induce the growth of hemopoietic cells, chiefly progenitor cells and mast cells. Moreover IL-7, a newly cloned lymphokine, was found to support the growth and expansion of the human nature T cells. Either T cell clones phenotype and function, or resting T cells were stimulated by IL-7. Finally, the lymphokine production by the T cell clones which have or not cytotoxic capacity was analysed. Different amounts of mRNA transcripts and translated proteins were produced by the two types of T cell clones. This could represent an important tool with which to classify T cells having a function unrelated to the membrane phenotype.