Analysis of lymphokine producing T helper cells at the clonal level

The quantitative representation of alloreactive helper T lymphocytes (HTL) within murine Lyt 1+2- cells has been analysed by the limiting dilution approach. Using three different experimental protocols evidence is presented that the HTL limiting the overall generation of both T help and IL-2 production may be distinct from the actual HTL providing T help or producing IL-2. While the former most likely represents the T inducer cell occurring at a frequency of about 1/2000 within Lyt 1/2- cells, the frequency of the latter is estimated to be about 1/200-1/500.