[Production of GM-CSF by human T lymphocytes purified and stimulated by Con A].

Production of granulomacrophage colony stimulating factor (GM-CSF) by human T lymphocytes has not yet been demonstrated due to insufficient monocyte depletion in cell suspensions. We studied GM-CSF production from normal blood T lymphocyte suspensions containing less than 0.1% of monocytes; moreover, human bone marrow samples were also depleted of adherent cells. A colony stimulating activity (CSA) was always found in the 11 healthy subjects studied following Con A stimulation. The colonies were principally of the granulocytic type. These results strongly suggest that normal human T cells have the capacity to produce CSA.