Mycoplasma-induced in vitro production of interleukin-2 and colony-stimulating activity

Mitogenic doses of membranes purified from Mycoplasma pneumoniae as well as concanavalin A (ConA) were tested for their ability to induce production of interleukin-2 (IL-2) and granulocyte-macrophage colony-stimulating activity (GM-CSA) by human peripheral blood mononuclear cells. Unlike ConA, M. pneumoniae exhibited a significantly lower mitogenic effect and lacked the ability to induce production of IL-2. On the other hand, peak levels of GM-CSA produced in the presence of M. pneumoniae and detected in colony assays of human target marrow cells were approximately 80% of those produced in the presence of ConA. Whereas ConA induced a similar time-related effect upon [3H]thymidine uptake and GM-CSA production, maximal GM-CSA production preceded the peak proliferative response to M. pneumoniae, thereby indicating that M. pneumoniae-induced production of GM-CSA is not quantitatively correlated with DNA synthesis. These findings may contribute to the understanding of the inflammatory manifestations induced by this organism.