title: Participation of granulocytes in in vitro regulation of suppressor cell activity.
abstract: In in vitro investigations factors were found in the specific granules of peripheral blood granulocytes of healthy subjects, which inhibited the induction of non-specific suppressor cells (S cells) in doses of 10 and 25 micrograms per 1 ml (1 X 10(6) cells) of 48-hour culture. In two-stage culture the S cells decreased the proliferation of responder lymphocytes (R cells) stimulated with Con A and pokeweed mitogen (PWM) by 56.8 +/- 2.4 per cent and 19.7 +/- 5.9 per cent, respectively. The above mentioned granulocyte factors (GF) caused a statistically significant reduction of S cell activity (p less than 0.01) or even its complete inhibition, depending on the mitogen stimulating the R cells (this inhibition was greater after stimulation of lymphocytes by PWM). Inactivation of proteolytic enzymes with di-isopropylfluorophosphate (DFP) failed to decrease the biological activity of these factors, which are released from the granulocytes after 30 minutes of granulocyte adherence to Petri dishes. Lymphocyte culture in a medium containing the supernatant from a culture of 1 X 10(6)/ml adherent granulocytes demonstrated increased proliferation of these lymphocytes and reduced activity of suppressor cells. On the other hand, an increase in the number of adherent granulocytes to 5 X 10(6)/ml of the medium produced a reverse effect: impairment of the proliferative response and enhancement of the activity of S cells.
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D003470:Culture Media; D006098:Granulocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2 / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008938:Mitosis; D011043:Pokeweed Mitogens / Q000494:pharmacology; D013268:Stimulation, Chemical; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000502:physiology*
chemical_list: D003470:Culture Media; D007376:Interleukin-2; D011043:Pokeweed Mitogens; D003208:Concanavalin A