[Stem cell inactivation by allogenic lymphocytes: characteristics of suppressor cells blocking the killer action of syngeneic lymphocytes].

The role of different T lymphocyte subpopulations in the process of allogeneic haemopoietic stem cell inactivation has been studied. The T lymphocyte subpopulations were fractionated in vivo using the homing properties (to the spleen and lymph nodes) plus sensitivity for ALS in vivo (recirculation properties), for thymectomy, for anti-Thy 1 serum in vitro and some others. The results obtained indicate that not only the killer lymphocytes, that provide stem cell inactivation, but also the suppressor cells, that provide inhibition of inactivation, take part in the reaction for allogeneic stem cells. Killer and suppressor cells differ alternatively in some physiological properties and may be separated for further studying.