Populations of thymocytes and peripheral blood leucocytes in leukaemia-bearing mice treated with G-CSF.

The influence of granulocyle-colony stimulating factor (G-CSF) on thymocyte subsets and peripheral blood leucocytes in leukaemia L1210-bearing mice was evaluated. Leukaemia-bearing mice have a markedly reduced L3T4+Lyt2+ thymocyte subpopulation. We observed "correction" of relative values of thymocyte subpopulations induced by treatment of mice with a G-CSF preparation. The suggestion is presented that this could result from liberation of lymphocyte T precursor cells from the bone marrow and increased homing of them into the thymus. The direct or indirect influence of G-CSF on the L3T4+Lyt2+ subpopulation of thymocytes is discussed.