GM-CSF and IFN-gamma-induced expression of human leucocyte antigen class II molecules on basophils of umbilical cord blood.

Aim: To determine whether basophils expressed human leucocyte antigen (HLA) class II molecules.

Methods: Basophils in umbilical cord blood were separated and purified with methods of density gradient centrifugation and immunomagnetic microbeads. The isolated basophils were cultured in RPMI-1640 plus 10 % fetal calf serum at 37 in a humidified atmosphere with 5 % CO2 and stimulated with granulocyte-macrophage colony-stimulating factor (GM-CSF) or interferon (IFN)-gamma for 20-60 h. The expression of HLA class II molecules on basophils was measured with fluorescence activated cell sorter (FACS).

Results: The purity of isolated basophils was > or = 83.5 %. After treated with GM-CSF 10 microg/L or IFN-gamma 100 kU/L, the expression of HLA class II molecules became detectable on membranous surface and at a higher level at 20 h, the percentage of expression was 10.2 %+/-2.1 % and 11.3 %+/-1.0 %, respectively.

Conclusion: Basophils possessed the potency of HLA class II molecular expression.