Effect of gamma interferon on the expression of class I MHC antigens on fresh leukemic cells and their susceptibility to lysis by lymphokine activated killer cells.

ABSTRACT

Relationship between MHC class I antigen expression on PBLs from leukemia patients and their susceptibility to lysis by LAK cells was investigated. LAK cells induced small yet significant lysis of leukemic cells. In nine out of 14 cases studied, treatment with Interferon gamma (200 U/ml for 48 hours) resulted in a decrease in the LAK susceptibility of leukemic cells. In six of these cases, there was a concomitant increase in the expression of class I MHC antigen expression. In three samples, the increase in MHC class I antigen expression was not accompanied by a decrease in LAK susceptibility. IFN treatment had no effect on the binding of leukemic cells to LAK effector cells.