Objective: To study the effect of IFN-alpha on the expressions of perforin and granzymes in IL-2-activated-lymphocytes.
Methods: NK and LAK activities were assayed by 4 hour standard 51Cr release test, the activity of perforin was detected by hemolysis method, expression of granzyme B was measured by ABC immunohistological method, expression of granzyme A was measured by BLT method.
Results: IFN-alpha significantly augmented the activities of NK and LAK in IL-2 activated peripheral blood lymphocytes (PBL) after 1 day culture. Perforin activity in lymphocytes was increased after 1 day exposure to IL-2 or IFN-alpha, and was enhanced when exposed to the combination of IL-2 and IFN-alpha. After 3 day culture, the perforin activity remained high in lymphocytes activated by IL-2 alone or in combination with IFN-alpha, while declined to control level in IFN-alpha exposed group. IL-2 and IFN-alpha alone or in combination had no effect on expression of granzyme A and B.
Conclusion: IFN-alpha enhances the cytotoxicity of lymphocytes activated by IL-2. The mechanism might be that IFN-alpha upregulates the perforin expression.