Suppressive effect of human interferon on memory cells primed to different HLA-D specificities

In primed lymphocyte typing (PLT), lymphocytes will respond with accelerated kinetics and increased magnitude when confronted with the same stimulating cells in a secondary MLC, or with other cells sharing their HLA-D determinants. Human lymphoblastoid interferon (HIF) caused a dose-dependent inhibition of 3H-TdR uptake in PLT cultures. Flow cytometry cell cycle analysis of HIF-treated PLT cells has shown reduced number of cells in S phase with a concomitant rise in the number of cells in the G0-G1 phase; this suggests that interferon has blocked the progression of PLT cells into S phase. Also HIF inhibited cells proliferation in response to a third party sharing a common determinant, Dw5 with the primary stimulator cell. HIF may be a potential immuno-suppressive agent for transplantation. The well-known antiviral effect of HIF might also prove useful in prevention opportunistic viral infection during transplantation.