Flight factors influence on human lymphocyte radioadaptive response and gamma-interferon production

Interferon-γ (IFN-γ) is a pleiotropic cytokine with antiproliferative and immunomodulatory activities that are crucial for the regulation of immune responses. We examined a group of military pilots. The examinees were divided into 3 subgroups: ground personnel (9 persons, control group), 17 pilots with <1000 h flight time, and 12 pilots with >1000 h flight time. No differences in IFN-α serum content after induction by NDV virus were detected. The quality of reparation is in many respects genetically determined; therefore, we used peripheral blood lymphocytes from pilots for in vitro detection of a radioadaptive response (RAR), which was evaluated by the number of chromosome aberrations. The adaptive response was observed in 7 individuals of the control group (78%), in 10 pilots who had <1000 flight hours (59%), and in 4 pilots having >1000 flight hours (33%). The examined individuals were divided into 2 groups depending on the presence of RAR, and IFN-γ production after radiation was measured. It was shown that at doses 0.05 Gy or 0.5 Gy no differences between groups were detected. Exposure with these doses sequentially in 48 h interval resulted to differently directed changes: lymphocytes of individuals with RAR produced more IFN-γ than before while cells of persons without RAR made it less. The quality of adaptive mechanists evaluated by RAR may be useful for estimation of individual sensitivity to radiation during radiotherapy in oncology and in prediction of professional risk.