Suppression of T-lymphocyte cytotoxicity following exposure to sinusoidally amplitude-modulated fields.
Significant inhibition of allogeneic cytotoxicity of the target cell MPC-11 by the murine cytotoxic T-lymphocyte line CTLL-1 was observed when the 4-h cytotoxicity assay was conducted in the presence of a 450-MHz field sinusoidally amplitude-modulated at 60 Hz. Exposure of the effector cells to the field prior to adding them to the target cells in the cytolytic assay resulted in a similar inhibition, suggesting a direct interaction of the field with the cytolytic T lymphocyte. The inhibition was preferentially expressed during the early allogeneic recognition phase. Field-exposed cytolytic cells recovered their full cytolytic capacity in 12.5 h. A differential susceptibility was observed with modulation frequencies from 0 to 100 Hz. Peak suppression occurred at 60 Hz modulation, with progressively smaller effects at 40, 16, and 3 Hz. The unmodulated carrier wave did not affect the cytotoxicity. Effects with 80- and 100-Hz modulation were smaller than at 60 Hz. These results demonstrate an inhibitory but recoverable effect by certain amplitude modulations of weak nonionizing radiation upon the cell-mediated cytolytic immune response.
D000818:Animals; D002460:Cell Line; D003602:Cytotoxicity, Immunologic / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D007111:Immunity, Cellular / Q000528:radiation effects*; D051379:Mice; D011840:Radiation, Nonionizing; D051381:Rats; D013602:T-Lymphocytes, Cytotoxic / Q000528:radiation effects*; D013997:Time Factors