Immunotropic Effects in Cultured Human Blood Mononuclear Cells Pre‐exposed to Low‐Level 1300 MHz Pulse‐Modulated Microwave Field

Abstract

The samples of mononuclear cells isolated from peripheral blood of healthy donors (N = 16) were exposed to 1300 MHz pulse‐modulated microwaves at 330 pps with 5 μs pulse width. The samples were exposed in an anechoic chamber at the average value of power density of S = 10 W/m² (1 mW/cm²). The average specific absorption rate (SAR) was measured in rectangular waveguide and the value of SAR = 0.18 W/kg was recorded. Subsequently, the exposed and control cells were assessed in the microculture system for several parameters characterizing their proliferative and immunoregulatory properties. Although the irradiation decreased the spontaneous incorporation of 3H‐thymidine, the proliferative response of lymphocytes to phytohemagglutinin (PHA) and to Con A as well as the T‐cell suppressive activity (SAT index) and the saturation of IL‐2 receptors did not change. Nevertheless, the lymphocyte production of interleukin (IL)‐10 increased (P < .001) and the concentration of IFNγ remained unchanged or slightly decreased in the culture supernatants. Concomitantly, the microwave irradiation modulated the monokine production by monocytes. The production of IL‐1β increased significantly (P < .01), the concentration of its antagonist (IL‐1ra) dropped by half (P < .01) and the tumor necrosis factor (TNF‐α) concentration remained unchanged. These changes of monokine proportion (IL‐1β vs. IL‐1ra) resulted in significant increase of the value of LM index (P < .01), which reflects the activation of monocyte immunogenic function. The results indicate that pulse‐modulated microwaves represent the potential of immunotropic influence, stimulating preferentially the immunogenic and proinflammatory activity of monocytes at relatively low levels of exposure.

• Microwaves
• Immune system
• Immunotropic effects
• Monokines
• Lymphocytes