Abstract
We have reported previously that millimeter waves (MMWs) protect T-cell functions from the toxic side effects of cyclophosphamide (CPA), an anticancer drug. Since the effect of MMWs has been reported to be mediated by endogenous opioids, the present study was undertaken to investigate the role of endogenous opioids in protection of T-cell functions by MMWs. The effect of MMWs (42.2 GHz, incident power density = 38 mW/cm2) was studied on CPA-induced suppression of cytokine release by T cells in the presence of selective opioid receptor antagonists (ORA). Production of cytokines was measured in CD4 T cells isolated from splenocytes. Treatment of mice with CPA suppressed the formation of Th1 cytokines (TNF-α, IFN-γ, and IL-2), shifting the overall balance toward Th2 (IL-4 and IL-5). MMW irradiation of CPA-treated groups up-regulated the production of Th1 cytokines suppressed by CPA. Treatment of the CPA+MMW group with selective kappa (κ) ORA further potentiated this effect of MMWs on Th1 cytokine production, whereas treatment with μ or δ ORA increased the imbalance of cytokine production in the Th2 direction. These results provide further evidence that endogenous opioids are involved in immunomodulation by MMWs.
Acknowledgements
This research was supported by a grant from the National Center for Complementary and Alternative Medicine, Grant Number: P01 AT002025. The authors are thankful to Dr. Sergey Shulga-Morskoy and Trivikram Gaddapara for their valuable assistance in this study.
Declaration of interest
The authors report no conflict of interest.