Immunomodulatory properties and attractiveness of volatile organic compounds from irradiated and bystander mice

The paper presents findings of the study of effects and role of volatile organic compounds (VOCs) participating in inter-species communication and the development of non-targeted bystander effect in groups of animals. Immunomodulatory properties and attractiveness of: a) VOCs in irradiated species urine, or b) volatile compounds in bystander mice after exposure to VOCs of irradiated mice were investigated. Reduction in responsiveness was observed both in mice after whole-body irradiation with 1 or 4 Gy and in bystander mice, the effect magnitude depended on radiation dose. At the same time VOCs from irradiated animals and bystander mice exerted immunosuppressive effects and were attractive for intact mice-recipients. Less pronounced functional and regulatory changes were observed in bystander mice. Natural volatiles excreted by intact mice stimulate immune responsiveness in 1Gy-irradiated mice and did not affect 4Gy-irradiated mice, it may be associated with radiation induced damage to lymphoid organs. Unlike irradiated mice, bystander mice are more sensitive to immunostimulation with natural volatiles from intact mice. It is clear that bystander mice are the olfactory communication link between irradiated and intact mice. Biological significance of combining attractiveness and immunomodulatory properties of volatile organic compounds of irradiated and intact animals is examined. Participation of bystander mice in cross olfactory interaction of irradiated and intact mice is expected to enable recovery of postradiation damage to immune responsiveness.