IMMUNOMODULATOR SENSITIVITY OF INNATEIMMUNITY CELLS IN HEALTHY HUMAN SUBJECTS DURING 21-DAY DRY IMMERSION

Sensitivity of natural killers (NK) to the immunosuppressive effect of multipotent mesenchymal stromal cells (MSCs) was investigated in vitroa 21-d dry immersion (DI) study with participation of normal human subjects. DI affected the NK sensitivity to IL-2 and IL-15 stimulation, expression of activating markers HLA-DR, CD314 and CD226, total paracrine activity and production of key anti-inflammatory mediators such as MIP-1b, MIP-1a, RANTES, IL-1a, IL-1b, etc. Prior to DI, the MSCs action on NK showed itself as suppression of late activation. During DI, the MSCs effects grew weak; however, interaction with MSCs smoothed out DI influence on the paracrine activity by stimulation of cytokines secretion. Therefore, DI decreased the NK sensitivity both to the activating stimuli and MSCs.