Effects of Acute Psychological Stress on Virus-Specific and Skin-Homing T Cells

Aims: We have recently shown that acute psychological stress specifically leads to a redistribution of naive and different subtypes of memory T cells. In this scenario, the stressor causes a relocation of less differentiated T cells into lymphatic tissue in order to encounter antigen, while antigen-experienced effector-type T cells are mobilized into the peripheral blood in order to, in case of local inflammation, home to different peripheral tissues. In our current study we investigated the consequences of this T cell redistribution for effector T cells mediating skin-related immune responses and anti-viral defense. Methods: We performed a FACS analysis of peripheral T cells in 20 test subjects undergoing a short laboratory mental stressor. Results: Exposure to an acute laboratory stressor caused a prolonged and highly significant decrease of potentially skin-homing CD4+ and CD8+ T cells expressing CLA in the peripheral blood. Furthermore, the stressor led to an increase in peripheral numbers of EBV-, CMV- and influenza-specific CD8+ T cells in the majority of our test subjects. Conclusions: Our findings suggest that acute psychological stress might lead to an increased anti-viral immune defense mediated by human T cells. We suggest that this reaction represents an evolutionary conserved response preparing the organism for a potentially threatening event. On the other hand, acute psychological stress leads to a decrease of skin-homing T cells in the peripheral blood. We suggest, as has been indicated by animal studies, that these T cells relocate into the skin as a first line of defense against an attack from „outside“ the organism. However a local enrichment of these effector type T cells within the skin might also lead to an exarcerbation of pre-oxiating inflammatory conditions, i.e. atopic dermatitis.