Selective reduction in CD2 expression on CD2(bright)/CD8⁺ lymphocytes from cynomolgus monkeys (Macaca fascicularis) in response to acute stress

Numerous reports have demonstrated a link between stressful stimuli and immune suppression. However, the cellular mechanisms by which stress impairs immune function are largely unknown. We have examined the effects of an acute stressor on the T cell population, specifically, the number and phenotype of T cells in a nonhuman primate model. In nonstressed adult monkeys, we found differences in the level of expression of CD2 on T cells, revealing two distinct subsets of T cells, CD2(dim) and CD2(bright) cells, with CD2(bright) cells predominately coexpressing CD8. In response to acute stress, we observed a significant loss in the number and percent of CD2(bright)/CD8⁺ cells, with percent of CD2(bright) cells returning to pre-stress values within 24 h.