[Surgical stress and CARS: involvement of T cell loss due to apoptosis].

ABSTRACT

The term compensatory anti-inflammatory response syndrome(CARS) is the cytokine antagonist cascade which down-regulates the inflammatory cascade that appeared to contribute to the onset of bacterial infection. CARS represents immunosuppression, in which state reduced numbers of T cells in blood were encountered. Here we have determined whether this T cell loss is a consequence of bacterial antigen-mediated activation-induced cell death(AICD). By flowcytometric analysis, less than 0.3% of freshly isolated T cells from healthy volunteers and patients with severe pneumonia were identified as apoptosis. However, during culture, the rate of apoptosis in peripheral blood T cells from patients was 3.0 + 0.9%, and increased further in the presence of anti-CD3(7.4 + 2.1%) and decreased when IL-2 was added(4.4 + 1.3%). In contrast, there were no changes observed in healthy volunteers on addition of anti-CD3. Further, anti-CD3 significantly increased susceptibility to apoptosis of CD45RO+ T cells, but not CD45RA+ T cells from patients. Collectively, these findings demonstrated that bacteria-reactive T cells were more susceptible to AICD, and AICD of CD45RO+ T cells, therefore, provides an explanation for the loss of bacteria-reactive T cells during CARS.