Transcriptome characterization of immune suppression from battlefield-like stress

Transcriptome alterations of leukocytes from soldiers who underwent eight-weeks of Army Ranger training (RASP, Ranger Assessment and Selection Program) were analyzed to evaluate impacts of battlefield-like stress on the immune response. About 1,400 transcripts were differentially expressed between pre- and post-RASP leukocytes. Upon functional analysis, immune response was the most enriched biological process, and most of the transcripts associated with the immune response were down-regulated. Microbial pattern recognition, chemotaxis, antigen presentation, and T-cell activation were among the most down-regulated immune processes. Post-RASP leukocytes exposed ex vivo to Staphylococcal enterotoxin B (SEB) showed a markedly impaired immune response to this superantigen compared to pre-RASP leukocytes, consistent with suppression of the immune response revealed by transcriptome analyses. A total of 20 subjects were included in the pre- and post-RASP study. The microarray was done using two chanel custom arrays consisting of about 9000 probes.