Transcriptome and microRNA Signatures of Staphylococcal enterotoxin B Exposure under the Background of Battlefieldlike Stress

Abstract

Leucocytes isolated from pre‐ and post‐training whole blood samples of US Army Ranger Cadets were exposed in vitro to Staphylococcal enterotoxin B (SEB) to analyze SEB‐induced regulation of gene expressions both in the presence and absence of severe‐stress. Gene profiling data showed suppression of immune response genes that are important in pattern recognition receptors, phagocytosis, antigen presentation, chemotaxis and activation of lymphocytes. Immune response genes that were suppressed by the training stressors remained suppressed after SEB exposure. Post‐training leucocytes seemed to be anergic towards SEB. Stress‐regulated microRNAs were identified as potential up‐stream regulators of many transcripts important in chemotaxis, antigen presentation, inflammation, lymphocyte activations and transcription factors important in immune response. Despite the complications due to suppressed immune responses seen at the end of the intensive Army Ranger Training, we have also identified other groups of genes that showed consistent differential expression towards SEB both in pre‐ and post‐training leukocytes. Some of these genes were SEB‐specific and have the potential to serve as diagnostic markers of SEB exposure irrespective of other pathophysiologic conditions.