Microarray analysis of the differential effects of open and laparoscopic surgery on murine splenic T-cells

Background. Surgical trauma depresses cell-mediated immunity of a duration and magnitude proportional to the degree of injury. However, the cellular mechanism underlying this effect is poorly understood. Microarrays were used to survey gene expression in murine splenic T-cells after pneumoperitoneum and laparotomy. Methods. C3H/HeJ mice were assigned randomly to undergo anesthesia alone, sham laparotomy, or CO₂ pneumoperitoneum and sacrificed 12 or 24 hours later. RNA was isolated from purified splenic T-cells and hybridized to Affymetrix oligonucleotide microarrays. Results. Relative to anesthesia, 116 genes after pneumoperitoneum and 398 genes after laparotomy showed a ≥2-fold change in expression at 12 hours. One hundred thirty-two genes after pneumoperitoneum and 157 genes after laparotomy met those criteria at 24 hours. Comparing surgical modalities, 177 genes were increased and 15 decreased ≥2-fold after laparotomy relative to pneumoperitoneum at 12 hours, compared with 44 and 5 genes respectively at 24 hours. Expression changes for 8 genes were validated by quantitative real-time polymerase chain reaction. Conclusions. Laparotomy and pneumoperitoneum alter splenic T-cell gene expression, with the most extensive changes occurring 12 hours after laparotomy. This study is one of the first comprehensive genomic studies of the molecular effects of surgical manipulation on immune function. The genes identified are potential targets for modulating the immune response to surgery.