Proteomic change of peripheral lymphocytes from scald injury and Pseudomonas aeruginosa sepsis in rabbits

Background: Increased susceptibility to infection has been related to impairment of lymphocyte-regulated immune responses after severe burn. The aim of this study is to identify the differential expression of proteins in circulating lymphocytes from scald injury and Pseudomonas aeruginosa sepsis in rabbits to provide a basis for pathogenesis of burns and sepsis. Methods: Rabbits were subjected to sham burn (A), 30% scald (B), A + bacterial challenge (C) or B + bacterial challenge (D). Bacterial challenge was inflicted by an injection of 2.0 × 108 CFU P. aeruginosa (ATCC27853) in the auricular vein 22 h after the burn procedure. The animals were sacrificed 24 h later. Lymphocytes were isolated, and the differential proteins in the lymphocytes from the experimental and control animals were identified by two-dimensional electrophoresis (2-DE) coupled with matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS), two of which were confirmed by Western blotting. Results: Nineteen differential protein spots were found by 2-DE and 12 spots (11 proteins) were identified. Differential expression of peroxiredoxin and annexin I was validated by Western blotting. Among the identified proteins, the expression levels of cofilin, cyclophilin A, ubiquitin, nucleoside diphosphate kinase, glutamate dehydrogenase and annexin I were down-regulated in group B, excessively down-regulated in group D, but mildly in group C, and peroxiredoxin was up-regulated in groups B and D. Conclusions: Proteome changes in lymphocytes from P. aeruginosa sepsis in the scalded rabbits were revealed, which are related to immune suppression and the pathogenesis of sepsis after scald injury.