Association for Academic Surgery The vagus nerve alters the pulmonary dendritic cell response to injury Debra M. Lowry, MD, Koji Morishita, MD, Brian P. Eliceiri, PhD, Vishal Bansal, MD, Raul Coimbra, MD, PhD, and Todd W. Costantini, MD* Division of Trauma, Surgical Critical Care, and Burns, Department of Surgery, University of California, San Diego Health Sciences, San Diego, California article info Article history: Received 6 March 2014 Received in revised form 29 May 2014 Accepted 4 June 2014 Available online 11 June 2014 Keywords: Burn Organ/tissue injury Sepsis/inflammatory response Acute lung injury Vagal nerve stimulation abstract Background: We have shown previously that vagal nerve stimulation (VNS) protects against burn-induced acute lung injury (ALI). Although the mobilization and activation of immune cells is central to tissue injury caused by the systemic inflammatory response, the specific inflammatory cell populations that are modulated by VNS have yet to be fully defined. The purpose of this study was to assess whether VNS alters inflammatory cell recruitment to the lung after severe burn injury. Materials and methods: Male C57BL/6 mice were subjected to 30% total body surface area steam burn with and without electrical stimulation of the right cervical vagus nerve. The relative levels of pulmonary dendritic cells (DC) and macrophages were compared at 4 h versus 24 h after burn injury. Lung tissue injury was characterized by histology to assess changes in lung architecture, and measure the protein levels of interleukin 6 and trans- forming growth factor-b1. Results: Severe burn caused an increase in pulmonary DC recruitment at 4 h after injury that persisted at 24 h after severe burn, whereas there was no change in the number of pulmonary macrophages. In contrast, VNS limited the burn-induced recruitment of pul- monary DC. VNS prevented histologic lung injury and attenuated the release of interleukin 6 and transforming growth factor-b1 in the lung after burn injury. Conclusions: VNS is an effective method to limit pulmonary DC recruitment to the lung and prevent ALI after burn injury. Identifying strategies to limit inflammatory cell recruitment to the lung may have clinical utility in preventing ALI in severely burned patients. ª 2014 Elsevier Inc. All rights reserved. 1. Introduction Severe injury such as trauma or burn is often associated with a systemic inflammatory response that results in tissue injury and multiorgan dysfunction. Acute lung injury (ALI) is a common site of distant organ injury that affects severely injured patients and can progress to acute respiratory distress syndrome (ARDS). ARDS develops in 6.5%e14.3% of severely burned patients leading to prolonged mechanical ventilation, longer intensive care unit, and hospital stays, This study was presented as an oral quick shot presentation at the ninth annual Academic Surgical Congress Meeting, February 4, 2014, San Diego, CA. * Corresponding author. Division of Trauma, Surgical Critical Care and Burns, Department of Surgery, University of California, San Diego Health Sciences, 200 W. Arbor Drive, #8896, San Diego, CA 92103 8896. Tel.: þ1 (619) 543 7200; fax: þ1 (619) 543 7202. E-mail address: tcostantini@ucsd.edu (T.W. Costantini). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.JournalofSurgicalResearch.com journal of surgical research 192 (2014) 12 e18 0022-4804/$ e see front matter ª 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jss.2014.06.012