Relationships between burn size, immunosuppression, and macrophage hyperactivity in a murine model of thermal injury

Michelle Alexander1, Irshad H Chaudry, Martin G Schwacha

  • 1Department of Surgery, University of Alabama at Birmingham, G094 Volker Hall, 1670 University Blvd., Birmingham, AL 35294-0019, USA.

Cellular Immunology
|April 30, 2003
PubMed

Burn injury induces immune dysfunction and alters numerous physiological parameters. While clinical studies indicate that burn injury size profoundly impacts patient immune status, only limited experimental studies have systematically addressed its impact on immune functional parameters. In the present study, mice were subjected to burn injuries of varying sizes and splenic immune cells (splenocytes and macrophages) were isolated 7 days thereafter. Burn injury suppressed splenic T-cell proliferation in an injury size-dependent manner that correlated with the release of the immunosuppressive mediators PGE(2) and nitric oxide. In addition, a shift towards an immunosuppressive Th-2 cytokine profile and a hyperactive macrophage phenotype (increased release of inflammatory mediators) was observed post-injury, however, this effect was in part independent of burn size. Thus, unlike patient survival data, burn injury-induced changes in immune function do not necessarily correlate with the size of the injury.