title: Increased Toll-like receptor 4 expression on T cells may be a mechanism for enhanced T cell response late after burn injury.
abstract: BACKGROUND
  Burn injury is associated with a dynamic T cell response. We have previously reported an enhanced functional T cell response 14 days after burn injury. Toll-like receptors (TLR), primarily expressed on innate immune cells, have recently been identified on certain T cell subsets, including activated and memory T cells. Our hypothesis is that increased TLR4 expression on memory T cells may be a mechanism for enhanced T cell response 14 days after burn injury.
  
  
  METHODS
  Splenocytes from wild-type C57Bl/6 mice were harvested 14 days after a 20% total body surface area (TBSA) scald burn or sham injury. Splenocytes ex vivo were surface stained either with monoclonal anti-CD3, anti-CD4, anti-CD8, or anti-CD44 antibodies or a two-step biotin-TLR4 monoclonal antibody-streptavidin-FITC surface stain and results analyzed by flow cytometry.
  
  
  RESULTS
  TLR4 expression is successfully detected on CD4 and CD8 T cells. TLR4 expression is significantly (p < 0.05) increased on CD4 T cells and CD8 T cells 14 days after burn injury. There is a significant (p < 0.05) increase in CD44 (memory) CD4 and CD44 (memory) CD8 T cells 14 days after burn injury and this is associated with a significant (p < 0.05) increase of TLR4 expression in both T cell populations.
  
  
  CONCLUSIONS
  This study demonstrates for the first time the potential role of TLR4 expression on memory T cells generated late after burn injury. Although further analysis is required, these data reiterate the importance of adaptive immunity and the complexity of the immune response to burn injury.
authors.affiliation: Department of Surgery, Division of Trauma, Critical Care, and Burns, North Carolina Jaycee Burn Center University of North Carolina, Chapel Hill, North Carolina 27599-7228, USA. bruce.cairns@med.unc.edu
authors.forename: Bruce
authors.initials: B
authors.lastname: Cairns
authors.forename: Robert
authors.initials: R
authors.lastname: Maile
authors.forename: Carie M
authors.initials: CM
authors.lastname: Barnes
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Frelinger
authors.forename: Anthony A
authors.initials: AA
authors.lastname: Meyer
mesh_terms: D000818:Animals; D002056:Burns / Q000235:genetics / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D005260:Female; D018960:Hyaluronan Receptors / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology* / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000276:immunology* / Q000378:metabolism
chemical_list: D018960:Hyaluronan Receptors; D051197:Toll-Like Receptor 4