title: Platelet factor 4 is highly upregulated in dendritic cells after severe trauma.
abstract: Dendritic cells (DCs) represent an important linkage between the innate and adaptive immune system and express proinflammatory transcriptomic products early after trauma. The use of a genomic approach recently revealed that platelet factor 4 (PF4) is significantly upregulated in DCs in patients after multiple trauma. However, knowledge about subsequent PF4 alteration and its potential clinical relevance in the context of multiple trauma is still limited. We used quantitative reverse transcription-polymerase chain reaction to analyze PF4 expression in both myeloid DCs (MDCs) and plasmocytoid DCs (PDCs) isolated from 10 patients after multiple trauma. Intracellular PF4 as well as HLA-DR expression were detected by flow cytometry. Furthermore, DCs and peripheral blood mononuclear cells were incubated on a monolayer of human umbilical endothelial cells and their adhesion properties were analyzed. The ratio of the DC subtypes (MDC and PDC) was assessed by flow cytometry. PF4 expression significantly increased on d 1 and d 2 as measured by reverse transcription-polymerase chain reaction. Intracellular PF4 content in MDCs and PDCs was significantly elevated in trauma patients compared with healthy controls. In addition, the surface antigen HLA-DR on MDCs was significantly elevated on d 1 and d 4 after trauma in patients compared with controls. However, cell adhesion of DCs did not show any significant differences between patients and controls. PF4 concentration in MDCs and PDCs significantly correlated with the injury severity score. These results confirm an early and subsequent posttraumatic activation of PF4 in DCs. PF4 also participates in the posttraumatic activation of DCs in relation to injury severity, a role that might be preferably based on the modification of receptor expression, whereas adhesion properties are largely unaffected.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, Johann Wolfgang Goethe-University, Frankfurt, Germany. Marcus.Maier@kgu.de
authors.forename: Marcus
authors.initials: M
authors.lastname: Maier
authors.forename: Emanuel V
authors.initials: EV
authors.lastname: Geiger
authors.forename: Dirk
authors.initials: D
authors.lastname: Henrich
authors.forename: Carolyn
authors.initials: C
authors.lastname: Bendt
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wutzler
authors.forename: Mark
authors.initials: M
authors.lastname: Lehnert
authors.forename: Ingo
authors.initials: I
authors.lastname: Marzi
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002448:Cell Adhesion; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006684:HLA-DR Antigens / Q000097:blood / Q000378:metabolism; D006801:Humans; D007963:Leukocytes, Mononuclear; D008297:Male; D010978:Platelet Factor 4 / Q000235:genetics / Q000378:metabolism*; D018709:Statistics, Nonparametric; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015599:Trauma Severity Indices; D015854:Up-Regulation / Q000187:drug effects; D014947:Wounds and Injuries / Q000235:genetics / Q000378:metabolism*
chemical_list: D006684:HLA-DR Antigens; D010978:Platelet Factor 4; D013755:Tetradecanoylphorbol Acetate