title: Relative chemokine and adhesion molecule expression in Mediterranean spotted fever and African tick bite fever.
abstract: OBJECTIVE
  Mediterranean spotted fever (MSF) caused by Rickettsia conorii (R. conorii) is a potential lethal disease while African tick bite fever (ATBF) caused by Rickettsia africae is a self-limiting flu-like illness. We hypothesized that different inflammatory potential in endothelial cells could contribute to the different clinical features in these rickettsioses.
  
  
  METHODS
  We analyzed the effect of heat-inactivated R. africae and R. conorii on the mRNA and protein levels of monocyte chemoattractant protein (MCP)-1, interleukin (IL)-8 and adhesion molecules in endothelial cells. Serum samples from patients with MSF (n=16) and ATBF (n=15) were collected before and after therapy.
  
  
  RESULTS
  R. conorii induced a marked increase in MCP-1, IL-8, and adhesion molecules in endothelial cells, involving toll-like receptor 4 activation. In contrast, R. africae induced MCP-1 expression, but only modest or no responses were seen on IL-8 and adhesion molecules. Comparable to the in vitro response, levels of IL-8 and adhesion molecules showed no or only a modest increase in ATBF patients while these inflammatory markers were markedly elevated during MSF.
  
  
  CONCLUSIONS
  Our findings suggest a superior inflammatory potential of R. conorii as compared to R. africae in endothelial cells, potentially related to the more severe inflammation in MSF comparing ATBF.
authors.affiliation: Research Institute for Internal Medicine, Rikshospitalet University Hospital, 0027 Oslo, Norway. jan.k.damas@ntnu.no
authors.forename: Jan K
authors.initials: JK
authors.lastname: Damås
authors.forename: Giovanni
authors.initials: G
authors.lastname: Davì
authors.forename: Mogens
authors.initials: M
authors.lastname: Jensenius
authors.forename: Francesca
authors.initials: F
authors.lastname: Santilli
authors.forename: Kari
authors.initials: K
authors.lastname: Otterdal
authors.forename: Thor
authors.initials: T
authors.lastname: Ueland
authors.forename: Trude H
authors.initials: TH
authors.lastname: Flo
authors.forename: Egil
authors.initials: E
authors.lastname: Lien
authors.forename: Terje
authors.initials: T
authors.lastname: Espevik
authors.forename: Stig S
authors.initials: SS
authors.lastname: Frøland
authors.forename: Giustina
authors.initials: G
authors.lastname: Vitale
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Pål
authors.initials: P
authors.lastname: Aukrust
mesh_terms: D000328:Adult; D000818:Animals; D001907:Boutonneuse Fever / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D002478:Cells, Cultured; D018925:Chemokines / Q000096:biosynthesis*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007299:Insect Bites and Stings / Q000150:complications*; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000096:biosynthesis; D012282:Rickettsia Infections / Q000276:immunology*; D016996:Rickettsieae / Q000276:immunology; D013987:Ticks
chemical_list: D015815:Cell Adhesion Molecules; D018925:Chemokines; D012333:RNA, Messenger