title: [Role of CD44 in monocyte transmigration across Cryptococcus neoformans-infected blood-brain barrier in vitro].
abstract: OBJECTIVE
  To explore the role of CD44 in monocyte adhesion to human brain microvascular endothelial cells (HBMECs) and monocyte migration across an in vitro model of blood-brain barrier (BBB) infected by Cryptococcus neoformans (Cn).
  
  
  METHODS
  An in vitro blood-brain barrier model was constructed using a transwell chamber covered with a HBMEC monolayer. The wild-type strain of Cn B4500FO2, TYCC645#32 strain with CPS1 gene deletion and PCIP strain with CPS1 complementation were chosen to infect the monolayer HBMECs. THP-1 cells were added to the upper chamber of transwell, and the relative migration rate was determined by counting the number of the cells entering the lower chambers. The inhibitory effects of anti-CD44 monoclonal antibody and the CD44 inhibitor bikunin were examined on THP-1 binding to and migration across HBMECs.
  
  
  RESULTS
  Cn infection of the HBMECs caused markedly enhanced THP-1 cell adhesion and migration across the monolyers (P<0.01) dependent on Cn concentration and exposure time. Addition of anti-CD44 monoclonal antibody and bikunin significantly lowered THP-1 adhesion and migration rates in the BBB model with Cn-infected HBMECs (P<0.01) with a dose dependence of the antibody (within 0-1 µg) and inhibitor (within 0-20 nmol/L). Both THP-1 adhesion rate and migration rate were lowered in the BBB model infected with CPS1 gene-deleted Cn but increased in the model infected with the complemented strain compared with those in the wild-type strain-infected model.
  
  
  CONCLUSIONS
  In the in vitro BBB model, CD44 expressed on HBMECs may play an essential role in monocyte adhesion to and migration across the BBB. The capsular hyaluronic acid may mediate Cn-induced monocyte adhesion and migration.
authors.affiliation: Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China. E-mail: zlk8289@qq.com.
authors.forename: Li-Ke
authors.initials: LK
authors.lastname: Zhang
authors.forename: Jia-Wen
authors.initials: JW
authors.lastname: Qiu
authors.forename: Xiao-Lu
authors.initials: XL
authors.lastname: Liang
authors.forename: Bao-Yi
authors.initials: BY
authors.lastname: Huang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: DU
authors.forename: Min
authors.initials: M
authors.lastname: Long
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.forename: Sheng-He
authors.initials: SH
authors.lastname: Huang
authors.forename: Hong
authors.initials: H
authors.lastname: Cao
mesh_terms: D001812:Blood-Brain Barrier / Q000276:immunology* / Q000382:microbiology; D001921:Brain / Q000166:cytology / Q000382:microbiology; D002460:Cell Line; D003453:Cryptococcosis / Q000276:immunology*; D003455:Cryptococcus neoformans; D042783:Endothelial Cells / Q000382:microbiology*; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology*
chemical_list: C497483:CD44 protein, human; D018960:Hyaluronan Receptors