title: HIV coreceptor and chemokine ligand gene expression in the male urethra and female cervix.
abstract: OBJECTIVE
  Isolates with a tropism for the coreceptor CCR5 are the predominant viral strain transmitted following heterosexual transmission. We have investigated coreceptor expression levels within male and female genital epithelia to assess whether selective transmission can be explained by elevated CCR5 expression within the genital epithelia per se.
  
  
  METHODS
  Individuals attending a local genitourinary medicine unit were recruited, and samples of genital epithelia obtained using either a cytobrush (females) or urethral swab (males). Expression of coreceptor and cell marker mRNAs was then determined by reverse transcription (RT)-PCR.
  
  
  METHODS
  RNA was recovered from the epithelial cell samples then used as templates in competitive quantitative RT-PCR to measure mRNA expression of key chemokines, coreceptors and cell-type markers in the epithelial cell samples. Cell-surface coreceptor expression was also assessed in a sample of patients using fluorescent cell staining.
  
  
  RESULTS
  CXCR4 and CCR3 coreceptors were expressed at significantly higher levels than CCR5 within the female endo- and ectocervix and distal end of the male urethra. Increased levels of cell surface expressed CXCR4 compared to CCR5 was confirmed in samples obtained from the female genital tract by FACS analysis.
  
  
  CONCLUSIONS
  The selective transmission of CCR5-tropic viral variants is unlikely to result simply from differential coreceptor abundance at the genital epithelia.
authors.affiliation: Division of Microbiology and Infectious Diseases Institute of Infection, Immunity and Inflammation, University of Nottingham, UK.
authors.forename: C Patrick
authors.initials: CP
authors.lastname: McClure
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Tighe
authors.forename: R Adrian
authors.initials: RA
authors.lastname: Robins
authors.forename: Deepa
authors.initials: D
authors.lastname: Bansal
authors.forename: Christine A
authors.initials: CA
authors.lastname: Bowman
authors.forename: Margaret
authors.initials: M
authors.lastname: Kingston
authors.forename: Jonathan K
authors.initials: JK
authors.lastname: Ball
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D000328:Adult; D000368:Aged; D002352:Carrier Proteins / Q000378:metabolism; D002584:Cervix Uteri / Q000378:metabolism*; D018946:Chemokine CCL5 / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D054397:Receptors, CCR3; D019713:Receptors, CCR5 / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000378:metabolism*; D019707:Receptors, Chemokine / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014521:Urethra / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C515350:CCR3 protein, human; D002352:Carrier Proteins; D018946:Chemokine CCL5; C493277:MAPKAP1 protein, human; D012333:RNA, Messenger; D054397:Receptors, CCR3; D019713:Receptors, CCR5; D019718:Receptors, CXCR4; D019707:Receptors, Chemokine