title: Effects of hepatitis B virus S protein on human sperm function.
abstract: BACKGROUND
  Hepatitis B virus (HBV) has been determined to exist in semen and male germ cells from patients with chronic HBV infection, but no data are yet available on the impact of HBV S protein (HBs), the main component of HBV envelop protein, on the human reproductive system. The purpose of this article was to investigate the effect of HBs on human sperm function.
  
  
  METHODS
  Sperm motility analyses, sperm penetration assays, mitochondrial membrane potential assays, immunolocalizations with confocal microscopy and flow cytometry analyses were performed.
  
  
  RESULTS
  HBs reduced sperm motility in a dose- and time-dependent manner and caused the loss of sperm mitochondrial membrane potential. HBs-HBs monoclonal antibody (MAb) complex apparently aggravated such impairments. After 4 h incubation with HBs at concentrations of 25, 50, 100 microg/ml, the percentages of sperm motility a+b significantly decreased compared with the control (P < 0.01). The fertilization rate and the fertilizing index in HBs-treated group were 40% and 0.57, respectively, which were significantly lower than 90% and 1.6, respectively, in the control (P < 0.01). The asialoglycoprotein receptor (ASGP-R) and HBs were found to localize mainly on the postacrosomal region. Both ASGP-R MAb and asialofoetuin, a high-affinity ligand of ASGP-R, inhibited the HBs-caused loss of sperm motility and mitochondrial membrane potential.
  
  
  CONCLUSIONS
  HBs had adverse effects on human sperm function, and ASGP-R may play a role in the uptake of HBs into sperm cells, as demonstrated by the competitive inhibition of ASGP-R MAb or asialofoetuin, resulting in diminished impairment caused by HBs.
authors.affiliation: Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, People's Republic of China.
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Zhou
authors.forename: Ping-Nan
authors.initials: PN
authors.lastname: Sun
authors.forename: Tian-Hua
authors.initials: TH
authors.lastname: Huang
authors.forename: Qing-Dong
authors.initials: QD
authors.lastname: Xie
authors.forename: Xiang-Jin
authors.initials: XJ
authors.lastname: Kang
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Liu
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D037263:Asialoglycoprotein Receptor / Q000378:metabolism; D001212:Asialoglycoproteins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005306:Fertilization; D060748:Fetuins; D006509:Hepatitis B / Q000378:metabolism*; D006514:Hepatitis B Surface Antigens / Q000378:metabolism / Q000502:physiology*; D006515:Hepatitis B virus / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D008297:Male; D008564:Membrane Potentials; D008928:Mitochondria / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism* / Q000821:virology; D013997:Time Factors; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins; D060748:Fetuins; D006514:Hepatitis B Surface Antigens; D008024:Ligands; D000509:alpha-Fetoproteins; C017029:asialofetuin