Effects of hepatitis B virus S protein on human sperm function.
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.
Zhou
Xiao-Ling
XL
Research Center for Reproductive Medicine, Shantou University Medical College, Shantou 515041, People's Republic of China.
Sun
Ping-Nan
PN
Huang
Tian-Hua
TH
Xie
Qing-Dong
QD
Kang
Xiang-Jin
XJ
Liu
Li-Min
LM
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
D000911:Antibodies, Monoclonal; D037263:Asialoglycoprotein Receptor; D001212:Asialoglycoproteins; D060748:Fetuins; D006514:Hepatitis B Surface Antigens; D008024:Ligands; D000509:alpha-Fetoproteins; C017029:asialofetuin