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Study of the early steps of the Hepatitis B Virus life cycle.

Lu X, Block T - Int J Med Sci (2004)

Bottom Line: Lu et al.Therefore, it is possible that to silence the over expressed SPIK and thus to reinstate the activity of indispensable cellular proteases can result in the restoration of the susceptibility of HepG2 cells for HBV infection.The establishing a stable cell line for study of the early steps of HBV life cycle by silencing of SPIK is discussed.

View Article: PubMed Central - PubMed

Affiliation: Jefferson Center for Biomedical Research and Agricultural Medicine, Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson University, Philadelphia, USA.

ABSTRACT
Hepatitis B virus (HBV) is a human pathogen, causing the serious liver disease. Despite considerable advances in the understanding of the natural history of HBV disease, most of the early steps in the virus life cycle remain unclear. Virus attachment to permissive cells, fusion and penetration through cell membranes and subsequent genome release, are largely a mystery. Current knowledge on the early steps of HBV life cycle has mostly come from molecular cloning, expression of individual genes and studies of the infection of duck hepatitis B virus (DHBV) with duck primary duck hepatocytes. However, considering of the difference of the surface protein of HBV and DHBV both in the composition and sequence, the degree to which information from DHBV applies to human HBV attachment and entry may be limited. A major obstacle to the study HBV infection is the lack of a reliable and sensitive in vitro infection system. We have found that the digestion of HBV and woodchuck hepatitis virus (WHBV) by protease V8 led to the infection of HepG2 cell, a cell line generally is refractory for their infection [Lu et al. J Virol. 1996. 70. 2277-2285 . Lu et al. Virus Research. 2001. 73(1): 27-4].. Further studies showed that a serine protease inhibitor Kazal (SPIK) was over expressed in the HepG2 cells. Therefore, it is possible that to silence the over expressed SPIK and thus to reinstate the activity of indispensable cellular proteases can result in the restoration of the susceptibility of HepG2 cells for HBV infection. The establishing a stable cell line for study of the early steps of HBV life cycle by silencing of SPIK is discussed.

No MeSH data available.


Related in: MedlinePlus

The structure of Hepatitis B virus surface proteins and its interesting regions for infection. A. The structure of HBsAg. B. The location of the interesting regions for HBV infection.
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Figure 1: The structure of Hepatitis B virus surface proteins and its interesting regions for infection. A. The structure of HBsAg. B. The location of the interesting regions for HBV infection.

Mentions: The HBV surface protein antigens (HBsAg) are comprised of three carboxyl-co-terminal HBs proteins termed large (LHBs), middle (MHBs) and small (SHBs, also called major) protein 3, 4. LHBs and MHBs also share the highly hydrophobic, repetitive, membrane-spanning S domain. In addition, MHBs has a 55 amino acid region called preS2, LHBs has an additional 109-120 amino acid long region called preS1 (dependent on the viral subtype) in their N-terminus (figure 1 A) 4. Although HBV surface proteins must certainly mediate early steps in the virus life cycle, the precise role for each glycoprotein in the entry and egress of the virus is controversial. We will thus discuss this now.


Study of the early steps of the Hepatitis B Virus life cycle.

Lu X, Block T - Int J Med Sci (2004)

The structure of Hepatitis B virus surface proteins and its interesting regions for infection. A. The structure of HBsAg. B. The location of the interesting regions for HBV infection.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC1074507&req=5

Figure 1: The structure of Hepatitis B virus surface proteins and its interesting regions for infection. A. The structure of HBsAg. B. The location of the interesting regions for HBV infection.
Mentions: The HBV surface protein antigens (HBsAg) are comprised of three carboxyl-co-terminal HBs proteins termed large (LHBs), middle (MHBs) and small (SHBs, also called major) protein 3, 4. LHBs and MHBs also share the highly hydrophobic, repetitive, membrane-spanning S domain. In addition, MHBs has a 55 amino acid region called preS2, LHBs has an additional 109-120 amino acid long region called preS1 (dependent on the viral subtype) in their N-terminus (figure 1 A) 4. Although HBV surface proteins must certainly mediate early steps in the virus life cycle, the precise role for each glycoprotein in the entry and egress of the virus is controversial. We will thus discuss this now.

Bottom Line: Lu et al.Therefore, it is possible that to silence the over expressed SPIK and thus to reinstate the activity of indispensable cellular proteases can result in the restoration of the susceptibility of HepG2 cells for HBV infection.The establishing a stable cell line for study of the early steps of HBV life cycle by silencing of SPIK is discussed.

View Article: PubMed Central - PubMed

Affiliation: Jefferson Center for Biomedical Research and Agricultural Medicine, Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson University, Philadelphia, USA.

ABSTRACT
Hepatitis B virus (HBV) is a human pathogen, causing the serious liver disease. Despite considerable advances in the understanding of the natural history of HBV disease, most of the early steps in the virus life cycle remain unclear. Virus attachment to permissive cells, fusion and penetration through cell membranes and subsequent genome release, are largely a mystery. Current knowledge on the early steps of HBV life cycle has mostly come from molecular cloning, expression of individual genes and studies of the infection of duck hepatitis B virus (DHBV) with duck primary duck hepatocytes. However, considering of the difference of the surface protein of HBV and DHBV both in the composition and sequence, the degree to which information from DHBV applies to human HBV attachment and entry may be limited. A major obstacle to the study HBV infection is the lack of a reliable and sensitive in vitro infection system. We have found that the digestion of HBV and woodchuck hepatitis virus (WHBV) by protease V8 led to the infection of HepG2 cell, a cell line generally is refractory for their infection [Lu et al. J Virol. 1996. 70. 2277-2285 . Lu et al. Virus Research. 2001. 73(1): 27-4].. Further studies showed that a serine protease inhibitor Kazal (SPIK) was over expressed in the HepG2 cells. Therefore, it is possible that to silence the over expressed SPIK and thus to reinstate the activity of indispensable cellular proteases can result in the restoration of the susceptibility of HepG2 cells for HBV infection. The establishing a stable cell line for study of the early steps of HBV life cycle by silencing of SPIK is discussed.

No MeSH data available.


Related in: MedlinePlus