Involvement of phosphatidylserine and non-phospholipid components of the hepatitis B virus envelope in human Annexin V binding and in HBV infection in vitro

1999 ◽  
Vol 31 (5) ◽  
pp. 783-790 ◽  
Author(s):  
Sandra De Meyer ◽  
Zuojiong Gong ◽  
Erik Depla ◽  
Geert Maertens ◽  
Sing Hiem Yap
Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 754
Author(s):  
Jisu Hong ◽  
Youngjin Choi ◽  
Yoonjoo Choi ◽  
Jiwoo Lee ◽  
Hyo Jeong Hong

Hepatitis B virus (HBV) is a global health burden that causes acute and chronic hepatitis. To develop an HBV-neutralizing antibody that effectively prevents HBV infection, we previously generated a human anti-preS1 monoclonal antibody (1A8) that binds to genotypes A–D and validated its HBV-neutralizing activity in vitro. In the present study, we aimed to determine the fine epitope and paratope of 1A8 to understand the mechanism of HBV neutralization. We performed alanine-scanning mutagenesis on the preS1 (aa 19–34, genotype C) and the heavy (HCDR) and light (LCDR) chain complementarity-determining regions. The 1A8 recognized the three residues (Leu22, Gly23, and Phe25) within the highly conserved receptor-binding motif (NPLGFFP) of the preS1, while four CDR residues of 1A8 were critical in antigen binding. Structural analysis of the epitope–paratope interaction by molecular modeling revealed that Leu100 in the HCDR3, Ala50 in the HCDR2, and Tyr96 in the LCDR3 closely interacted with Leu22, Gly23, and Phe25 of the preS1. Additionally, we found that 1A8 also binds to the receptor-binding motif (NPLGFLP) of infrequently occurring HBV. The results suggest that 1A8 may broadly and effectively block HBV entry and thus have potential as a promising candidate for the prevention and treatment of HBV infection.


Author(s):  
Kemal Fariz Kalista ◽  
Maryati Surya ◽  
Silmi Mariya ◽  
Diah Iskandriati ◽  
Irsan Hasan ◽  
...  

Background: Hepatitis B virus (HBV) infection is still one of the biggest health problems in the world, which could lead to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Treatment for HBV infection has not yet achieved a functional cure. More studies are needed to investigate human HBV (HuHBV), but the scarcity of animal models for HuHBV infection became a barrier. Recently, many studies have shown that Tupaia are suitable for the study of HuHBV. The purpose of this study was to develop a primary tupaia hepatocyte (PTH) culture from T. javanica, a species of Tupaia found in Indonesia, and to prove that HuHBV can replicate in the PTH.Method: In vitro experimental study using PTH isolated from five wild adult T. javanica in Primate Research Center, IPB University. HuHBV was taken from humans with HBsAg and HBV-DNA (+). PTH cells then were infected with HuHBV after reaching 80% confluence. Observation on PTH cells was done everyday for 20 days. Qualitative and quantitative HBsAg were measured using a CMIA while HBV-DNA and cccDNA were measured by RT-PCR.Results: A cytopathic effect was seen on day post infection (DPI)-16. HBsAg and HBV-DNA were detected from DPI-2 until DPI-18, with HBV-DNA level peaked on DPI-12. cccDNA concentration was fluctuating from DPI-2 until DPI-20 with highest level on DPI-16.Conclusion: HuHBV could infect and replicate in PTH from T. javanica can be infected with HuHBV and HuHBV can replicate in the PTH from T. javanica.


2020 ◽  
Author(s):  
zhaoqing zeng ◽  
yuyang li ◽  
jinhong yu ◽  
jing liu ◽  
shijun chen ◽  
...  

Abstract Aims & background: IFI16 plays an important role in innate immunity against invasive microbial infection by sensing double-stranded DNA viruses due to caspase-1-dependent inflammasome activation and subsequent maturation and secretion of IL-1β. However, the role of IFI16 in regulating the immune response to viruses in vivo and in vitro, especially in sensing hepatitis B virus (HBV), has not been examined. We hypothesized that the expression of IFI16 increases corresponding to HBV-mediated inflammation in patients with hepatitis B virus associated glomerulonephritis (HBV-GN), a condition which activates inflammatory mechanisms and causes renal damage. To test this hypothesis, we therefore analyzed the expression of IFI16 and inflammatory factors in HBV-GN tissues and cell lines relative to the inflammatory response to HBV infection. Methods: A total 75 patients with chronic nephritis(CN) including 50 with HBV-GN and 25 with chronic glomerulonephritis (CCN) involved in this study. Each CN patient received renal biopsy, and immunohistochemistry(IHC) was used to detect the expression of IFI16 and inflammatory factors Caspase-1 and IL-1β in the biopsy specimens. Following IFI16 was transfected in HBV-infected and HBV-uninfected human glomerular mesangial (HGM) cell line and HEK-293T cell line, expression of Caspase-1 and IL-1β were detected by Western blot and qRT- PCR. Results: IFI16 expression in HBV-GN biopsies (80.0%) was significantly higher than in CGN (24.0%) and positively correlated with caspase-1 and IL-1𝛽 expression in HBV-GN. In vitro, over expression IFI16 increased caspase-1 and IL-1𝛽 expression in HBV -infected HGM and HEK-293T. Conclusions: The elevation of IFI16 during HBV infection or replication may contribute to renal damage due to inflammation, thus providing a putative therapeutic target and a new avenue for researching the pathogenesis of HBV-GN.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xianzhong Jiang ◽  
Bin Zhang ◽  
Junsheng Zhao ◽  
Yi Xu ◽  
Haijun Han ◽  
...  

Abstract Single nucleotide polymorphisms (SNPs) and genes associated with susceptibility to hepatitis B virus (HBV) infection that have been identified by genome-wide association studies explain only a limited portion of the known heritability, indicating more genetic variants remain to be discovered. In this study, we adopted a new research strategy to identify more susceptibility genes and variants for HBV infection. We first performed genetic association analysis of 300 sib-pairs and 3,087 case-control samples, which revealed that 36 SNPs located in 31 genes showed nominal associations with HBV infection in both samples. Of these genes, we selected SEC24D for further molecular analysis according to the following two main lines of evidence. First, a time course analysis of the expression profiles from HBV-infected primary human hepatocytes (PHH) demonstrated that SEC24D expression increased markedly as time passed after HBV infection (P = 4.0 × 10−4). Second, SNP rs76459466 in SEC24D was adversely associated with HBV risk (ORmeta = 0.82; Pmeta = 0.002), which again indicated that SEC24D represents a novel susceptibility gene for HBV infection. Moreover, SEC24D appeared to be protective against HBV infection in vitro. Consistently, we found that SEC24D expression was significantly enhanced in non-infected liver tissues (P = 0.002). We conclude that SEC24D is a novel candidate gene linked to susceptibility to HBV infection.


2006 ◽  
Vol 80 (24) ◽  
pp. 11935-11945 ◽  
Author(s):  
Matthieu Blanchet ◽  
Camille Sureau

ABSTRACT The hepatitis B virus (HBV) envelope proteins have the ability to assemble three types of viral particles, (i) the empty subviral particles (SVPs), (ii) the mature HBV virions, and (iii) the hepatitis delta virus (HDV) particles, in cells that are coinfected with HBV and HDV. To gain insight into the function of the HBV envelope proteins in morphogenesis of HBV or HDV virions, we have investigated subdomains of the envelope proteins that have been shown or predicted to lie at the cytosolic face of the endoplasmic reticulum membrane during synthesis, a position prone to interaction with the inner core structure. These domains, referred to here as cytosolic loops I and II (CYL-I and -II, respectively), were subjected to mutagenesis. The mutations were introduced in the three HBV envelope proteins, designated small, middle, and large (S-HBsAg, M-HBsAg, and L-HBsAg, respectively). The mutants were expressed in HuH-7 cells to evaluate their capacity for self-assembly and formation of HBV or HDV virions when HBV nucleocapsid or HDV ribonucleoprotein, respectively, was provided. We found that SVP-competent CYL-I mutations between positions 23 and 78 of the S domain were permissive to HBV or HDV virion assembly. One mutation (P29A) was permissive for synthesis of the S- and M-HBsAg but adversely affected the synthesis or stability of L-HBsAg, thereby preventing the assembly of HBV virions. Furthermore, using an in vitro infection assay based on the HepaRG cells and the HDV model, we have shown that particles coated with envelope proteins bearing CYL-I mutations were fully infectious, hence indicating the absence of an infectivity determinant in this region. Finally, we demonstrated that the tryptophan residues at positions 196, 199, and 201 in CYL-II, which were shown to exert a matrix function for assembly of HDV particles (I. Komla-Soukha and C. Sureau, J. Virol. 80:4648-4655, 2006), were dispensable for both assembly and infectivity of HBV virions.


2003 ◽  
Vol 77 (9) ◽  
pp. 5519-5523 ◽  
Author(s):  
Camille Sureau ◽  
Chantal Fournier-Wirth ◽  
Patrick Maurel

ABSTRACT Hepatitis delta virus (HDV) particles are coated with the large (L), middle (M), and small (S) hepatitis B virus envelope proteins. In the present study, we constructed glycosylation-defective envelope protein mutants and evaluated their capacity to assist in the maturation of infectious HDV in vitro. We observed that the removal of N-linked carbohydrates on the S, M, and L proteins was tolerated for the assembly of subviral hepatitis B virus (HBV) particles but was partially inhibitory for the formation of HDV virions. However, when assayed on primary cultures of human hepatocytes, virions coated with S, M, and L proteins lacking N-linked glycans were infectious. Furthermore, in the absence of M, HDV particles coated with nonglycosylated S and L proteins retained infectivity. These results indicate that carbohydrates on the HBV envelope proteins are not essential for the in vitro infectivity of HDV.


2021 ◽  
Author(s):  
Li Liu ◽  
Xiuhua Zhao ◽  
Shuangshuang Xie ◽  
Cheng Li ◽  
Yue Guo ◽  
...  

Abstract Aims & backgroundIFI16 plays an important role in innate immunity against invasive microbial infection by sensing double-stranded DNA viruses due to caspase-1-dependent inflammasome activation and subsequent maturation and secretion of IL-1β. However, the role of IFI16 in regulating the immune response to viruses in Hepatitis B Virus-Associated Glomerulonephritis(HBV-GN), especially in sensing the hepatitis B virus (HBV), has not been determined. In this study,, we investigated the inflammatory role of IFI16 in HBV-GN.MethodsA total of 75 kidney tissues including 50 HBV-GN and 25 chronic glomerulonephritis (CCN) were collected to determine expression of IFI16, Caspase-1, and IL-1𝛽 by immunohistochemistry (IHC), and then the correlation between them was analyzed. In vitro, the overexpression or knockdown of IFI16 in regulating the immune response to HBV infection in the human glomerular mesangial (HGM) cell line and HEK-293T cell line. Quantitative Real-time PCR and western blotting were used to determine the expression of IFI16, Caspase-1 and IL-1β. The role effect of IFI16 in vivo was further investigated.ResultsIFI16 expression in HBV-GN biopsies (80.0%) was significantly higher than in CGN (24.0%) and was positively correlated with caspase-1 and IL-1𝛽 expression in HBV-GN. In vitro, over expression of IFI16 increased caspase-1 and IL-1𝛽 expression in HBV-infected HGM and HEK-293T cell lines, whereas knockdown of IFI16 mRNA by siRNA resulted in downregulation of the caspase-1 and IL-1𝛽 expression in both cell lines.ConclusionsThe elevation of IFI16 during HBV infection or replication may contribute to renal damage due to inflammation, thus providing a putative therapeutic target and a new avenue for studying the pathogenesis of HBV-GN.


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