Sequential administration of virus-like particle-based nanomedicine to elicit enhanced tumor chemotherapy.

Protein cages have played a long-standing role in biomedicine applications, especially in tumor chemotherapy. Among protein cages, virus like particles (VLPs) have received attention for their potential applications in vaccine development and targeted drug delivery. However, most of the existing protein-based platform technologies are plagued with immunological problems that may limit their systemic delivery efficiency as drug carriers. Here, we show that using immune-orthogonal protein cages sequentially and modifying the dominant loop epitope can circumvent adaptive immune responses and enable effective drug delivery using repeated dosing. We genetically modified three different hepadnavirus core protein derived VLPs as delivery vectors for doxorubicin (DOX). These engineered VLPs have similar assembly characteristics, particle sizes, and immunological properties. Our results indicated that there was negligible antibody cross-reactivity in either direction between these three RGD-VLPs in mice that were previously immunized against HBc VLPs. Moreover, the sequential administration of multiple RGD-VLP-based nanomedicine (DOX@RGD-VLPs) could effectively reduce immune clearance and inhibited tumor growth. Hence, this study could provide an attractive protein cage-based platform for therapeutic drug delivery.

[Intervention effects of estradiol on myocardial ischemia- reperfusion injury of rat and its mechanisms].

Objective: To study the effects of estradiol (E2) on alleviating myocardial ischemia/reperfusion(I/R) injury through estrogen receptorß(ERß) mediated extracellular regulated protein kinases(ERK) pathway activation. Methods: Eighty-four adult female SD rats were ovariectomized and randomly divided into control group, NC siRNA adeno-associated virus (AAV) group received sham operation, the myocardial I/R injury model was prepared by ligation of the left anterior descending coronary artery in I/R group, E2+I/R group, NC siRNA AAV+I/R group, NC siRNA AAV+E2+I/R group and ERß-siRNA AAV+E2+I/R group. E2+I/R group, NC siRNA AAV+E2+I/R group and ERß-siRNA AAV+E2+I/R group were treated with E2 0.8 mg/kg by gavage for 60 days before modeling. NC siRNA AAV+I/R group, NC siRNA AAV+E2+I/R group, and ERß-siRNA AAV+E2+I/R group were treated with AAV by caudal vein injection 24 h before modeling. After 120 min of reperfusion, the contents of serum lactate dehydrogenase (LDH), phosphocreatine kinase (CK), phosphocreatine kinase isoenzyme (CK-MB), myocardial infarction area and the expressions of ERß, p-ERK, the contents of tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1 ß), malondialdehyde (MDA) and total antioxidant capacity (T-AOC) in myocardium were measured. Results: The contents of serum LDH, CK, CK-MB, myocardial infarction area and the contents of TNF-α, IL-1 ß, MDA in myocardium of I/R group were higher than those of the control group, the expression levels of ERß and p-ERK and the content of T-AOC were lower than those in the control group (P＜0.05). The contents of serum LDH, CK and CK-MB, myocardial infarction area and the contents of TNF-α, IL-1 ß and MDA in myocardium of E2+I/R group were lower than those of the I/R group, the expression levels of ERß and p-ERK and the content of T-AOC were higher than those of the I/R group(P＜0.05). After knockdown ERß by caudal vein injection of ERß-siRNA AAV, the contents of serum LDH, CK and CK-MB, myocardial infarction area and the contents of TNF-α, IL-1 ß and MDA in myocardium of ERß-siRNA AAV+E2+I/R group were higher than those of NC-siRNA AAV+E2+I/R, the expression levels of ERß and p-ERK and the content of T-AOC were lower than those of NC-siRNA AAV+E2+I/R(P＜0.05). Conclusion: E2 has protective effects on myocardial I / R injury in ovariectomized rats, which are related to the promotion of ERß mediating the activation of ERK pathway, reducing inflammatory and oxidative stress responses.

Dual-Antigen-Loaded Hepatitis B Virus Core Antigen Virus-like Particles Stimulate Efficient Immunotherapy Against Melanoma.

Tumor cells are rich in antigens, which provide a reliable antigen library for the design of personalized vaccines. However, an effective tumor vaccine vector that can efficiently deliver antigens to lymphoid organs to stimulate strong CD8+ cytotoxic T-lymphocyte immune response is still lacking. Here we designed a dual-antigen delivery system based on hepatitis B virus core antigen virus-like particles (HBc VLPs). We first confirmed that different antigen-loaded HBc VLP monomers could be assembled into nanoparticles (hybrid VLPs). Hybrid VLPs could slightly enhance bone marrow-derived dendritic cell maturation in vitro. Strikingly, hybrid VLPs could generate antigen-specific antitumor immunity and innate immunity in vivo which could significantly inhibit tumor growth or metastatic formation in a subcutaneous tumor or lung metastatic tumor model, respectively. Moreover, dual-epitope vaccination generated enhanced T-cell responses that potently inhibited tumor growth and metastatic formation. Together, this study provides a new powerful concept for cancer immunotherapy and suggests a novel design for VLP-based personalized nanomedicine.

Preparation and preliminary evaluation of hepatitis B core antigen virus like nanoparticles loaded with indocyanine green.

BACKGROUND: In recent years, nanotechnology has attracted a plethora of attention due of its ability to effectively diagnose and treat various tumors. Virus-like particles (VLPs) have good biocompatibility, are safe and non-toxic, and have an internal hollow space, and as such they are often used as nano drug carriers. In recent years, it has become one of the hot spots in the field of biopharmaceutical engineering. METHODS: In this study, the tumor-targeting peptide RGD (Arg-Gly-Asp) was genetically inserted into the major immunodominant region (MIR) of the hepatitis B virus core protein (HBc). A series of characterization, including stability and optical properties, were evaluated. A visual diagnosis and analysis of the efficacy against tumor cells were conducted at the cell level and using a live animal model. RESULTS: This study demonstrated that the recombinant HBc-based VLPs could participate in self-assembly of monodispersed nanoparticles with well-defined morphology, and the near-infrared dye indocyanine green (ICG) could be packaged into the VLPs without any chemical modification. Moreover, the HBc-based VLPs could specifically target cancer cells via the interaction with overexpressed integrin αvß3. The treatment with ICG-loaded HBc-based VLPs showed significant inhibition of 4T1 breast cancer cell growth (84.87% tumor growth inhibition). The in vivo imaging experiments demonstrated that the ICG-loaded HBc-based VLPs generated excellent fluorescence in tumor sites in 4T1 breast cancer bearing mice. This provided crucial information on tumor mass location, boundaries, and shape. Moreover, compared to free ICG, the nanosystem showed significantly longer blood circulation time and superior accuracy in targeting the tumor. CONCLUSIONS: The ICG-loaded HBc-based VLPs prepared in this study were of good stability and biocompatibility. It showed strong tumor targeting specificity and tumor visualization. Thus, it is expected to provide a new experimental basis and theoretical support for the integration of VLPs in the clinical diagnosis and treatment of breast cancer.

Bioengineered Nanocage from HBc Protein for Combination Cancer Immunotherapy.

Protein nanocages are promising multifunctional platforms for nanomedicine owing to the ability to decorate their surfaces with multiple functionalities through genetic and/or chemical modification to achieve desired properties for therapeutic and diagnostic purposes. Here, we describe a model antigen (OVA peptide) that was conjugated to the surface of a naturally occurring hepatitis B core protein nanocage (HBc NC) by genetic modification. The engineered OVA-HBc nanocages (OVA-HBc NCs), displaying high density repetitive array of epitopes in a limited space by self-assembling into symmetrical structure, not only can induce bone marrow derived dendritic cells (BMDC) maturation effectively but also can be enriched in the draining lymph nodes. Naïve C57BL/6 mice immunized with OVA-HBc NCs are able to generate significant and specific cytotoxic T lymphocyte (CTL) responses. Moreover, OVA-HBc NCs as a robust nanovaccine can trigger preventive antitumor immunity and significantly delay tumor growth. When combined with a low-dose chemotherapy drug (paclitaxel), OVA-HBc NCs could specifically inhibit progression of an established tumor. Our findings support HBc-based nanocages with modularity and scalability as an attractive nanoplatform for combination cancer immunotherapy.

Improved Stable Indocyanine Green (ICG)-Mediated Cancer Optotheranostics with Naturalized Hepatitis B Core Particles.

In recent years, hepatitis B core protein virus-like particle (HBc VLP) is an impressive biomaterial, which has attracted considerable attention due to favorable properties such as structural stability, high uptake efficiency, and biocompatibility in biomedical applications. Heretofore, only a few attempts have been made to apply it in physical, chemical, and biological therapy for cancer. In this study, a tumor-targeting RGD-HBc VLP is first fabricated through genetic engineering. For image-guided cancer phototherapy, indocyanine green (ICG) is loaded into RGD-HBc VLP via a disassembly/reassembly pathway and electrostatic attraction with high efficiency. The self-assembled stable RGD-HBc VLP significantly improves body retention (fourfold longer), aqueous stability, and target specificity of ICG. Remarkably, these positive reformations promote more accurate and sensitive imaging of U87MG tumor, as well as prolonged tumor destruction in comparison with free ICG. Moreover, the photothermal and photodynamic effect on tumors are quantitatively differentiated by multiple linear regression analysis. Overall, less-potent medicinal ICG can be perfectly rescued by bioengineered HBc VLP to realize enhanced cancer optotheranostics.

Design of Fusion Proteins for Efficient and Soluble Production of Immunogenic Ebola Virus Glycoprotein in Escherichia coli.

The Ebola hemorrhagic fever caused by Ebola virus is an extremely dangerous disease, and effective therapeutic agents are still lacking. Platforms for the efficient production of vaccines are crucial to ensure quick response against an Ebola virus outbreak. Ebola virus glycoprotein (EbolaGP) on the virion surface is responsible for membrane binding and virus entry, thus becoming the key target for vaccine development. However, heterologous expression of this protein still faces engineering challenges such as low production levels and insoluble aggregation. Here, the authors design and compare various fusion strategies, attaching great importance to the solubility-enhancing effect, and tag removal process. It is found that a C-terminal intein-based tag greatly enhances the solubility of EbolaGP and allows one-step chromatographic purification of the untagged EbolaGP through thiol-catalyzed self-cleavage. The purified untagged EbolaGP alone or with Freund's adjuvant are highly immunogenic, as confirmed in a mouse model. Consequently, the present study puts forward a new strategy for the efficient and soluble expression of untagged immunogenic EbolaGP. The intein-based protein fusion approach may be of importance for the large-scale production of Ebola virus subunit vaccine.

Modularized peptides modified HBc virus-like particles for encapsulation and tumor-targeted delivery of doxorubicin.

Virus-mimicking particles have made great contribution to the development of nanomedicine. Herein, several modularized peptides (lipophilic NS5A peptide, 6xHis tag, and tumor-targeting peptide RGD) were genetically inserted into the C-terminus and the major immunodominant loop region (MIR) of hepatitis B core protein (HBc), respectively. This study demonstrated that the recombinant HBc-based VLPs could participate in self-assembly of monodisperse nanoparticles (33.6±3.5nm) with well-defined morphology, and DOX can be packaged into VLNPs without any chemical modification. Moreover, the HBc-based VLPs could specifically target to cancer cells via the interaction with overexpressed integrin αvß3. The treatment with DOX-loaded HBc-based VLPs showed a significant inhibition of tumor growth (90.7% TGI) and less cardiotoxicity in B16F10 tumor-bearing mice models than that with the free DOX. Importantly, the results may offer an easy way to give a variety of ideal functional modulations for VLPs, thereby extending its potential biomedicine applications.

An Adenovirus Vaccine Expressing Ebola Virus Variant Makona Glycoprotein Is Efficacious in Guinea Pigs and Nonhuman Primates.

A licensed vaccine against Ebola virus (EBOV) remains unavailable, despite >11 000 deaths from the 2014-2016 outbreak of EBOV disease in West Africa. Past studies have shown that recombinant vaccine viruses expressing EBOV glycoprotein (GP) are able to protect nonhuman primates (NHPs) from a lethal EBOV challenge. However, these vaccines express the viral GP-based EBOV variants found in Central Africa, which has 97.3% amino acid homology to the Makona variant found in West Africa. Our previous study showed that a recombinant adenovirus serotype 5 (Ad5)-vectored vaccine expressing the Makona EBOV GP (MakGP) was safe and immunogenic during clinical trials in China, but it is unknown whether the vaccine protects against EBOV infection. Here, we demonstrate that guinea pigs immunized with Ad5-MakGP developed robust humoral responses and were protected against exposure to guinea pig-adapted EBOV. Ad5-MakGP also elicited specific B- and T-cell immunity in NHPs and conferred 100% protection when animals were challenged 4 weeks after immunization. These results support further clinical development of this candidate and highlight the utility of Ad5-MakGP as a prophylactic measure in future outbreaks of EBOV disease.

Enhanced mucosal immune responses induced by a combined candidate mucosal vaccine based on Hepatitis A virus and Hepatitis E virus structural proteins linked to tuftsin.

Hepatitis A virus (HAV) and Hepatitis E virus (HEV) are the most common causes of infectious hepatitis. These viruses are spread largely by the fecal-oral route and lead to clinically important disease in developing countries. To evaluate the potential of targeting hepatitis A and E infection simultaneously, a combined mucosal candidate vaccine was developed with the partial open reading frame 2 (ORF2) sequence (aa 368-607) of HEV (HE-ORF2) and partial virus protein 1 (VP1) sequence (aa 1-198) of HAV (HA-VP1), which included the viral neutralization epitopes. Tuftsin is an immunostimulatory peptide which can enhance the immunogenicity of a protein by targeting it to macrophages and dendritic cells. Here, we developed a novel combined protein vaccine by conjugating tuftsin to HE-ORF2 and HA-VP1 and used synthetic CpG oligodeoxynucleotides (ODNs) as the adjuvant. Subsequent experiments in BALB/c mice demonstrated that tuftsin enhanced the serum-specific IgG and IgA antibodies against HEV and HAV at the intestinal, vaginal and pulmonary interface when delivered intranasally. Moreover, mice from the intranasally immunized tuftsin group (HE-ORF2-tuftsin + HA-VP1-tuftsin + CpG) showed higher levels of IFN-γ-secreting splenocytes (Th1 response) and ratio of CD4+/CD8+ T cells than those of the no-tuftsin group (HE-ORF2 + HA-VP1 + CpG). Thus, the tuftsin group generated stronger humoral and cellular immune responses compared with the no-tuftsin group. Moreover, enhanced responses to the combined protein vaccine were obtained by intranasal immunization compared with intramuscular injection. By integrating HE-ORF2, HA-VP1 and tuftsin in a vaccine, this study validated an important concept for further development of a combined mucosal vaccine against hepatitis A and E infection.

Genetic diversity of hepatitis A virus in China: VP3-VP1-2A genes and evidence of quasispecies distribution in the isolates.

Hepatitis A virus (HAV) is the most common cause of infectious hepatitis throughout the world, spread largely by the fecal-oral route. To characterize the genetic diversity of the virus circulating in China where HAV in endemic, we selected the outbreak cases with identical sequences in VP1-2A junction region and compiled a panel of 42 isolates. The VP3-VP1-2A regions of the HAV capsid-coding genes were further sequenced and analyzed. The quasispecies distribution was evaluated by cloning the VP3 and VP1-2A genes in three clinical samples. Phylogenetic analysis demonstrated that the same genotyping results could be obtained whether using the complete VP3, VP1, or partial VP1-2A genes for analysis in this study, although some differences did exist. Most isolates clustered in sub-genotype IA, and fewer in sub-genotype IB. No amino acid mutations were found at the published neutralizing epitope sites, however, several unique amino acid substitutions in the VP3 or VP1 region were identified, with two amino acid variants closely located to the immunodominant site. Quasispecies analysis showed the mutation frequencies were in the range of 7.22 x 10(-4) -2.33 x 10(-3) substitutions per nucleotide for VP3, VP1, or VP1-2A. When compared with the consensus sequences, mutated nucleotide sites represented the minority of all the analyzed sequences sites. HAV replicated as a complex distribution of closely genetically related variants referred to as quasispecies, and were under negative selection. The results indicate that diverse HAV strains and quasispecies inside the viral populations are presented in China, with unique amino acid substitutions detected close to the immunodominant site, and that the possibility of antigenic escaping mutants cannot be ruled out and needs to be further analyzed.

[Prokaryotic expression and characterization of two recombinant receptor-binding domain(RBD) proteins of human coronavirus NL63(HcoV-NL63)].

The receptor-binding domain(RBD) protein of HCoV-NL63 is a major target in the development of diagnostic assay and vaccine, it has a pivotal role in receptor attachment, viral entry and membrane fusion. In this study, we prepared 2 purified recombinant HCoV-NL63 RBD proteins using in E. coli system and identified the proteins by Western blotting. We first optimized codon and synthesized the RL (232-684aa)coding gene, then amplified the RL or RS(476-616aa) coding gene via PCR using different primers . The RL or RS coding gene was cloned into the pM48 expression vector fused with TrxA tag. The RBD (RL and RS) of HCoV-NL63 were expressed majorly as inclusion body when expressed in E. coli BL21pLys S under different conditions. The expressed products were purified by affinity chromatography then analyzed by SDS-PAGE and Western blotting. Our results showed that the recombinant RBD proteins were maximally expressed at 37 degrees C with 0. 8mM IPTG induction for 4h. RL or RS protein with 95 % purity was obtained and reacted positively with anti-sera from mice immunized with the recombinant vaccinia virus (Tiantan strain) in which HCoV-NL63 RL or RS protein was expressed. In conclusion, the purified recombinant RBD proteins(RL and RS)derived from E. coli were first prepared in China and they might provide a basis for further exploring biological role and vaccine development of HCoV-NL63.

[Establishing a high-titer infectious avian influenza A (H5N1) pseudotyped viral particle].

A transient four-plasmid cotransfection system was used to construct avian influenza A (H5N1) pseudotyped viral particle (H5N1Pp) by incorporating hemagglutinin (HA) protein and neuraminidase (NA) protein from H5N1 avian influenza virus onto Murine leukemia virus pseudotyped viral particles, the transmission electron microscopy, infectivity titer assay, hemagglutination assay, neutralization assay of H5N1Pp were studied. We established a pseudotyped H5N1 viral particle at a high titer of 10(8) Pp/mL, the morphology,the hemagglutination activity and neutralization specificity of H5N1Pp is simililar to wild H5N1 virus. The research result sets a platform for studying this virus, including its receptors, the functional analysis of HA and NA, neutralizing antibodies and anti-H5N1 drug development.

Genotyping of acute hepatitis a virus isolates from China, 2003-2008.

Hepatitis A virus (HAV) is usually transmitted by an oral-fecal route and is prevalent not only in developing countries but also in developed countries. In the present study, the phylogenetic characterization of the VP1/2A junction region (321 nucleotides) of China HAV isolates was examined. Anti-HAV IgM-positive serum samples were collected from 8 provinces, including 20 cities or counties in China from 2003 to 2008; 337 isolates from 406 HAV patients' serum samples were amplified by RT-PCR, sequenced at the VP1/2A junction region and aligned with the published sequences from GenBank to establish phylogenetic analysis. All China HAV isolates in this study belonged to genotype I, with 98.8% (333/337) of samples clustering in sub-genotype IA and 1.2% (4/337) in sub-genotype IB. In addition, sub-genotype IA isolates clustered into four groups (92.7-100% nucleotide identity), and the samples collected from all China HAV isolates in this investigation showed 87.5-100% nucleotide identity, but the amino acids in this region were more conserved (95.2-100% identity). Few unique amino acid changes could be deduced (VP1-253: Glu → Gly; 2A-34: Pro → Ala; 2A-33: Leu → Phe). Genetically identical or similar HAV strains existed in some investigated areas in China during different years, suggesting that an indigenous strain has been circulating in those regions. This report provides new data on the genetic relatedness and molecular epidemiology of HAV isolates from China as well as the distribution of sub-genotype IA and IB in this part of the world.

Distribution and hepatocellular carcinoma-related viral properties of hepatitis B virus genotypes in Mainland China: a community-based study.

INTRODUCTION: Hepatitis B virus (HBV) genotypes, replication status, and mutations have been associated with the risk of hepatocellular carcinoma (HCC). Our aim was to study the distribution and HCC-related viral properties of HBV genotypes/subgenotypes in Mainland China. METHODS: A multistage cluster probability sampling method was applied to select 81,775 participants between 1 and 59 years at 160 national disease surveillance points. We examined hepatitis B surface antigen, HBV genotypes and subgenotypes, hepatitis B e antigen, viral load, and mutations in the PreS and core promoter regions of HBV genome. RESULTS: HBV subgenotypes B2 (27.3%), C1 (10.7%), and C2 (58.0%) were predominant. Genotype D (D1, 80.8%) was frequent in the Uygur. We identified a new subgenotype, C9, mainly in Tibetans. Compositions of subgenotypes B2 and C1 and genotype mixture increased from the North to Central South, which was consistently associated with the increasing prevalence of hepatitis B surface antigen. Hepatitis B e antigen positivity and viral loads were higher in the young with genotype B and declined more rapidly with increasing age than those with genotype C. In contrast to G1896A, PreS deletion, T31C, T1753V, and A1762T/G1764A were more frequent in subgenotype C2 than in subgenotype B2. A1762T/G1764A, T1753V, C1653T, and G1896A, except PreS deletion, consecutively increased with increasing age. CONCLUSION: HBV subgenotypes B2, C1, and C2 are endemic in Mainland China. HBV genotype C exhibits less replication activity in the young and harbors higher frequencies of the HCC-associated mutations than genotype B. IMPACT: These basic data could help evaluate the association of HBV variations with HCC.

Neuraminidase and hemagglutinin matching patterns of a highly pathogenic avian and two pandemic H1N1 influenza A viruses.

BACKGROUND: Influenza A virus displays strong reassortment characteristics, which enable it to achieve adaptation in human infection. Surveying the reassortment and virulence of novel viruses is important in the prevention and control of an influenza pandemic. Meanwhile, studying the mechanism of reassortment may accelerate the development of anti-influenza strategies. METHODOLOGY/PRINCIPAL FINDINGS: The hemagglutinin (HA) and neuraminidase (NA) matching patterns of two pandemic H1N1 viruses (the 1918 and current 2009 strains) and a highly pathogenic avian influenza A virus (H5N1) were studied using a pseudotyped particle (pp) system. Our data showed that four of the six chimeric HA/NA combinations could produce infectious pps, and that some of the chimeric pps had greater infectivity than did their ancestors, raising the possibility of reassortment among these viruses. The NA of H5N1 (A/Anhui/1/2005) could hardly reassort with the HAs of the two H1N1 viruses. Many biological characteristics of HA and NA, including infectivity, hemagglutinating ability, and NA activity, are dependent on their matching pattern. CONCLUSIONS/SIGNIFICANCE: Our data suggest the existence of an interaction between HA and NA, and the HA NA matching pattern is critical for valid viral reassortment.

Generation of neutralizing monoclonal antibodies against Enterovirus 71 using synthetic peptides.

Enterovirus 71 (EV71) has led to recent outbreaks of hand, foot and mouth disease (HFMD) in China, resulting in high mortality. In this study, several monoclonal antibodies were generated by immunizing mice with two synthetic peptides, SP55 and SP70, containing amino acids 163-177 and 208-222 of VP1. The specificities of the anti-EV71 peptide monoclonal antibodies were confirmed by Western blot analysis and immunocytochemistry against EV71 virus. Most importantly, we have identified a monoclonal antibody, clone 22A12, which shows strong neutralizing activity against EV71 in an in vitro neutralization assay. Because there is no vaccine available and treatment is very limited, mouse anti-EV71 monoclonal antibody, clone 22A12, could be a promising candidate to be humanized and used for treatment of EV71 infection.

Hemagglutinin and neuraminidase matching patterns of two influenza A virus strains related to the 1918 and 2009 global pandemics.

The current pandemic influenza A (H1N1) virus has revealed a complicated reassortment of various influenza A viruses. The biological study of these viruses, especially of the viral envelope proteins hemagglutinin (HA) and neuraminidase (NA), is urgently needed for the control and prevention of H1N1 viruses. We have generated H1N1-2009 and H1N1-1918 pseudotyped particles (pp) with high infectivity. Combinations of HA1918+NA2009 and HA2009+NA1918 also formed infectious H1N1pps, among which the HA2009+NA1918 combination resulted in the most highly infectious pp. Our study demonstrated that some reassortments of H1N1 viruses may hold the potential to produce higher infectivity than do their ancestors.

Hepatitis C virus envelope glycoproteins complementation patterns and the role of the ecto- and transmembrane domains.

We separated E1 and E2 of hepatitis C virus (HCV) genotypes 1a, 1b, and 2a into two individual expression plasmids and replaced the transmembrane domains of 1b and 2a E1 and E2 with that of genotype 1a. The complementation features of E1 and E2 as well as the contributions of both the ecto- and transmembrane domains to the formation of the E1E2 complex were evaluated using the HCV pseudoparticle(s) (HCVpp(s)) system. We demonstrated that 1aE2 could not only complement its native 1aE1, but could also complement 1bE1 as well; in genotype 1b, glycoprotein complex formation is primarily dependent on the overall biological characteristics of the intact native E1 and E2; in genotype 2a, although the interaction of intact native E1 and E2 is critical for the formation of the glycoprotein complex, the ectodomain made a greater contribution than that of the transmembrane domain. Our study provides valuable findings regarding HCV E1 and E2 biology and will be of use in both anti-HCV strategy and understanding on the mechanisms of coinfection of different HCV strains.

[Combination profiles of hepatitis B marks for Chinese in serosurvey in 2006].

OBJECTIVE: To summarize the combination profile of hepatitis B markers by age and immunization history of Chinese. METHODS: Population of age 1-59 years were sampled from 160 counties of National Disease Surveillance in 31 provinces by multi-stage random sampling method. Demographic information and hepatitis B vaccination history was collected by questionnaire, and 2-4ml serum sample was taken for testing HBsAg, Anti-HBs and Anti-HBc by ELISA method. RESULTS: 16 combinations of hepatitis B markers (HBsAg, Anti-HBs, Anti-HBc, HBeAg and Anti-HBe) were found during the testing, anti-HBs was mainly found among 1-4 years old children, accounted 69.77%. Among 15-59 years, negative markers were mainly profile. Among immunized population, the older, the lower rate of anti-HBs, while among un-immunized population, except negative for all markers and anti-HBs were observed, Infected markers was account for high proportion. CONCLUSION: The profile could be used for guiding the laboratory testing by different epidemiologic characteristics, and can provide information for reference.