Patient-centered and integrated outreach care for chronic hepatitis C patients with serious mental illness in Taiwan.

Patients with serious mental illness have a higher risk of hepatitis C virus (HCV) infection but suboptimal HCV care. The current study aimed to facilitate HCV treatment uptake by implementing an integrated outreach care model. Multidisciplinary outreach screening followed by HCV reflex testing and onsite treatment for schizophrenia patients was accomplished through the coordination of nongovernmental organizations, remote specialists, and local care providers. The objective was microelimination effectiveness, defined as the multiplication of the rates of anti-HCV antibodies screening, accurate HCV RNA diagnosis, treatment allocation, treatment completion, and sustained virological response (SVR12; no detectable HCV RNA throughout 12 weeks in the post-treatment follow-up period). A total of 1478 of the 2300 (64.3%) psychiatric patients received HCV mass screening. Seventy-three (4.9%) individuals were seropositive for anti-HCV antibodies. Of the 73 anti-HCV seropositive patients, all (100%) received HCV reflex testing, and 29 (37.7%) patients had HCV viremia. Eight patients (34.8%) had advanced liver disease, including 3 with liver cirrhosis and 2 with newly diagnosed hepatocellular carcinoma. Twenty-three of the 24 (95.8%) patients who stayed in the healthcare system received and completed 8 weeks of glecaprevir/pibrentasvir treatment and post-treatment follow-up without significant DDIs or adverse events. The SVR12 rate was 100%. The microelimination effectiveness in the current study was 61.6%. Individuals with serious mental illness are underserved and suffer from diagnostic delays. This patient-centered and integrated outreach program facilitated HCV care in this marginalized population.

[Survey of prevalence of hepatitis C in people aged 1-69 years in Henan Province, 2020].

Objective: To understand the infection status and epidemiological characteristics of hepatitis C in people aged 1-69 years in Henan Province in 2020. Methods: The estimated sample size was 5 827. From August to December 2020, multistage sampling was used to select 8 counties (districts) in Henan, and two survey sites were selected in each county (district), and a questionnaire survey was conducted in local people aged 1-69 years, blood samples were collected from them for anti-HCV, HCV RNA and genotype detections. Results: A total of 5 165 people aged 1-69 years completed the questionnaire survey. Men accounted for 44.76% (2 312/5 165), women accounted for 55.24% (2 853/5 165). In the people aged 1-69 years, the overall prevalence rates of anti-HCV and HCV RNA were 0.69% (95%CI: 0.68%-0.70%) and 0.20% (95%CI: 0.19%-0.21%) respectively. The prevalence rates of anti-HCV and HCV RNA were 0.48% (95%CI: 0.46%-0.50%), 0.09% (95%CI: 0.08%-0.10%) in men and 0.86% (95%CI: 0.85%-0.87%), 0.30% (95%CI: 0.28%-0.32%) in women. The prevalence rates of anti-HCV and HCV RNA increased with age. The prevalence rates of anti-HCV and HCV RNA were 0.87% (95%CI: 0.86%-0.88%), 0.28% (95%CI: 0.26%-0.30%) in urban residents and 0.53% (95%CI: 0.51%-0.55%), 0.14% (95%CI: 0.13%-0.15%) in rural residents. The genotyping results of 10 HCV RNA positive samples ware genotype 1b (4/10), genotype 2 (3/10), genotype 1b/3 (1/10), genotype 1b/3/6 (1/10) and genotype 2/6 (1/10). Conclusions: The prevalence of hepatitis C was low in Henan in 2020. It is necessary to strengthen hepatitis C surveillance in people aged 40 years and above. The major HCV genotypes were 1b and 2, and mixed genotype infection existed.

Survey of prevalence of hepatitis C in people aged 1-69 years in Henan Province, 2020 / 中华流行病学杂志

Objective: To understand the infection status and epidemiological characteristics of hepatitis C in people aged 1-69 years in Henan Province in 2020. Methods: The estimated sample size was 5 827. From August to December 2020, multistage sampling was used to select 8 counties (districts) in Henan, and two survey sites were selected in each county (district), and a questionnaire survey was conducted in local people aged 1-69 years, blood samples were collected from them for anti-HCV, HCV RNA and genotype detections. Results: A total of 5 165 people aged 1-69 years completed the questionnaire survey. Men accounted for 44.76% (2 312/5 165), women accounted for 55.24% (2 853/5 165). In the people aged 1-69 years, the overall prevalence rates of anti-HCV and HCV RNA were 0.69% (95%CI: 0.68%-0.70%) and 0.20% (95%CI: 0.19%-0.21%) respectively. The prevalence rates of anti-HCV and HCV RNA were 0.48% (95%CI: 0.46%-0.50%), 0.09% (95%CI: 0.08%-0.10%) in men and 0.86% (95%CI: 0.85%-0.87%), 0.30% (95%CI: 0.28%-0.32%) in women. The prevalence rates of anti-HCV and HCV RNA increased with age. The prevalence rates of anti-HCV and HCV RNA were 0.87% (95%CI: 0.86%-0.88%), 0.28% (95%CI: 0.26%-0.30%) in urban residents and 0.53% (95%CI: 0.51%-0.55%), 0.14% (95%CI: 0.13%-0.15%) in rural residents. The genotyping results of 10 HCV RNA positive samples ware genotype 1b (4/10), genotype 2 (3/10), genotype 1b/3 (1/10), genotype 1b/3/6 (1/10) and genotype 2/6 (1/10). Conclusions: The prevalence of hepatitis C was low in Henan in 2020. It is necessary to strengthen hepatitis C surveillance in people aged 40 years and above. The major HCV genotypes were 1b and 2, and mixed genotype infection existed.

Analysis of antibodies from HCV elite neutralizers identifies genetic determinants of broad neutralization.

The high genetic diversity of hepatitis C virus (HCV) complicates effective vaccine development. We screened a cohort of 435 HCV-infected individuals and found that 2%-5% demonstrated outstanding HCV-neutralizing activity. From four of these patients, we isolated 310 HCV antibodies, including neutralizing antibodies with exceptional breadth and potency. High neutralizing activity was enabled by the use of the VH1-69 heavy-chain gene segment, somatic mutations within CDRH1, and CDRH2 hydrophobicity. Structural and mutational analyses revealed an important role for mutations replacing the serines at positions 30 and 31, as well as the presence of neutral and hydrophobic residues at the tip of the CDRH3. Based on these characteristics, we computationally created a de novo antibody with a fully synthetic VH1-69 heavy chain that efficiently neutralized multiple HCV genotypes. Our findings provide a deep understanding of the generation of broadly HCV-neutralizing antibodies that can guide the design of effective vaccine candidates.

Characterization of linear epitope specificity of antibodies potentially contributing to spontaneous clearance of hepatitis C virus.

BACKGROUND: Around 30% of the HCV infected patients can spontaneously clear the virus. Cumulative evidence suggests the role of neutralizing antibodies in such spontaneous resolution. Understanding the epitope specificity of such antibodies will inform the rational vaccine design as such information is limited to date. In addition to conformational epitope targeted antibodies, linear epitope specific antibodies have been identified that are broadly cross reactive against diverse HCV strains. In this study, we have characterized the potential role of three conserved linear epitopes in the spontaneous clearance of HCV. METHODS: We tested the reactivity of sera from chronic patients (CP) and spontaneous resolvers (SR) with linear peptides corresponding to three conserved regions of HCV envelope protein E2 spanning amino acids 412-423, 523-532 and 432-443 using ELISA. Subsequently, we characterized the dependency of HCV neutralization by the reactive serum samples on the antibodies specific for these epitopes using pseudoparticle-based neutralization assay. In ELISA most of the CP sera showed reactivity to multiple peptides while most of the SR samples were reactive to a single peptide suggesting presence of more specific antibodies in the SR sera. In most of the HCVpp neutralizing sera of particular peptide reactivity the neutralization was significantly affected by the presence of respective peptide. HCV neutralization by CP sera was affected by multiple peptides while 75% of the HCVpp neutralizing SR sera were competed by the 432 epitope. CONCLUSIONS: These findings suggest that individuals who spontaneously resolve HCV infection at the acute phase, can produce antibodies specific for conserved linear epitopes, and those antibodies can potentially play a role in the spontaneous viral clearance. The epitope present in the 432-443 region of E2 was identified as the primary neutralizing epitope with potential role in spontaneous viral clearance and this epitope potentiates for the design of immunogen for prophylactic vaccine.

Identification of two novel anti-HCV E2 412-423 epitope antibodies by screening a Chinese-specific phage library.

The hepatitis C virus (HCV) E2 412-423 linear epitope has been found to be highly conserved across multiple HCV genotypes. The antibodies against this epitope have broadly neutralizing activity. Considering the poor immunogenicity of the epitope in humans and significant diversity in the global distribution of HCV genotypes, the aim of this study was to construct an anti-HCV phage library by using a series of optimal strategies to screen novel broadly neutralizing antibodies from Chinese donors. mRNA was isolated from peripheral blood samples of 39 patients who were anti-HCV positive. A phage library was constructed by inserting a single-chain variable fragment (scFv) gene repertoire into the T7Select10-3b vector. A synthetic peptide representing the HCV E2 N-terminal 412-423 region was used as "bait" for bio-panning. The binding affinities of phage clones to the synthetic peptide were evaluated through peptide-ELISA. Two scFv clones (R3-19 and R4-85) showing the strongest binding affinities were selected. The complementarity-determining regions (CDRs) of these clones were aligned with those of other previously reported broadly neutralizing anti-HCV antibodies, and multiple conserved amino acid sites were found. The optimized procedures ensured that two novel scFv antibodies were isolated from a constructed phage library and showed specific binding to the poorly immunogenic HCV E2 412-423 linear epitope. Keywords: phage antibody library; hepatitis C virus; broadly neutralizing antibody; synthetic peptide.

Serum inducible protein-10 chemokine as a biomarker for clearance of HCV with and without treatment in Egyptian patients.

BACKGROUND AND AIMS: Assessment of the potential predictive value of serum inducible protein-10 chemokine (IP-10) in the clearance of HCV in Egyptian patients with and without treatment. MATERIALS AND METHODS: Ninety Egyptian individuals were involved in the current study where, 20 patients (23%) were chronic HCV (positive HCV antibodies and positive HCV RNA without treatment, 20 (22%) were healthy individuals (negative for both HCV antibodies and HCV RNA, 20 (22%) were natural clearance (positive HCV antibodies and negative for HCV RNA without treatment), 20 (22%) were achieved SVR after treatment (responders group, HCV positive and negative for HCV RNA after treatment) and 10 (11%) were non responders (positive HCV antibodies and still positive HCV RNA after treatment). HCV RNA was quantitated by real time PCR and serum IP10 level was measured by commercial ELISA kit. All biochemical and hematological examinations included liver function, CBC and alphefeto protein were assessed. RESULTS: The mean serum levels of IP-10 were significantly higher (p< 0.001) in CHC patients (345.4 ± 100) pg/ml compared with healthy control group (101.5 ± 31.4) and natural clearance group (103.2 ± 40.7). Also serum levels of IP-10 was significantly elevated in non-responders group (257.4 ± 52.5) compared with each of SVR group (103.5 ± 43.5) (p< 0.001) and healthy group (101.5 ± 31.4), (p< 0.001). Prediction of a clinical response based on a IP10 chemokine revealed high sensitivity (93%), specificity (96%), negative predictive value (96%), and area under curve is (1.00). Moreover, there is no correlation ((R= 0.05), P value p< 0.795) between serum level of IP-10 and HCV viral load. CONCLUSION: IP10 is a useful non-invasive biomarker for viral clearance and might be used to apply patients according to the predictable treatment outcome. Accordingly, patients who are unlikely to respond to treatment would avoid unnecessary exposure to medication that is related with high morbidity.

Hepatitis C virus genotype diversity and distribution among methadone maintenance treatment patients in Jiangsu, China.

BACKGROUND: Heroin users are vulnerable and represent a highly-infected reservoir for hepatitis C virus (HCV) infection. This study investigated HCV prevalence and genotypes distribution among heroin users who received methadone maintenance treatment (MMT) in Jiangsu. METHODS: From June to December in 2016, a total of 534 patients among nine MMT clinics in six regions of Jiangsu were enrolled, with their demographic characteristics collected and serum samples tested for HCV antibody. 395 samples were seropositive and furthered to RNA extraction. HCV NS5B region fragments were amplified and subsequently sequenced. RESULTS: Among HCV seropositive samples, 240 were characterized by NS5B partial sequences and classified into four genotypes (GPs) and eight subtypes. HCV GP3 predominated and accounted for 66.3%, followed by GP1 (27.5%), GP6 (4.2%) and GP2 (2.1%). HCV subtypes 3b (41.7%) and 3a (24.6%) were the most common subtypes. None of the demographic characteristics showed a significant difference when comparing with HCV genotypes. The geographic feature shown GPs in six regions were the same, but the frequency of subtypes exhibited regional divergence. Phylogenetic analyses demonstrated that 3b had become a local endemic in Jiangsu. CONCLUSION: The distribution of HCV subtypes among heroin users in Jiangsu province was complex. The data could provide more precise estimates for HCV prevalence and genotype distribution as well as heroin users of Jiangsu province.

Isolation of HCV Neutralizing Antibodies by Yeast Display.

Yeast surface display (YSD) enables efficient screening and selection of single chain variable fragments (scFvs) of heavy (VH) and light (VL) chains that bind to target antigen with different affinities. Assembly of a scFv library from cDNA usually involves adding different primers and linkers (Gly4/Ser)3 through multiple rounds of PCR amplification and purification. We describe here a simplified scFv assembly method by creating a modified YSD vector with a built-in linker that reduces the time of assembly and decreases accumulated base exchanges due to PCR errors. In addition, we describe a bias screening strategy toward maximizing novel antibodies of interest by a combination of memory B cell selection and depletion by binding to mutant antigens that do not bind to previously identified monoclonal antibodies.

Expression of a functional intrabody against hepatitis C virus core protein in Escherichia coli and silkworm pupae.

It has been shown that the single-domain intrabody 2H9-L against the hepatitis C virus (HCV) capsid (core) protein inhibits the viral propagation and NF-κB promoter activity induced by the HCV core. In this study, 2H9-L fused with the FLAG tag sequence was expressed in both Escherichia coli and silkworm pupae and then purified. In addition, the full-length and its C terminal deletions of the HCV core protein, i.e., 1-123 amino acid residues (C123), 1-152 amino acid residues (C152), 1-177 amino acid residues (C177) and 1-191 amino acid residues (C191), were expressed as fusion proteins with a 6 × His tag at their N-terminus in E. coli and then purified. Approximately 175 and 132 µg of the intrabody were purified from 100 ml of E. coli culture and 10 silkworm pupae, respectively, by affinity chromatography. The C123, C152, C177 and C191 HCV core protein variants were purified to approximately 152, 127, 103 and 155 µg, respectively, from 100 ml of E. coli culture. An ELISA in which the intrabodies were immobilized revealed that the intrabodies purified from both hosts were bound to all HCV core protein variants. However, their binding to the C191 appeared to be weak compared to their bindings to the other HCV core protein variants. When C152 was immobilized in the ELISA, the binding of each intrabody to the core protein was also observed. These purified intrabodies can be used in biochemical analyses of the inhibitory mechanism of HCV propagation and as protein interference reagents, thus providing a potential pathway to developing a new type of antiviral drug.

Antibody Repertoire Analysis of Hepatitis C Virus Infections Identifies Immune Signatures Associated With Spontaneous Clearance.

Hepatitis C virus (HCV) is a major public health concern, with over 70 million people infected worldwide, who are at risk for developing life-threatening liver disease. No vaccine is available, and immunity against the virus is not well-understood. Following the acute stage, HCV usually causes chronic infections. However, ~30% of infected individuals spontaneously clear the virus. Therefore, using HCV as a model for comparing immune responses between spontaneous clearer (SC) and chronically infected (CI) individuals may empower the identification of mechanisms governing viral infection outcomes. Here, we provide the first in-depth analysis of adaptive immune receptor repertoires in individuals with current or past HCV infection. We demonstrate that SC individuals, in contrast to CI patients, develop clusters of antibodies with distinct properties. These antibodies' characteristics were used in a machine learning framework to accurately predict infection outcome. Using combinatorial antibody phage display library technology, we identified HCV-specific antibody sequences. By integrating these data with the repertoire analysis, we constructed two antibodies characterized by high neutralization breadth, which are associated with clearance. This study provides insight into the nature of effective immune response against HCV and demonstrates an innovative approach for constructing antibodies correlating with successful infection clearance. It may have clinical implications for prognosis of the future status of infection, and the design of effective immunotherapies and a vaccine for HCV.

MSM starting preexposure prophylaxis are at risk of hepatitis C virus infection.

OBJECTIVES AND DESIGN: Hepatitis C virus (HCV) has been recognized as an emerging sexually transmitted infection (STI) among HIV-positive MSM. However, HIV-negative MSM at high risk for HIV might also be at increased risk for HCV. We studied the HCV prevalence in HIV-negative MSM who start preexposure prophylaxis (PrEP) in Amsterdam. Phylogenetic analysis was used to compare HCV strains obtained from HIV-negative and HIV-positive MSM. METHODS: At enrolment in the Amsterdam PrEP demonstration project, HIV-negative MSM were tested for the presence of HCV antibodies and HCV RNA. If positive for HCV RNA, an HCV NS5B gene fragment (709 bp) was sequenced and compared with HCV isolates from HIV-positive MSM (n = 223) and risk groups other than MSM (n = 153), using phylogenetic analysis. RESULTS: Of 375 HIV-negative MSM enrolled in Amsterdam PrEP, 18 (4.8%, 95% confidence interval 2.9-7.5%) of participants were anti-HCV and/or HCV RNA positive at enrolment; 15 of 18 (83%) had detectable HCV RNA. HCV genotyping showed genotype 1a (73%), 4d (20%), and 2b (7%). All HCV-positive MSM starting PrEP were part of MSM-specific HCV clusters containing MSM with and without HIV. CONCLUSION: HCV prevalence among HIV-negative MSM who started PrEP was higher than previously reported. All HIV-negative HCV-positive MSM were infected with HCV strains already circulating among HIV-positive MSM. The increasing overlap between sexual networks of HIV-positive and HIV-negative MSM might result in an expanding HCV-epidemic irrespective of HIV-status. Hence, routine HCV testing should be offered to MSM at high risk for HIV, especially for those enrolling in PrEP programs.

Comparative analysis of variation and selection in the HCV genome.

Genotype 1 of the hepatitis C virus (HCV) is the most prevalent of the variants of this virus. Its two main subtypes, HCV-1a and HCV-1b, are associated to differences in epidemic features and risk groups, despite sharing similar features in most biological properties. We have analyzed the impact of positive selection on the evolution of these variants using complete genome coding regions, and compared the levels of genetic variability and the distribution of positively selected sites. We have also compared the distributions of positively selected and conserved sites considering different factors such as RNA secondary structure, the presence of different epitopes (antibody, CD4 and CD8), and secondary protein structure. <10% of the genome was found to be under positive selection, and purifying selection was the main evolutionary process acting in both subtypes. We found differences in the number of positively selected sites between subtypes in several genes (Core, HVR2 in E2, P7, helicase in NS3 and NS4a). Heterozygosity values in positively selected sites and the rate of non-synonymous substitutions were significantly higher in subtype HCV-1b. Logistic regression analyses revealed that similar selective forces act at the genome level in both subtypes: RNA secondary structure and CD4 T-cell epitopes are associated with conserved sites, while CD8 T-cell epitopes are associated with positive selection in both subtypes. These results indicate that similar selective constraints are acting along HCV-1a and HCV-1 b genomes, despite some differences in the distribution of positively selected sites at independent genes.

Limited naturally occurring escape in broadly neutralizing antibody epitopes in hepatitis C glycoprotein E2 and constrained sequence usage in acute infection.

Broadly neutralizing antibodies have been associated with spontaneous clearance of the hepatitis C infection as well as viral persistence by immune escape. Further study of neutralizing antibody epitopes is needed to unravel pathways of resistance to virus neutralization, and to identify conserved regions for vaccine design. All reported broadly neutralizing antibody (BNAb) epitopes in the HCV Envelope (E2) glycoprotein were identified. The critical contact residues of these epitopes were mapped onto the linear E2 sequence. All publicly available E2 sequences were then downloaded and the contact residues within the BNAb epitopes were assessed for the level of conservation, as well as the frequency of occurrence of experimentally-proven resistance mutations. Epitopes were also compared between two sequence datasets obtained from samples collected at well-defined time points from acute (<180days) and chronic (>180days) infections, to identify any significant differences in residue usage. The contact residues for all BNAbs were contained within 3 linear regions of the E2 protein sequence. An analysis of 1749 full length E2 sequences from public databases showed that only 10 out of 29 experimentally-proven resistance mutations were present at a frequency >5%. Comparison of subtype 1a viral sequences obtained from samples collected during acute or chronic infection revealed significant differences at positions 610 and 655 with changes in residue (p<0.05), and at position 422 (p<0.001) with a significant difference in variability (entropy). The majority of experimentally-described escape variants do not occur frequently in nature. The observed differences between acute and chronically isolated sequences suggest constraints on residue usage early in infection.

Humanized-VHH transbodies that inhibit HCV protease and replication.

There is a need for safe and broadly effective anti-HCV agents that can cope with genetic multiplicity and mutations of the virus. In this study, humanized-camel VHHs to genotype 3a HCV serine protease were produced and were linked molecularly to a cell penetrating peptide, penetratin (PEN). Human hepatic (Huh7) cells transfected with the JFH-1 RNA of HCV genotype 2a and treated with the cell penetrable nanobodies (transbodies) had a marked reduction of the HCV RNA intracellularly and in their culture fluids, less HCV foci inside the cells and less amounts of HCV core antigen in culture supernatants compared with the infected cells cultured in the medium alone. The PEN-VHH-treated-transfected cells also had up-regulation of the genes coding for the host innate immune response (TRIF, TRAF3, IRF3, IL-28B and IFN-ß), indicating that the cell penetrable nanobodies rescued the host innate immune response from the HCV mediated-suppression. Computerized intermolecular docking revealed that the VHHs bound to residues of the protease catalytic triad, oxyanion loop and/or the NS3 N-terminal portion important for non-covalent binding of the NS4A protease cofactor protein. The so-produced transbodies have high potential for testing further as a candidate for safe, broadly effective and virus mutation tolerable anti-HCV agents.

In vitro molecular evolution of AL NEIBMs improved immunoglobulin (Ig) binding and antibody detection.

AL (SpA A domain-PpL B3 domain), LD5 (PpL B3 domain-SpA D domain-PpL B3 domain-SpA D domain-PpL B3 domain, L-D-L-D-L) and LD3 (PpL B3 domain-SpA D domain-PpL B3 domain, L-D-L) are novel evolved Ig binding molecules (NEIBMs) derived from the in vitro molecular evolution of combinatorial phage libraries displaying randomly rearranged Ig-binding domains of protein A and protein L. These molecules all showed novel Ig-binding properties of double-site binding to the VH3 and Vκ regions of human Ig Fab and high affinity for human IgM, which enhanced IgM detection in the anti-HCV ELISA assay. In this double-site binding, the A domain binds to the VH3 chain with low affinity. Whether the appropriate mutations in the A domain could improve this binding remains unknown. In this study, four combinatorial phage libraries displaying AL mutants with random mutations at different amino acid positions in the A domain were constructed. Seven AL mutant phages with significantly improved Ig binding activity were obtained from the phage library displaying AL mutants randomly mutated at positions 27 and 34 through human IgM-directed in vitro evolution. Two of the seven prokaryotically expressed AL mutants, AL (VV) and AL (KA), exhibited IgM and IgG binding activities equivalent to those of wild-type AL, whereas other mutants showed attenuated binding. However, after labeling with HRP, AL (VV) and AL (KA) showed improved IgM and IgG binding activity, which significantly improved the detection in the anti-HCV assay. Thus, the present study demonstrates that the binding properties of AL were successfully improved through phage-based molecular evolution, which could substantially contribute to the use of AL in antibody detection, and provides an example of successful protein engineering through in vitro molecular evolution.

The spectrum of undiagnosed hepatitis C virus infection in a US HIV clinic.

United States guidelines endorse one-time HCV antibody screening at HIV diagnosis. Rescreening HCV-seronegative patients on a regular basis is still not policy, although HIV-infected persons have reasonably substantial HCV incidence. We evaluated routine risk factor-independent HCV antibody re-testing in a Rhode Island HIV clinic. We instituted annual HCV antibody testing for HCV-seronegative patients who had not been rescreened in a year or more. Testing based on clinical suspicion continued. We conducted a chart review of new antibody-positive cases in the first year of rescreening, July 2006 to June 2007. Of 245 rescreened patients, 11 (4.5%) seroconverted. Five (45%) were female. Median time between last negative and first positive result was 32 months (range 8-98 months). Six (55%) had documented risk factors and 6 (55%) elevated ALT (> 45 IU/L) between antibody tests; none prompted re-testing. One seroconverter died of hepatocellular carcinoma 3.7 years after HCV diagnosis. A twelfth was rescreened for suspected acute HCV based on ALT of 515 IU/L. He had newly detectable HCV RNA then seroconversion, and achieved SVR following 6 months of treatment in the acute phase for genotype 1 infection. Incident HCV is not uncommon among HIV-infected patients in care. Rescreening identified undiagnosed HCV in this population. HCV RNA should be checked promptly in HCV-seronegative persons with ALT elevation. We observed consequences of late diagnosis (hepatocellular carcinoma) and benefits of early diagnosis (cure with treatment of acute HCV). Adding annual rescreening to the Ryan White Program would facilitate earlier identification of undiagnosed HCV and create an instant widespread surveillance system, providing HCV incidence data.

Humanized-VH/VHH that inhibit HCV replication by interfering with the virus helicase activity.

NS3 helicase is a pivotal enzyme involved in the early and late phases of hepatitis C virus (HCV) replication. The primary sequence and tertiary structure of this virus enzyme differ from human helicase to a certain extent; thus this virus protein has potential as a novel anti-HCV target. In this study, recombinant C-terminal NS3 protein of HCV genotype 3a with endowed helicase activity was produced and used as antigen by selecting VH/V(H)H display phage clones from an established humanized-camel single domain antibody library that bound specifically to HCV helicase. The VH/V(H)H derived from phage transfected Escherichia coli clones were linked molecularly to a cell penetrating peptide, i.e., penetratin (PEN). The cell penetrable VH/V(H)H (transbodies) could reduce the amounts of the HCV RNA released into the cell culture fluid and inside Huh7 cells infected with pJFH1 replicon with a greater effect on the former compared to the latter. Regions and residues of the helicase bound by the transbodies were determined by phage mimotope searching and multiple alignments as well as homology modeling and molecular docking. The epitope of one transbody (PEN-V(H)H9) encompassed residues 588RLKPTLHGPTPLLYRLGA605 of the domain 3 necessary for helicase activity while another transbody (PEN-VH59) interacted with the areas covering the phenylalanine loop and arginine clamp of the domain 2 which are important for the proper folding of the enzyme as well as nucleic acid substrate binding. Although the molecular mechanisms of the prototypic transbodies on NS3 helicase need further investigation, these transbodies have high potential as novel, safe and mutation tolerable anti-HCV agents.

A synthetic codon-optimized hepatitis C virus nonstructural 5A DNA vaccine primes polyfunctional CD8+ T cell responses in wild-type and NS5A-transgenic mice.

The hepatitis C virus (HCV) nonstructural (NS) 5A protein has been shown to promote viral persistence by interfering with both innate and adaptive immunity. At the same time, the HCV NS5A protein has been suggested as a target for antiviral therapy. In this study, we performed a detailed characterization of HCV NS5A immunogenicity in wild-type (wt) and immune tolerant HCV NS5A-transgenic (Tg) C57BL/6J mice. We evaluated how efficiently HCV NS5A-based genetic vaccines could activate strong T cell responses. Truncated and full-length wt and synthetic codon-optimized NS5A genotype 1b genes were cloned into eukaryotic expression plasmids, and the immunogenicity was determined after i.m. immunization in combination with in vivo electroporation. The NS5A-based genetic vaccines primed high Ab levels, with IgG titers of >10(4) postimmunization. With respect to CD8(+) T cell responses, the coNS5A gene primed more potent IFN-γ-producing and lytic cytotoxic T cells in wt mice compared with NS5A-Tg mice. In addition, high frequencies of NS5A-specific CD8(+) T cells were found in wt mice after a single immunization. To test the functionality of the CTL responses, the ability to inhibit growth of NS5A-expressing tumor cells in vivo was analyzed after immunization. A single dose of coNS5A primed tumor-inhibiting responses in both wt and NS5A-Tg mice. Finally, immunization with the coNS5A gene primed polyfunctional NS5A-specific CD8(+) T cell responses. Thus, the coNS5A gene is a promising therapeutic vaccine candidate for chronic HCV infections.