F protein increases CD4+CD25+ T cell population in patients with chronic hepatitis C

Evaluating HIV drug resistance in the middle East and North Africa and its associated factors: a systematic review

OBJECTIVE

One of the obstacles to achieving successful treatment of HIV infections is the development and spread of mutations linked to resistance. Thus, it is important to monitor the prevalence and occurrence of drug resistance in HIV consistently. This study aimed to investigate how drug resistance affects the effectiveness of ART.

METHODS

This systematic review focused on surveying ART resistance in both treatment-naïve and treatment-experienced PWH from 2004 to 2024.

RESULTS

Out of 101 potential publications, 41 studies were included in this review. ART-experienced PWH in MENA countries commonly receive a regimen consisting of two NRTI drugs in combination with one NNRTI drug. The most frequent mutations were found in NRTIs (M184V, D67N, V75M, M41L, and T69N), NNRTIs (K103N, K101E, V106A, and G190S), and PIs (M36I and H69K). The ART-experienced groups in Israel and Iran presented the highest rates of resistance, reaching 52.78% and 43.03%, respectively, whereas the ART-naïve group in Turkey presented a resistance rate of 53.57%. The most prevalent HIV-1 subtypes in the region were B, CRF35-AD, CRF01-AE, A1, CR02-AG, C, and D. A high frequency of drug resistance mutations, such as M184V and K103N/S, was observed in the CRF35-AD, A, and C subtypes.

CONCLUSION

This is the first report to provide deep insight into ART resistance patterns in the MENA region among both ART-naïve and ART-experienced PWH. The results revealed a significant occurrence of drug resistance to RTIs, PIs, and INSTIs among both groups. This finding highlights the importance of prescribing the INTIs in native and PWH with resistance to RTIs and/or PIs to increase the chance of response to ART as well as regular monitoring of resistance to ART in MENA countries. This also involves identifying the key factors contributing to drug resistance, including inadequate adherence to ART and a lack of adequate monitoring systems to prevent treatment failure. Since the MENA region is significant as an economic challenge, PWH with poor adherence to ART medication and insufficient monitoring systems may hinder successful infection control; therefore, HIV control strategies may prevent viruses from spreading in other countries.

CLINICAL TRIAL NUMBER

Not applicable.

Design of multivalent-epitope vaccine models directed toward the world's population against HIV-Gag polyprotein: Reverse vaccinology and immunoinformatics

Significant progress has been made in HIV-1 research; however, researchers have not yet achieved the objective of eradicating HIV-1 infection. Accordingly, in this study, eucaryotic and procaryotic in silico vaccines were developed for HIV-Gag polyproteins from 100 major HIV subtypes and CRFs using immunoinformatic techniques to simulate immune responses in mice and humans. The epitopes located in the conserved domains of the Gag polyprotein were evaluated for allergenicity, antigenicity, immunogenicity, toxicity, homology, topology, and IFN-γ induction. Adjuvants, linkers, CTLs, HTLs, and BCL epitopes were incorporated into the vaccine models. Strong binding affinities were detected between HLA/MHC alleles, TLR-2, TLR-3, TLR-4, TLR-7, and TLR-9, and vaccine models. Immunological simulation showed that innate and adaptive immune cells elicited active and consistent responses. The human vaccine model was matched with approximately 93.91% of the human population. The strong binding of the vaccine to MHC/HLA and TLR molecules was confirmed through molecular dynamic stimulation. Codon optimization ensured the successful translation of the designed constructs into human cells and E. coli hosts. We believe that the HIV-1 Gag vaccine formulated in our research can reduce the challenges faced in developing an HIV-1 vaccine. Nevertheless, experimental verification is necessary to confirm the effectiveness of these vaccines in these models.

Reverse vaccinology approaches to design a potent multiepitope vaccine against the HIV whole genome: immunoinformatic, bioinformatics, and molecular dynamics approaches

Substantial advances have been made in the development of promising HIV vaccines to eliminate HIV-1 infection. For the first time, one hundred of the most submitted HIV subtypes and CRFs were retrieved from the LANL database, and the consensus sequences of the eleven HIV proteins were obtained to design vaccines for human and mouse hosts. By using various servers and filters, highly qualified B-cell epitopes, as well as HTL and CD8 + epitopes that were common between mouse and human alleles and were also located in the conserved domains of HIV proteins, were considered in the vaccine constructs. With 90% coverage worldwide, the human vaccine model covers a diverse allelic population, making it widely available. Codon optimization and in silico cloning in prokaryotic and eukaryotic vectors guarantee high expression of the vaccine models in human and E. coli hosts. Molecular dynamics confirmed the stable interaction of the vaccine constructs with TLR3, TLR4, and TLR9, leading to a substantial immunogenic response to the designed vaccine. Vaccine models effectively target the humoral and cellular immune systems in humans and mice; however, experimental validation is needed to confirm these findings in silico.

Potential roles of core and core+1 proteins during the chronic phase of hepatitis C virus infection

The HCV Core protein is a multifunctional protein that interacts with many viral and cellular proteins. In addition to the encapsidation of the viral genome, it can disturb various cellular pathways and impede antiviral cellular responses such as interferon (IFN) production. The Core protein can also disrupt the functions of immune cells against HCV. The Core protein helps viral infection persistency by interfering with apoptosis. The Core+1 protein plays a significant role in inducing chronic HCV infection through diverse mechanisms. We review some of the mechanisms by which Core and Core+1 proteins facilitate HCV infection to chronic infection. These proteins could be considered for designing more sufficient treatments and effective vaccines against HCV.

Hepatitis C virus alternative reading frame protein (ARFP): Production, features, and pathogenesis

Earlier observation suggests that hepatitis C virus (HCV) is a single-stranded RNA virus which encodes at least 10 viral proteins. F protein is a novel protein which has been discovered recently. These studies suggest three mechanisms for the production of this protein concerning ribosomal frameshift at codon 10, initial translation at codons 26 and 85 or 87. In this study, the association between protein F and chronicity of hepatocellular carcinoma (HCC) has been reviewed. Evidence suggests that humoral immune system can recognize this protein and produce antibodies against it. By detecting antibodies in infected people, investigators found that F protein might have a role in HCV infection causing chronic cirrhosis and HCC as higher prevalence was found in patients with mentioned complications. The increment of CD4+, CD25+, and FoxP3+ T cells, along with CD8+ T cells with low expression of granzyme B, also leads to weaker responses of the immune system which helps the infection to become chronic. Moreover, it contributes to the survival of the virus in the body through affecting the production of interferon. F protein also might play roles in the disease development, resulting in HCC. The existence of F protein affects cellular pathways through upregulating p53, c-myc, cyclin D1, and phosphorylating Rb. This review will summarize these effects on immune system and related mechanisms in cellular pathways.

Antibody Development to HCV Alternate Reading Frame Protein in Liver Transplant Candidate and its Computational Analysis

Background::

HCV Alternate Reading Frame Protein (ARFP) is a frameshift product of HCV-core encoding. Here, we characterized specific anti-ARFP antibodies in Liver Transplant Candidate (LTC) and chronic HCV-infected patients.

Methods::

The ARFP gene was cloned and the recombinant protein was purified using Nickel chromatography and confirmed by western blotting. ELISA was developed using recombinant core-1a, core- 1b, ARFP-1a protein, and 99-residue synthetic ARFP 1b peptide. By several Bioinformatics tools, general properties, immunogenic epitopes, and structures of these proteins were obtained.

Results::

The seroprevalence of anti-core and anti-ARFP antibodies was 100% in LTC patients, but only 75.2% and 94.3% of chronic patients had evidence of anti-ARFP and anti-core antibodies, respectively. In-silico results demonstrated physicochemical features, antigen properties and potential interactors that could describe progression toward advanced liver disease.

Conclusion::

As the first report, the prevalence of anti-ARFP antibodies in LTC patients is of the order of 100% and titer of anti-ARFP antibody was significantly higher in LTC patients compared to chronic individuals, suggesting the possible role of ARFP in the progression toward advanced liver disease. In addition, docking analysis determined several interactor proteins such as prefoldin 2, cathepsin B, vitronectin, and angiotensinogen that have an important role in progression to chronic infection and liver disease development.

Bioinformatics Analysis of Domain 1 of HCV-Core Protein: Iran

Hepatitis C virus (HCV) infection is a serious global health problem and a cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma (HCC). Bioinformatics software has been an effective tool to study the HCV genome as well as core domains. Our research was based on employing several bioinformatics software applications to find important mutations in domain 1 of core protein in Iranian HCV infected samples from 2006 to 2017, and an investigation of general properties, B-cell and T-cell epitopes, modification sites, and structure of domain 1. Domain 1 sequences of 188 HCV samples isolated from 2006 to 2017, Iran, were retrieved from NCBI gene bank. Using several tools, all sequences were analyzed for determination of mutations, physicochemical analysis, B-cell epitopes prediction, T-cell and CTL epitopes prediction, post modification, secondary and tertiary structure prediction. Our analysis determined several mutations in some special positions (70, 90, 91, and 110) that are associated with HCC and hepatocarcinogenesis, efficacy of triple therapy and sustained virological response, and interaction between core and CCR6. Several B-cell, T-cell, and CTL epitopes were recognized. Secondary and tertiary structures were mapped fordomain1 and core proteins. Our study, as a first report, offered inclusive data about frequent mutation in HCV-core gene domain 1 in Iranian sequences that can provide helpful analysis on structure and function of domain 1 of the core gene.

Cytokine profile in chronic hepatitis C: An observation

The data addressing cytokine profile in chronically infected HCV patients are conflicting, ranging from Th1 or Th2 cytokine prevalence to the expression of both types of cytokines. Therefore, the aim of this study was to evaluate cytokine profile in these patients. Cytokine sera levels in HCV patients and healthy controls were evaluated using 13plex FlowCytomix Multiplex. Median values of both proinflammatory and anti-inflammatory cytokines were lower in HCV patients then in controls. In addition, the number of subjects producing detectable quantities of cytokines was significantly lower in the group of HCV patients. Yet, cytokine levels in those patients were remarkably heterogeneous ranging from low to extremely high, much higher than the maximal values in control group. Similarly, grouping data according to HCV genotype, HCV RNA load, ALT/AST ratio and the stage of fibrosis showed marked standard deviations, reflecting high intragroup diversity. No correlation was found between each disease-related factor and cytokine levels. Patients investigated in our and similar studies were disparate pursuant to characteristics of the hosts, pathogen and course of the disease. Therefore, the inconsistency of the literature data regarding cytokine pattern in chronic HCV patients may be a consequence of the disregarded/overlooked heterogeneity of these patients.

Role of serum level and genetic variation of IL-28B in interferon responsiveness and advanced liver disease in chronic hepatitis C patients

Interleukin-28B (IL-28B) is suspected to be associated with response to treatment and one of the basic immunological backgrounds in liver transplant candidate (LTC). We aimed to assess whether genotypes of IL-28B can play a role in therapeutic response or advanced stages of liver disease. A total of 364 subjects were genotyped for IL-28B rs12979860 and rs8099917 SNPs using PCR-RFLP assay. Moreover, IL-28 serum level, HCV loads, and genotype were performed. A significant increase was observed in the frequencies of unfavorable rs12979860 genotypes/CT + TT in the chronic hepatitis C (CHC) and LTC groups. In the case of rs8099917, CHC group had a significantly higher frequency of unfavorable genotypes/GT + GG compared to the healthy group. IL-28B serum level was also significantly higher in healthy group compared with the CHC and LTC groups. There were no differences in the distribution of the IL-28B genotypes and haplotypes between responder and non-responder patients. Our results suggest, for the first time, that unfavorable rs12979860 genotypes can be considered one of the important immunological backgrounds in the Iranian LTC population that was confirmed with the lower IL-28 serum level compared to healthy group. Besides, there was a possible association of favorable IL-28B genotypes with lower odds of susceptibility to CHC infection but no support for a positive association between analyzed SNPs and an outcome of therapy. Moreover, non-CT haplotypes may be regarded as a genetic risk factor that can increase the chance of infection with HCV and progression toward end-stage HCV-related liver disease.

Comparative Immunogenicity in Rabbits of the Polypeptides Encoded by the 5' Terminus of Hepatitis C Virus RNA

Recent studies on the primate protection from HCV infection stressed the importance of immune response against structural viral proteins. Strong immune response against nucleocapsid (core) protein was difficult to achieve, requesting further experimentation in large animals. Here, we analyzed the immunogenicity of core aa 1–173, 1–152, and 147–191 and of its main alternative reading frame product F-protein in rabbits. Core aa 147–191 was synthesized; other polypeptides were obtained by expression in E. coli. Rabbits were immunized by polypeptide primes followed by multiple boosts and screened for specific anti-protein and anti-peptide antibodies. Antibody titers to core aa 147–191 reached 10⁵; core aa 1–152, 5 × 10⁵; core aa 1–173 and F-protein, 10⁶. Strong immunogenicity of the last two proteins indicated that they may compete for the induction of immune response. The C-terminally truncated core was also weakly immunogenic on the T-cell level. To enhance core-specific cellular response, we immunized rabbits with the core aa 1–152 gene forbidding F-protein formation. Repeated DNA immunization induced a weak antibody and sustained proliferative response of broad specificity confirming a gain of cellular immunogenicity. Epitopes recognized in rabbits overlapped those in HCV infection. Our data promotes the use of rabbits for the immunogenicity tests of prototype HCV vaccines.