Prevalence of Naturally Occurring Resistance Associated Substitutions in NS3/4AProtease Inhibitors in Iranian HCV/HIV Infected Patients.

BACKGROUND: Hepatitis C virus (HCV) acts in the host as a complicated mixture of related variants with the potency to genetically escape host immune responses. Direct acting antivirals (DAAs) have been approved for HCV treatment with shorter duration, better cure rates and lower side effects. However, naturally occurring resistance associated substitutions (RASs) create some obstacles to this antiviral therapy success. OBJECTIVE: In this study, we aimed at the determination of the naturally occurring NS3/4A RASs in HCV/human immunodeficiency virus (HIV)infected patients. METHODS: A total of 120 DAA-naïve HCV-HIV co-infected patients were included. HCV NS3/4Agenome region was amplified with PCR and mutation analysis was performed by Sanger sequencing technique. The amino acid sequence diversity of the region was analyzed using geno2pheno HCV. RESULTS: Phylogenetic analysis showed that 73 cases were infected by 3a and 47 subjects by subtype1a. The overall RASs among studied subjects were observed in 6 (5%) individuals from 120 studied cases who were infected with HCV 1a. V36M/L, Q80L, S122G/L, R155T/G, A156S, D168Y/N and S174A/N/T mutations were detected in this study. CONCLUSION: Although the prevalence of RASs was totally low in this study, the presence of several cases of double and triple mutants among this population suggests prior evaluation of protease inhibitors related mutations before initiation of standard treatment and also an investigation on a large population could be of high value.

HIV-1 p24-nef DNA Vaccine Plus Protein Boost Expands T-Cell Responses in BALB/c.

BACKGROUND: There have been massive efforts on vaccine development against HIV-1 since its discovery. Various approaches have been taken to attention, including rational vaccine design, optimized delivery systems and heterologous regimen to eradicate the virus. DNA vaccines fundamentally induce host immune responses by genetically engineered plasmids encoding antigens and expressed in vivo without the need of the specific delivery system. Therefore, long-term endogenous antigen expression could be possible. OBJECTIVE: In this study, we aimed at evaluation and comparison of DNA and protein vaccine based on two forms of full and truncated HIV-1 p24-nef antigens by in silico design in BLALB/c. METHODS: The recombinant pcDNA3.1 harboring two sets of HIV-1 p24 and nef genes in truncated and full forms were generated and applied to immunize BALB/c along with the corresponding proteins via three different DNA/DNA, DNA/protein and protein/protein regimens. RESULTS: The results showed that the applied regimens could elicit strong immune responses in comparison with controls and the prim-boost DNA/protein regimen reached the highest immune induction (p < 0.05). Moreover, prime-boost approach was assessed more successfully in a qualitatively broad Th1 response induction. The truncated form of the antigens, p24(80-231 aa)-AAY- Nef (120-150), was evaluated more immunogenic in agreement with the in silico investigation. CONCLUSION: The truncated form of p24-Nef was evaluated highly immunogenic specially when applied in prim-boost DNA/Protein regimen and could be investigated in other delivery systems and a proper animal model to achieve a therapeutic vaccine candidate against HIV-1.

Production of Recombinant HIV-1 p24-Nef Protein in Two Forms as Potential Candidate Vaccines in Three Vehicles.

BACKGROUND: Different approaches have been investigated to develop a preventive or therapeutic vaccine, although none of them has been fully practical. Therapeutic vaccines against HIV-1 have been studied with the aim of eliminating the virus from reservoir cells with or without HAART (Highly Active Antiretroviral Therapy). Fusion proteins with the most immunogenic features among conserved regions can facilitate this achievement in such a variable virus. To achieve the most immunogenic and also conserved regions, bioinformatics tools are widely used to predict antigens' features before applying them. OBJECTIVE: This study aimed at the in vitro evaluation of p24 -Nef fusion protein based on the previous in silico design to achieve a potential therapeutic subunit vaccine against HIV-1. METHODS: The truncated form of p24-Nef using AAY flexible linker and the full protein were expressed and evaluated in the prokaryotic system and confirmed by western blotting. We also used pcDNA3.1 to transfect Lenti-X 293T cells. Moreover, lentiviral vectors were applied to produce recombinant virions harboring the genes of interest and cell transduction. RESULTS: Both fusion proteins in a truncated and a full form were expressed and confirmed by Anti Nef polyclonal antibody in western blotting. Recombinant virions were generated and transduced Lenti-X 293T cells confirming by immunofluorescence microscope and p24 ELISA assay kit. Transduced cells were analyzed by SDS-PAGE and western blotting, which resulted in approved protein expression. CONCLUSION: Fusion protein of p24 and Nef is well expressed in eukaryotic cell lines according to its pre-evaluated features by bioinformatics tools.

Updated Studies on the Development of HIV Therapeutic Vaccine.

BACKGROUND: Among the various types of pharmaceuticals, vaccines have a special place. However, in the case of HIV, nearly after 40 years of its discovery, an effective vaccine still is not available. The reason lies in several facts mainly the variability and smartness of HIV as well as the complexity of the interaction between HIV and immune responses. A robust, effective, and longterm immunity is undoubtedly what a successful preventive vaccine should induce in order to prevent the infection of HIV. Failure of human trials to this end has led to the idea of developing therapeutic vaccines with the purpose of curing already infected patients by boosting their immune responses against the virus. Nevertheless, the exceptional ability of the virus to escape the immune system based on the genetically diverse envelope and variable protein products have made it difficult to achieve an efficient therapeutic vaccine. OBJECTIVE: We aimed at studying and comparing different approaches to HIV therapeutic vaccines. METHODS: In this review, we summarized the human trials undergoing on HIV therapeutic vaccination which are registered in the U.S. clinical trial database (clinicaltrials.gov). These attempts are divided into different tables, according to the type of formulation and application in order to classify and compare their results. RESULT/CONCLUSION: Among several methods applied in studied clinical trials which are mainly divided into DNA, Protein, Peptide, Viral vectors, and Dendritic cell-based vaccines, protein vaccine strategy is based on Tat protein-induced anti-Tat Abs in 79% HIV patients. However, the studies need to be continued to achieve a durable efficient immune response against HIV-1.

Induction of a Robust Humoral Response using HIV-1 VLPMPER-V3 as a Novel Candidate Vaccine in BALB/c Mice.

BACKGROUND: Several approaches have not been successful to suppress HIV (Human immunodeficiency virus) infection among infected individuals or to prevent it yet. In order to expand strong HIV specific humoral and cellular responses, Virus-like particles (VLPs) as potential vaccines show significant increase in neutralizing antibodies secretion, T-cell count and also secretion of cytokines. OBJECTIVE: This study aimed at immunological evaluation of VLPs harboring high copy of MPERV3 in BALB/c mice. METHODS: Female BALB/c mice were immunized with homologous and heterologous primeboosting regimens of HIV-1 VLPMPER-V3. Their immune responses were evaluated for humoral responses (Total IgG and IgG isotyping) and cellular responses (IFN-γ, IL-5 secretion, in vitro CTL assay and T cell proliferation) and compared in immunized mice. RESULTS: The data showed robust induction of humoral response in mice groups which received different regimens of VLP. Furthermore, analysis of cytokine profile indicated that the highest IL-5 secretion was related to VLP+M50 group and confirmed the dominance of Th2 immunity in this group. CONCLUSION: This study showed that VLP MPER-V3 as a potential vaccine candidate has the potency as an effective prophylactic vaccine and this finding guarantees further investigations to achieve a promising HIV-1 vaccine candidate.

In Silico Design and Immunologic Evaluation of HIV-1 p24-Nef Fusion Protein to Approach a Therapeutic Vaccine Candidate.

BACKGROUND: Acquired immune deficiency syndrome (HIV/AIDS) has been a major global health concern for over 38 years. No safe and effective preventive or therapeutic vaccine has been developed although many products have been investigated. Computational methods have facilitated vaccine developments in recent decades. Among HIV-1 proteins, p24 and Nef are two suitable targets to provoke the cellular immune response. However, the fusion form of these two proteins has not been analyzed in silico yet. OBJECTIVE: This study aimed at the evaluation of possible fusion forms of p24 and Nef in order to achieve a potential therapeutic subunit vaccine against HIV-1. METHOD: In this study, various computational approaches have been applied to predict the most effective fusion form of p24-Nef including CTL (Cytotoxic T lymphocytes) response, immunogenicity, conservation and population coverage. Moreover, binding to MHC (Major histocompatibility complex) molecules was assessed in both human and BALB/c. RESULTS: After analyzing six possible fusion protein forms using AAY linker, we came up with the most practical form of p24 from 80 to 231 and Nef from 120 to 150 regions (according to their reference sequence of HXB2 strain) using an AAY linker, based on their peptides affinity to MHC molecules which are located in a conserved region among different virus clades. The selected fusion protein contains seventeen MHC I antigenic epitopes, among them KRWIILGLN, YKRWIILGL, DIAGTTSTL and FPDWQNYTP are fully conserved between the virus clades. Furthermore, analyzed class I CTL epitopes showed greater affinity binding to HLA-B 57*01, HLA-B*51:01 and HLA-B 27*02 molecules. The population coverage with the rate of >70% coverage in the Persian population supports this truncated form as an appropriate candidate against HIV-I virus. CONCLUSION: The predicted fusion protein, p24-AAY-Nef in a truncated form with a high rate of T cell epitopes and high conservancy rate among different clades, provides a helpful model for developing a therapeutic vaccine candidate against HIV-1.

Lack of TNF-α Gene Polymorphism (rs1799724) Association with Sustained Virological Response in Iranian Patients with Chronic HCV Infection.

Infection with the hepatitis C virus is a major public health concern which can lead to carcinoma and liver failure. It has been shown that single nucleotide polymorphisms can affect the level of gene activity of tumor necrosis factor (TNF) which has an important role, especially in viral infections which can lead to apaptosis of infected hepatocellular cells. We investigated the impact of three possible genotypes for rs1800629 or A/G single nucleotide polymorphism located downstream of TNFα gene promoter in groups of control (n=76) and chronic hepatitis C patients (n=89) focusing on the response to treatment among sensitive and resistant groups. Genomic DNA was extracted from 500 µl prepheral whole blood and PCR and RFLP were used to amplify the region of interest and genotyping. With statistical analyzes a p-value <0.05 was considered meaningful. There was no significant difference in distribution of the possible three genotypes among healthy individuals and patients (P=0.906, OR=1.194, CI=0.063-22.790). However, the frequency of the G allele was higher in patients whereas A allele was more common among healthy individuals (p<0.0001). Further studies with more samples appears to be necessary.

Correlation Study Between IL-28B Gene Polymorphism (rs8099917SNP) and Sustained Virological Response in Iranian Patients with Chronic Hepatitis C.

BACKGROUND: The current standard treatment for hepatitis C is a combination of pegylated interferon alpha and ribavirin (peg-IFNα/RBV). Recent studies have shown that single nucleotide polymorphisms (SNPs) near the interleukin 28B (IL28B) gene coding for IFN-λ3 were associated with the antiviral treatment response. Therefore, in this study, we determined the distribution of the rs8099917 (T/G) polymorphism with sustained virological response (SVR) to chronic hepatitis C virus infection among Iranian patients. METHODS: This cross-sectional study was performed on 150 blood samples based on 93 patients with chronic HCV genotypes 1 and 3 including 71 SVR positive, 22 negative, and 57 healthy individual controls. DNA was extracted from the samples and the frequency of the polymorphism was analyzed the using PCR-RFLP method. Finally, the products were detected on 3.5% agarose gel electrophoresis. RESULTS: The analysis of the data for G/T polymorphism showed that the GG genotype was identified in 6 patients of 71 who achieved SVR, while the GT heterozygous was found in 33 patients and SVR was achieved in 19. Finally, the TT was detected in 53 patients and 7 patients were resistant to treatment. CONCLUSIONS: The results showed significant effects of G allele carriers on susceptibility to HCV infection com-pared to the other allele (T) in our studied population (p = 0.013, OR = 2.23, 95% CI = 1.18-4.21), but we did not find a significant correlation for SVR to therapy in patients with genotype TT (p = 0.055, OR = 0.48, 95% CI = 0.23-1.01). However, further studies with more samples are necessary.

Impact of TGF-ß1 Gene Polymorphism (rs1800469) on Treatment Response to Pegylated Interferon/Ribavirin in Iranian Patients with Hepatitis C.

BACKGROUND: Hepatitis C virus as a major cause of chronic liver disease affects more than 170 million people worldwide. Recent studies have claimed that single nucleotide polymorphisms (SNPs) for the transforming growth factor-ß1 (TGF-ß1) gene were strongly associated with the antiviral treatment response. Thus, the present study aimed at the determination of distribution of the rs1800469 (C/T) polymorphism among Iranian with chronic hepatitis C. METHODS: A total of 165 blood samples including 68 SVR positive and 21 non-responder samples from individuals suffering chronic hepatitis C and also 76 healthy individual controls were analyzed in this cross-sectional study. DNA was isolated from the samples using a DNA extraction standard kit. Then the frequency of the polymorphism was analyzed using PCR-RFLP method. Eventually, the products of interest were detected on 2.5% agarose gel electrophoresis. RESULTS: The distribution of the C/T polymorphism between healthy individuals and patients were obtained as TT: 22.4%, TC: 46%, CC: 31.6%, and TT: 19.1%, TC: 48.3%, CC: 32.6%, respectively. Furthermore, the CC genotype was identified in 20 patients of whom 68 achieved SVR, while the CT heterozygous was found in 43 patients and SVR was achieved in 38. Finally, the TT was detected in 17 patients, and 7 patients did not achieve SVR. CONCLUSIONS: We observed a significant difference of C allele frequency with SVR as compared to the T allele among patients (p = 0.064). On the other hand, there is no correlation between the polymorphism and susceptibility to HCV infection. However, further studies with more samples seem to be necessary.