Comparison of HIV-1 Vif and Vpu accessory proteins for delivery of polyepitope constructs harboring Nef, Gp160 and P24 using various cell penetrating peptides

The Role of Peptides in Combatting HIV Infection: Applications and Insights

Peptide-based inhibitors represent a promising approach for the treatment of HIV-1, offering a range of potential advantages, including specificity, low toxicity, and the ability to target various stages of the viral lifecycle. This review outlines the current state of research on peptide-based anti-HIV therapies, highlighting key advancements and identifying future research directions. Over the past few years, there has been significant progress in developing synthetic peptide-based drugs that target various stages of the viral life cycle, including entry and replication. These approaches aim to create effective anti-HIV therapies. Additionally, peptides have proven valuable in the development of anti-HIV vaccines. In the quest for effective HIV vaccines, discovering potent antigens and designing suitable vaccine strategies are crucial for overcoming challenges such as low immunogenicity, safety concerns, and increased viral load. Innovative strategies for vaccine development through peptide research are, therefore, a key focus area for achieving effective HIV prevention. This review aims to explore the strategies for designing peptides with anti-HIV activity and to highlight their role in advancing both therapeutic and preventive measures against HIV.

Immunoinformatic Identification of Multiple Epitopes of gp120 Protein of HIV-1 to Enhance the Immune Response against HIV-1 Infection

Acquired Immunodeficiency Syndrome is caused by the Human Immunodeficiency Virus (HIV), and a significant number of fatalities occur annually. There is a dire need to develop an effective vaccine against HIV-1. Understanding the structural proteins of viruses helps in designing a vaccine based on immunogenic peptides. In the current experiment, we identified gp120 epitopes using bioinformatic epitope prediction tools, molecular docking, and MD simulations. The Gb-1 peptide was considered an adjuvant. Consecutive sequences of GTG, GSG, GGTGG, and GGGGS linkers were used to bind the B cell, Cytotoxic T Lymphocytes (CTL), and Helper T Lymphocytes (HTL) epitopes. The final vaccine construct consisted of 315 amino acids and is expected to be a recombinant protein of approximately 35.49 kDa. Based on docking experiments, molecular dynamics simulations, and tertiary structure validation, the analysis of the modeled protein indicates that it possesses a stable structure and can interact with Toll-like receptors. The analysis demonstrates that the proposed vaccine can provoke an immunological response by activating T and B cells, as well as stimulating the release of IgA and IgG antibodies. This vaccine shows potential for HIV-1 prophylaxis. The in-silico design suggests that multiple-epitope constructs can be used as potentially effective immunogens for HIV-1 vaccine development.

HIV-1 Accessory Proteins: Which one is Potentially Effective in Diagnosis and Vaccine Development?

BACKGROUND

The combination antiretroviral therapy (cART) could increase the number of circulating naive CD4 T lymphocytes, but was not able to eradicate human immunodeficiency virus-1 (HIV-1) infection.

OBJECTIVE

Thus, induction of strong immune responses is important for control of HIV-1 infection. Furthermore, a simple and perfect serological method is required to detect virus in untreated-, treated- and drug resistant- HIV-1 infected individuals.

METHODS

This study was conducted to assess and compare immunogenic properties of Nef, Vif, Vpr and Vpu accessory proteins as an antigen candidate in mice and their diagnostic importance in human as a biomarker.

RESULTS

Our data showed that in mice, all heterologous prime/ boost regimens were more potent than homologous prime/ boost regimens in eliciting Th1 response and Granzyme B secretion as CTL activity. Moreover, the Nef, Vpu and Vif proteins could significantly increase Th1 immune response. In contrast, the Vpr protein could considerably induce Th2 immune response. On the other hand, among four accessory proteins, HIV-1 Vpu could significantly detect treated group from untreated group as a possible biomarker in human.

CONCLUSION

Generally, among accessory proteins, Nef, Vpu and Vif antigens were potentially more suitable vaccine antigen candidates than Vpr antigen. Human antibodies against all these proteins were higher in HIV-1 different groups than healthy group. Among them, Vpu was known as a potent antigen in diagnosis of treated from untreated individuals. The potency of accessory proteins as an antigen candidate in an animal model and a human cohort study are underway.

Evaluation of HIV-1 Regulatory and Structural Proteins as Antigen Candidate in Mice and Humans

BACKGROUND

The diagnosis of HIV infection is important among different groups. Moreover, combination antiretroviral therapy is used to treat HIV-1, but it cannot eradicate the infection. Thus, the development of therapeutic vaccines, along with antiretroviral therapy, is recommended. This study evaluates the values of four HIV proteins as antigen candidates in therapeutic vaccine design as well as a possible diagnostic marker for HIV infection in humans.

METHODS

In this study, the HIV-1 Tat and Rev regulatory proteins and structural Gp120 and p24 proteins were generated in E. coli expression system. Their immunogenicity was evaluated in BALB/ c mice using homologous and heterologous prime/boost strategies. Moreover, the detection of anti- HIV IgG antibodies against these recombinant proteins was assessed in untreated (Naïve/ HIV-infected), treated, and drug-resistant patients compared to the healthy (control) group as a possible diagnostic marker for HIV infection.

RESULTS

In humans, our results showed that among HIV-1 proteins, anti-Gp120 antibody was not detected in treated individuals compared to the healthy (control) group. The levels of anti-Gp120 antibody were significantly different between the treated group and Naïve as well as drug-resistant subjects. Moreover, the level of anti-p24 antibody was significantly lower in the treated group than the Naive group. In mice, the results of immunization indicated that the Rev antigen could significantly induce IgG2a, IgG2b, and IFN-γ secretion aimed at Th1 response as well as Granzyme B generation as CTL activity in comparison with other antigens. Furthermore, the heterologous DNA prime/ protein boost regimen was more potent than the homologous regimen for stimulation of cellular immunity.

CONCLUSION

Briefly, the levels of both anti-Gp120 and anti-p24 antibodies can be considered for the diagnosis of the HIV-infected individuals in different groups compared to the healthy group. Moreover, among four recombinant proteins, Rev elicited Th1 cellular immunity and CTL activity in mice as an antigen candidate in therapeutic vaccine development.

Evolutionary Timeline of Genetic Delivery and Gene Therapy

There are more than 3,500 genes that are being linked to hereditary diseases or correlated with an elevated risk of certain illnesses. As an alternative to conventional treatments with small molecule drugs, gene therapy has arisen as an effective treatment with the potential to not just alleviate disease conditions but also cure them completely. In order for these treatment regimens to work, genes or editing tools intended to correct diseased genetic material must be efficiently delivered to target sites. There have been many techniques developed to achieve such a goal. In this article, we systematically review a variety of gene delivery and therapy methods that include physical methods, chemical and biochemical methods, viral methods, and genome editing. We discuss their historical discovery, mechanisms, advantages, limitations, safety, and perspectives.

In Silico and in Vivo Analysis of HIV-1 Rev Regulatory Protein for Evaluation of a Multiepitope-based Vaccine Candidate

In silico-designed multiepitope conserved regions of human immunodeficiency virus 1 (HIV-1) proteins would be a beneficial strategy for antigen design which induces effective anti-HIV-1 T-cell responses. The conserved multiple HLA-DR-binding epitopes of Rev protein were identified using IEDB MHC-I prediction tools and SYFPEITHI webserver to screen potential T-cell epitopes. We analyzed toxicity, allergenicity, immunogenicity, hemolytic activity, cross-reactivity, cell-penetrating peptide (CPP) potency, and molecular docking of the candidate epitopes using several immune-informatics tools. Afterward, we designed a novel multiepitope construct based on non-toxic and non-allergenic Rev, Nef, Gp160 and P24-derived cytotoxic T cell (CTL) and T-helper cell (HTL) epitopes. Next, the designed construct (Nef-Rev-Gp160-P24) was subjected to three B-cell epitope prediction webservers, ProtParam and Protein-Sol to obtain the physicochemical features. Then, the recombinant multiepitope DNA and polypeptide constructs were complexed with different CPPs for nanoparticle formation and pass them via the cell membranes. Finally, the immunogenicity of multiepitope constructs in a variety of modalities was evaluated in mice. The results demonstrated that groups immunized with heterologous DNA+ MPG or HR9 CPP prime/rNef-Rev-Gp160-P24 polypeptide + LDP-NLS CPP boost regimens could significantly produce higher levels of IFN-γ and Granzyme B, and lower amounts of IL-10 than other groups. Moreover, higher levels of IgG2a and IgG2b were observed in all heterologous prime-boost regimens than homologous DNA or polypeptide regimens. Altogether, the present findings indicated that the Nef-Rev-Gp160-P24 polypeptide meets the criteria to be potentially useful as a multiepitope-based vaccine candidate against HIV-1 infection.

Cppsite 2.0: An Available Database of Experimentally Validated Cell-Penetrating Peptides Predicting their Secondary and Tertiary Structures

One of the biggest barriers in drug and vaccine development is to find an effective delivery system. Cell-penetrating peptides (CPPs) play a crucial role for delivery of biological cargoes and pass them through the membranes. Several databases have been developed for therapeutic peptides as potential drug candidates and delivery vehicles. A rapid growth has occurred in many patents and research articles on CPPs as therapeutic peptides. To save time and cost in laboratories, prediction and design of CPPs before in vitro/in vivo experiments using computational methods and online web servers are rational. Various online web servers which provide prediction of CPPs including CellPPD, CPPpred, CPPred-RF and MLCPP, and also different curated databases that present validated information of CPPs such as CPPsite 2.0 have been developed up to now. Two methods including CellPPD and CPPpred were applied to predict and design potent CPPs. CPPsite 2.0 is a user-friendly updated database that provides various information about CPPs and contains 1855 entries. This database provides comprehensive information on experimentally tested CPPs and prediction of their secondary and tertiary structures to realize their structure-function relationship. Furthermore, each entry presents information of a CPP including chirality, origin, nature of peptide, sub-cellular localization, uptake mechanism and efficiency, amino acid composition, hydrophobicity, and physicochemical properties. One of main goals of CPPsite 2.0 database is to provide the latest datasets of CPPs for analysis and development of CPP prediction methods. CPPsite 2.0 is freely available at https://webs.iiitd.edu.in/raghava/cppsite.

Antiviral therapy for the sexually transmitted viruses: recent updates on vaccine development

INTRODUCTION

The sexually transmitted infections (STIs) caused by viruses including human T cell leukemia virus type-1 (HTLV-1), human immunodeficiency virus-1 (HIV-1), human simplex virus-2 (HSV-2), hepatitis C virus (HCV), hepatitis B virus (HBV), and human papillomavirus (HPV) are major public health issues. These infections can cause cancer or result in long-term health problems. Due to high prevalence of STIs, a safe and effective vaccine is required to overcome these fatal viruses.

AREAS COVERED

This review includes a comprehensive overview of the literatures relevant to vaccine development against the sexually transmitted viruses (STVs) using PubMed and Sciencedirect electronic search engines. Herein, we discuss the efforts directed toward development of effective vaccines using different laboratory animal models including mice, guinea pig or non-human primates in preclinical trials, and human in clinical trials with different phases.

EXPERT OPINION

There is no effective FDA approved vaccine against the sexually transmitted viruses (STVs) except for HBV and HPV as prophylactic vaccines. Many attempts are underway to develop vaccines against these viruses. There are several approaches for improving prophylactic or therapeutic vaccines such as heterologous prime/boost immunization, delivery system, administration route, adjuvants, etc. In this line, further studies can be helpful for understanding the immunobiology of STVs in human. Moreover, development of more relevant animal models is a worthy goal to induce effective immune responses in humans.

An overview of in silico vaccine design against different pathogens and cancer

INTRODUCTION

Due to overcome the hardness of the vaccine design, computational vaccinology is emerging widely. Prediction of T cell and B cell epitopes, antigen processing analysis, antigenicity analysis, population coverage, conservancy analysis, allergenicity assessment, toxicity prediction, and protein-peptide docking are important steps in the process of designing and developing potent vaccines against various viruses and cancers. In order to perform all of the analyses, several bioinformatics tools and online web servers have been developed. Scientists must take the decision to apply more suitable and precise servers for each part based on their accuracy.

AREAS COVERED

In this review, a wide-range list of different bioinformatics tools and online web servers has been provided. Moreover, some studies were proposed to show the importance of various bioinformatics tools for predicting and developing efficient vaccines against different pathogens including viruses, bacteria, parasites, and fungi as well as cancer.

EXPERT OPINION

Immunoinformatics is the best way to find potential vaccine candidates against different pathogens. Thus, the selection of the most accurate tools is necessary to predict and develop potent preventive and therapeutic vaccines. To further evaluation of the computational and in silico vaccine design, in vitro/in vivo analyses are required to develop vaccine candidates.

B1 protein: a novel cell penetrating protein for in vitro and in vivo delivery of HIV-1 multi-epitope DNA constructs

Objectives

Enhancement of the potential ability of biomacromolecules to cross cell membranes is a critical step for development of effective therapeutic vaccine especially DNA vaccine against human immunodeficiency virus-1 (HIV-1) infection. The supercharged proteins were known as powerful weapons for delivery of different types of cargoes such as DNA and protein. Hence, we applied B1 protein with + 43 net charges obtained from a single frameshift in the gene encoding enhanced green fluorescent protein (eGFP) for delivery of two multi-epitope DNA constructs (nef-vpu-gp160-p24 and nef-vif-gp160-p24) in vitro and in vivo for the first time. For this purpose, B1 protein was generated in bacterial expression system under native conditions, and used to interact with both DNA constructs.

Results

Our data indicated that B1 protein (~ 27 kDa) was able to form a stable nanoparticle (~ 80–110 nm) with both DNA constructs at nitrogen: phosphate (N: P) ratio of 1:1. Moreover, the transfection efficiency of B1 protein for DNA delivery into HEK-293T cell line indicated that the cellular uptake of nef-vif-gp160-p24 DNA/ B1 and nef-vpu-gp160-p24 DNA/ B1 nanoparticles was about 32–35% with lower intensity as compared to TurboFect commercial reagent. On the other hand, immunization of BALB/c mice with different modalities demonstrated that B1 protein could enhance the levels of antibody, IFN-gamma and Granzyme B eliciting potent and strong Th1-directed cellular immunity.

Conclusion

Generally, our findings showed the potency of B1 protein as a promising gene delivery system to improve an effective therapeutic vaccine against HIV-1 infection.