In silico identification of epitope-based vaccine candidates against HTLV-1

HTLV-1 vaccination Landscape: Current developments and challenges

Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus that is distinguished for its correlation to myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukemia/lymphoma (ATLL). As well, HTLV-1 has been documented to have links with other inflammatory diseases, such as uveitis and dermatitis. According to the World Health Organization (WHO), the global distribution of HTLV-1 infection is estimated to extend between 5 and 10 million individuals. Recent efforts in HTLV-1 vaccine development primarily involve selecting viral components, such as antigens, from structural and non-structural proteins. These components are chosen to trigger a vigorous immune response from cytotoxic T lymphocytes (CTLs), helper T lymphocytes (HTLs), and B cells. Investigation into developing a vaccine against HTLV-1 is ongoing, and current surveys have explored several approaches, including viral vector vaccines, DNA vaccines, protein and peptide vaccines, dendritic cell-based vaccines, mRNA vaccines, and other platforms. Despite these investigations have shown promising results, challenges like the necessity for long-term protective immunity, addressing viral diversity, and managing potential side effects remain. It is critical to keep track of the progress made in HTLV-1 vaccination research to comprehend the development status and its possible impacts. The evolving nature of vaccine development underscores the importance of staying informed about advancements as we strive to combat HTLV-1-associated diseases through effective vaccination strategies. In this review, our goal is to provide an overview of the current status of HTLV-1 vaccination efforts, emphasizing the progress, challenges, and potential future directions in this vital area of research.

Rational design of B-cell and T-cell multi epitope-based vaccine against Zika virus, an in silico study

The Zika virus (ZKV) is a single-stranded positive-sense, enveloped RNA virus. Zika infection during pregnancy can cause congenital microcephaly, Guillain-Barré syndrome, miscarriage, and other CNS abnormalities. The world needs safe and effective vaccinations to fight against ZIKV infection since vaccination is generally regarded as one of the most effective ways to prevent infectious diseases. In the present work, we used immunoinformatics and docking studies to construct a vaccine containing multi-epitopes using the structural and non-structural proteins of ZKV. The structural models of ZKV proteins (PrE, PrM, NS1, and NS2A) were constructed using Pyre2 and RaptorX servers. The epitopes of B-cell, T-cell (HTL and CTL), and IFN-γ were predicted, and each epitope's immunogenic nature and physiochemical properties were confirmed. As an adjuvant, the CPG-Oligodeoxynucleotide, an agonist of Toll-like receptor 9 (TLR9), is associated to cytotoxic T-lymphocytes (CTL) epitopes via PAPAP linker. To assess the binding affinity and the tendency of the designed vaccine to induce an immune response through TLR9, molecular docking was done. In the next step, molecular dynamics (MD) simulation to 100 nanoseconds (ns) was used to evaluate the stability of the interaction of the designed vaccine with TLR9. The designed vaccine is predicted to be highly antigenic, non-toxic, soluble, and stable with low flexibility in MD simulation. MD studies indicated that the finalized vaccine-TLR9 docked complex was stable during simulation time. The vaccine construct is able to stimulate both humoral and cellular immune responses. We suppose that our constructed model of the vaccine may have the ability to induce the host immune response against ZKV. Further studies, including in vitro and in vivo experimental analyses, are needed to prove the constructed vaccine's efficacy with multi-epitopes.Communicated by Ramaswamy H. Sarma.

New Perspectives about Drug Candidates Targeting HTLV-1 and Related Diseases

Among the human T-lymphotropic virus (HTLV) types, HTLV-1 is the most prevalent, and it has been linked to a spectrum of diseases, including HAM/TSP, ATLL, and hyperinfection syndrome or disseminated strongyloidiasis. There is currently no globally standard first-line treatment for HTLV-1 infection and its related diseases. To address this, a comprehensive review was conducted, analyzing 30 recent papers from databases PubMed, CAPES journals, and the Virtual Health Library (VHL). The studies encompassed a wide range of therapeutic approaches, including antiretrovirals, immunomodulators, antineoplastics, amino acids, antiparasitics, and even natural products and plant extracts. Notably, the category with the highest number of articles was related to drugs for the treatment of ATLL. Studies employing mogamulizumab as a new perspective for ATLL received greater attention in the last 5 years, demonstrating efficacy, safe use in the elderly, significant antitumor activity, and increased survival time for refractory patients. Concerning HAM/TSP, despite corticosteroid being recommended, a more randomized clinical trial is needed to support treatment other than corticoids. The study also included a comprehensive review of the drugs used to treat disseminated strongyloidiasis in co-infection with HTLV-1, including their administration form, in order to emphasize gaps and facilitate the development of other studies aiming at better-directed methodologies. Additionally, docking molecules and computer simulations show promise in identifying novel therapeutic targets and repurposing existing drugs. These advances are crucial in developing more effective and targeted treatments against HTLV-1 and its related diseases.

Human T-cell lymphotropic virus type 1 (HTLV-1) proposed vaccines: a systematic review of preclinical and clinical studies

BACKGROUND

Numerous vaccination research experiments have been conducted on non-primate hosts to prevent or control HTLV-1 infection. Therefore, reviewing recent advancements for status assessment and strategic planning of future preventative actions to reduce HTLV-1 infection and its consequences would be essential.

METHODS

MEDLINE, Scopus, Web of Science, and Clinicaltrials.gov were searched from each database's inception through March 27, 2022. All original articles focusing on developing an HTLV-1 vaccine candidate were included.

RESULTS

A total of 47 studies were included. They used a variety of approaches to develop the HTLV-1 vaccine, including DNA-based, dendritic-cell-based, peptide/protein-based, and recombinant vaccinia virus approaches. The majority of the research that was included utilized Tax, Glycoprotein (GP), GAG, POL, REX, and HBZ as their main peptides in order to develop the vaccine. The immunization used in dendritic cell-based investigations, which were more recently published, was accomplished by an activated CD-8 T-cell response. Although there hasn't been much attention lately on this form of the vaccine, the initial attempts to develop an HTLV-1 immunization depended on recombinant vaccinia virus, and the majority of results seem positive and effective for this type of vaccine. Few studies were conducted on humans. Most of the studies were experimental studies using animal models. Adenovirus, Cytomegalovirus (CMV), vaccinia, baculovirus, hepatitis B, measles, and pox were the most commonly used vectors.

CONCLUSIONS

This systematic review reported recent progression in the development of HTLV-1 vaccines to identify candidates with the most promising preventive and therapeutic effects.

Design peptide and multi-epitope protein vaccine candidates against monkeypox virus using reverse vaccinology approach: an in-silico study

Monkeypox is a zoonotic virus that has recently affected different countries worldwide. On July 23, 2022, the WHO declared the outbreak of monkeypox as a public health emergency of international concern. Surveillance studies conducted in Central Africa in the 1980s and later during outbreaks in the same region showed smallpox vaccines to be clinically somewhat effective against Monkeypox virus. However, there is no specific vaccine against this virus. This research used bioinformatics techniques to establish a novel multi-epitope vaccine candidate against Monkeypox that can induce a strong immune response. Five well-known antigenic proteins (E8L, A30L, A35R, A29L, and B21R) of the virus were picked and assessed as possible immunogenic peptides. Two suitable peptide candidates were selected according to bio-informatics analysis. Based upon in silico evaluation, two multi-epitope vaccine candidates (ALALAR and ALAL) were built with rich-epitope domains consisting of high-ranking T and B-cell epitopes. After predicting and evaluating the 3D structure of the protein candidates, the most efficient 3D models were considered for docking studies with Toll-like receptor 4 (TLR4) and the HLA-A * 11:01, HLA-A*01:01, HLA-A*02:01, HLA-A*03:01, HLA-A*07:02, HLA-A*15:01, HLA-A*30:01 receptors. Subsequently, molecular dynamics (MD) simulation of up to 150 nanoseconds was employed to assess the durability of the interaction of the vaccine candidates with immune receptors. MD studies showed that M5-HLA-A*11:01, ALAL-TLR4, and ALALAR-TLR4 complexes were stable during simulation. Analysis of the in silico outcomes indicates that the M5 peptide and ALAL and ALALAR proteins may be suitable vaccine candidates against the Monkeypox virus.Communicated by Ramaswamy H. Sarma.

Recombinant GPEHT Fusion Protein Derived from HTLV-1 Proteins with Alum Adjuvant Induces a High Immune Response in Mice

The human T-cell leukemia virus type 1 (HTLV-1) is a positive single-stranded RNA virus that belongs to the delta retrovirus family. As a result, a vaccine candidate that can be recognized by B cells and T cells is a good candidate for generating a durable immune response. Further, the GPEHT protein is a multi-epitope protein designed based on the Gag, Pol, Env, Hbz, and Tax proteins of HTLV-1. In developing a suitable and effective vaccine against HTLV-1, the selection of a designed protein (GPEHT) with the formulation of an alum adjuvant was conducted. In this study, we assessed the potential of a multi-epitope vaccine candidate for stimulating the immune response against HTLV-1. In assessing the type of stimulated immune reaction, total IgG, IgG1, and IgG2a isotypes, as well as the cytokines associated with Th1 (IFN-γ), Th2 (IL-4), and Th17 (IL-17), were analyzed. The outcomes showed that the particular antisera (total IgG) were more elevated in mice that received the GPEHT protein with the alum adjuvant than those in the PBS+Alum control. A subcutaneous vaccination with our chimera protein promoted high levels of IgG1 and IgG2a isotypes. Additionally, IFN-γ, IL-4, and IL-17 levels were significantly increased after spleen cell stimulation in mice that received the GPEHT protein. The immunogenic analyses revealed that the GPEHT vaccine candidate could generate humoral and cell-mediated immune reactions. Ultimately, this study suggests that GPEHT proteins developed with an alum adjuvant can soon be considered as a prospective vaccine to more accurately evaluate their protective efficacy against HTLV-1.

Repurposing antiviral drugs against HTLV-1 protease by molecular docking and molecular dynamics simulation

Human T-cell leukemia virus type I (HTLV-1) belongs to the delta retrovirus family and the etiological agent of adult T-cell leukemia (ATL(. While the current HTLV-1 therapy, relies on using Zidovudine plus IFN-γ, there is no FDA approved drugs against it. In silico drug repurposing is a fast and accurate way for screening US-FDA approved drugs to find a therapeutic option for the HTLV-1 infection. So that, this research aims to analyze a dataset of approved antiviral drugs as a potential prospect for an anti-viral drug against HTLV-1 infection. Molecular docking simulation was performed to identify interactions of the antiviral drugs with the key residues in the HTLV-1 protease binding site. Then, molecular dynamics simulation was also performed for the potential protein-ligand complexes to confirm the stable behavior of the ligands inside the binding pocket. The best docking scores with the target was found to be Simeprevir, Atazanavir, and Saquinavir compounds which indicate that these drugs can firmly bind to the HTLV-1 protease. The MD simulation confirmed the stability of Simeprevir-protease, Atazanavir-Protease, and Saquinavir-Protease interactions. Clearly, these compounds should be further evaluated in experimental assays and clinical trials to confirm their actual activity against HTLV-1 infection.Communicated by Ramaswamy H. Sarma.