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

Determination of COVID-19 Late Disorders as Possible Long-COVID and/or Vaccination Consequences

In this era in which the vast majority of the global population have developed COVID-19 infection and/or got vaccinated against it, identification of the late disorders as the vaccines' side effect or long-COVID manifestation seems essential. This study included the vaccinated individuals of 4 different vaccine regimens including inactivated virus-based, subunit protein, and adenovirus-based vaccines in a follow-up schedule 6-month post the booster shot. All the documented vaccine adverse events were thoroughly assessed considering the cases' medical history by Adverse Events Committee of Pasteur Institute of Iran. Totally 329 individuals who got 3 doses of vaccination were followed 6 months after the booster shots among whom 41 (12.4%) cases with the mean age of 40.9 ± 10.48 years had a type of disorder. Gynecological and osteoarticular involvements were the most common recorded disorders of which 73.1% were possibly linked to vaccination outcomes and the rest were affected by both long-COVID-19 and vaccination. Notably, the average time of symptoms persistence was 155 ± 10.4 days. This study has the advantage of long-term follow-up which presents various forms of late events in each episode of COVID-19 infection and vaccination. About 26.8% of people with persistent complications suffered from both long-COVOD/ vaccination in whom the differentiation between the vaccine side effect and long-COVID manifestation was quite challenging. Long-term follow-up studies in large population seems essential to outline the role of long-COVID and vaccination regarding persistent complications.

An engineered HIV-1 Gag-based VLP displaying high antigen density induces strong antibody-dependent functional immune responses

Antigen display on the surface of Virus-Like Particles (VLPs) improves immunogenicity compared to soluble proteins. We hypothesised that immune responses can be further improved by increasing the antigen density on the surface of VLPs. In this work, we report an HIV-1 Gag-based VLP platform engineered to maximise the presence of antigen on the VLP surface. An HIV-1 gp41-derived protein (Min), including the C-terminal part of gp41 and the transmembrane domain, was fused to HIV-1 Gag. This resulted in high-density MinGag-VLPs. These VLPs demonstrated to be highly immunogenic in animal models using either a homologous (VLP) or heterologous (DNA/VLP) vaccination regimen, with the latter yielding 10-fold higher anti-Gag and anti-Min antibody titres. Despite these strong humoral responses, immunisation with MinGag-VLPs did not induce neutralising antibodies. Nevertheless, antibodies were predominantly of an IgG2b/IgG2c profile and could efficiently bind CD16-2. Furthermore, we demonstrated that MinGag-VLP vaccination could mediate a functional effect and halt the progression of a Min-expressing tumour cell line in an in vivo mouse model.

Tracing the recent updates on vaccination approaches and significant adjuvants being developed against HIV

INTRODUCTION

Human Immunodeficiency Virus type 1 (HIV1); the causative agent of Acquired Immunodeficiency Syndrome (AIDS), has been a major target of the scientific community to develop an anti-viral therapy. Some successful discoveries have been made during the last two decades in the form of availability of antiviral therapy in endemic regions. Nevertheless, a total cure and safety vaccine has not yet been designed to eradicate HIV from the world.

AREAS COVERED

The purpose of this comprehensive study is to compile recent data regarding therapeutic interventions against HIV and to determine future research needs in this field. A systematic research strategy has been used to gather data from recent, most advanced published electronic sources. Literature based results show that experiments at the invitro level and animal models are continuously in research annals and are providing hope for human trials.

EXPERT OPINION

There is still a gap and more work is needed in the direction of modern drug and vaccination designs. Moreover coordination is necessary among researchers, educationists, public health workers, and the general community to communicate and coordinate the repercussions associated with the deadly disease. It is important for taking timely measures regarding mitigation and adaptation with HIV in future.

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.

Evaluation of transduced dendritic cells expressing HIV-1 p24-Nef antigens in HIV-specific cytotoxic T cells induction as a therapeutic candidate vaccine

Various approaches have been investigated to prevent or eliminate HIV-1 since 1981. However, the virus has been affecting human population worldwide with no effective vaccine yet. The conserved regions among the viral genes are suitable targets in mutable viruses to induce the immune responses via an effective delivery platform. In this study, we aimed at evaluation of p24 and nef in two forms of full and truncated genes as two fusion antigenic forms according to our previous bioinformatics analysis. The designed antigens were then transferred through ex vivo generated dendritic cells and also proteins in BALB/c to assess and compare immunogenicity. p24 and Nef amino acid sequences were aligned, then, the most conserved regions were selected and two fusion forms as the truncated (p24:80-231aa-Nef:120-150aa) and the full from (p24-Nef) were cloned and expressed in prokaryotic and eukaryotic systems. Lentiviral vectors were applied to generate recombinant virions harboring the genes of interest to transduce generated murine dendritic cells. BALB/c mice received the recombinant DCs or recombinant proteins according to the defined schedule. IgG development was assessed to determine humoral immune activity and cellular immune responses were evaluated by IL-5 and IFN-y induction. Granzyme B secretion was also investigated to determine CTL activity in different immunized groups. The data showed high induction of cellular immune responses in dendritic cell immunization specifically in immunized mice with the truncated form of the p24 and Nef by high secretion of IFN-y and strong CTL activity. Moreover, protein/ DC prime-boost formulation led to stronger Th1 pathway and strong CTL activation in comparison with other formulations. The generated recombinant dendritic cells expressing p24-Nef induced humoral and cellular immunity in a Th1 pathway specifically with the in silico predicted truncated antigen which could be of high value as a dendritic cell therapeutic vaccine candidate against HIV-1.

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.

Production and Evaluation of the Properties of HIV-1-Nef-MPER-V3 Fusion Protein Harboring IMT-P8 Cell Penetrating Peptide

BACKGROUND

Finding a safe and effective vaccine for HIV-1 infection is still a major concern.

OBJECTIVE

This study aimed to design and produce a recombinant Nef-MPER V3 protein fused with IMT-P8 using E. coli expression system to provide a potential HIV vaccine with high cellular penetrance.

METHODS

After synthesizing the DNA sequence of the fusion protein, the construct was inserted into the pET-28 expression vector. The recombinant protein expression was induced using 1 mM IPTG and the product was purified through affinity chromatography. Characterization of cellular delivery, toxicity and immunogenicity of the protein was carried out.

RESULTS

The recombinant protein was expressed and confirmed by the anti-Nef antibody through western blotting. Data analyses showed that the protein possessed no considerable toxicity effect and has improved the IMT-P8 penetration rate in comparison to a control sample. Moreover, the antigen immunogenicity of the protein induced specific humoral response in mice.

CONCLUSION

It was concluded that IMT-P8-Nef-MPER-V3 fusion protein has a high penetrance rate in mammalian cell line and low toxicity, thus it can be potentially considered as a vaccine against HIV-1.

Dendritic Cells/Macrophages-Targeting Feature of Ebola Glycoprotein and its Potential as Immunological Facilitator for Antiviral Vaccine Approach

In the prevention of epidemic and pandemic viral infection, the use of the antiviral vaccine has been the most successful biotechnological and biomedical approach. In recent times, vaccine development studies have focused on recruiting and targeting immunogens to dendritic cells (DCs) and macrophages to induce innate and adaptive immune responses. Interestingly, Ebola virus (EBOV) glycoprotein (GP) has a strong binding affinity with DCs and macrophages. Shreds of evidence have also shown that the interaction between EBOV GP with DCs and macrophages leads to massive recruitment of DCs and macrophages capable of regulating innate and adaptive immune responses. Therefore, studies for the development of vaccine can utilize the affinity between EBOV GP and DCs/macrophages as a novel immunological approach to induce both innate and acquired immune responses. In this review, we will discuss the unique features of EBOV GP to target the DC, and its potential to elicit strong immune responses while targeting DCs/macrophages. This review hopes to suggest and stimulate thoughts of developing a stronger and effective DC-targeting vaccine for diverse virus infection using EBOV GP.