Therapeutic Vaccine Candidates Research Articles

Location and expression kinetics of Tc24 in different life stages of Trypanosoma cruzi.

Tc24-C4, a modified recombinant flagellar calcium-binding protein of Trypanosoma cruzi, is under development as a therapeutic subunit vaccine candidate to prevent or delay progression of chronic Chagasic cardiomyopathy. When combined with Toll-like receptor agonists, Tc24-C4 immunization reduces parasitemia, parasites in cardiac tissue, and cardiac fibrosis and inflammation in animal models. To support further research on the vaccine candidate and its mechanism of action, murine monoclonal antibodies (mAbs) against Tc24-C4 were generated. Here, we report new findings made with mAb Tc24-C4/884 that detects Tc24-WT and Tc24-C4, as well as native Tc24 in T. cruzi on ELISA, western blots, and different imaging techniques. Surprisingly, detection of Tc24 by Tc24-C/884 in fixed T. cruzi trypomastigotes required permeabilization of the parasite, revealing that Tc24 is not exposed on the surface of T. cruzi, making a direct role of antibodies in the induced protection after Tc24-C4 immunization less likely. We further observed that after immunostaining T. cruzi-infected cells with mAb Tc24-C4/884, the expression of Tc24 decreases significantly when T. cruzi trypomastigotes enter host cells and transform into amastigotes. However, Tc24 is then upregulated in association with parasite flagellar growth linked to re-transformation into the trypomastigote form, prior to host cellular escape. These observations are discussed in the context of potential mechanisms of vaccine immunity.

Combination immunotherapy with two attenuated Listeria strains carrying shuffled HPV-16 E6E7 protein causes tumor regression in a mouse tumor model

Cervical cancer continues to impose a heavy burden worldwide, and human papilloma virus (HPV) infection, especially persistent infection with type 16 (HPV-16), is known to be the primary etiological factor. Therapeutic vaccines are urgently needed because prophylactic vaccines are ineffective at clearing pre-existing HPV infection. Here, two recombinant Listeria strains (LMΔ-E6E7 & LIΔ-E6E7) with deletions of the actA and plcB genes, expressing the shuffled HPV-16 E6E7 protein were constructed. The strains were delivered into the spleen and liver by intravenous inoculation, induced antigen-specific cellular immunity and were eliminated completely from the internal organs several days later. Intravenously treating with single strain for three times, or with both strains alternately for three times significantly reduced the tumor size and prolonged the survival time of model mice. Combination immunotherapy with two strains seemed more effective than immunotherapy with single strain in that it enhanced the survival of the mice, and the LMΔ-E6E7-prime-LIΔ-E6E7-boost strategy showed significant stronger efficacy than single treatment with the LIΔ-E6E7 strain. The antitumor effect of this treatment might due to its ability to increase the proportion of CD8+ T cells and reduce the proportion of T regulatory cells (Tregs) in the intratumoral milieu. This is the first report regarding Listeria ivanovii-based therapeutic vaccine candidate against cervical cancer. Most importantly we are the first to confirm that combination therapy with two different recombinant Listeria strains has a more satisfactory antitumor effect than administration of a single strain. Thus, we propose a novel prime-boost treatment strategy.

Therapeutic vaccination for treatment of chronic hepatitis B.

SummaryChronic hepatitis B infection remains a serious global health threat, contributing to a large number of deaths through liver cirrhosis and hepatocellular carcinoma. Current treatment does not eradicate disease, and therefore new treatments are urgently needed. In acute hepatitis B virus (HBV) a strong immune response is necessary to clear the virus, but in chronic infection the immune response is weakened and dysfunctional. Therapeutic vaccination describes the process of inoculating individuals with a non‐infective form of viral antigen with the aim of inducing or boosting existing HBV‐specific immune responses, resulting in sustained control of HBV infection. In this review we outline the rationale for therapeutic vaccination in chronic HBV infection, discuss previous and ongoing trials of novel HBV therapeutic vaccine candidates and outline strategies to improve vaccine efficacy going forward.

Identification of novel hepatitis B virus therapeutic vaccine candidates derived from polymerase protein.

Hepatitis B virus (HBV) infection is a worldwide health problem with high morbidity and mortality rates. The therapeutic vaccine is a promising method of treatment, and HBV polymerase plays a vital role in viral replication. Therefore, a therapeutic vaccine that binds to HBV DNA polymerase may control HBV infection. We predicted and selected epitopes of polymerase using online databases and analysis software. We then performed molecular docking and peptide binding assays to evaluate the binding energies and affinities between polymerase epitopes and the HLA-A0201 molecule. Finally, we induced T cells from the peripheral blood mononuclear cells (PBMCs) of healthy donors using each epitope and quantified the functions of epitope-specific T cells by IFN-γELISPOT assay, T2 cell cytotoxicity assay, HepG2.2.15 cell cytotoxicity assay and HBV gene expression assays. Four epitopes (RVTGGVFLV, GLLGFAAPF, LLDDEAGPL and YMDDVVLGA) had low binding energy and two epitopes (RVTGGVFLV and GLLGFAAPF) had a high binding affinity. The T cells stimulated by two epitopes (GLLGFAAPF and HLYSHPIIL) had a greater ability to induce immune response and suppress HBV. The HBV DNA polymerase epitopes identified in this study are promising targets for designing an epitope-based therapeutic vaccine against HBV.

A novel therapeutic HBV vaccine candidate induces strong polyfunctional cytotoxic T cell responses in mice

Background & AimsCurrent standard-of-care suppresses HBV replication, but does not lead to a functional cure. Treatment aiming to cure chronic hepatitis B (CHB) is believed to require the induction of strong cellular immune responses, such as by therapeutic vaccination.MethodsWe designed a therapeutic HBV vaccine candidate (YF17D/HBc-C) using yellow fever vaccine YF17D as a live-attenuated vector to express HBV core antigen (HBc). Its ability to induce potent cellular immune responses was assessed in a mouse model that supports flavivirus replication.ResultsFollowing a HBc protein prime, a booster of YF17D/HBc-C was found to induce vigorous cytotoxic T cell responses. In a direct head-to-head comparison, these HBc-specific responses exceeded those elicited by adenovirus-vectored HBc. Target-specific T cells were not only more abundant, but also showed a higher degree of polyfunctionality, with HBc-specific CD8+ T cells producing interferon γ and tumour necrosis factor α in addition to granzyme B. This immune phenotype translated into a superior cytotoxic effector activity toward HBc-positive cells in YF17D/HBc-C vaccinated animals in vivo.ConclusionsThe results presented here show the potential of YF17D/HBc-C as a vaccine candidate to treat CHB, and warrant follow-up studies in preclinical animal models of HBV persistence in which other candidate vaccines have been unable to achieve a sustained virologic response.Lay summaryResolution of CHB requires the induction of strong cellular immune responses. We used the yellow fever vaccine as a vector for HBV antigens and show that it is capable of inducing high levels of HBV-specific T cells that produce multiple cytokines simultaneously and are cytotoxic in vivo.

Development of Delivery Systems Enhances the Potency of Cell-Based HIV-1 Therapeutic Vaccine Candidates.

An effective therapeutic vaccine to eradicate HIV-1 infection does not exist yet. Among different vaccination strategies, cell-based vaccines could achieve in clinical trials. Cell viability and low nucleic acid expression are the problems related to dendritic cells (DCs) and mesenchymal stem cells (MSCs), which are transfected with plasmid DNA. Thus, novel in vitro strategies are needed to improve DNA transfection into these cells. The recent study assessed immune responses generated by MSCs and DCs, which were derived from mouse bone marrow and modified with Nef antigen using novel methods in mice. For this purpose, an excellent gene transfection approach by mechanical methods was used. Our data revealed that the transfection efficacy of Nef DNA into the immature MSCs and DCs was improved by the combination of chemical and mechanical (causing equiaxial cyclic stretch) approaches. Also, chemical transfection performed two times with 48-hour intervals further increased gene expression in both cells. The groups immunized with Nef DC prime/rNef protein boost and then Nef MSC prime/rNef protein boost were able to stimulate high levels of IFN-γ, IgG2b, IgG2a, and Granzyme B directed toward Th1 responses in mice. Furthermore, the mesenchymal or dendritic cell-based immunizations were more effective compared to protein immunization for enhancement of the Nef-specific T-cell responses in mice. Hence, the use of chemical reagent and mechanical loading simultaneously can be an excellent method in delivering cargoes into DCs and MSCs. Moreover, DC- and MSC-based immunizations can be considered as promising approaches for protection against HIV-1 infections.

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.

Sampling SARS-CoV-2 Proteomes for Predicted CD8 T-Cell Epitopes as a Tool for Understanding Immunogenic Breadth and Rational Vaccine Design.

Predictive models for vaccine design have become a powerful and necessary resource for the expeditiousness design of vaccines to combat the ongoing SARS-CoV-2 global pandemic. Here we use the power of these predicted models to assess the sequence diversity of circulating SARS-CoV-2 proteomes in the context of an individual’s CD8 T-cell immune repertoire to identify potential. defined regions of immunogenicity. Using this approach of expedited and rational CD8 T-cell vaccine design, it may be possible to develop a therapeutic vaccine candidate with the potential for both global and local coverage.

Co\u2010administration of 2\u20193\u2019-cGAMP STING activator and CpG-C adjuvants with a mutated form of HPV 16 E7 protein leads to tumor growth inhibition in the mouse model

Persistent infection with high-risk genotypes of human papillomavirus (HPV) is the leading cause of cervical cancer. The HPV oncoprotein E7 is constitutively expressed in cervical cancer and considered as an essential target for tumor-specific immunity. The goal of this study was to develop a candidate therapeutic vaccine based on the mutated E7 protein that had possibly reduced transformation capacity while was able to elicit a robust immune response. Therefore, the mutant type of HPV 16 E7 (E7GRG) protein was recombinantly expressed in E. coli. The protein was then purified and formulated with 2’-3’cGAMP CDN and/or CpG-C ODN adjuvants and subcutaneously injected to female C57BL/6 mice. To evaluate the immunogenic response, lymphocyte proliferation, secretion levels of IFN-γ and IL-4 cytokines, granzyme B level, and total IgG and subclasses of IgG antibody were measured. The anti-tumor activity was evaluated in tumor-harboring C57BL/6 mice. The highest rate of cell proliferation, IFN-γ and granzyme B levels, and amount of IgG antibody were found in mice group that were injected by E7GRG + 2′-3′cGAMP + CpG-C. Therapeutic immunization with E7GRG + 2′-3′cGAMP + CpG-C also significantly suppressed TC-1 tumor growth in mice. In conclusion, the results demonstrated that E7GRG + 2′-3′cGAMP + CpG-C induced strong cell-mediated and humoral immune responses that resulted in inhibition of tumor in mouse model.

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

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. 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. 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. 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. 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.

Comparison of Exosomes Derived from Non- and Gamma-Irradiated Melanoma Cancer Cells as a Potential Antigenic and Immunogenic Source for Dendritic Cell-Based Immunotherapeutic Vaccine.

Cancer cells can secrete exosomes under various stressful conditions, whose functions are involved in the delivery of various biologically active materials into host cells and/or modulation of host immune responses. Therefore, an improved understanding of the immunological interventions that stress-induced tumor exosomes have may provide novel therapeutic approaches and more effective vaccine designs. Here, we confirmed the phenotypical and functional alterations of dendritic cells (DCs), which act as a bridge between the innate and adaptive arms of immunity, following non-irradiated (N-exo) and gamma-irradiated melanoma cancer cell-derived exosome (G-exo) stimulation, and evaluated the N-exo- and G-exo-stimulated DCs as therapeutic cancer vaccine candidates. We demonstrated that G-exo-stimulated DCs result in DC maturation by the upregulation of surface molecule expression, pro-inflammatory cytokine release, and antigen-presenting ability, and the downregulation of endocytic capacity. In addition, these cells promoted T cell proliferation and the generation of T helper type 1 (Th1) and interferon (IFN)-γ-producing CD8+ T cells. However, N-exo-stimulated DCs induced semi-mature phenotypes and functions, eventually inhibiting T cell proliferation, decreasing IFN-γ, and increasing IL-10-producing CD4+ T cells. In addition, although N-exo and G-exo stimulations showed similar levels of antigen-specific IFN-γ production, which served as tumor antigen sources in melanoma-specific T cells, G-exo-stimulated DC vaccination conferred a stronger tumor growth inhibition than N-exo-stimulated DC vaccination; further, this was accompanied by a high frequency of tumor-specific, multifunctional effector T cells. These results suggest that gamma irradiation could provide important clues for designing and developing effective exosome vaccines that can induce strong immunogenicity, especially tumor-specific multifunctional T cell responses.

Vaccination Strategies for the Control and Treatment of HPV Infection and HPV-Associated Cancer.

Human papillomavirus (HPV) is the most common sexually transmitted infection, currently affecting close to 80 million Americans. Importantly, HPV infection is recognized as the etiologic factor for numerous cancers, including cervical, vulval, vaginal, penile, anal, and a subset of oropharyngeal cancers. The prevalence of HPV infection and its associated diseases are a significant problem, affecting millions of individuals worldwide. Likewise, the incidence of HPV infection poses a significant burden on individuals and the broader healthcare system. Between 2011 and 2015, there were an estimated 42,700 new cases of HPV-associated cancers each year in the United States alone. Similarly, the global burden of HPV is high, with around 630,000 new cases of HPV-associated cancer occurring each year. In the last decade, a total of three preventive major capsid protein (L1) virus-like particle-based HPV vaccines have been licensed and brought to market as a means to prevent the spread of HPV infection. These prophylactic vaccines have been demonstrated to be safe and efficacious in preventing HPV infection. The most recent iteration of the preventive HPV vaccine, a nanovalent, L1-VLP vaccine, protects against a total of nine HPV types (seven high-risk and two low-risk HPV types), including the high-risk types HPV16 and HPV18, which are responsible for causing the majority of HPV-associated cancers. Although current prophylactic HPV vaccines have demonstrated huge success in preventing infection, existing barriers to vaccine acquisition have limited their widespread use, especially in low- and middle-income countries, where the burden of HPV-associated diseases is highest. Prophylactic vaccines are unable to provide protection to individuals with existing HPV infections or HPV-associated diseases. Instead, therapeutic HPV vaccines capable of generating T cell-mediated immunity against HPV infection and associated diseases are needed to ameliorate the burden of disease in individuals with existing HPV infection. To generate a cell-mediated immune response against HPV, most therapeutic vaccines target HPV oncoproteins E6 and E7. Several types of therapeutic HPV vaccine candidates have been developed including live-vector, protein, peptide, dendritic cell, and DNA-based vaccines. This chapter will review the commercially available prophylactic HPV vaccines and discuss the recent progress in the development of therapeutic HPV vaccines.

Advancing Immunotherapeutic Vaccine Strategies Against Pulmonary Tuberculosis.

Chemotherapeutic intervention remains the primary strategy in treating and controlling tuberculosis (TB). However, a complex interplay between therapeutic and patient-related factors leads to poor treatment adherence. This in turn continues to give rise to unacceptably high rates of disease relapse and the growing emergence of drug-resistant forms of TB. As such, there is considerable interest in strategies that simultaneously improve treatment outcome and shorten chemotherapy duration. Therapeutic vaccines represent one such approach which aims to accomplish this through boosting and/or priming novel anti-TB immune responses to accelerate disease resolution, shorten treatment duration, and enhance treatment success rates. Numerous therapeutic vaccine candidates are currently undergoing pre-clinical and clinical assessment, showing varying degrees of efficacy. By dissecting the underlying mechanisms/correlates of their successes and/or shortcomings, strategies can be identified to improve existing and future vaccine candidates. This mini-review will discuss the current understanding of therapeutic TB vaccine candidates, and discuss major strategies that can be implemented in advancing their development.

A Phase 1 Randomized Trial of Specific Active α‐Synuclein Immunotherapies PD01A and PD03A in Multiple System Atrophy

Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disease with limited symptomatic treatment options. Aggregation of α‐synuclein in oligodendrocytes is believed to be a central mechanism of the neurodegenerative process. PD01A and PD03A are 2 novel therapeutic vaccine candidates containing short peptides as antigenic moieties that are designed to induce a sustained antibody response, specifically targeting pathogenic assemblies of α‐synuclein. The objectives of the current study were to evaluate primarily the safety and tolerability of PD01A and PD03A in patients with early MSA. Thirty patients (11 women) were randomized to receive 5 subcutaneous injections of either PD01A (n = 12), PD03A (n = 12), or placebo (n = 6) in this patient‐ and examiner‐blinded, placebo‐controlled, 52‐week phase 1 clinical trial (ClinicalTrial.gov identifier: NCT02270489). Immunogenicity and clinical scores were assessed as secondary objectives. Twenty‐nine patients reported a total of 595 treatment‐emergent adverse events (mild or moderate, n = 555; severe, n = 40). Treatment‐related adverse events included 190 injection‐site reactions typically observed in vaccination trials with similar per‐subject incidence in the treatment groups over time. Sustained IgG titers were observed in the PD01A‐treated group, and 89% of treated patients developed a PD01‐specific antibody response after receiving all injections. Induced antibodies displayed clear reactivity to the α‐synuclein target epitope. Titers and antibody responder rate (58%) were lower in the PD03A‐treated group. In conclusion, both PD01A and PD03A were safe and well tolerated. PD01A triggered a rapid and long‐lasting antibody response that specifically targeted the α‐synuclein epitope. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Treg-inducing capacity of genomic DNA of Bifidobacterium longum subsp. infantis.

Background: Allergic and autoimmune diseases comprise a group of inflammatory disorders caused by aberrant immune responses in which CD25+ forkhead box P3-positive regulatory T cells (Treg) cells that normally suppress inflammatory events are often poorly functioning. This has stimulated an intensive investigative effort to find ways of increasing Tregs as a method of therapy for these conditions. Commensal microbiota known to have health benefits in humans include the lactic acid-producing, probiotic bacteria B. longum subsp. infantis and Lactobacillus rhamnosus. Mechanistically, several mechanisms have been proposed to explain how probiotics may favorably affect host immunity, including the induction of Tregs. Analysis of emerging data from several laboratories, including our own, suggest that DNA methylation may be an important determinant of immune reactivity responsible for Treg induction. Although methylated CpG moieties in normal mammalian DNA are both noninflammatory and lack immunogenicity, unmethylated CpGs, found largely in microbial DNA, are immunostimulatory and display proinflammatory properties. Objective: We hypothesize that microbiota with more DNA methylation may potentiate Treg induction to a greater degree than microbiota with a lower content of methylation. The purpose of the present study was to test this hypothesis by studying the methylation status of whole genomic DNA (gDNA) and the Treg-inducing capacity of purified gDNA in each of the probiotic bacteria B. longum subsp. infantis and L. rhamnosus, and a pathogenic Escherichia coli strain B. Results: We showed that gDNA from B. longum subsp. infantis is a potent Treg inducer that displays a dose-dependent response pattern at a dose threshold of 20 µg of gDNA. No similar Treg-inducing responses were observed with the gDNA from L. rhamnosus or E. coli. We identified a unique CpG methylated motif in the gDNA sequencing of B. longum subsp. infantis which was not found in L. rhamnosus or E. coli strain B. Conclusion: Although the literature indicates that both B. longum subsp. infantis and L. rhamnosus strains contribute to health, our data suggest that they do so by different mechanisms. Further, because of its small molecular size, low cost, ease of synthesis, and unique Treg-inducing feature, this methylated CpG oligodeoxynucleotide (ODN) from B. longum would offer many attractive features for an ideal novel therapeutic vaccine candidate for the treatment of immunologic diseases, such as the allergic and autoimmune disorders, in which Treg populations are diminished.

Assessing the composition of the plasma membrane of Leishmania (Leishmania) infantum and L. (L.) amazonensis using label-free proteomics

Protozoan parasites of the genus Leishmania are causative agents of leishmaniasis, a wide range of diseases affecting 12 million people worldwide. The species L. infantum and L. amazonensis are etiologic agents of visceral and cutaneous leishmaniasis, respectively. Most proteome analyses of Leishmania have been carried out on whole-cell extracts, but such an approach tends to underrepresent membrane-associated proteins due to their high hydrophobicity and low solubility. Considering the relevance of this category of proteins in virulence, invasiveness and the host-parasite interface, this study applied label-free proteomics to assess the plasma membrane sub-proteome of L. infantum and L. amazonensis. The number of proteins identified in L. infantum and L. amazonensis promastigotes was 1168 and 1455, respectively. After rigorous data processing and mining, 157 proteins were classified as putative plasma membrane-associated proteins, of which 56 proteins were detected in both species, six proteins were detected only in L. infantum and 39 proteins were exclusive to L. amazonensis. The quantitative analysis revealed that two proteins were more abundant in L. infantum, including the glucose transporter 2, and five proteins were more abundant in L. amazonensis. The identified proteins associated with distinct processes and functions. In this regard, proteins of L. infantum were linked to metabolic processes whereas L. amazonensis proteins were involved in signal transduction. Moreover, transmembrane transport was a significant process among the group of proteins detected in both species and members of the superfamily of ABC transporters were highly represented. Interestingly, some proteins of this family were solely detected in L. amazonensis, such as ABCA9. GP63, a well-known virulence factor, was the only GPI-anchored protein identified in the membrane preparations of both species. Finally, we found several proteins with uncharacterized functions, including differentially abundant ones, highlighting a gap in the study of Leishmania proteins. Proteins characterization could provide a better biological understanding of these parasites and deliver new possibilities regarding the discovery of therapeutic targets, drug resistance and vaccine candidates.

Polyvalent therapeutic vaccine for type 2 diabetes mellitus: Immunoinformatics approach to study co-stimulation of cytokines and GLUT1 receptors

BackgroundType 2 diabetes mellitus (T2DM) is a worldwide disease that have an impact on individuals of all ages causing micro and macro vascular impairments due to hyperglycemic internal environment. For ultimate treatment to cure T2DM, association of diabetes with immune components provides a strong basis for immunotherapies and vaccines developments that could stimulate the immune cells to minimize the insulin resistance and initiate gluconeogenesis through an insulin independent route.MethodologyImmunoinformatics based approach was used to design a polyvalent vaccine for T2DM that involved data accession, antigenicity analysis, T-cell epitopes prediction, conservation and proteasomal evaluation, functional annotation, interactomic and in silico binding affinity analysis.ResultsWe found the binding affinity of antigenic peptides with major histocompatibility complex (MHC) Class-I molecules for immune activation to control T2DM. We found 13-epitopes of 9 amino acid residues for multiple alleles of MHC class-I bears significant binding affinity. The downstream signaling resulted by T-cell activation is directly regulated by the molecular weight, amino acid properties and affinity of these epitopes. Each epitope has important percentile rank with significant ANN IC50 values. These high score potential epitopes were linked using AAY, EAAAK linkers and HBHA adjuvant to generate T-cell polyvalent vaccine with a molecular weight of 35.6 kDa containing 322 amino acids residues. In silico analysis of polyvalent construct showed the significant binding affinity (− 15.34 Kcal/mol) with MHC Class-I. This interaction would help to understand our hypothesis, potential activation of T-cells and stimulatory factor of cytokines and GLUT1 receptors.ConclusionOur system-level immunoinformatics approach is suitable for designing potential polyvalent therapeutic vaccine candidates for T2DM by reducing hyperglycemia and enhancing metabolic activities through the immune system.

Gaining insights on immune responses to the novel coronavirus, COVID-19 and therapeutic challenges

SARS-CoV-2 is a new member of coronaviruses that its sudden spreading put the health care system of most countries in a tremendous shock. For controlling of the new infection, COVID-19, many efforts have been done and are ongoing to defeat this virus in the combat field. In this review, we focused on how the immune system behaves toward the virus and the relative possible consequences during their interactions. Then the therapeutic steps and potential vaccine candidates have been described in a hope to provide a better prospective of effective treatment and preventive strategies to the novel SARS-CoV in near future.

Bivalent therapeutic vaccine against HPV16/18 genotypes consisting of a fusion protein between the extra domain A from human fibronectin and HPV16/18 E7 viral antigens.

BackgroundIn vivo targeting of human papillomavirus (HPV) derived antigens to dendritic cells might constitute an efficient immunotherapeutic strategy against cervical cancer. In previous works, we have shown that the extra domain A from murine fibronectin (mEDA) can be used to target antigens to toll-like receptor 4 (TLR4) expressing dendritic cells and induce strong antigen-specific immune responses. In the present study, we have produced a bivalent therapeutic vaccine candidate consisting of the human EDA (hEDA) fused to E7 proteins from HPV16 and HPV18 (hEDA-HPVE7-16/18) and evaluate its potential as a therapeutic vaccine against cervical cancer.Materials and methodsRecombinant fusion proteins containing HPV E7 proteins from HPV16 and HPV18 virus subtypes fused to hEDA were produced and tested in vitro on their capacity to bind TLR4 and induce the production of tumor necrosis factor-α or interleukin (IL)-12 by human monocytes and dendritic cells. The immunogenicity and potential therapeutic activity of the vaccine in combination with cisplatin or with the TLR3 agonist molecules polyinosinic‐polycytidylic acid (Poly IC) or Poly ICLC was evaluated in mice bearing subcutaneous or genital orthotopic HPV16 TC-1 tumors.ResultshEDA-HPVE7-16/18 prototype vaccine binds human TLR4 and stimulate TLR4-dependent signaling pathways and IL-12 production by human monocyte-derived dendritic cell. Vaccination with hEDA-HPVE7-16/18 induced strong HPVE7-specific Cytotoxic T lymphocyte (CTL) responses and eliminated established tumors in the TC-1-based tumor model. The antitumor efficacy was significantly improved by combining the fusion protein with cisplatin or with the TLR-3 ligand Poly IC and especially with the stabilized analog Poly ICLC. Moreover, hEDA-HPVE7-16/18+Poly ICLC induced full tumor regression in 100% of mice bearing orthotopic genital HPV tumors.ConclusionOur results suggest that this therapeutic vaccine formulation may be an effective treatment for cervical tumors that do not respond to current therapies.

Vaccines and Drug Therapeutics to Lock Down Novel Coronavirus Disease 2019 (COVID-19): A Systematic Review of Clinical Trials

The ongoing novel coronavirus disease 2019 (COVID-19) pandemic has been responsible for millions of infections and hundreds of thousands of deaths. To date, there is no approved targeted treatment, and many investigational therapeutic agents and vaccine candidates are being considered for the treatment of COVID-19. To extract and summarize information on potential vaccines and therapeutic agents against COVID-19 at different stages of clinical trials from January to March 2020, we reviewed major clinical trial databases such as ClinicalTrials.gov, WHO International Clinical Trials Registry Platform (ICTRP), and other primary registries between January and March 15, 2020. Interventional studies at different phases under the COVID-19 pipeline were included. A total of 249 clinical trials were identified between January to March 15, 2020. After filtering observational studies (194 studies), a total of 56 interventional trials were considered. The majority of clinical trials have been conducted on chloroquine (n=10) and traditional Chinese medications (TCMs; n=10), followed by antivirals (n=8), anti-inflammatory/immunosuppressants (n=9), cellular therapies (n=4), combinations of different antivirals therapies (n=3), antibacterial (n=1), and other therapies (n=5). Five vaccines are under phase I, and there are a couple of phase III trials on the Bacillus Calmette-Guérin (BCG) vaccine under investigation among healthcare workers. Many novel compounds and vaccines against COVID-19 are currently under investigation. Some candidates have been tested for other viral infections and are listed for clinical trials against the COVID-19 pipeline. Currently, there are no effective specific antivirals or drug combinations available for the treatment of COVID-19.