Synthesis of two glycolipid antigens of the causative agent of Lyme disease

As a prelude to development of a human vaccine against Lyme disease, the first chemical synthesis of glycolipid antigens of Borrelia burkholderi is reported. First, cholesteryl β-d-galactopyranoside was synthesized and was converted to partially protected congeners having the HO-6 group of the galactose moiety unprotected. Treatment of these intermediates with palmitic and oleic acid, respectively, under dehydrative conditions followed by removal of the protecting groups afforded cholesteryl 6-O-palmitoyl/oleoyl-β-d-galactopyranosides that were identical to the glycolipids isolated from B. burkholderi.     

Operational issues and network effects in vaccine markets

One of the most important concerns for managing public health is the prevention of infectious diseases. Although vaccines provide the most effective means for preventing infectious diseases, there are two main reasons why it is often difficult to reach a socially optimal level of vaccine coverage: (i) the emergence of operational issues (such as yield uncertainty) on the supply side, and (ii) the existence of negative network effects on the consumption side. In particular, uncertainties about production yield and vaccine imperfections often make manufacturing some vaccines a risky process and may lead the manufacturer to produce below the socially optimal level. At the same time, negative network effects provide incentives to potential consumers to free ride off the immunity of the vaccinated population. In this research, we consider how a central policy-maker can induce a socially optimal vaccine coverage through the use of incentives to both consumers and the vaccine manufacturer. We consider a monopoly market for an imperfect vaccine; we show that a fixed two-part subsidy is unable to coordinate the market, but derive a two-part menu of subsidies that leads to a socially efficient level of coverage.     

Structural and immunogenicity analysis of reconstructed ancestral and consensus P48/45 for cross-species anti malaria transmission-blocking vaccine

The development of the anti-malaria vaccine holds a promising future in malaria control. One of the anti-malaria vaccine strategies known as the transmission-blocking vaccine (TBV) is to inhibit the parasite transmission between humans and mosquitoes by targeting the parasite gametocyte. Previously, we found that P48/45 included in the 6-Cysteine protein family shared by Plasmodium sp. We also detected vaccine properties possessed by all human-infecting Plasmodium and could be used as a cross-species anti-malaria vaccine. In this study, we investigated the efficacy of P48/45 through the ancestral and consensus reconstruction approach. P48/45 phylogenetic and time tree analysis was done by RAXML and BEAST2. GRASP server and Ugene software were used to reconstruct ancestral and consensus sequences, respectively. The protein structural prediction was made by using a psipred and Rosetta program. Each protein characteristic of P48/45 was analyzed by assessing hydrophobicity and Post-Translational Modification sites. Meanwhile, the Epitope sequence for B-cell, T-cell, and HLA was determined using an immunoinformatics approach. Lastly, molecular docking simulation was done to determine native binding interactions of P48/45-P230. The result showed a distinct protein characteristic of ancestral and consensus sequences. The immunogenicity analysis revealed the number of epitopes in the ancestral sequence is greater than the consensus sequence. The study also found a conserved epitope located in the binding site and consists of specific Post-Translational Modification sites. Hence, our research provides detailed insight into ancestral and consensus P48/45 efficacy for the cross-species anti-malaria vaccine.     

Physicochemical properties of SARS-CoV-2 for drug targeting,virus inactivation and attenuation,vaccine formulation and quality control

The material properties of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its proteins are discussed. We review the viral structure, size, rigidity, lipophilicity, isoelectric point, buoyant density and centrifugation conditions, stability against pH, temperature, UV light, gamma radiation, and susceptibility to various chemical agents including solvents and detergents. Possible inactivation, downstream, and formulation conditions are given including suitable buffers and some first ideas for quality-control methods. This information supports vaccine development and discussion with competent authorities during vaccine approval and is certainly related to drug-targeting strategies and hygienics. Several instructive tables are given, including the pI and grand average of hydropathicity (GRAVY) of SARS-CoV-1 and -2 proteins in comparison. SARS-CoV-1 and SARS-CoV-2 are similar in many regards, so information can often be derived. Both are unusually stable, but sensitive at their lipophilic membranes. However, since seemingly small differences can have strong effects, for example, on immunologically relevant epitope settings, unevaluated knowledge transfer from SARS-CoV-1 to SARS-CoV-2 cannot be advised. Published knowledge regarding downstream processes, formulations and quality assuring methods is, as yet, limited. However, standard approaches employed for other viruses and vaccines seem to be feasible including virus inactivation, centrifugation conditions, and the use of adjuvants.     

Designing a potent L1 protein-based HPV peptide vaccine: A bioinformatics approach

BackgroundOncogenic human papilloma viruses (HPV) are the cause of various types of cancer, specifically cervical cancer. L1 protein is the main protein of HPV capsid which targeted in many vaccine-producing attempts. However, they have not enough coverage on the various high risk HPV types. Therefore, having a low cost potent HPV vaccine to protect against all members of the α-papillomaviridea family will be promising. In this study, L1 protein-based peptide vaccine was designed using immunoinformatics methods which provides physicochemical properties such as stability in room temperature, potential of antigenicity, non-allergic properties and no requirement with eukaryotic host system.ResultsThe designed vaccine has two HPV conserved epitopes with lengths 18 and 27 amino acids in all members of α-papillomaviridea. These peptides promote humoral and cellular immunity and INF-γ responses. In order to ensure strong induction of immune responses, Flagellin, a Toll like receptor 5(TLR-5) agonist, and a short synthetic toll like receptor 4 (TLR-4) agonist were also joined to the epitopes. Structure of the designed- vaccine was validated using Rampage and ERRAT and a high quality 3D structure of the vaccine protein was provided. Docking studies demonstrated an appropriate and stable interaction between the vaccine and TLR-5.ConclusionsThe vaccine is expected to have a high quality structure and suitable properties including high stability, solubility and a high potential to be expressed in E.coli. High potentiality of the vaccine in inducing humoral and cellular immune responses, may be considered as an anti-tumor vaccine.     

Analysis of the cellular Aspergillus fumigatus proteome that reacts with sera from rabbits developing an acquired immunity after experimental aspergillosis

Invasive aspergillosis caused by the mould Aspergillus fumigatus is a life‐threatening lung or systemic infection in the immunocompromised host. In this study, a protective immune response against the disease was achieved in two infected rabbits, and the cellular fungal antigenic proteome that mediated such a response was investigated against the background of vaccine development efforts. Altogether, 59 different Aspergillus proteins were found becoming reactive in the course of the developing immunity, many of which are described in this context for the first time. These included proteins related to oxidative stress management, glycolysis and other metabolic pathways. As oxidative stress is suspected to be one of the major defense mechanisms, the results may indicate at least in part a continuous response of the pathogen to evade the host's immune system. In addition, proteins with suspected cell surface association or crucial function for fungal cell development were identified. As these antigens are newly recognized during the process of the developing immunoprotection, they may not only represent valuable infection markers but also importantly broaden the list of possible vaccine candidates.     

Gas and Particle Dynamics of a Contoured Shock Tube for Pre-clinical Microparticle Drug Delivery

We investigate the gas-particle dynamics of a device designed for biological pre-clinical experiments. The device uses transonic/supersonic gas flow to accelerate microparticles such that they penetrate the outer skin layers. By using a shock tube coupled to a correctly expanded nozzle, a quasi-one-dimensional, quasi-steady flow (QSF) is produced to uniformly accelerate the microparticles. The system utilises a microparticle “cassette” (a diaphragm sealed container) that incorporates a jet mixing mechanism to stir the particles prior to diaphragm rupture. Pressure measurements reveal that a QSF exit period – suitable for uniformly accelerating microparticles – exists between 155 and 220 mus after diaphragm rupture. Immediately preceding the QSF period, a starting process secondary shock was shown to form with its (x,t) trajectory comparing well to theoretical estimates. To characterise the microparticle, flow particle image velocimetry experiments were conducted at the nozzle exit, using particle payloads with varying diameter (2.7–48 μm), density (600–16,800 kg/m³) and mass (0.25–10 mg). The resultant microparticle velocities were temporally uniform. The experiments also show that the starting process does not significantly influence the microparticle nozzle exit velocities. The velocity distribution across the nozzle exit was also uniform for the majority of microparticle types tested. For payload masses typically used in pre-clinical drug and vaccine applications (≤ 1 mg), it was demonstrated that payload scaling does not affect the microparticle exit velocities. These characteristics show that the microparticle exit conditions are well controlled and are in agreement with ideal theory. These features combined with an attention to the practical requirements of a pre-clinical system make the device suitable for investigating microparticle penetration into the skin for drug delivery.     

Precise Epitope Organization with Self-adjuvant Framework Nucleic Acid for Efficient COVID-19 Peptide Vaccine Construction

Peptide vaccines have advantages in easy fabrication and high safety, but their effectiveness is hampered by the poor immunogenicity of the epitopes themselves. Herein, we constructed a series of framework nucleic acids (FNAs) with regulated rigidity and size to precisely organize epitopes in order to reveal the influence of epitope spacing and carrier rigidity on the efficiency of peptide vaccines. We found that assembling epitopes on rigid tetrahedral FNAs (tFNAs) with the appropriate size could efficiently enhance their immunogenicity. Further, by integrating epitopes from SARS-CoV-2 on preferred tFNAs, we constructed a COVID-19 peptide vaccine which could induce high titers of IgG against the receptor binding domain (RBD) of SARS-CoV-2 spike protein and increase the ratio of memory B and T cells in mice. Considering the good biocompatibility of tFNAs, our research provides a new idea for developing efficient peptide vaccines against viruses and possibly other diseases.     

An innovative method for quality control of conjugated Haemophilus influenzae vaccines: A short review of two-dimensional nanoparticle electrophoresis

This article provides an overview of a 2D agarose electrophoretic procedure for the characterization of semi-synthetic Haemophilus influenzae type b meningitis vaccines that were prepared for the immunization of small children. The analysis of such vaccines has been particularly challenging because the vaccine particles (i) are highly negatively charged, (ii) are as large as or even larger than intact viruses, and (iii) have a continuous (polydisperse) size distribution because of randomizing steps in the vaccine production (sonification and crosslinking). As a result of these characteristics, 1D electrophoresis of the vaccines produced smears without discernable peaks, but with a second dimension of separation a characteristic vaccine fingerprint was obtained. Whereas O’Farrell gels can accomplish a 2D separation according to size and charge for samples with protein-sized particles, nondenaturing 2D agarose electrophoresis achieves a similar result for much larger virus-sized particles. The separation principle, however, is different. Even though the 2D electrophoretic method was developed from 1983 to 1995, it remains a promising tool for vaccine quality control and for predicting vaccine effectiveness. Modern technology makes the analysis significantly more practical and affordable than it was more than 10 years ago, and the method is applicable to a variety of conjugated vaccines and complex mixtures of virus-sized particles.     

Proteome-scale identification of Leishmania infantum for novel vaccine candidates: A hierarchical subtractive approach

Vaccines are one of the most significant achievements in medical science. However, vaccine design is still challenging at all stages. The selection of antigenic peptides as vaccine candidates is the first and most important step for vaccine design. Experimental selection of antigenic peptides for the design of vaccines is a time-consuming, labor-intensive and expensive procedure. More recently, in the light of computer-aided biotechnology and reverse vaccinology, the precise selection of antigenic peptides and rational vaccine design against many pathogens have developed. In this study, the whole proteome of Leishmania infantum was analyzed using a pipeline of algorithms. From the set of 8045 proteins of L. infantum, sixteen novel antigenic proteins were derived using a hierarchical proteome subtractive analysis. These novel vaccine targets can be utilized as top candidates for designing the new prophylactic or therapeutic vaccines against visceral leishmaniasis. Significantly, all the sixteen novel vaccine candidates are non-allergen antigenic proteins that have not been used for the design of vaccines against visceral leishmaniasis until now.