Bioinformatics analysis of structural protein to approach a vaccine candidate against Vibrio cholerae infection.

The bacteria Vibrio cholerae causes cholera, an acute diarrheal infection that can lead to dehydration and even death. Over 100,000 people die each year as a result of epidemic diseases; vaccination has emerged as a successful strategy for combating cholera. This study uses bioinformatics tools to create a multi-epitope vaccine against cholera infection using five structural polyproteins from the V. cholerae (CTB, TCPA, TCPF, OMPU, and OMPW). The antigenic retrieved protein sequence were analyzed using BCPred and IEDB bioinformatics tools to predict B cell and T cell epitopes, respectively, which were then linked with flexible linkers together with an adjuvant to boost it immunogenicity. The construct has a theoretical PI of 6.09, a molecular weight of 53.85 kDa, and an estimated half-life for mammalian reticulocytes in vitro of 4.4 h. These results demonstrate the construct's longevity. The vaccine design was docked against the human toll-like receptor (TLR) to evaluate compatibility and effectiveness; also other additional post-vaccination assessments were carried out on the designed vaccine. Through in silico cloning, its expression was determined. The results show that it has a CAI value of 0.1 and GC contents of 58.97% which established the adequate expression and downstream processing of the vaccine construct, and our research demonstrated that the multi-epitope subunit vaccine exhibits antigenic characteristics. Additionally, we carried out an in silico immunological simulation to examine the immune reaction to an injection. Our results strongly suggest that the vaccine candidate on further validation would induce immune response against the V. cholerae infection.

Immunoinformatics design of multi-epitope peptide for the diagnosis of Schistosoma haematobium infection.

Schistosoma haematobium has been identified as a significant cause of urogenital disease, as well as a risk factor for bladder cancer and HIV/AIDS. The parasites are obtained trans-dermally by swimming or wading in contaminated freshwater, and they are also transmitted to humans by freshwater snails. The organisms infect the vasculature of the gastrointestinal or genitourinary tracts. Worms live in blood vessels and lay eggs that become embedded in the bladder wall, causing chronic immune-mediated disease and squamous cell carcinoma growth. The primary goal of this research is to predict and design a novel synthetic protein containing multiple immunodominant B cell epitopes using three schistosome proteins: XP-012801068.2, XP-012801892.2, and XP-012793835.2 softwares were used to analyze the proteins' primary, secondary, and tertiary structures (BepiPred, BcPred).The B cell construct was then evaluated using I-TASSER server, and physicochemical properties, as well as homology modeling of the 3 D structure of the protein, was obtained. In silico analyses revealed regions with high immunogenicity. For XP-012801068.2, three epitopes are found between residues 292-334, 3-22, and 314-333; for XP-012801892.2, three epitopes are found in the residues 184-236, 81-100, and 329-348 for XP-012793835.2, four epitopes are found in the residues 185-222, 469-512, 649-713, and 338-357. The construct's has an average length of 308 bp, instability index of 49.96, theoretical PI of 4.2 and a C score -1.59. Furthermore, these parameters analyzed reveals that the constructed multi-epitope peptide has the potential to provide a theoretical basis for the development of a Schistosoma haematobium diagnostic kit.Communicated by Ramaswamy H. Sarma.

Designing a conserved peptide-based subunit vaccine against SARS-CoV-2 using immunoinformatics approach.

The widespread of coronavirus (COVID-19) is a new global health crisis that poses a threat to the world. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in bats and was discovered first in Wuhan, Hubei province, China in December 2019. Immunoinformatics and bioinformatics tools were employed for the construction of a multi-epitope subunit vaccine to prevent the diseases. The antigenicity, toxicity and allergenicity of all epitopes used in the construction of the vaccine were predicted and then conjugated with adjuvants and linkers. Vaccine Toll-Like Receptors (2, 3, 4, 8 and 9) complex was also evaluated. The vaccine construct was antigenic, non-toxic and non-allergic, which indicates the vaccines ability to induce antibodies in the host, making it an effective vaccine candidate. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40203-020-00062-x.

Exploration of surface glycoprotein to design multi-epitope vaccine for the prevention of Covid-19.

Stimulation and generation of T and B cell-mediated long-term immune response are essential for the curbing of a deadly virus such as SAR-CoV-2 (Severe Acute Respiratory Corona Virus 2). Immunoinformatics approach in vaccine design takes advantage of antigenic and non-allergenic epitopes present on the spike glycoprotein of SARS-CoV-2 to elicit immune responses. T cells and B cells epitopes were predicted, and the selected residues were subjected to allergenicity, antigenicity and toxicity screening which were linked by appropriate linkers to form a multi-epitope subunit vaccine. The physiochemical properties of the vaccine construct were analyzed, and the molecular weight, molecular formula, theoretical isoelectric point value, half-life, solubility score, instability index, aliphatic index and GRAVY were predicted. The vaccine structure was constructed, refined, validated, and disulfide engineered to get the best model. Molecular binding simulation and molecular dynamics simulation were carried out to predict the stability and binding affinity of the vaccine construct with TLRs. Codon acclimatization and in silico cloning were performed to confirm the vaccine expression and potency. Results obtained indicated that this novel vaccine candidate is non-toxic, capable of initiating the immunogenic response and will not induce an allergic reaction. The highest binding energy was observed in TLR4 (Toll-like Receptor 4) (-1398.1), and the least is TLR 2 (-1479.6). The steady rise in Th (T-helper) cell population with memory development was noticed, and IFN-g (Interferon gamma) was provoked after simulation. At this point, the vaccine candidate awaits animal trial to validate its efficacy and safety for use in the prevention of the novel COVID-19 (Coronavirus Disease 2019) infections.

Laboratory diagnosis of COVID-19 in Africa: availability, challenges and implications.

The COVID-19 infection has been a matter of urgency to tackle around the world today, there exist 200 countries around the world and 54 countries in Africa that the COVID-19 infection cases have been confirmed. This situation prompted us to look into the challenges African laboratories are facing in the diagnosis of novel COVID-19 infection. A limited supply of essential laboratory equipment and test kits are some of the challenges faced in combatting the novel virus in Africa. Also, there is inadequate skilled personnel, which might pose a significant danger in case there is a surge in COVID-19 infection cases. The choice of diagnostic method in Africa is limited as there are only two available diagnostic methods being used out of the six methods used globally, thereby reducing the opportunity of supplementary diagnosis, which will further lead to inappropriate diagnosis and affect the accuracy of diagnostic reports. Furthermore, challenges like inadequate power supply, the method used in sample collection, storage and transportation of specimens are also significant as they also pose their respective implication. From the observations, there is an urgent need for more investment into the laboratories for proper, timely, and accurate diagnosis of COVID-19.