Designing of a new multi-epitope vaccine against Leishmania major using Leish-F1 epitopes: An In-silico study.

Cutaneous leishmaniasis (CL) is the most common form of the disease which can cause malignant lesions on the skin. Vaccination for the prevention and treatment of leishmaniasis can be the most effective way to combat this disease. In this study, we designed a novel multi-epitope vaccine against Leishmania major (L. major) using immunoinformatics tools to assess its efficacy in silico. Sequences of Leish-F1 protein (TSA, Leif, and LMSTI1) of L. major were taken from GenBank. The helper T (Th) and cytotoxic T (Tc) epitopes of the protein were predicted. The final multi-epitope consisted of 18 CTL epitopes joined by AAY linker. There were also nine HTL epitopes in the structure of the vaccine construct, joined by GPGPG linker. The profilin adjuvant (the toll-like receptor 11 agonist) was also added into the construct by AAY Linker. There were 613 residues in the structure of the vaccine construct. The multi-epitope vaccine candidate was stable and non-allergic. The data obtained from the binding of final multi-epitope vaccine-TLR11 residues (band lengths and weighted scores) unveiled the ligand and the receptor high score of binding affinity. Moreover, in silico assessment of the vaccine construct cloning achieved its suitable expression in E. coli host. Based on these results, the current multi-epitope vaccine prevents L. major infection in silico, while further confirmatory assessments are required.

Therapeutic Effects of Mesenchymal Stem Cells Expressing Erythropoietin on Cancer-Related Anemia in Mice Model.

BACKGROUND: Cancer-related anemia (CRA) negatively influences cancer patients' survival, disease progression, treatment efficacy, and quality of life (QOL). Current treatments such as iron therapy, red cell transfusion, and erythropoietin-stimulating agents (ESAs) may cause severe adverse effects. Therefore, the development of long-lasting and curative therapies is urgently required. OBJECTIVE: In this study, a cell and gene therapy strategy was developed for in vivo delivery of EPO cDNA by way of genetic engineering of human Wharton's jelly mesenchymal stem cells (hWJMSCs) to produce and secrete human EPO protein for extended periods after transplantation into the mice model of CRA. METHODS: To evaluate CRA's treatment in cancer-free and cancerous conditions, first, a recombinant breast cancer cell line 4T1 which expressed herpes simplex virus type 1 thymidine kinase (HSV1-TK) by a lentiviral vector encoding HSV1-TK was developed and injected into mice. After three weeks, all mice developed metastatic breast cancer associated with acute anemia. Then, ganciclovir (GCV) was administered for ten days in half of the mice to clear cancer cells. Meanwhile, another lentiviral vector encoding EPO to transduce hWJMSCs was developed. Following implantation of rhWJMSCs-EPO in the second group of mice, peripheral blood samples were collected once a week for ten weeks from both groups. RESULTS: Analysis of peripheral blood samples showed that plasma EPO, hemoglobin (Hb), and hematocrit (Hct) concentrations significantly increased and remained at therapeutic for >10 weeks in both treatment groups. CONCLUSION: Data indicated that rhWJMSCs-EPO increased the circulating level of EPO, Hb, and Hct in both mouse subject groups and improved the anemia of cancer in both cancer-free and cancerous mice.

Exploring membrane proteins of Leishmania major to design a new multi-epitope vaccine using immunoinformatics approach.

Leishmaniasis is one of the major global endemic diseases. Among all the different forms of the disease, cutaneous Leishmaniasis has the highest prevalence worldwide. Treatment with current drugs has not had a significant effect on the improvement of the disease. An attempt to replace an appropriate vaccine that can stimulate host cellular immunity and induce the response of Major histocompatibility complex I (MHCI) and Major histocompatibility complex II (MHCII) against Leishmania is essential. Vaccine production remains a challenge despite the use of different antigens for vaccination against Leishmania major. Hence, we were used the immunoinformatics approach to design a new multi-epitope vaccine against L. major using immunogenic outer membrane proteins. Helper T-lymphocyte (HTL) and Cytotoxic T lymphocyte (CTL) epitopes were predicted and for final confirmation of the selected epitopes, docking analysis, and molecular dynamics simulation was performed. Then, GDGDG linker and profilin adjuvant were added to enhance the immunity of vaccines. The designed vaccine was evaluated in terms of molecular weight, PI, immunogenicity, and allergenicity. Moreover, the secondary and three-dimensional structure of the final construct was identified. In silico cloning approach was carried out to improve expression of the vaccine construct. Finally, molecular docking, followed by molecular dynamic was performed to determine the interaction between multi-epitope vaccine and TLR11. We hope that the designed vaccine can be a good candidate for the development of cutaneous leishmaniasis vaccine. but its effectiveness should be assessed in vivo.

A lentiviral vaccine expressing KMP11-HASPB fusion protein increases immune response to Leishmania major in BALB/C.

Hydrophilic acylated surface protein B (HASPB) is an immunogenic Leishmania-specific protein that antibodies are produced against it in the sera of Leishmania-infected individuals. Kinetoplastid membrane protein 11 (KMP11) is another Leishmania antigen and considered as the suitable candidate for vaccine development Leishmaniasis. It is a highly conserved surface protein expressed in both promastigotes and amastigotes. In this study, KMP11 and HASPB coding sequences were cloned into a pCDH-cGFP lentiviral vector as a fusion protein to be used as a DNA vaccine against L. major. The KMP11-HASPB fusion protein was successfully expressed as evidenced by RT-PCR and Western blot assays. The effect of the vaccine was determined by evaluating the level of IFN-γ, IL-10, IgG1, and IgG2a performed using ELISA as well as determining the parasite load after challenge with L. major in vaccinated mice. The results revealed that IFN-γ, IL-10, IgG1, and IgG2a significantly increased after vaccination using KMP11-HASPB-expressing lentiviruses in BALB/c mice. It is noteworthy that the level of IFN-γ and IgG2a was higher than that of IL-10 and IgG1, respectively, which indicates the activation Th1 cells, macrophages, and cellular immunity. Moreover, the parasite load in the spleen and lymph node of vaccinated mice after challenge was significantly lower than that of controls.

Locked nucleic acid -anti- let-7a induces apoptosis and necrosis in macrophages infected with Leishmania major.

BACKGROUND: Protozoan parasites of the genus Leishmania are etiologic agents which are intracellular pathogens of vertebrates and replicate inside infected macrophages. Leishmania have developed complex strategies to reverse host immune responses in favor of it. One of the major species causing cutaneous involvements is Leishmania major. MicroRNAs (miRNA) are non-coding small RNAs encoding 22-nucleotide (nt) long RNAs. miRNAs affect diverse biological processes, including cell cycle, proliferation, differentiation, growth and development, metabolism, aging, apoptosis, gene expression and immune regulation. This study aimed at evaluating apoptosis and necrosis after transfection locked nucleic acid (LNA) inhibitor of let-7a in the human macrophages miRNAs upon infectionwith L. major. MATERIALS AND METHODS: Inhibition of let-7a in macrophages was derived originally from the human monocytes (MDM), using locked nucleic acid (LNA) antagomir. The total cellular RNA was extracted 24 and 48 h post transfection. The levels o Let-7a expression was measured by qPCR Real Time using specific primer. Annexin-V/Propidium Iodide staining method was performed to detect apoptosis and necrosis in the MDM cells. Data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. RESULTS: Let-7a inhibition increased the MDM cells apoptosis and necrosis using flow cytometry method. CONCLUSIONS: The results suggested that inhibition of let-7a could be a new approach in treatment of leishmaniasis.