Immunoinformatics analysis of Brucella melitensis to approach a suitable vaccine against brucellosis.

BACKGROUND: Brucellosis caused by B. melitensis is one of the most important common diseases between humans and livestock. Currently, live attenuated vaccines are used for this disease, which causes many problems, and unfortunately, there is no effective vaccine for human brucellosis. The aim of our research was to design a recombinant vaccine containing potential immunogenic epitopes against B. melitensis. METHODS: In this study, using immunoinformatics approaches, 3 antigens Omp31, Omp25, and Omp28 were identified and the amino acid sequence of the selected antigens was determined in NCBI. Signal peptides were predicted by SignaIP-5.0 server. To predict B-cell epitopes from ABCpred and Bcepred servers, to predict MHC-I epitopes from RANKPEP and SYFPEITHI servers, to predict MHC-II epitopes from RANKPEP and MHCPred servers, and to predict CTL epitopes were used from the CTLPred server. Potentially immunogenic final epitopes were joined by flexible linkers. Finally, allergenicity (AllerTOP 2.0 server), antigenicity (Vaxijen server), physicochemical properties (ProtParam server), solubility (Protein-sol server), secondary (PSIPRED and GRO4 servers) and tertiary structure (I-TASSER server), refinement (GalaxyWEB server), validation (ProSA-web, Molprobity, and ERRAT servers), and optimization of the codon sequence (JCat server) of the structure of the multi-epitope vaccine were analyzed. RESULTS: The analysis of immunoinformatics tools showed that the designed vaccine has high quality, acceptable physicochemical properties, and can induce humoral and cellular immune responses against B. melitensis bacteria. In addition, the high expression level of recombinant antigens in the E. coli host was observed through in silico simulation. CONCLUSION: According to the results in silico, the designed vaccine can be a suitable candidate to fight brucellosis and in vitro and in vivo studies are needed to evaluate the research of this study.

Design of a Novel Recombinant Multi-Epitope Vaccine against Triple-Negative Breast Cancer

Background: Triple-negative breast cancer (TNBC) is determined by the absence of ERBB2, estrogen and progesterone receptors' expression. Cancer vaccines, as the novel immunotherapy strategies, have emerged as promising tools for treating the advanced stage of TNBC. The aim of this study was to evaluate Carcinoembryonic antigen (CEA), Metadherin (MTDH), and Mucin 1 (MUC-1) proteins as vaccine candidates against TNBC. Methods: In this research, a novel vaccine was designed against TNBC by using different immunoinformatics and bioinformatics approaches. Effective immunodominant epitopes were chosen from three antigenic proteins, namely CEA, MTDH, and MUC-1. Recombinant TLR4 agonists were utilized as an adjuvant to stimulate immune responses. Following the selection of antigens and adjuvants, appropriate linkers were chosen to generate the final recombinant protein. To achieve an excellent 3D model, the best predicted 3D model was required to be refined and validated. To demonstrate whether the vaccine/TLR4 complex is stable or not, we performed docking analysis and dynamic molecular simulation. Result: Immunoinformatics and bioinformatics evaluations of the designed construct demonstrated that this vaccine candidate could effectively be used as a therapeutic armament against TNBC. Conclusion: Bioinformatics studies revealed that the designed vaccine has an acceptable quality. Investigating the effectiveness of this vaccine can be confirmed by supplementary in vitro and in vivo studies.

Extraction, Chemical Composition, Antioxidant Property, and In-vitro Anticancer Activity of Silymarin from Silybum marianum on Kb and A549 Cell Lines.

INTRODUCTION: This study aimed to evaluate the antioxidant property of Silymarin (SM) extracted from the seed of Silybum marianum and its anticancer activity on KB and A549 cell lines following 24, 48, and 72 h of treatment. METHODS: Ten grams of powdered S. marianum seeds were defatted using n-hexane for 6 hours and then extracted by methanol. The Silymarin extracted of extraction components. The extracted components of Silymarin were measured by spectrophotometric assay and HPLC analysis. 2, 2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, phenol content, total flavonoid content, and total antioxidant capacity were measured to detect the antioxidant properties of SM. The anticancer activity of the SM on cell lines evaluated by MTT. RESULTS: In HPLC analysis, more than 50% of the peaks were related to silybin A and B. SM was reduced DPPH (the stable free radical) with a 50% inhibitory concentration (IC50) of 6.56 µg/ ml in comparison with butylated hydroxyl toluene (BHT), which indicated an IC50 of ~3.9 µg/ ml. The cytotoxicity effect of SM on the cell lines was studied by MTT assay. The cytotoxicity effect of the extracted Silymarin on KB and A549 cell lines was observed up to 80 and 70% at 156 and 78 µg/ml, respectively. The IC50 value of the extracted SM on KB and A549 cell lines after 24 hours of treatment was seen at 555 and 511 µg/ml, respectively. CONCLUSION: Due to the good antioxidant and anticancer properties of the isolated Silymarin, its use as an anticancer drug is suggested.