(47)]. found to be non-inducers of CD4+ IL-10 against both active VL as well as treated VL subjects. This obtaining suggests there is no role of these peptides CEP-1347 in the pathogenesis of antigens that induce CD4+ Th1 and Th17 responses, which could be used to potentiate a human universal T-epitope vaccine against VL. are not fully effective, due to drug resistance, high toxicity, cost, and different modes of administration (8, 9). Therefore, vaccination remains an alternative for the prevention and control of this dreadful parasitic disease. Several studies have demonstrated the crucial role of a Th1 immune response that not only protects against the primary contamination but also results in a lifelong immunity to re-infection (10, 11). CD4+ T-cells play a crucial role in immune protection by releasing a variety of cytokines, such as interleukin-12 (IL-12), gamma interferon (IFN-), tumor necrosis factor- (TNF-), and chemokines such as CCXCC motif chemokine ligand 10 (CXCL-10), and regulated on activation, normal T cell expressed and secreted (RANTES) (12). Although immune activation by CD8+ T-cells through granzyme activities and by the release of IFN- is usually reported, CD4+ T-cells are pre-dominantly involved in immune cell activation against by producing IFN-, macrophage migration inhibitory factor, and tumor necrosis factor/lymphotoxin (TNF/LT) (13). Conversely, diverse cytokines such as interleukin-4, IL-10, and transforming growth factor , have been shown to modulate Th1 responses, deter macrophage activation, and therefore exacerbate the disease (14, 15). Many leishmanial targets have already been identified and vaccination with component proteins, such as CPs (16, 17), gp63 (18), LeIF (19), KmP-11 (20), ODC (21), and PDI (10), induces CD4+ T-cell-mediated cellular immune activation indicating a Th1-type immune response. Although many of these strategies have resulted in protection in the mouse model, with the exception of Leish-F1, many of them have either failed to prevent natural contamination or have offered no protection in monkey and human models (22C25). In spite of extensive information regarding various life stages of for the immunogenic CD4+ T-cell epitope. The antigenicity and immunogenic Rabbit polyclonal to PGM1 potential (IL-10 and IFN-) of peptides were further determined. The molecular docking approach was also utilized further to verify the antigen presentation. We identified the most important epitopes as P1-P6, which are capable of protecting against contamination by by evoking the cell-mediated immune response. Materials and Methods Selection of the Antigens The wide transcriptome analysis of species CEP-1347 revealed an alteration in their gene expression in the diverse stress conditions. Previously, we mined the genes derived from tools that can predict the nature of MHC class-II epitope as either an IFN- inducer or IL-10 inducer, respectively (43, 44). Molecular Dynamics Simulation To study the intrinsic dynamics of atoms and molecules of the top ranked HLA-epitope complexes, molecular dynamics (MD) simulations were conducted using GROMACS v5.0 as described elsewhere (45, 46). A GROMOS 54A7 force-field was employed for amino acid interaction with the simulation of a water model by the simple point charge (SPC) method. Seven systems (including the CEP-1347 control complex) were prepared by the addition of SPC water molecules (to cover the surface of each complex, 10????10????10?? water box of cubic dimensions). To neutralize each system, a concentration of 0.15?M Na+/Cl? counter ions was added. Then the solvated systems were energy-minimized with 2,000 iterations on a convergence threshold of 1 1?kcal.