Comparison of the effects of probiotic strains (Lactobacillus gasseri, Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Limosilactobacillus fermentum) isolated from human and food products on the immune response of CT26 tumor-bearing mice.

This study aimed to compare the effects of the probiotic bacteria, L. gasseri (52b), L. plantarum (M11), L. acidophilus (AC2), and L. fermentum (19SH), isolated from human source and traditional food products on the modulation of the immune system and inflammatory response on BALB/c mouse model bearing CT26 tumor. Five groups of female inbred BALB/c mice were orally administered with the probiotics and their mixes (MIX, at a 1:1 ratio) at varying dosages (1.5 × 108 cfu/ml and 1.2 × 109 cfu/ml) before and after the injection of a subcutaneous CT26 tumor over the course of 38 days via gavage. Finally, their effects on the tumor apoptosis and the cytokine levels in spleen cell cultures were analyzed and compared. M11, MIX, and 52b groups had the greatest levels of interleukin-12 (IL-12) and interferon gamma (IFN-γ) production. The highest production level of granzyme B (GrB) was related to the MIX and 52b groups. Moreover, these groups showed the lowest production level of (IL-4) and transforming growth factor beta (TGF-ß). Furthermore, the groups of MIX and 52b demonstrated the greatest amount of lymphocyte proliferation of spleen cells in response to the tumor antigen. The delayed-type hypersensitivity (DTH) response significantly increased in the groups of MIX and 52b compared with the control (p < 0.05). The findings demonstrated that the oral treatment of the human strain (52b) and the combination of these bacteria generated strong T helper type 1 (Th1) immune responses in the tumor tissue of the tumor-bearing mice, which led to the suppression of the tumor development.

Preparing a database of corrected protein structures important in cell signaling pathways.

Background and purpose: Precise structures of macromolecules are important for structure-based drug design. Due to the limited resolution of some structures obtained from X-ray diffraction crystallography, differentiation between the NH and O atoms can be difficult. Sometimes a number of amino acids are missing from the protein structure. In this research, we intend to introduce a small database that we have prepared for providing the corrected 3D structure files of proteins frequently used in structure-based drug design protocols. Experimental approach: 3454 soluble proteins belonging to the cancer signaling pathways were collected from the PDB database from which a dataset of 1001 was obtained. All were subjected to corrections in the protein preparation step. 896 protein structures out of 1001 were corrected successfully and the decision on the remained 105 proposed twelve for homology modeling to correct the missing residues. Three of them were subjected to molecular dynamics simulation for 30 ns. Findings / Results: 896 corrected proteins were perfect and homology modeling on 12 proteins with missing residues in the backbone resulted in acceptable models according to Ramachandran, z-score, and DOPE energy plots. RMSD, RMSF, and Rg values verified the stability of the models after 30 ns molecular dynamics simulation. Conclusion and implication: A collection of 1001 proteins were modified for some defects such as adjustment of the bond orders and formal charges, and addition of missing side chains of residues. Homology modeling corrected the amino missing backbone residues. This database will be completed for quite a lot of water-soluble proteins to be uploaded to the internet.

Comparison of probiotic Lactobacillus strains isolated from dairy and Iranian traditional food products with those from human source on intestinal microbiota using BALB/C mice model.

This study compares the probiotic Lactobacillus strains isolated from dairy and Iranian traditional food products with those from human sources on intestinal microbiota using BALB/C mice model. First, Lactiplantibacillus plantarum (M11), Limosilactobacillus fermentum (19SH), Lactobacillus acidophilus (AC2), and Lactobacillus gasseri (52b) strains, isolated from either Iranian traditionally fermented products or human (healthy woman vaginal secretions), identified with molecular methods and selected based on the surface hydrophobicity, auto- and co-aggregation, were investigated for their probiotic properties and compared with their standard probiotic strains in vitro. The native strains and their mixtures (MIX) were then orally fed to five groups of female inbred BALB/C mice over the course of 38 days by gavage at 0.5 and 4 McFarland, respectively, equal to 1.5 × 108 and 1 × 109 cfu/ml. Feeding paused for 6 days to test the bacteria's adhesion in vivo. According to the findings, the probiotic Lactobacillus strain isolated from human source (52b) exhibited the best in vitro and in vivo adhesion ability. Probiotic Lactobacillus strains isolated from Iranian traditional food products (19SH and AC2) had the most co-aggregation with Listeria monocytogenes (ATTC 7644), Salmonella enterica subsp. enterica (ATCC 13,076), and Escherichia coli (NCTC 12,900 O157:H7) in vitro. These strains produced the most profound decreasing effect on the mice intestinal microbiota and pathogens in vivo. The difference in the strains and their probiotic potential is related to the sources from which they are isolated as well as their cell walls. The results suggest that (19SH and 52b strains) are the best candidates to investigate the cell wall and its effect on the host immune system.