Whole Genome Mining and Characterization of a New Probiotic Strain Levilactobacillus brevis ILSH3 from Handia: An Ethnic Fermented Beverage of Odisha, India.

Isolation and characterization of probiotics from traditional fermented food have contributed many beneficial strains to the field of health and nutritional sciences. Handia, a traditional fermented alcoholic beverage popular in different parts of Odisha, was our source of isolation. This study characterizes one such potential bacteria, Levilactobacillus brevis ILSH3 (H3) isolated from Handia. The investigation for the probiotic attributes as per ICMR-DBT guidelines qualified the checkpoint assays like acid and bile tolerance, bile salt hydrolase activity, antimicrobial properties, and pathogen exclusion ability. The whole genome sequence of H3 (2,460,966 bp in size with GC content of 45.62%) was subjected to comparative genome analysis for its taxonomic identification and validation of probiotic potential. Various genes pertaining to its probiotic potential were identified in the genome and it showed zero matches against any pathogenic families. Metabolite profiling of cell-free supernatant using liquid chromatography-mass spectrometry revealed the presence of essential amino acids, short-chain fatty acids, antimicrobial molecules, immunomodulatory molecules, and flavor/aroma-enhancing compounds. Immunomodulatory property investigation using Bioplex and qRT-PCR showed a reduction in the levels of pro-inflammatory cytokines in L. brevis ILSH3-treated Caco-2 cells. Collectively, the results demonstrate that this Handia-origin bacteria Levilactobacillus brevis ILSH3 possesses desirable attributes of a probiotic, which is now open for nutritional and health biologists to explore. This new probiotic strain may show promising results when utilized in healthcare or functional foods.

Statins abrogate gemcitabine-induced PD-L1 expression in pancreatic cancer-associated fibroblasts and cancer cells with improved therapeutic outcome.

A combination of chemotherapy with immunotherapy has been proposed to have better clinical outcomes in Pancreatic Ductal Adenocarcinoma (PDAC). On the other hand, chemotherapeutics is known to have certain unwanted effects on the tumor microenvironment that may mask the expected beneficial effects of immunotherapy. Here, we have investigated the effect of gemcitabine (GEM), on two immune checkpoint proteins (PD-L1 and PD-L2) expression in cancer associated fibroblasts (CAFs) and pancreatic cancer cells (PCCs). Findings of in vitro studies conducted by using in-culture activated mouse pancreatic stellate cells (mPSCs) and human PDAC patients derived CAFs demonstrated that GEM significantly induces PD-L1 and PD-L2 expression in these cells. Moreover, GEM induced phosphorylation of STAT1 and production of multiple known PD-L1-inducing secretory proteins including IFN-γ in CAFs. Upregulation of PD-L1 in PSCs/CAFs upon GEM treatment caused T cell inactivation and apoptosis in vitro. Importantly, Statins suppressed GEM-induced PD-L1 expression both in CAFs and PCCs while abrogating the inactivation of T-cells caused by GEM-treated PSCs/CAFs. Finally, in an immunocompetent syngeneic orthotopic mouse pancreatic tumor model, simvastatin and GEM combination therapy significantly reduced intra-tumor PD-L1 expression and noticeably reduced the overall tumor burden and metastasis incidence. Together, the findings of this study have provided experimental evidence that illustrates potential unwanted side effects of GEM that could hamper the effectiveness of this drug as mono and/or combination therapy. At the same time the findings also suggest use of statins along with GEM will help in overcoming these shortcomings and warrant further clinical investigation.

Gemcitabine induces polarization of mouse peritoneal macrophages towards M1-like and confers antitumor property by inducing ROS production.

In patients with pancreatic cancer (PC), the peritoneal cavity is the second-most common site of metastasis after the liver. Peritoneal macrophages (PMs) have been demonstrated to play a significant role in the peritoneal metastases of different cancers. Gemcitabine (GEM) is known to affect PC-associated immune cells, including macrophages. However, its effect on PMs and its possible clinical implication is yet to be investigated. In this study, mouse-derived PMs were treated with GEM ex vivo to analyze the polarization status. Production of GEM-induced reactive oxygen species (ROS) and reactive nitrogen species was evaluated using DCFH-DA, DAF-FM, and Griess assay. Antitumor effects of PMs on UN-KC-6141and UN-KPC-961 murine PC cells were evaluated in presence and absence of GEM in vitro. Similarly, effect of GEM on human THP-1 macrophage polarization and its tumoricidal effect was studied in vitro. Furthermore, the effect of GEM-treated PMs on peritoneal metastasis of UN-KC-6141 cells was evaluated in a syngeneic mouse model of PC. GEM upregulated M1 phenotype-associated molecular markers (Tnf-α and Inos) in vitro in PMs obtained from naïve mouse. Moreover, IL-4-induced M2-like PMs reverted to M1-like after GEM treatment. Co-culture of UN-KC-6141 and UN-KPC-961 cancer cells with PMs in the presence of GEM increased apoptosis of these cells, whereas cell death was markedly reduced after N-acetyl-L-cysteine treatment. Corroborating these findings co-culture of GEM-treated human THP-1 macrophages also induced cell death in MIAPaCa-2 cancer cells. GEM-treated PMs injected intraperitoneally along with UN-KC-6141 cells into mice extended survival period, but did not stop disease progression and mortality. Together, GEM induced M1-like polarization of PMs from naive and/or M2-polarized PMs in a ROS-dependent manner. GEM-induced M1-like PMs prompted cytotoxicity in PC cells and delayed disease progression in vivo.