DRG2 is required for surface localization of PD-L1 and the efficacy of anti-PD-1 therapy.

More than half of tumor patients with high PD-L1 expression do not respond to anti-PD-1/PD-L1 therapy, and the underlying mechanisms are yet to be clarified. Here we show that developmentally regulated GTP-binding protein 2 (DRG2) is required for response of PD-L1-expressing tumors to anti-PD-1 therapy. DRG2 depletion enhanced IFN-γ signaling and increased the PD-L1 level in melanoma cells. However, it inhibited recycling of endosomal PD-L1 and reduced surface PD-L1 levels, which led to defects in interaction with PD-1. Anti-PD-1 did not expand effector-like T cells within DRG2-depleted tumors and failed to improve the survival of DRG2-depleted tumor-bearing mice. Cohort analysis revealed that patients bearing melanoma with low DRG2 protein levels were resistant to anti-PD-1 therapy. These findings identify DRG2 as a key regulator of recycling of endosomal PD-L1 and response to anti-PD-1 therapy and provide insights into how to increase the correlation between PD-L1 expression and response to anti-PD-1 therapy.

FOXO1 Is a Key Mediator of Glucocorticoid-Induced Expression of Tristetraprolin in MDA-MB-231 Breast Cancer Cells.

The mRNA destabilizing factor tristetraprolin (TTP) functions as a tumor suppressor by down-regulating cancer-associated genes. TTP expression is significantly reduced in various cancers, which contributes to cancer processes. Enforced expression of TTP impairs tumorigenesis and abolishes maintenance of the malignant state, emphasizing the need to identify a TTP inducer in cancer cells. To search for novel candidate agents for inducing TTP in cancer cells, we screened a library containing 1019 natural compounds using MCF-7 breast cancer cells transfected with a reporter vector containing the TTP promoter upstream of the luciferase gene. We identified one molecule, of which the enantiomers are betamethasone 21-phosphate (BTM-21-P) and dexamethasone 21-phosphate (BTM-21-P), as a potent inducer of TTP in cancer cells. We confirmed that BTM-21-P, DXM-21-P, and dexamethasone (DXM) induced the expression of TTP in MDA-MB-231 cells in a glucocorticoid receptor (GR)-dependent manner. To identify potential pathways linking BTM-21-P and DXM-21-P to TTP induction, we performed an RNA sequencing-based transcriptome analysis of MDA-MB-231 cells at 3 h after treatment with these compounds. A heat map analysis of FPKM expression showed a similar expression pattern between cells treated with the two compounds. The KEGG pathway analysis results revealed that the upregulated DEGs were strongly associated with several pathways, including the Hippo signaling pathway, PI3K-Akt signaling pathway, FOXO signaling pathway, NF-κB signaling pathway, and p53 signaling pathway. Inhibition of the FOXO pathway using a FOXO1 inhibitor blocked the effects of BTM-21-P and DXM-21-P on the induction of TTP in MDA-MB-231 cells. We found that DXM enhanced the binding of FOXO1 to the TTP promoter in a GR-dependent manner. In conclusion, we identified a natural compound of which the enantiomers are DXM-21-P and BTM-21-P as a potent inducer of TTP in breast cancer cells. We also present new insights into the role of FOXO1 in the DXM-21-P- and BTM-21-P-induced expression of TTP in cancer cells.

Pedobacter luteus sp. nov., isolated from soil.

Two strains of Gram-staining-negative, rod-shaped bacteria that were motile by gliding, N7d-4(T) and B4a-b5, were isolated during a study of culturable bacteria in soil cultivated with potatoes. These isolates grew at 15-37 °C and at pH 6.5-7.0. The major cellular fatty acids were summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), anteiso-C15 : 0, iso-C15 : 0, iso-C17 : 0 3-OH and iso-C17 : 1ω9c. The major polar lipids were phosphatidyl-N-methylethanolamine and phosphatidylethanolamine. The strains contained d-18 : 0 and d-19 : 0 sphingosines. The DNA G+C contents of strains N7d-4(T) and B4a-b5 were 48.5 and 46.9 mol% (HPLC), respectively. A phylogenetic analysis based on 16S rRNA gene sequences showed that strains N7d-4(T) and B4a-b5 were affiliated with Pedobacter species in the family Sphingobacteriaceae. Strains N7d-4(T) and B4a-b5 shared 99.9 % sequence similarity, and the most closely related Pedobacter type strains were Pedobacter composti TR6-06(T) (96.5 and 96.7 % sequence similarity, respectively), P. oryzae N7(T) (95.4 and 95.6 %) and P. caeni LMG 22862(T) (94.0 and 94.4 %). Phenotypic data and phylogenetic inference clearly distinguished the two isolates from other Pedobacter species. Based on these data, the isolates are considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter luteus sp. nov. is proposed. The type strain is N7d-4(T) ( = KCTC 22699(T)  = DSM 22385(T)).

Agrimonia eupatoria protects against chronic ethanol-induced liver injury in rats.

This study examined the hepatoprotective effects of Agrimonia eupatoria water extract (AE) against chronic ethanol-induced liver injury. Rats were fed a Lieber-DeCarli liquid diet for 8 weeks. Animals were treated orally with AE at 10, 30, 100, and 300 mg/kg/day. After chronic consumption of ethanol, serum aminotransferase activities and pro-inflammatory cytokines markedly increased, and those increases were attenuated by AE. The cytochrome P450 2E1 activity and lipid peroxidation increased after chronic ethanol consumption, while reduced glutathione concentration decreased. Those changes were attenuated by AE. Chronic ethanol consumption increased the levels of Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 protein expression, inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expression, and nuclear translocation of nuclear factor-kappa B, which was attenuated by AE. Our results suggest that AE ameliorates chronic ethanol-induced liver injury, and that protection is likely due to the suppression of oxidative stress and TLR-mediated inflammatory signaling.

Paenibacillus pectinilyticus sp. nov., isolated from the gut of Diestrammena apicalis.

During a search for exo-enzyme-producing bacteria in the gut of an insect, Diestrammena apicalis, a novel bacterium capable of degrading pectin was isolated. The isolate, designated strain RCB-08(T), comprised Gram-positive, endospore-forming, motile rods capable of growth at 15-30 degrees C and pH 6.0-8.7. The DNA G+C content of the isolate was 51.5 mol% and the predominant cellular fatty acid was anteiso-C(15 : 0) (74.1 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain RCB-08(T) was affiliated with a cluster within the Paenibacillaceae, and was related most closely to Paenibacillus chondroitinus NBRC 15376(T), with a sequence similarity of 96.7 %. The DNA-DNA relatedness value for strain RCB-08(T) with P. chondroitinus NBRC 15376(T) was 15.0 %. Strain RCB-08(T) hydrolysed pectin, but not cellulose, casein, starch or xylan. Strain RCB-08(T) could be clearly distinguished from other Paenibacillus species on the basis of characteristics observed using a polyphasic approach. Therefore strain RCB-08(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus pectinilyticus sp. nov. is proposed. The type strain is RCB-08(T) (=KCTC 13222(T)=CECT 7358(T)).

Paenibacillus pueri sp. nov., isolated from Pu'er tea.

Pu'er tea is a fermented drink made from the leaves of the tea plant, Camellia sinensis. Two novel bacteria, designated strains b09i-3(T) and b13i-1, were isolated during the process of fermentation of this tea. These isolates were Gram-positive, endospore-forming, motile rods that grew at 25-42 degrees C and pH 5.5-10.4. The DNA G+C content was 56.6-58.4 mol%, the predominant isoprenoid quinone was MK-7 and the predominant cellular fatty acid was anteiso-C(15 : 0) (49.0-50 % of the total). Phylogenetic analysis based on 16S rRNA gene sequences showed that strains b09i-3(T) and b13i-1 shared 99.9 % similarity and were affiliated with a cluster within the family Paenibacillaceae. Strains b09i-3(T) and b13i-1 were related most closely to Paenibacillus ginsengihumi DCY16(T) (97 % 16S rRNA gene sequence similarity). Levels of DNA-DNA relatedness between the two novel isolates and P. ginsengihumi DCY16(T) were below 56 %. The phylogenetic and phenotypic characteristics of these novel isolates allowed them to be distinguished clearly from recognized species of the genus Paenibacillus. Based on these data, strains b09i-3(T) and b13i-1 are considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus pueri sp. nov. is proposed. The type species is b09i-3(T) (=KCTC 13223(T)=CECT 7360(T)).

A culture-based study of the bacterial communities within the guts of nine longicorn beetle species and their exo-enzyme producing properties for degrading xylan and pectin.

In this study, bacterial communities within the guts of several longicorn beetles were investigated by a culture-dependent method. A total of 142 bacterial strains were isolated from nine species of longicorn beetle, including adults and larvae. A comparison of their partial 16S rRNA gene sequences showed that most of the bacteria constituting the gut communities can typically be found in soil, plants and the intestines of animals, and approximately 10% were proposed as unreported. Phylogenetic analysis demonstrated that the bacterial species comprised 7 phyla, and approximately half were Gammaproteobacteria. Actinobacteria were the second most populous group (19%), followed by Firmicutes (13%) and Alphaproteobacteria (11%). Betaproteobacteria, Flavobacteria, and Acidobacteria were minor constituents. The taxonomic compositions of the isolates were variable according to the species of longicorn beetle. Particularly, an abundance of Actinobacteria existed in Moechotypa diphysis and Mesosa hirsute, which eat broadleaf trees; however, no Actinobacteria were isolated from Corymbia rubra and Monochamus alternatus, which are needle-leaf eaters. Considerable proportions of xylanase and pectinase producing bacteria in the guts of the longicorn beetles implied that the bacteria may play an important role in the digestion of woody diets. Actinobacteria and Gammaproteobacteria were the dominant xylanase producers in the guts of the beetles.

The diversity of culturable organotrophic bacteria from local solar salterns.

We isolated and cultured bacteria inhabiting solar saltern ponds in Taean-Gun, Chungnam Province, Korea. All of the isolated 64 strains were found to be moderately halophilic bacteria, growing in a salt range of 2-20 %, with an optimal concentration of 5% salt. Bacterial diversity among the isolated halophiles was evaluated via RFLP analyses of PCR-amplified 16S rDNAs, followed by phylogenetic analysis of the partial 16S rDNA sequences. The combination of restriction enzyme digestions with HaeIII, CfoI, MspI and RsaI generated 54 distinct patterns. A neighbor-joining tree of the partial 16S rDNA sequences resulted in the division of the 64 strains into 2 major groups, 45 strains of gamma-Proteobacteria (70.3%) and 19 strains of Firmicutes (29.7%). The alpha-Proteobacteria and Cytophaga-Flavobacterium-Bacterioides groups, which were repeatedly found to exist in thalassohaline environments, were not represented in our isolates. The gamma-Proteobacteria group consisted of several subgroups of the Vibrionaceae (37.5%), Pseudoalteromonadaceae (10.9%), Halomonadaceae (7.8%), Alteromonadaceae (7.8%), and Idiomarinaceae (6.3%). Members of Salinivibrio costicola (29.7%) were the most predominant species among all of the isolates, followed by Halobacillus treperi (12.5%). Additionally, three new species candidates were found, based on similarities of the 16S rDNA sequences to those of previously published species.