Epigenetic modulation of immune synaptic-cytoskeletal networks potentiates γδ T cell-mediated cytotoxicity in lung cancer.

γδ T cells are a distinct subgroup of T cells that bridge the innate and adaptive immune system and can attack cancer cells in an MHC-unrestricted manner. Trials of adoptive γδ T cell transfer in solid tumors have had limited success. Here, we show that DNA methyltransferase inhibitors (DNMTis) upregulate surface molecules on cancer cells related to γδ T cell activation using quantitative surface proteomics. DNMTi treatment of human lung cancer potentiates tumor lysis by ex vivo-expanded Vδ1-enriched γδ T cells. Mechanistically, DNMTi enhances immune synapse formation and mediates cytoskeletal reorganization via coordinated alterations of DNA methylation and chromatin accessibility. Genetic depletion of adhesion molecules or pharmacological inhibition of actin polymerization abolishes the potentiating effect of DNMTi. Clinically, the DNMTi-associated cytoskeleton signature stratifies lung cancer patients prognostically. These results support a combinatorial strategy of DNMTis and γδ T cell-based immunotherapy in lung cancer management.

Distribution of Bacterial Endophytes in the Non-lesion Tissues of Potato and Their Response to Potato Common Scab.

The response of plant endophytes to disease within infected tissues has been well demonstrated, but the corresponding response of endophytes in non-lesion tissues remains unclear. Here, we studied the composition and distribution of bacterial endophytes in potato roots (RE), stems (SE), and tubers (TE), and explored the response of endophytes in non-lesion tissues to potato common scab (PCS), which is a soil-borne disease caused by pathogenic Streptomyces and results in serious losses to the global economy every year. Via high-throughput sequencing, it was seen that the composition of endophytes in roots, stems, and tubers had significant differences (P < 0.05) and the distribution of the bacterial communities illustrated a gradient from soil to root to tuber/stem. PCS significantly reduced bacterial endophytes α-diversity indexes, including ACE and the number of observed operational taxonomic units (OTUs), of RE without significantly reducing the indexes of SE and TE. No significant effect on the composition of endophytes were caused by PCS in roots, tubers, or stems between high PCS severity (H) and low PCS severity (L) infections at the community level, but PCS did have a substantial impact on the relative abundance of several specific endophytes. Rhizobium and Sphingopyxis were significantly enriched in root endophytes with low PCS severity (REL); Delftia and Ochrobactrum were significantly enriched in stem endophytes with low PCS severity (SEL); Pedobacter, Delftia, and Asticcacaulis were significantly enriched in tuber endophytes with high PCS severity (TEH). OTU62, a potential PCS pathogen in this study, was capable of colonizing potato tubers, roots, and stems with few or no symptoms present. Co-occurrence networks showed that the number of correlations to OTU62 was higher than average in these three tissue types, suggesting the importance of OTU62 in endophytic communities. This study clarified the distribution and composition of potato endophytes in tubers, roots, and stems, and demonstrated the response of endophytes in non-lesion tissues to PCS.

Material conversion, microbial community composition and metabolic functional succession during green soybean hull composting.

In this study, green soybean hulls and maize straw were used for composting to explore the dynamics of material conversion, bacterial and fungal communities and metabolic functions. The results showed that bacterial and fungal communities had different temporal successions during composting. The bacterium Streptosporangiaceae was a biomarker in the thermophilic stage of composting, and the fungus Chaetomiaceae was a biomarker in the thermophilic stage and cooling stage. In the bacterial network, the germination index (GI) had a time-delayed association with Truepera, Pseudomonas and Methylococcaceae, which represented the key physicochemical characteristics that affect the community. In the fungal community, the GI, pH, fulvic acid (FA) and temperature etc. had a joint effect. Carbohydrate metabolism and amino acid metabolism were the main metabolic pathways, and saprotrophs represented the dominant fungal trophic mode in the composting process. These results provide a reference from screening specific and efficient agents to accelerate natural vegetable composting.

Systematic Identification of Pathogenic Streptomyces sp. AMCC400023 That Causes Common Scab and Genomic Analysis of Its Pathogenicity Island.

Potato scab, a serious soilborne disease caused by Streptomyces spp., occurs in potato-growing areas worldwide and results in severe economic losses. In this paper, the pathogenicity of Streptomyces strain AMCC400023, isolated from potato scabs in Hebei Province, China, was verified systematically by the radish seedling test, the potato tuber slice assay, the potted back experiment, and the detection of phytotoxin thaxtomin A. Morphological, physiological, and biochemical characteristics were determined, and the 16S ribosomal RNA analyses of Streptomyces sp. AMCC400023 were carried out. To obtain the accurate taxonomic status of the pathogen strain, the whole genome was sequenced, and the phylogenetic tree among 31 Streptomyces genomes was formed. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) were analyzed, and at the same time, the toxicity-related genes between Streptomyces sp. AMCC400023 and Streptomyces scabiei were compared, all based on the whole-genome level. All of the data supported that, instead of a member of S. scabiei, test strain Streptomyces sp. AMCC400023 was a distinct phytopathogen of potato common scab, which had a relatively close relationship with S. scabiei while separating clearly from S. scabiei at least in the species level of taxonomic status. The complete pathogenicity island (PAI) composition of Streptomyces sp. AMCC400023 was identified, which contained a toxin region and a colonization region. It was conjectured that the PAI of Streptomyces sp. AMCC400023 might be directly or indirectly acquired from S. scabiei 87-22 by horizontal gene transfer, or at the very least, there was a very close homologous relationship between the two pathogens as indicated by a series of analyses, such as phylogenetic relationships among 31 Streptomyces species, ANI and isDDH analyses, PAI structure mapping, thaxtomin A synthetic gene cluster tree construction, and most important, the collinearity analysis at the genome level.

The occurrence of potato common scab correlates with the community composition and function of the geocaulosphere soil microbiome.

BACKGROUND: Soil microorganisms can mediate the occurrence of plant diseases. Potato common scab (CS) is a refractory disease caused by pathogenic Streptomyces that occurs worldwide, but little is known about the interactions between CS and the soil microbiome. In this study, four soil-root system compartments (geocaulosphere soil (GS), rhizosphere soil (RS), root-zone soil (ZS), and furrow soil (FS)) were analyzed for potato plants with naturally high (H) and low (L) scab severity levels. We aimed to determine the composition and putative function of the soil microbiome associated with potato CS. RESULTS: The copy numbers of the scab phytotoxin biosynthetic gene txtAB and the bacterial 16S rRNA gene as well as the diversity and composition of each of the four soil-root system compartments were examined; GS was the only compartment that exhibited significant differences between the H and L groups. Compared to the H group, the L group exhibited a lower txtAB gene copy number, lower bacterial 16S copy number, higher diversity, higher co-occurrence network complexity, and higher community function similarity within the GS microbiome. The community composition and function of the GS samples were further revealed by shotgun metagenomic sequencing. Variovorax, Stenotrophomonas, and Agrobacterium were the most abundant genera that were significantly and positively correlated with the scab severity level, estimated absolute abundance (EAA) of pathogenic Streptomyces, and txtAB gene copy number. In contrast, Geobacillus, Curtobacterium, and unclassified Geodermatophilaceae were significantly negatively correlated with these three parameters. Compared to the function profiles in the L group, several genes involved in "ABC transporters," the "bacterial secretion system," "quorum sensing (QS)," "nitrogen metabolism," and some metabolism by cytochrome P450 were enriched in the H group. In contrast, some antibiotic biosynthesis pathways were enriched in the L group. Based on the differences in community composition and function, a simple model was proposed to explain the putative relationships between the soil microbiome and CS occurrence. CONCLUSIONS: The GS microbiome was closely associated with CS severity in the soil-root system, and the occurrence of CS was accompanied by changes in community composition and function. The differential functions provide new clues to elucidate the mechanism underlying the interaction between CS occurrence and the soil microbiome, and varying community compositions provide novel insights into CS occurrence.

Production and in vitro antioxidant activity of exopolysaccharide by a mutant, Cordyceps militaris SU5-08.

Cordyceps militaris SU5-08 was derived from an initial strain (C. militaris SU5) by ultraviolet mutagenesis of protoplasts, and the extraction parameters for C. militaris SU5-08 exopolysaccharide (EPS) produced during submerged culture were optimized. The extraction rate of EPS was 1919.16±165.27 mg/l, which was 120.38±11.36% higher than that of C. militaris SU5. The in vitro scavenging effects of EPS of C. militaris SU5-08 on hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at a dosage of 5 g/l were 63.64±3.52%, 75.27±5.16%, and 6.46±5.03%, respectively. The reducing power of EPS of C. militaris SU5-08 was 0.21±0.01. The results suggest that the EPS of C. militaris SU5-08 can be used as a potential antioxidant which enhances adaptive immune responses.

Extraction and in vitro antioxidant activity of intracellular polysaccharide by Pholiota adiposa SX-02.

Response surface methodology (RSM) was used to optimize the extraction parameters for Pholiota adiposa SX-02 intracellular polysaccharide (IPS) produced during submerged culture. The optimum conditions of IPS extraction were predicted to be, ultrasonic power at 564.93 W, precipitation time 30.34 h and pH 8.28, and IPS yield was estimated at 19.75%. The actual value of IPS under these conditions was 20.51%. The in vitro antioxidant results showed that the inhibition effects of IPS at a dosage of 250 mg/l on superoxide anion, hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were 74.66 ± 5.31%, 69.20 ± 5.13%, and 75.20 ± 6.73%, respectively, which were 27.51 ± 2.23%, 16.58 ± 1.33%, and 9.46 ± 0.72% higher than that of butylated hydroxytoluene (BHT), respectively. The reducing power of IPS was 0.32 ± 0.02 (absorbance at 700 nm), 39.13 ± 3.47% higher than that of BHT. The results provide a reference for large-scale extraction of IPS by P. adiposa SX-02 in industrial fermentation and the IPS can be used as a potential antioxidant which enhances adaptive immune responses.

Extraction and antioxidant activities of intracellular polysaccharide from Pleurotus sp. mycelium.

The extraction conditions of intracellular polysaccharide (IPS) from Pleurotus sp. mycelium in submerged culture were investigated. Four parameters affecting the IPS extraction, ultrasonic treatment time, extraction temperature, extraction time and ethanol concentration, were determined by single factor tests and then optimized by orthogonal experiments. Under the optimized conditions, the extraction rates of IPS of Pleurotus nebrodensis SJ-02, Pleurotus eryngii SI-01 and Pleurotus corncopiae SS-01 were 7.1+/-0.4%, 7.5+/-0.3%, and 8.2+/-0.5%, respectively. The in vitro hydroxyl radical inhibition percentages of IPS of three mushrooms were 32.2+/-2.8%, 16.1+/-1.5%, and 38.7+/-3.1%, respectively. The scavenging effects of IPS on superoxide anion radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were 19.1+/-1.5%, 16.3+/-1.3%, 20.3+/-1.8%, 17.9+/-1.6%, 16.8+/-1.4%, and 20.5+/-1.7%, respectively. The results provide a reference for large-scale production of IPS by Pleurotus sp. in industrial fermentation.

Extraction optimization and in vivo antioxidant activities of exopolysaccharide by Morchella esculenta SO-01.

Response surface methodology was used to optimize extraction parameters for Morchella esculenta SO-01 exopolysaccharide (EPS) produced during submerged culture. The optimum conditions for EPS extraction were predicted to be, concentration at 84.07 degrees C, precipitation for 22.19 h and pH 8.44, and EPS production was estimated at 5.45 g/L. The actual yield of EPS under these conditions was 5.32 g/L. The antioxidant capacity of the EPS was measured in vivo after filling the stomach with different doses of EPS and results showed that the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of blood, spleen, liver, heart, and kidney were increased by 125%, 46.11%, 23.33%, 12.19%, 41.29%, and 63.24%, 63.12%, 166.54%, 98.01%, 57.68%, respectively, and that malonaldehyde (MDA) of blood, spleen, liver, heart, and kidney were decreased by 21.80%, 67.84%, 28.48%, 56.15%, 41.62%. The results provide a reference for large-scale extraction of EPS by M. esculenta SO-01 in industrial fermentation.

[A Sinorhizoboium meliloti strain that can nodulate soybean plants].

Sinorhizobium meliloti XJ96077 was isolated from root nodules of alfalfa (Medicago sativa) in Xinjiang Region of China. Nodulation experiments showed that both soybean and alfalfa were effectively nodulated by XJ96077. The DNA (G+ C) mol% of strain XJ96077 was 61.9%. The DNA homologies of strain XJ96077 were 93% and 80% with S. meliloti USDA1002T and 042BM, respectively. These results showed that XJ96077 belongs to Sinorhizobium meliloti. To prove the capability of XJ96077 to nodulate both soybean and alfalfa, constitutively expressed green fluorescence protein gene gfp was introduced to XJ96077, and the recombinant strain XJ96077(G) was obtained. Root nodules of the soybean and alfalfa inoculated with XJ96077(G) and the expression of gfp were observed using the confocal laser scanning microscope. XJ96077 showed various nodulation capacities with different soybean cultivars.