A novel extremely halophilic archaeon, strain XF10 T , was isolated from a salt lake in China. This organism was neutrophilic, non-motile and pleomorphic, and was rod, coccus or irregularly shaped. It required at least 15 M NaCl for growth and grew in a wide range of MgCl 2 concentrations (0005-05 M). Lipid extract of whole cells contained two glycolipids with the same chromatographic properties as two unidentified glycolipids found in the two described Natrinema species, Natrinema pellirubrum and Natrinema pallidum. Phylogenetic analysis based on 16S rDNA sequence comparison revealed that strain XF10T clustered with the two described Natrinema species and several other strains (strains T5.7, GSL-11 and Haloterrigena turkmenica JCM 9743) with more than 981 % sequence similarities, suggesting that strain XF10

BackgroundRadioimmunotherapy has a promising antitumor effect in hepatocellular carcinoma (HCC), depending on the regulatory effect of radiotherapy on tumor immune microenvironment. Ionizing radiation (IR)-induced DNA damage repair (DDR) pathway activation leads to the inhibition of immune microenvironment, thus impairing the antitumor effect of radioimmunotherapy. However, it is unclear whether inhibition of the DDR pathway can enhance the effect of radioimmunotherapy. In this study, we aim to explore the role of DDR inhibitor AZD6738 on the combination of radiotherapy and immune checkpoint inhibitors (ICIs) in HCC.MethodsC57BL/6 mouse subcutaneous tumor model was used to evaluate the ability of different treatment regimens in tumor growth control and tumor recurrence inhibition. Effects of each treatment regimen on the alterations of immunophenotypes including the quantification, activation, proliferating ability, exhaustion marker expression, and memory status were assessed by flow cytometry.ResultsAZD6738 further increased radiotherapy-stimulated CD8+T cell infiltration and activation and reverted the immunosuppressive effect of radiation on the number of Tregs in mice xenografts. Moreover, compared with radioimmunotherapy (radiotherapy plus anti-PD-L1 (Programmed death ligand 1)), the addition of AZD6738 boosted the infiltration, increased cell proliferation, enhanced interferon (IFN)-γ production ability of TIL (tumor-infiltrating lymphocyte) CD8+T cells, and caused a decreasing trend in the number of TIL Tregs and exhausted T cells in mice xenografts. Thus, the tumor immune microenvironment was significantly improved. Meanwhile, triple therapy (AZD6738 plus radiotherapy plus anti-PD-L1) also induced a better immunophenotype than radioimmunotherapy in mice spleens. As a consequence, triple therapy displayed greater benefit in antitumor efficacy and mice survival than radioimmunotherapy. Mechanism study revealed that the synergistic antitumor effect of AZD6738 with radioimmunotherapy relied on the activation of cyclic GMP–AMP synthase /stimulator of interferon genes (cGAS/STING) signaling pathway. Furthermore, triple therapy led to stronger immunologic memory and lasting antitumor immunity than radioimmunotherapy, thus preventing tumor recurrence in mouse models.ConclusionsOur findings indicate that AZD6738 might be a potential synergistic treatment for radioimmunotherapy to control the proliferation of HCC cells, prolong survival, and prevent tumor recurrence in patients with HCC by improving the immune microenvironment.

INTRODUCTIONThe biotechnological potential and evolutionary significance of thermophiles has led to intensive studies on the biology of anaerobic, saccharolytic thermophiles, which are found in all types of thermal habitats (Brock, 1986 ;Wiegel et al., 1985 ;Kristjansson & Stetter, 1992). Most of these isolates have been characterized and described as members of the genera Thermoanaerobacter, Thermoanaerobacterium and Clostridium (Weigel & Ljungdahl, 1981 ;Lee et al., 1993). Anaerobic thermophiles have been isolated from widely distributed hot springs, for example Thermoanaerobacter brockii (Zeikus et al., 1979) and Thermoanaerobacterium xylanolyticum (Lee et al., 1993) The GenBank accession number for the 16S rRNA gene sequence of strain MB4 T is AF209708.New Zealand (Patel et al., 1985) and Thermoanaerobacter italicus from a thermal spa in Italy (Kozianowski et al., 1997). To date, there are few reports on anaerobic thermophiles from Chinese hot springs. During investigations on the microbial diversity of Chinese hot springs, we isolated a new thermophilic bacterium designated strain MB4 T , which is classified as a new member of the genus Thermoanaerobacter on the basis of phenotypic and phylogenetic analyses. The name Thermoanaerobacter tengcongensis is proposed. METHODSSample source. Mixed sediment and water samples were taken from a hot spring in Tengcong, located in Yunnan Province, China. At the site of sampling, the temperature was 86 mC, the pH value was 7n0 and the NaCl concentration was 0n25 % (w\v).Enrichment, isolation and cultivation. The modified MB medium (Fardeau et al., 1997) used for the experimental studies contained (per litre distilled water) : NH % Cl, 1n0 g;

All members of the genera Haloarcula and Halomicrobium whose names have been validly published were surveyed for 16S rRNA gene polymorphism, and the transcription of the genes from two species was investigated during growth at different NaCl concentrations. The species of Haloarcula and Halomicrobium harbour at least two different 16S rRNA gene copies, and 18 new sequences of 16S rRNA genes were obtained. The type I and type II 16S rRNA genes of Haloarcula are divergent at 4.8-5.6% of their nucleotide positions. The type III and type IV 16S rRNA genes from Halomicrobium mukohataei JCM 9738(T) are 9.0% divergent, which represents the highest intraspecific divergent 16S rRNA genes so far seen. Phylogenetic analysis based on 16S rRNA genes indicated that all type I 16S rRNA genes were clustered, and the same was true for the type II 16S rRNA genes of Haloarcula species. The two clusters, respectively generated from type I and type II 16S rRNA genes, were sharply separated and their divergences (4.8-5.6%) are in the range of various divergence usually found between genera in the order Halobacteriales (about 5-10%). Results from reverse transcription-PCR showed that the type I and type II copies of Har. amylolytica BD-3(T) and type III and type IV copies of Hmc. mukohataei JCM 9738(T) were all transcribed to 16S rRNA molecules under different salt concentrations (15-28% NaCl).