Detecting and characterizing new endofungal bacteria in new hosts: Pandoraea sputorum and Mycetohabitans endofungorum in Rhizopus arrhizus.

The fungus Rhizopus arrhizus (=R. oryzae) is commonly saprotrophic, exhibiting a nature of decomposing organic matter. Additionally, it serves as a crucial starter in food fermentation and can act as a pathogen causing mucormycosis in humans and animals. In this study, two distinct endofungal bacteria (EFBs), associated with individual strains of R. arrhizus, were identified using live/dead staining, fluorescence in situ hybridization, transmission electron microscopy, and 16S rDNA sequencing. The roles of these bacteria were elucidated through antibiotic treatment, pure cultivation, and comparative genomics. The bacterial endosymbionts, Pandoraea sputorum EFB03792 and Mycetohabitans endofungorum EFB03829, were purified from the host fungal strains R. arrhizus XY03792 and XY03829, respectively. Notably, this study marks the first report of Pandoraea as an EFB genus. Compared to its free-living counterparts, P. sputorum EFB03792 exhibited 28 specific virulence factor-related genes, six specific CE10 family genes, and 74 genes associated with type III secretion system (T3SS), emphasizing its pivotal role in invasion and colonization. Furthermore, this study introduces R. arrhizus as a new host for EFB M. endofungorum, with EFB contributing to host sporulation. Despite a visibly reduced genome, M. endofungorum EFB03829 displayed a substantial number of virulence factor-related genes, CE10 family genes, T3SS genes, mobile elements, and significant gene rearrangement. While EFBs have been previously identified in R. arrhizus, their toxin-producing potential in food fermentation has not been explored until this study. The discovery of these two new EFBs highlights their potential for toxin production within R. arrhizus, laying the groundwork for identifying suitable R. arrhizus strains for fermentation processes.

Taxonomy, Phylogeny, Divergence Time Estimation, and Biogeography of the Family Pseudoplagiostomataceae (Ascomycota, Diaporthales).

Species of Pseudoplagiostomataceae were mainly introduced as endophytes, plant pathogens, or saprobes from various hosts. Based on multi-locus phylogenies from the internal transcribed spacers (ITS), the large subunit of nuclear ribosomal RNA gene (LSU), partial DNA-directed RNA polymerase II subunit two gene (rpb2), the partial translation elongation factor 1-alpha gene (tef1α), and the partial beta-tubulin gene (tub2), in conjunction with morphological characteristics, we describe three new species, viz. Pseudoplagiostoma alsophilae sp. nov., P. bambusae sp. nov., and P. machili sp. nov. Molecular clock analyses on the divergence times of Pseudoplagiostomataceae indicated that the conjoint ancestor of Pseudoplagiostomataceae and Apoharknessiaceae occurred in the Cretaceous period. and had a mean stem age of 104.1 Mya (95% HPD of 86.0-129.0 Mya, 1.0 PP), and most species emerged in the Paleogene and Neogene period. Historical biogeography was reconstructed for Pseudoplagiostomataceae by the RASP software with a S-DEC model, and suggested that Asia, specifically Southeast Asia, was probably the ancestral area.

[Modulation of TLR9 on anti-tumor immune responses of peripheral blood mononuclear cells from patients with non-small-cell lung cancer].

OBJECTIVE: To assess the modulation of TLR9 on anti-tumor immune responses in peripheral blood mononuclear cells (PBMC) from patients with non-small-cell lung cancer (NSCLC). METHODS: PBMCs were isolated from 36 NSCLC patients. Lung cancer cells were isolated from these patients and further enriched. PBMCs were cultured in RPMI-1640 medium (blank control group), and medium with cytosine guanine oligodeoxynucleotide (CpG ODN, an TLR9 agonist) or control ODN for 72 h; and then flow cytometry was used to examine the expression of CD69 antigen on the surface of CD3 cells, [3H]-thymidine incorporation method was used to examine the cell proliferation, and the IFN-alpha level in the supernatant was measured. Another PBMCs were cultured in medium with interleukin (IL)-1 and then CpG ODN, control ODN, and CpG ODN + chloroquine or inhibitory ODN were added respectively for 24-48 h. Then the IFN-alpha in the supernatant was measured. Subsets were assessed by flow cytometry and the expression of TLR9-mRNA in freshly isolated PBMC was detected by RT-PCR. The production of interferon (IFN)-alpha in the PBMCs was measured by ELISA. The proliferation of the PBMCs was determined by [3H]-thymidine incorporation. The PBMCs co-cultured with CpG ODN and autologous lung tumor cells treated with mitomycin C were used as effector cells, and K562 cells and autologous tumor cells were used as target cells flow cytometry was used to detect the capacity of PBMCs to kill autologous lung tumor cells and K562 cells. Meanwhile we investigated the intracellular expression of IFN-gamma and IL-4 in CD8+ T. RESULTS: The expression level of TLR9 of the PBMCs from patients was not significantly different from that of the PBMCs from the healthy donors. The proportion of CD69 antigen expressing CD3+ T cells of the CpG ODN group was (39.5 +/- 8.9)%, significantly higher than those of the blank control group [(8.8 +/- 1.2)%, t = 40.30, P = 0.00] ands control ODN group [(10.6 +/- 1.0)%, t = 41.85, P = 0.00]. Examination with beta liquid scintillation counter showed that the cpm value of the CpG ODN group was (1.61 +/- 0.20) x 10(4), significantly higher than those of the blank control group [(0.27 +/- 0.14) x 10(4), t = 20.43, P = 0.00] and control ODN group [(0.34 +/- 0.13) x 10(4), t =20.20, P = 0.00]. Chloroquine and inhibitory ODN dose-dependently inhibited the IFN-alpha levels in the supernatant. The CD4 + T/CD8 + T of the CpG ODN group was (3.44 +/- 0.20), significantly higher than those of the control ODN group (1.73 +/- 0.27, t = 19.85, P = 0.00) and blank control group (1.69 +/- 0.13, t = 29.32, P = 0.00). The IFN-gamma positive CD8 + T cells of the CpG ODN group was (18.5 +/- 4.2)%, significantly higher than those of the control ODN group [(4.2 +/- 1.0)%, t = 24.12, P = 0.00] and blank control group [(3.1 +/- 1.2)%, t = 25.1, P = 0.00]. There was no significant differences in the proportion of IL-4 positive CD8 + T cells among different groups. When the E/T was 40:1 the killing capacity of PBMCs against the K562 cells was (19.5 +/- 1.0), significantly higher than those of the control ODN group (7.9 +/- 1.1, t = 19.9, P = 0.00) and blank control group (5.1 +/- 1.6, t = 21.9, P = 0.00), and the killing capacity of PBMCs against the autologous lung tumor cells was (29.8 +/- 2.1), significantly higher than those of the control ODN group (8.1 +/- 0.9, t = 36.9, P = 0.00) and blank control group (5.7 +/- 1.6, t = 35.7, P = 0.00). CONCLUSION: TLR9 signal takes part in the immunomodulation of PBMCs. The activation of TLR9 results in enhanced anti-tumor response in the PBMCs against autologous lung cancer cells and K562 cells.

[A study on the mechanisms of mycobacterial clearance induced by CpG-oligodeoxynucleotides in mice].

OBJECTIVE: To investigate the possible mechanisms of mycobacterial clearance induced by CpG-oligodeoxynucleotides (CpG-ODN) in mice. METHODS: Eight-week-old female BALB/c mice were treated with intraperitoneal CpG-ODN (30 microg), while the control mice with normal saline. After 2 weeks, the control mice and the CpG-treated mice were infected with Mycobacterium tuberculosis (1 x 10(6) colony-forming units, H(37)Rv strain) through the tail vein. At 3 weeks, 4 weeks and 6 weeks after mycobacterial infection, the lung and the spleen tissues were examined for histopathological changes. Real time-PCR was performed to measure the messenger RNA (mRNA) of interleukin (IL)-12, IL-18, interferon (IFN)-gamma, IL-4, IL-10 and inducible nitric oxide synthase (iNOS) in the tissues. The homogenates of lungs and spleens were cultured, and the colonies were counted after a 4 weeks incubation period at 37 degrees C. RESULTS: At 3 weeks and 4 weeks of mycobacterial infection, CpG-ODN-pretreated mice showed less mycobacterial burden in the lungs and the spleens than that in the control mice [(0 +/- 0) x 10(6) CFU/g vs (32 +/- 11) x 10(6) CFU/g, (0 +/- 0) x 10(6) CFU/g vs (10 +/- 4) x 10(6) CFU/g; (26 +/- 4) x 10(6) CFU/g vs (56 +/- 8) x 10(6) CFU/g, (4 +/- 3) x 10(6) CFU/g vs (27 +/- 8) x 10(6) CFU/g]. At 4 weeks of mycobacterial infection, CpG-ODN-pretreated mice displayed increased levels of IL-18 mRNA, IFN-gamma mRNA, iNOS mRNA [(3.6 +/- 0.5, 1.6 +/- 1.1, 0.32 +/- 0.14) vs (0.20 +/- 0.10, 23.17 +/- 4.72, 16.18 +/- 5.09)], and decreased level of IL-12p40 mRNA (5.66 +/- 0.64 vs 14.54 +/- 1.89), but there was no difference in the levels of IL-4 mRNA and IL-10 mRNA in the lungs between CpG-ODN-pretreated mice and the control mice [(0.30 +/- 0.09 vs 0.26 +/- 0.05), (0.28 +/- 0.05 vs 0.29 +/- 0.08)]. CpG-ODN-pretreated mice displayed increased levels of IL-18 mRNA, IFN-gamma mRNA, iNOS mRNA [(5.54 +/- 1.29 vs 0.79 +/- 0.36), (0.52 +/- 0.07 vs 0.21 +/- 0.06), (9.07 +/- 1.81 vs 5.97 +/- 1.44)], and decreased levels of IL-12p40 mRNA, IL-4 mRNA and IL-10 mRNA [(2.10 +/- 0.27 vs 5.07 +/- 0.39), (0.23 +/- 0.10 vs 1.21 +/- 0.26), (0.10 +/- 0.04 vs 0.57 +/- 0.13)] in the spleens as compared with the control mice. In CpG-ODN-pretreated mice, expression level of IFN-gamma mRNA in the lungs at 6 weeks post-infection was higher than that at 4 weeks post-infection (0.95 +/- 0.27 vs 0.32 +/- 0.14). CONCLUSION: The activation of Toll-like receptor-9 (TLR-9) with CpG-ODN could enhance murine mycobacterial clearance in vivo. TLR-9-induced anti-mycobacterial activity involves increased expression of IL-18, IFN-gamma, and iNOS but decreased expression of IL-4 and IL-10.