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BackgroundSystemic lupus erythematosus, characterized by persistent inflammation, is a complex autoimmune disorder with no known cure. Immunosuppressants used in treatment put patients at a higher risk of infections. New knowledge of disease modulators, such as symbiotic bacteria, can enable fine-tuning of parts of the immune system, rather than suppressing it altogether.ResultsDysbiosis of gut microbiota promotes autoimmune disorders that damage extraintestinal organs. Here we report a role of gut microbiota in the pathogenesis of renal dysfunction in lupus. Using a classical model of lupus nephritis, MRL/lpr, we found a marked depletion of Lactobacillales in the gut microbiota. Increasing Lactobacillales in the gut improved renal function of these mice and prolonged their survival. We used a mixture of 5 Lactobacillus strains (Lactobacillus oris, Lactobacillus rhamnosus, Lactobacillus reuteri, Lactobacillus johnsonii, and Lactobacillus gasseri), but L. reuteri and an uncultured Lactobacillus sp. accounted for most of the observed effects. Further studies revealed that MRL/lpr mice possessed a "leaky" gut, which was reversed by increased Lactobacillus colonization. Lactobacillus treatment contributed to an anti-inflammatory environment by decreasing IL-6 and increasing IL-10 production in the gut. In the circulation, Lactobacillus treatment increased IL-10 and decreased IgG2a that is considered to be a major immune deposit in the kidney of MRL/lpr mice. Inside the kidney, Lactobacillus treatment also skewed the Treg-Th17 balance towards a Treg phenotype. These beneficial effects were present in female and castrated male mice, but not in intact males, suggesting that the gut microbiota controls lupus nephritis in a sex hormone-dependent manner.ConclusionsThis work demonstrates essential mechanisms on how changes of the gut microbiota regulate lupus-associated immune responses in mice. Future studies are warranted to determine if these results can be replicated in human subjects.

We present the design of a ten-cavity magnetron extracting TE11 mode through compact diffraction output (DO). The effect of the DO length and the depth of the vane on the performance of the ten-cavity magnetron are investigated to design a compact diffraction structure. By adjusting the length of DO and the depth of the tapered cavities to provide a proper Qe, the output power and power conversion efficiency have been improved. Simulation results of the magnetron with compact DO (the length of the DO is about half an operation wavelength) show that the microwave power of 3.0 MW with a high conversion efficiency of 62% at 2.4 GHz is achieved under an applied voltage of 56 kV and a fixed axial magnetic field of 0.24 T. In addition, the length of the anode block is designed longer than the cathode to arrange the permanent magnet, which has been preliminary designed. [ABSTRACT FROM AUTHOR]

Researchers have discovered bacteria that can degrade chlorate and perchlorate, which are common contaminants in water. All of the isolates from wastewater and a perchlorate-degrading bioreactor used oxygen and chlorate as the terminal electron acceptor.

Background Rotavirus vaccines have poor efficacy in infants from low- and middle-income countries. Gut microbiota is thought to influence the immune response to oral vaccines. Thus, we developed a gnotobiotic (Gn) pig model of enteric dysbiosis to study the effects of human gut microbiota (HGM) on immune responses to rotavirus vaccination, and the effects of rotavirus challenge on the HGM by colonizing Gn pigs with healthy HGM (HHGM) or unhealthy HGM (UHGM). The UHGM was from a Nicaraguan infant with a high enteropathy score (ES) and no seroconversion following administration of oral rotavirus vaccine, while the converse was characteristic of the HHGM. Pigs were vaccinated, a subset was challenged, and immune responses and gut microbiota were evaluated. Results Significantly more rotavirus-specific IFN-[gamma] producing T cells were in the ileum, spleen, and blood of HHGM than those in UHGM pigs after three vaccine doses, suggesting HHGM induces stronger cell-mediated immunity than UHGM. There were significant correlations between multiple Operational Taxonomic Units (OTUs) and frequencies of IFN-[gamma] producing T cells at the time of challenge. There were significant positive correlations between Collinsella and CD8+ T cells in blood and ileum, as well as CD4+ T cells in blood, whereas significant negative correlations between Clostridium and Anaerococcus, and ileal CD8+ and CD4+ T cells. Differences in alpha diversity and relative abundances of OTUs were detected between the groups both before and after rotavirus challenge. Conclusion Alterations in microbiome diversity and composition along with correlations between certain microbial taxa and T cell responses warrant further investigation into the role of the gut microbiota and certain microbial species on enteric immunity. Our results support the use of HGM transplanted Gn pigs as a model of human dysbiosis during enteric infection, and oral vaccine responses. Keywords: Enteric dysbiosis, Gnotobiotic pig, Rotavirus, Vaccine, Enteric immunity, Author(s): Erica L. Twitchell[sup.1] , Christine Tin[sup.1] , Ke Wen[sup.1] , Husen Zhang[sup.2] , Sylvia Becker-Dreps[sup.3] , M. Andrea Azcarate-Peril[sup.4] , Samuel Vilchez[sup.5] , Guohua Li[sup.1] , Ashwin Ramesh[sup.1] , [...]

We generated a neonatal pig model with human infant gut microbiota (HGM) to study the effect of a probiotic on the composition of the transplanted microbiota following rotavirus vaccination and challenge. All the HGM-transplanted pigs received two doses of an oral attenuated rotavirus vaccine. The gut microbiota of vaccinated pigs were investigated for effects of Lactobacillus rhamnosus GG (LGG) supplement and homotypic virulent human rotavirus (HRV) challenge. High-throughput sequencing of V4 region of 16S rRNA genes demonstrated that HGM-transplanted pigs carried microbiota similar to that of the C-section delivered baby. Firmicutes and Proteobacteria represented over 98% of total bacteria in the human donor and the recipient pigs. HRV challenge caused a phylum-level shift from Firmicutes to Proteobacteria. LGG supplement prevented the changes in microbial communities caused by HRV challenge. In particular, members of Enterococcus in LGG-supplemented pigs were kept at the baseline level, while they were enriched in HRV challenged pigs. Taken together, our results suggested that HGM pigs are valuable for testing the microbiota's response to probiotic interventions for treating infantile HRV infection. Keywords: Microbiota, Gnotobiotic pigs, Rotavirus, Vaccine, Lactobacillus, Probiotics, Author(s): Husen Zhang[sup.1] , Haifeng Wang[sup.2,5] , Megan Shepherd[sup.3] , Ke Wen[sup.2] , Guohua Li[sup.2] , Xingdong Yang[sup.2] , Jacob Kocher[sup.2] , Ernawati Giri-Rachman[sup.2] , Allan Dickerman[sup.4] , Robert Settlage[sup.4] [...]

It has long been recognized that the mammalian gut microbiota has a role in the development and activation of the host immune system. Much less is known on how host immunity regulates the gut microbiota. Here we investigated the role of adaptive immunity on the mouse distal gut microbial composition by sequencing 16 S rRNA genes from microbiota of immunodeficient Rag1−/− mice, versus wild-type mice, under the same housing environment. To detect possible interactions among immunological status, age and variability from anatomical sites, we analyzed samples from the cecum, colon, colonic mucus and feces before and after weaning. High-throughput sequencing showed that Firmicutes, Bacteroidetes and Verrucomicrobia dominated mouse gut bacterial communities. Rag1− mice had a distinct microbiota that was phylogenetically different from wild-type mice. In particular, the bacterium Akkermansia muciniphila was highly enriched in Rag1−/− mice compared with the wild type. This enrichment was suppressed when Rag1−/− mice received bone marrows from wild-type mice. The microbial community diversity increased with age, albeit the magnitude depended on Rag1 status. In addition, Rag1−/− mice had a higher gain in microbiota richness and evenness with increase in age compared with wild-type mice, possibly due to the lack of pressure from the adaptive immune system. Our results suggest that adaptive immunity has a pervasive role in regulating gut microbiota's composition and diversity. [ABSTRACT FROM AUTHOR]