Fecal microbiota transfer from autoimmune dry eye disease model mice to conventional mice induces ocular surface inflammation and stereotypic B cell receptor repertoire development in lacrimal gland
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ABSTRACT: In this study, we transferred gut microbiota of SS-like autoimmune dry eye disease model mice to conventional B6 mice (NOD-FMT). After the transfer, NOD-FMT mice experienced a dramatic change in the gut microbiomes and showed clinicopathological features of SS, including increased corneal fluorescein staining score, decreased tear production, elevated levels of IL-6 mRNA, decreased levels of MUC5AC mRNA encoding mucin. Additionally, we observed that NOD-FMT mice shared stereotypic B cell receptor (BCR) clonotypes with a much higher frequency compared to control group. B cell clones encoding these stereotypic BCR clonotypes developed and expanded locally in the lacrimal gland, and achieved systemic presence in certain clonotypes.
Project description:Primary B cell receptor (BCR)/antibody variable region exons are generated by V(D)J recombination with junctional diversification creating immensely diverse antigen contact-encoding CDR3s. While most antigen-driven germinal centers (GCs) are transient, gut microbiota-dependent intestinal Peyer’s patch (PP) GCs are chronic. The nature of chronic PP GC BCR repertoires and somatic hyper-mutation (SHM) patterns has remained enigmatic. To elucidate the physiological repertoire of PP GC BCRs, we developed a high throughput antibody repertoire and SHM assay. Remarkably, PP GCs from different mice expanded public clonotypes, each often with identical IgH CDR3. These CDR3s represent innate-like BCRs that appear much more frequently than expected in naïve B cell repertoire by IGoR modeling, but not frequently enough to enter PP GCs at the observed recurrence without cellular selection. Consistently, some public clonotypes are gut microbiota-dependent and encode antibodies reactive to bacteria glycans, while others are not. SPF fecal transfer to germ-free (GF) mice restored two germ-dependent clonotypes, providing direct evidence for BCR selection. In support of this, we identified recurrently selected SHMs in four of the public clonotypes, demonstrating affinity maturation in chronic PP GCs. Our findings suggest that persistent gut antigens select for innate-like BCR clonotypes to seed chronic PP GCs.
Project description:The growing evidence suggest that the effect of Alzheimer’s Disease (AD) is not solely restricted to the brain. Numerous groups investigated the relation between the central nervous system and peripheral system, whereupon the peripheral system is closely involved in accordance with the progression of disease and systemic immunity. In our previous report, we identified shared B cell receptor (BCR) sequences among 10 AD patients which showed similar class-switching orientation, identical isotypes and high somatic hypermutation rate. For further investigation, we recruited 44 patients with AD at baseline and 37 patients for second follow-up to identify the shared BCR sequences among patients and persistent BCR within an individual patient. We were able to annotate 3983 unique AD specific BCR clonotypes and one of the clonotype showed binding affinity against human Aβ42 peptide. Our finding can provide evidence of common BCRs in AD patients exposed to antigenic stimulus which are related to AD pathogenesis.
Project description:Age-dependent changes of the gut-associated microbiome have been linked to increased frailty and systemic inflammation. This study found that age-associated changes of the gut microbiome of BALB/c and C57BL/6 mice could be reverted by co-housing of aged (22 months old) and adult (3 months old) mice for 30-40 days or faecal microbiota transplantation (FMT) from adult into aged mice. This was demonstrated using high-throughput sequencing of the V3-V4 hypervariable region of bacterial 16S rRNA gene isolated from faecal pellets collected from 3-4 months old adult and 22-23 months old aged mice before and after co-housing or FMT.
Project description:Stereotypic behavior (SB) is common in emotional stress-involved psychiatric disorders and is often attributed to glutamatergic impairments, but the underlying mechanisms are unknown. To challenge the causal involvement of cholinergic neuromodulation in SB, we studied TgR mice with impaired cholinergic transmission due to over-expression of the stress-inducible soluble ‘readthrough’ acetylcholinesterase-R (AChE-R) variant. RNA-sequencing revealed 37 differentially expressed microRNAs in TgR mice hippocampi, 8 of which targeting over 5 human cholinergic-related transcripts each. Further, microarray tests of TgR prefrontal cortices displayed up to 428 long RNA transcripts differentially expressed from those of FVB/N mice, primarily glutamatergic-related mRNA transcripts (P<1x10-3). Suggesting behavioral relevance, TgR brains presented c-fos over-expression at motor behavior-regulating brain regions and immune-labeled AChE-R excess in SB-regulating basal ganglia, limbic brain nuclei and the brain stem. Compatible with this, TgR mice showed impaired organization of behavior, performance errors in a serial maze test, escape-like locomotion and less rearing under changed environmental familiarity/novelty conditions. Our findings attribute stress-induced SB to previously unknown microRNA-mediated perturbation of cholinergic/glutamatergic networks, support malfunctioning hierarchical control of cholinergic signaling as impairing the behavioral inhibitory regulation via glutamatergic neuromodulation and underscore new therapeutic strategies for correcting stereotypic behaviors.
Project description:This study aimed to analyze changes in gut microbiota composition in mice after transplantation of fecal microbiota (FMT, N = 6) from the feces of NSCLC patients by analyzing fecal content using 16S rRNA sequencing, 10 days after transplantation. Specific-pathogen-free (SPF) mice were used for each experiments (N=4) as controls.
Project description:Rationale: Physical exercise is essential for skeletal integrity and bone health. The gut microbiome, as a pivotal modulator of overall physiologic states, is closely associated with skeletal homeostasis and bone metabolism. However, the potential role of intestinal microbiota in the exercise-mediated bone gain remains unclear. Methods: We conducted microbiota depletion and fecal microbiota transplantation (FMT) in ovariectomy (OVX) mice and aged mice to investigate whether the transfer of gut ecological traits could confer the exercise-induced bone protective effects. The study analyzed the gut microbiota and metabolic profiles via 16S rRNA gene sequencing and LC-MS untargeted metabolomics to identify key microbial communities and metabolites responsible for bone protection. Transcriptome sequencing and RNA interference were employed to explore the molecular mechanisms. Results: We found that gut microbiota depletion hindered the osteogenic benefits of exercise, and FMT from exercised osteoporotic mice effectively mitigated osteopenia. Comprehensive profiling of the microbiome and metabolome revealed that the exercise-matched FMT reshaped intestinal microecology and metabolic landscape. Notably, alterations in bile acid metabolism, specifically the enrichment of taurine and ursodeoxycholic acid, mediated the protective effects on bone mass. Mechanistically, FMT from exercised mice activated the apelin signaling pathway and restored the bone-fat balance in recipient MSCs. Conclusion: Our study underscored the important role of the microbiota-metabolic axis in the exercise-mediated bone gain, heralding a potential breakthrough in the treatment of osteoporosis.
Project description:Transcriptome analysis of submandibular glands in female MyD88+/+ and MyD88−/− NOD mice. Sjögren's syndrome (SS) is an autoimmune disease characterized by dysfunction of salivary glands (SGs) and lacrimal glands, which is caused by chronic inflammation associated with autoantibody and autoreactive lymphocyte infiltration. The pathogenic mechanism of SS has not been fully elucidated. Infiltrated lymphocytes form regularized structures similar to lymphoid follicles of secondary lymphoid organs, such as T/B cell compartments, high endothelial venules (HEVs), lymphatic vessels, and germinal centers, therefore being believed as an ectopic lymphoid tissue called tertiary lymphoid organs (TLO). We previously found that deletion of the Toll-like receptor/IL-1 receptor (TLR/IL-1R) adaptor molecule gene Myd88 in SS model mice NOD reduced the frequency of lymphocyte infiltration and HEV formation in SGs. In this study, we analyzed the effect of MyD88 deficiency on lymphoid follicle formation in SGs of NOD mice. Microarray analysis showed decreased expression of genes related to TLO, such as Cxcl13 and Cxcr5, in Myd88-deficient SGs. These results indicate that deficiency of TLR/IL-1R signaling decrease gene expression ot chemokines in SGs, suggesting MyD88-dependent signaling is directly involved in formation of lymphoid follicles in SS.
Project description:Purpose: To determine whether previously observed behavioral differences in alcoholic human patients after fecal microbiota transplantation (FMT) could be transferred to mice. Methods: Fecal microbiota samples from a previously published phase 1, double-blind, randomized clinical trial of AUD-related cirrhosis patients were used to colonize germ-free mice. Fecal material was transferred to 10-15-week-old GF C57BL/6 male mice by daily gavage for 3 day. The mice were housed in sterile individually filtered cages for 15 days after which stool was collected and then they underwent the alcohol preference experiment using 2-bottle choice drinking (water and 20% ethanol v/v). Microbial DNA was isolated from stool samples by sequencing the V1 and V2 variable regions of the bacterial 16S rRNA gene were sequenced using Multitag fusion primers and sequenced on an Ion Torrent PGM next-generation sequencer. Intestinal mucosa, liver, and prefrontal cortex tissue was collected from mice at time of sacrifice. RNAseq was used to measure gene expression in pre-FMT and post-FMT samples. RNAseq data were aligned to the mouse genome (GRCm39) using STAR (version 2.7.9a) and counts were generated with HTSeq (version 0.13.5). Genes with very low counts across the study (defined as fewer than 10 counts in more than 2 samples) were eliminated before differential expression analysis. Low count genes were determined separately for each tissue type. The DESeq2 package for R was then used to measure differential expression between pre-FMT and post-FMT mice in the intestine, liver, and PFC. Benjamini and Hochberg False Discovery Rate (FDR) was used to correct for multiple testing with FDR ≤ 0.2 considered significant. Results: Mice colonized with post-FMT stool significantly reduced ethanol acceptance, intake and preference versus pre-FMT colonized mice. Microbial taxa that were higher in post-FMT humans were also associated with lower alcohol intake and preference in mice. RNAseq further showed that differential gene expression, post-FMT, occurred in the intestine rather than the liver and prefrontal cortex. Conclusions: FMT leads to significant change in gut microbiome population, which in turn alters gene expression in the intestine. FMT also significantly affects alcohol consumption. The microbiotal-intestinal interface may alter gut-liver-brain axis and reduce alcohol consumption in humans.