Although the importance of genome organization for transcriptional regulation of cell-fate decisions and function is clear, the changes in chromatin architecture and how these impact effector and memory CD8 T cell differentiation remain unknown. Using Hi-C, we studied how genome configuration is integrated with CD8 T cell differentiation during infection and investigated the role of CTCF, a key chromatin remodeler, in modulating CD8 T cell fates through CTCF knockdown approaches and perturbation of specific CTCF-binding sites. We observed subset-specific changes in chromatin organization and CTCF binding and revealed that weak-affinity CTCF binding promotes terminal differentiation of CD8 T cells through the regulation of transcriptional programs.
View Article and Find Full Text PDFThe impact of aging on intestinal stem cells (ISCs) has not been fully elucidated. In this study, we identified widespread epigenetic and transcriptional alterations in old ISCs. Using a reprogramming algorithm, we identified a set of key transcription factors (Egr1, Irf1, FosB) that drives molecular and functional differences between old and young states.
View Article and Find Full Text PDFHigh-heat processed foods contain proteins that are partially resistant to enzymatic digestion and pass through to the colon. The fermentation of resistant proteins by gut microbes produces products that may contribute to chronic disease risk. This pilot study examined the effects of a resistant protein diet on growth, fecal microbiome, protein fermentation metabolites, and the biomarkers of health status in pigs as a model of human digestion and metabolism.
View Article and Find Full Text PDFEndolysin enzymes from bacteriophage cause bacterial lysis by degrading the peptidoglycan cell wall. The streptococcal C1 phage endolysin PlyC, is the most potent endolysin described to date and can rapidly lyse group A, C, and E streptococci. PlyC is known to bind the Group A streptococcal cell wall, but the specific molecular target or the binding site within PlyC remain uncharacterized.
View Article and Find Full Text PDFBackground: High blood pressure (BP) continues to be a major, poorly controlled but modifiable risk factor for cardiovascular death. Among key Western lifestyle factors, a diet poor in fiber is associated with prevalence of high BP. The impact of lack of prebiotic fiber and the associated mechanisms that lead to higher BP are unknown.
View Article and Find Full Text PDFHypertension is a complex and modifiable condition in which environmental factors contribute to both onset and progression. Recent evidence has accumulated for roles of diet and the gut microbiome as environmental factors in blood pressure regulation. However, this is complex because gut microbiomes are a unique feature of each individual reflecting that individual's developmental and environmental history creating caveats for both experimental models and human studies.
View Article and Find Full Text PDFAutoreactivity to myeloperoxidase (MPO) causes anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), with rapidly progressive glomerulonephritis. Here, we show that a Staphylococcus aureus peptide, homologous to an immunodominant MPO T-cell epitope (MPO), can induce anti-MPO autoimmunity. The peptide (6PGD) is part of a plasmid-encoded 6-phosphogluconate dehydrogenase found in some S.
View Article and Find Full Text PDFPre-leukemic stem cells (pre-LSCs) give rise to leukemic stem cells through acquisition of additional gene mutations and are an important source of relapse following chemotherapy. We postulated that cell-cycle kinetics of pre-LSCs may be an important determinant of clonal evolution and therapeutic resistance. Using a doxycycline-inducible H2B-GFP transgene in a mouse model of T-cell acute lymphoblastic leukemia to study cell cycle in vivo, we show that self-renewal, clonal evolution and therapeutic resistance are limited to a rare population of pre-LSCs with restricted cell cycle.
View Article and Find Full Text PDFMosquitoes transmit a diverse group of human flaviviruses including West Nile, dengue, yellow fever, and Zika viruses. Mosquitoes are also naturally infected with insect-specific flaviviruses (ISFs), a subgroup of the family not capable of infecting vertebrates. Although ISFs are not medically important, they are capable of altering the mosquito's susceptibility to flaviviruses and may alter host fitness.
View Article and Find Full Text PDFAge-associated decreases in primary CD8 T cell responses occur, in part, due to direct effects on naive CD8 T cells to reduce intrinsic functionality, but the precise nature of this defect remains undefined. Aging also causes accumulation of antigen-naive but semi-differentiated "virtual memory" (T) cells, but their contribution to age-related functional decline is unclear. Here, we show that T cells are poorly proliferative in aged mice and humans, despite being highly proliferative in young individuals, while conventional naive T cells (T cells) retain proliferative capacity in both aged mice and humans.
View Article and Find Full Text PDFThe Helicobacter pylori phase variable gene modH, typified by gene HP1522 in strain 26695, encodes a N-adenosine type III DNA methyltransferase. Our previous studies identified multiple strain-specific modH variants (modH1 - modH19) and showed that phase variation of modH5 in H. pylori P12 influenced expression of motility-associated genes and outer membrane protein gene hopG.
View Article and Find Full Text PDFBackground: Acinetobacter baumannii is a pathogen of major importance in intensive care units worldwide, with the potential to cause problematic outbreaks and acquire high-level resistance to antibiotics. There is an urgent need to understand the mechanisms of A. baumannii pathogenesis for the future development of novel targeted therapies.
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