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901.
Woojong Lee Brock Kingstad-Bakke Brett Paulson Autumn Larsen Katherine Overmyer Chandranaik B. Marinaik Kelly Dulli Randall Toy Gabriela Vogel Katherine P. Mueller Kelsey Tweed Alex J. Walsh Jason Russell Krishanu Saha Leticia Reyes Melissa C. Skala John-Demian Sauer Dmitry M. Shayakhmetov Joshua Coon Krishnendu Roy M. Suresh 《PLoS pathogens》2021,17(1)
There is a critical need for adjuvants that can safely elicit potent and durable T cell-based immunity to intracellular pathogens. Here, we report that parenteral vaccination with a carbomer-based adjuvant, Adjuplex (ADJ), stimulated robust CD8 T-cell responses to subunit antigens and afforded effective immunity against respiratory challenge with a virus and a systemic intracellular bacterial infection. Studies to understand the metabolic and molecular basis for ADJ’s effect on antigen cross-presentation by dendritic cells (DCs) revealed several unique and distinctive mechanisms. ADJ-stimulated DCs produced IL-1β and IL-18, suggestive of inflammasome activation, but in vivo activation of CD8 T cells was unaffected in caspase 1-deficient mice. Cross-presentation induced by TLR agonists requires a critical switch to anabolic metabolism, but ADJ enhanced cross presentation without this metabolic switch in DCs. Instead, ADJ induced in DCs, an unique metabolic state, typified by dampened oxidative phosphorylation and basal levels of glycolysis. In the absence of increased glycolytic flux, ADJ modulated multiple steps in the cytosolic pathway of cross-presentation by enabling accumulation of degraded antigen, reducing endosomal acidity and promoting antigen localization to early endosomes. Further, by increasing ROS production and lipid peroxidation, ADJ promoted antigen escape from endosomes to the cytosol for degradation by proteasomes into peptides for MHC I loading by TAP-dependent pathways. Furthermore, we found that induction of lipid bodies (LBs) and alterations in LB composition mediated by ADJ were also critical for DC cross-presentation. Collectively, our model challenges the prevailing metabolic paradigm by suggesting that DCs can perform effective DC cross-presentation, independent of glycolysis to induce robust T cell-dependent protective immunity to intracellular pathogens. These findings have strong implications in the rational development of safe and effective immune adjuvants to potentiate robust T-cell based immunity. 相似文献
902.
903.
Brett H. Kirkland Nemat O. Keyhani 《Journal of industrial microbiology & biotechnology》2011,38(2):327-335
Hydrophobins represent a class of unique fungal proteins that have low molecular mass, are cysteine rich, and can self-assemble
into two-dimensional arrays at water/air interfaces. These highly surface-active proteins are able to decrease the surface
tension of water, thus allowing fungal structures to penetrate hydrophobic–hydrophilic barriers. Due to their unusual biophysical
properties, hydrophobins have been suggested for use in a wide range of biotechnological applications. Here we describe a
simple method for producing a functionally active class I hydrophobin derived from the entomopathogenic fungus, Beauveria bassiana, in an E. coli host. N-terminal modifications were required for proper expression and purification, and the hydrophobin was expressed as
a fusion partner to a cleavable N-terminus chitin-binding domain-intein construct. The protein was purified and reconstituted
from E. coli inclusion bodies. Self-assembly of the recombinant hydrophobin was followed kinetically using a thioflavin T fluorescence
binding assay, and contact angle measurements of purified recombinant hydrophobin protein (mHyd2) films on a variety of substrata
demonstrated its surface modification ability, which remained stable for at least 4 months. Filament or fibril-like structures
were imaged using atomic force and transmission electron microscopy. These data confirmed the functional properties of the
purified protein and indicate amino acid flexibility at the N-terminus, which can be exploited for various applications of
these proteins. 相似文献
904.
Plemel RL Lobingier BT Brett CL Angers CG Nickerson DP Paulsel A Sprague D Merz AJ 《Molecular biology of the cell》2011,22(8):1353-1363
Traffic through late endolysosomal compartments is regulated by sequential signaling of small G proteins of the Rab5 and Rab7 families. The Saccharomyces cerevisiae Vps-C protein complexes CORVET (class C core vacuole/endosome tethering complex) and HOPS (homotypic fusion and protein transport) interact with endolysosomal Rabs to coordinate their signaling activities. To better understand these large and intricate complexes, we performed interaction surveys to assemble domain-level interaction topologies for the eight Vps-C subunits. We identified numerous intersubunit interactions and up to six Rab-binding sites. Functional modules coordinate the major Rab interactions within CORVET and HOPS. The CORVET-specific subunits, Vps3 and Vps8, form a subcomplex and physically and genetically interact with the Rab5 orthologue Vps21. The HOPS-specific subunits, Vps39 and Vps41, also form a subcomplex. Both subunits bind the Rab7 orthologue Ypt7, but with distinct nucleotide specificities. The in vivo functions of four RING-like domains within Vps-C subunits were analyzed and shown to have distinct functions in endolysosomal transport. Finally, we show that the CORVET- and HOPS-specific subunits Vps3 and Vps39 bind the Vps-C core through a common region within the Vps11 C-terminal domain (CTD). Biochemical and genetic experiments demonstrate the importance of these regions, revealing the Vps11 CTD as a key integrator of Vps-C complex assembly, Rab signaling, and endosomal and lysosomal traffic. 相似文献
905.
DeRose YS Wang G Lin YC Bernard PS Buys SS Ebbert MT Factor R Matsen C Milash BA Nelson E Neumayer L Randall RL Stijleman IJ Welm BE Welm AL 《Nature medicine》2011,17(11):1514-1520
Development and preclinical testing of new cancer therapies is limited by the scarcity of in vivo models that authentically reproduce tumor growth and metastatic progression. We report new models for breast tumor growth and metastasis in the form of transplantable tumors derived directly from individuals undergoing treatment for breast cancer. These tumor grafts illustrate the diversity of human breast cancer and maintain essential features of the original tumors, including metastasis to specific sites. Co-engraftment of primary human mesenchymal stem cells maintains phenotypic stability of the grafts and increases tumor growth by promoting angiogenesis. We also report that tumor engraftment is a prognostic indicator of disease outcome for women with newly diagnosed breast cancer; orthotopic breast tumor grafting is a step toward individualized models for tumor growth, metastasis and prognosis. This bank of tumor grafts also serves as a publicly available resource for new models in which to study the biology of breast cancer. 相似文献
906.
Ashley Woodcock Eric D Bateman William W Busse Jan L?tvall Neil G Snowise Richard Forth Loretta Jacques Brett Haumann Eugene R Bleecker 《Respiratory research》2011,12(1):132
Background
Fluticasone furoate (FF) is a novel long-acting inhaled corticosteroid (ICS). This double-blind, placebo-controlled randomized study evaluated the efficacy and safety of FF 200 mcg or 400 mcg once daily, either in the morning or in the evening, and FF 200 mcg twice daily (morning and evening), for 8 weeks in patients with persistent asthma.Methods
Asthma patients maintained on ICS for ≥ 3 months with baseline morning forced expiratory volume in one second (FEV1) 50-80% of predicted normal value and FEV1 reversibility of ≥ 12% and ≥ 200 ml were eligible. The primary endpoint was mean change from baseline FEV1 at week 8 in pre-dose (morning or evening [depending on regimen], pre-rescue bronchodilator) FEV1.Results
A total of 545 patients received one of five FF treatment groups and 101 patients received placebo (intent-to-treat population). Each of the five FF treatment groups produced a statistically significant improvement in pre-dose FEV1 compared with placebo (p < 0.05). FF 400 mcg once daily in the evening and FF 200 mcg twice daily produced similar placebo-adjusted improvements in evening pre-dose FEV1 at week 8 (240 ml vs. 235 ml). FF 400 mcg once daily in the morning, although effective, resulted in a smaller improvement in morning pre-dose FEV1 than FF 200 mcg twice daily at week 8 (315 ml vs. 202 ml). The incidence of oral candidiasis was low (0-4%) and UC excretion was comparable with placebo for all FF groups.Conclusions
FF at total daily doses of 200 mcg or 400 mcg was significantly more effective than placebo. FF 400 mcg once daily in the evening had similar efficacy to FF 200 mcg twice daily and all FF regimens had a safety tolerability profile generally similar to placebo. This indicates that inhaled FF is an effective and well tolerated once-daily treatment for mild-to-moderate asthma.Trial registration
NCT00398645 相似文献907.
Garrison-Schilling KL Grau BL McCarter KS Olivier BJ Comeaux NE Pettis GS 《Environmental microbiology》2011,13(3):643-654
Vibrio vulnificus is a Gram-negative bacterium found in estuaries and coastal waters and is associated with human disease caused by ingestion of raw shellfish. Pathogenesis is directly related to the presence of capsular polysaccharide (CPS). Encapsulated virulent strains exhibit an opaque colony phenotype, while unencapsulated attenuated strains appear translucent. A third colony type, rugose, is caused by expression of rugose extracellular polysaccharide (rEPS) and forms robust biofilms. Vibrio vulnificus undergoes phase variation associated with altered levels of CPS and rEPS, and we show here that calcium (Ca2(+) ) significantly increases the rate of CPS and rEPS phase variation in this species. Interestingly, multiple phenotypic responses to increased [Ca2(+) ] were observed among strains, which suggests the existence of underlying cognate genetic or epigenetic differences. Certain translucent isolates contained deletions at the group I CPS operon, inferring increased [Ca2(+) ] upregulates existing phase variation mechanisms. Expanding on a previous observation (Kierek and Watnick, Proc. Natl. Acad. Sci. USA 100: 14357-14362, 2003), increased [Ca2(+) ] also enhanced biofilm formation for all phase variants. Our results show that Ca2(+) promotes both polysaccharide phase variation and biofilm formation of the resulting phase variants, thereby likely serving a dual role in persistence of V. vulnificus in the environment. 相似文献
908.
Shames SR Bhavsar AP Croxen MA Law RJ Mak SH Deng W Li Y Bidshari R de Hoog CL Foster LJ Finlay BB 《Cellular microbiology》2011,13(10):1542-1557
Enteropathogenic and enterohaemorrhagic Escherichia coli (EPEC and EHEC respectively) are attaching and effacing bacterial pathogens that cause devastating diarrhoeal disease worldwide. These pathogens depend on a type III secretion system, which functions as a molecular syringe to translocate bacterial effector proteins directly into infected host cells. One of these effectors, NleC, was recently described as a zinc metalloprotease that targets NF-κB Rel-A (p65) and thus contributes to dampening of inflammatory signalling during EPEC and EHEC infection. We have identified the acetyltransferase p300 as an additional target of NleC. Several biochemical techniques were employed to demonstrate specific binding of p300 by NleC. We also show that NleC causes decreased abundance of p300 in cellular nuclei and that the metalloprotease domain of NleC is responsible for this phenotype. Furthermore, we demonstrate that overexpression of p300 can antagonize repression of IL-8 secretion by EPEC and that siRNA knock-down of p300 dampens IL-8 secretion by EPEC ΔnleC-infected cells. We have therefore identified a second target of NleC and provided the first example of a bacterial virulence factor targeting the acetyltransferase p300. 相似文献
909.
Fungal and oomycete pathogens cause many destructive diseases of plants and important diseases of humans and other animals. Fungal and oomycete plant pathogens secrete numerous effector proteins that can enter inside host cells to condition susceptibility. Until recently it has been unknown if these effectors enter via pathogen-encoded translocons or via pathogen-independent mechanisms. Here we review recent evidence that many fungal and oomycete effectors enter via receptor-mediated endocytosis, and can do so in the absence of the pathogen. Surprisingly, a large number of these effectors utilize cell surface phosphatidyinositol-3-phosphate (PI-3-P) as a receptor, a molecule previously known only inside cells. Binding of effectors to PI-3-P appears to be mediated by the cell entry motif RXLR in oomycetes, and by diverse RXLR-like variants in fungi. PI-3-P appears to be present on the surface of animal cells also, suggesting that it may mediate entry of effectors of fungal and oomycete animal pathogens, for example, RXLR effectors found in the oomycete fish pathogen, Saprolegnia parasitica. Reagents that can block PI-3-P-mediated entry have been identified, suggesting new therapeutic strategies. 相似文献
910.
Delaney JR Sutphin GL Dulken B Sim S Kim JR Robison B Schleit J Murakami CJ Carr D An EH Choi E Chou A Fletcher M Jelic M Liu B Lockshon D Moller RM Pak DN Peng Q Peng ZJ Pham KM Sage M Solanky A Steffen KK Tsuchiya M Tsuchiyama S Johnson S Raabe C Suh Y Zhou Z Liu X Kennedy BK Kaeberlein M 《Aging cell》2011,10(6):1089-1091
Activation of Sir2 orthologs is proposed to increase lifespan downstream of dietary restriction. Here, we describe an examination of the effect of 32 different lifespan-extending mutations and four methods of DR on replicative lifespan (RLS) in the short-lived sir2Δ yeast strain. In every case, deletion of SIR2 prevented RLS extension; however, RLS extension was restored when both SIR2 and FOB1 were deleted in several cases, demonstrating that SIR2 is not directly required for RLS extension. These findings indicate that suppression of the sir2Δ lifespan defect is a rare phenotype among longevity interventions and suggest that sir2Δ cells senesce rapidly by a mechanism distinct from that of wild-type cells. They also demonstrate that failure to observe lifespan extension in a short-lived background, such as cells or animals lacking sirtuins, should be interpreted with caution. 相似文献