Torrey Pines Institute for Molecular Studies

About: Torrey Pines Institute for Molecular Studies is a nonprofit organization based out in San Diego, California, United States. It is known for research contribution in the topics: T cell & Antigen. The organization has 2323 authors who have published 2217 publications receiving 112618 citations.

Involvement of Secretory and Endosomal Compartments in Presentation of an Exogenous Self-Glycolipid to Type II NKT Cells

Abstract: Natural Killer T (NKT) cells recognize both self and foreign lipid Ags presented by CD1 molecules. Although presentation of the marine sponge-derived lipid αGalCer to type I NKT cells has been well studied, little is known about self-glycolipid presentation to either type I or type II NKT cells. Here we have investigated presentation of the self-glycolipid sulfatide to a type II NKT cell that specifically recognizes a single species of sulfatide, namely lyso-sulfatide but not other sulfatides containing additional acyl chains. In comparison to other sulfatides or αGalCer, lyso-sulfatide binds with lower affinity to CD1d. Although plate-bound CD1d is inefficient in presenting lyso-sulfatide at neutral pH, it is efficiently presented at acidic pH and in the presence of saposin C. The lysosomal trafficking of mCD1d is required for αGalCer presentation to type I NKT cells, it is not important for presentation of lyso-sulfatide to type II NKT cells. Consistently, APCs deficient in a lysosomal lipid-transfer protein effectively present lyso-sulfatide. Presentation of lyso-sulfatide is inhibited in the presence of primaquine, concanamycin A, monensin, cycloheximide, and an inhibitor of microsomal triglyceride transfer protein but remains unchanged following treatment with brefeldin A. Wortmannin-mediated inhibition of lipid presentation indicates an important role for the PI-3kinase in mCD1d trafficking. Our data collectively suggest that weak CD1d-binding self-glycolipid ligands such as lyso-sulfatide can be presented via the secretory and endosomal compartments. Thus this study provides important insights into the exogenous self-glycolipid presentation to CD1d-restricted T cells.

Selective κ receptor partial agonist HS666 produces potent antinociception without inducing aversion after i.c.v. administration in mice.

Abstract: Background and purpose The κ opioid (KOP) receptor has a central role in modulating neurotransmission in central and peripheral neuronal circuits that subserve pain and other behavioural responses. Although KOP agonists do not produce euphoria or lead to respiratory suppression, they induce dysphoria and sedation. We hypothesized that brain-penetrant KOP receptor ligands possessing biased agonism towards G protein signalling over β-arrestin2 recruitment would produce robust antinociception with fewer liabilities of use. Experimental approach Two new diphenethylamines with high KOP receptor selectivity, HS665 and HS666, were assessed following i.c.v. administration in mouse assays of antinociception with the 55°C warm-water tail-withdrawal test, locomotor activity in the rotorod and conditioned place preference. The [35S]GTPγS binding and β-arrestin2 recruitment in vitro assays were used to characterize biased agonism. Key results HS665 (KOP agonist) and HS666 (KOP partial agonist) demonstrated dose-dependent antinociception after i.c.v. administration mediated by the KOP receptor. We found that the two highly selective KOP ligands display in vitro varying bias signalling toward G protein coupling consistent with a reduced liability profile reflected by the reduced sedation and absence of conditioned place aversion for HS666. Conclusions and implications HS665 and HS666 activate central KOP receptors to produce potent antinociception, with HS666 displaying pharmacological characteristics of a KOP analgesic with reduced liability for aversive and dysphoric effects correlating to its low efficacy in the β-arrestin2 signalling pathways. Our data provide further understanding of the contribution of activation of central KOP receptors in pain suppression, and the prospect of dissociating the antinociceptive effects of HS665 and HS666 from KOP-mediated adverse effects.

TFEB Overexpression in the P301S Model of Tauopathy Mitigates Increased PHF1 Levels and Lipofuscin Puncta and Rescues Memory Deficits

Abstract: Transcription factor EB (TFEB) was recently shown to be a master regulator of autophagy lysosome pathway. Here, we successfully generated and characterized transgenic mice overexpressing flag-TFEB. Enhanced autophagy in the flag-TFEB transgenic mice was confirmed by an increase in the cellular autophagy markers, as determined by both immunoblots and transmission electron microscopy. Surprisingly, in the flag-TFEB mice we observed increased activity of senescence-associated β-galactosidase by ∼66% of neurons in the cortex (p

Large-scale recoding of a bacterial genome by iterative recombineering of synthetic DNA

Abstract: The ability to rewrite large stretches of genomic DNA enables the creation of new organisms with customized functions. However, few methods currently exist for accumulating such widespread genomic changes in a single organism. In this study, we demonstrate a rapid approach for rewriting bacterial genomes with modified synthetic DNA. We recode 200 kb of the Salmonella typhimurium LT2 genome through a process we term SIRCAS (stepwise integration of rolling circle amplified segments), towards constructing an attenuated and genetically isolated bacterial chassis. The SIRCAS process involves direct iterative recombineering of 10-25 kb synthetic DNA constructs which are assembled in yeast and amplified by rolling circle amplification. Using SIRCAS, we create a Salmonella with 1557 synonymous leucine codon replacements across 176 genes, the largest number of cumulative recoding changes in a single bacterial strain to date. We demonstrate reproducibility over sixteen two-day cycles of integration and parallelization for hierarchical construction of a synthetic genome by conjugation. The resulting recoded strain grows at a similar rate to the wild-type strain and does not exhibit any major growth defects. This work is the first instance of synthetic bacterial recoding beyond the Escherichia coli genome, and reveals that Salmonella is remarkably amenable to genome-scale modification.