Molecular chaperones HSP90 and HSP70 are essential regulators of the folding and activation of a disparate ensemble of client proteins. They function through ATP hydrolysis and the assembly of multiprotein complexes with cochaperones and clients. While their therapeutic relevance is recognized, important details underlying the links between ATP-dependent conformational dynamics and clients/cochaperones recruitment remain elusive. Allosteric modulators represent fundamental tools to obtain molecular insights into functional regulation. By selective perturbation of different aspects of HSP90/HSP70 activities, allosteric drugs can tune rather than completely inhibit signaling cascades, providing information on the relationships between structure-dynamics and function. Herein, we review advances in the design of HSP90 and HSP70 allosteric modulators. We consider inhibitors and activators in different biochemical and disease models. We discuss these compounds as probes to decipher the complexity of the chaperone machinery and that at the same time represent starting leads for the development of drugs against cancer and neurodegeneration.
Glyco-gold nanoparticles combine in a single entity the peculiar properties of gold nanoparticles with the biological activity of carbohydrates. The result is an exciting nanosystem, able to mimic the natural multivalent presentation of saccharide moieties and to exploit the peculiar optical properties of the metallic core. In this review, we present recent advances on glyco-gold nanoparticle applications in different biological fields, highlighting the key parameters which inspire the glyco nanoparticle design.
Deficiencies in enzymes of the lysosomal glycosphingolipid degradation pathway or in lysosomal lipid transfer proteins cause an imbalance in lipid metabolism and induce accumulation of certain lipids. A possible impact of such an imbalance on the presentation of lipid antigens to lipid-reactive T cells has only been hypothesized but not extensively studied so far. Here we demonstrate that presentation of lipid antigens to, and development of, lipid-reactive CD1d-restricted NKT cells, are impaired in mice deficient in the lysosomal enzyme b-galactosidase (bGal) or the lysosomal lipid transfer protein Niemann-Pick C (NPC) 2. Importantly, the residual populations of NKT cells selected in bGal -/-and NPC2 -/-mice showed differential TCR and CD4 repertoire characteristics, suggesting that differential selecting CD1d:lipid antigen complexes are formed. Furthermore, we provide direct evidence that accumulation of lipids impairs lipid antigen presentation in both cases. However, the mechanisms by which imbalanced lipid metabolism affected lipid antigen presentation were different. Based on these results, the impact of lipid accumulation should be generally considered in the interpretation of immunological deficiencies found in mice suffering from lipid metabolic disorders.Supporting information for this article is available at http://www.wiley-vch.de/contents/jc_2040/2007/37160_s.pdf IntroductionDefects in lysosomal lipid trafficking or degradation result in a severe imbalance of lipid metabolism. Little is known about the consequences of such an imbalance on the presentation of lipid antigens to lipid-reactive T cells, e.g., the important immunoregulatory invariant (i) NKT cell subset (Va14i and Va24i NKT cells in mice and humans, respectively), which recognizes glycolipid antigens presented by the MHC class I-like molecule Abbreviations: a-GalCer: a-galactosylceramide (KRN7000) Á a/bGal: a/b-galactosidase Á DN: CD4 -CD8 -double negative Á DP: CD4 + CD8 + double positive Á Hex: hexosaminidase Á HSA: heat-stable Ag Á i: invariant Á iGb3: isoglobotrihexosylceramide Á NB-DNJ: N-butyldeoxynojirimycin Á NPC: NiemannPick C Eur. J. Immunol. 2007Immunol. . 37: 1431Immunol. -1441 CD1d. In mice, the TCR of Va14i NKT cells is composed of an invariant Va14-Ja18 chain, paired preferentially with a restricted b chain, mostly containing Vb8.2 or Vb7 (the human equivalents are Va24-Ja18 and Vb11) [1][2][3][4]. Va14i NKT cells are implicated in the regulation of antitumor immunity, antimicrobial responses, and the balance between tolerance and autoimmunity [5,6]. Va14i NKT cells, which can be either CD4 + or CD4 -CD8 -double negative (DN), are a thymus-dependent population derived from CD4 + CD8 + double-positive (DP) thymocytes [7][8][9][10][11]. Different maturation stages of developing thymic Va14i NKT cells have been described, characterized by the sequential acquisition of CD44 and NK1.1 in C57BL/6 mice [12][13][14]. Unlike conventional MHC-dependent T cells, Va14i NKT cells are not positively selected by thymic epithelial cell...
This work is a step forward toward synthetic nanosystems combining carbohydrate antigens and immunogenic peptides as potential carbohydrate-based vaccines.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.