Post Glycosylation Diversification (PGD): An Approach for Assembling Collections of Glycosylated Small Molecules

2018 ◽  
Author(s):  
Zachary Cannone ◽  
Ala Shaqra ◽  
Chris Lorenc ◽  
Liza Henowitz ◽  
Santosh Keshipeddy ◽  
...  
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
T Cell Activation ◽  
Cell Activation ◽  
De Novo ◽  
Protein Translation ◽  
Compound Libraries ◽  
Activation Assay ◽  
Small Molecule Libraries ◽  
New Compounds

Many small molecule natural products with are adorned with a carbohydrate as part of their molecular structure that acts to mediate key interactions with the target, attenuate physicochemical properties, or both. Facile incorporation of a carbohydrate group on de novo small molecules would enable these valuable properties to be leveraged in the evaluation of focused compound libraries. Here we report a new approach for the synthesis of glycosylated small molecule libraries that puts the glycosylation early in the synthesis of library compounds. Functionalized aglycones subsequently participate in chemoselective diversification reactions distal to the carbohydrate. A number of desosaminyl glycosides were prepared from only a few starting glycosides, using click cycloadditions, acylations, and Suzuki couplings as diversification reactions. New compounds were characterized for their inhibition of bacterial protein translation, bacterial growth, and in a T-cell activation assay.

Post Glycosylation Diversification (PGD): An Approach for Assembling Collections of Glycosylated Small Molecules

2018 ◽  
Author(s):  
Zachary Cannone ◽  
Ala Shaqra ◽  
Chris Lorenc ◽  
Liza Henowitz ◽  
Santosh Keshipeddy ◽  
...  
Keyword(s):  
Small Molecules ◽  
Small Molecule ◽  
T Cell Activation ◽  
Cell Activation ◽  
De Novo ◽  
Protein Translation ◽  
Compound Libraries ◽  
Activation Assay ◽  
Small Molecule Libraries ◽  
New Compounds

Many small molecule natural products with are adorned with a carbohydrate as part of their molecular structure that acts to mediate key interactions with the target, attenuate physicochemical properties, or both. Facile incorporation of a carbohydrate group on de novo small molecules would enable these valuable properties to be leveraged in the evaluation of focused compound libraries. Here we report a new approach for the synthesis of glycosylated small molecule libraries that puts the glycosylation early in the synthesis of library compounds. Functionalized aglycones subsequently participate in chemoselective diversification reactions distal to the carbohydrate. A number of desosaminyl glycosides were prepared from only a few starting glycosides, using click cycloadditions, acylations, and Suzuki couplings as diversification reactions. New compounds were characterized for their inhibition of bacterial protein translation, bacterial growth, and in a T-cell activation assay.

scholarly journals Inhibition of HIV-1 immune modulation by small molecules targeting viral Nef-host CD80 interface

2021 ◽  
Author(s):  
Anusmrithi U Sharma ◽  
Shweta Sharma ◽  
Gandhimathi Arumugam ◽  
Archana Padmanabhan Nair ◽  
Srinivas Ambala ◽  
...  
Keyword(s):  
T Cell ◽  
Small Molecules ◽  
Small Molecule ◽  
T Cell Activation ◽  
Protein Interaction ◽  
Cell Activation ◽  
Mutational Analysis ◽  
Protein Protein Interaction ◽  
Interaction Interface ◽  
Hiv 1

HIV-1 causes diverse immunomodulatory responses in the host, including the down-regulation of co-stimulatory proteins CD80/86, mediated by HIV-1 protein Nef, blunting T-cell activation. Using a screening cascade of biochemical and cell-based assays, we identified potent small molecules representing three chemical scaffolds namely amino pyrimidine, phenoxy acetamide and bi-aryl heteroaryl carbamate which target the protein-protein interaction interface of CD80/86 and Nef with sub-micromolar potency. These molecules restore CD80/86 surface levels in HIV-1-Nef infected antigen presenting cells and T-cell activation. Nef-CD80 interface and small molecule binding sites were mapped by using computational docking and structural studies, followed by validation by mutational analysis. This analysis resulted in the identification of two key residues, K99 and R111, which were associated with down-modulation of CD80 surface levels by Nef and important for small molecule binding. Targeting these interacting residues disabled Nef-mediated down-modulation of CD80 surface levels, consequently restoring T-cell activation. Thus, we validate a new target, the Nef-CD80/86 protein-protein interaction interface, with a potential to develop new inhibitors to counteract the immunomodulatory consequences of HIV-1.

scholarly journals STEM-20. A CANCER STEM CELL-SELECTIVE APOPTOSIS-INDUCING SMALL MOLECULE FOR THE TREATMENT OF GBM

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii200-ii200
Author(s):  
Stephen Skirboll ◽  
Natasha Lucki ◽  
Genaro Villa ◽  
Naja Vergani ◽  
Michael Bollong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cancer Stem Cells ◽  
Small Molecules ◽  
Small Molecule ◽  
Large Scale ◽  
Critical Role ◽  
Tumor Formation ◽  
Cell Type ◽  
Caspase 1 ◽  
Activation Assay

Abstract INTRODUCTION Glioblastoma multiforme (GBM) is the most aggressive form of primary brain cancer. A subpopulation of multipotent cells termed GBM cancer stem cells (CSCs) play a critical role in tumor initiation and maintenance, drug resistance, and recurrence following surgery. New therapeutic strategies for the treatment of GBM have recently focused on targeting CSCs. Here we have used an unbiased large-scale screening approach to identify drug-like small molecules that induce apoptosis in GBM CSCs in a cell type-selective manner. METHODS A luciferase-based survival assay of patient-derived GBM CSC lines was established to perform a large-scale screen of ∼one million drug-like small molecules with the goal of identifying novel compounds that are selectively toxic to chemoresistant GBM CSCs. Compounds found to kill GBM CSC lines as compared to control cell types were further characterized. A caspase activation assay was used to evaluate the mechanism of induced cell death. A xenograft animal model using patient-derived GBM CSCs was employed to test the leading candidate for suppression of in vivo tumor formation. RESULTS We identified a small molecule, termed RIPGBM, from the cell-based chemical screen that induces apoptosis in primary patient-derived GBM CSC cultures. The cell type-dependent selectivity of RIPGBM appears to arise at least in part from redox-dependent formation of a proapoptotic derivative, termed cRIPGBM, in GBM CSCs. cRIPGBM induces caspase 1-dependent apoptosis by binding to receptor-interacting protein kinase 2 (RIPK2) and acting as a molecular switch, which reduces the formation of a prosurvival RIPK2/TAK1 complex and increases the formation of a proapoptotic RIPK2/caspase 1 complex. In an intracranial GBM xenograft mouse model, RIPGBM was found to significantly suppress tumor formation. CONCLUSIONS Our chemical genetics-based approach has identified a small molecule drug candidate and a potential drug target that selectively targets cancer stem cells and provides an approach for the treatment of GBMs.

scholarly journals Immune Restoration Diseases Reflect Diverse Immunopathological Mechanisms

2009 ◽  
Vol 22 (4) ◽  
pp. 651-663 ◽  
Author(s):  
Patricia Price ◽  
David M. Murdoch ◽  
Upasna Agarwal ◽  
Sharon R. Lewin ◽  
Julian H. Elliott ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Responses ◽  
T Cell Activation ◽  
Cell Activation ◽  
De Novo ◽  
Granulomatous Inflammation ◽  
T Cell Response ◽  
Immune Restoration ◽  
Immunological Parameters ◽  
Varicella Zoster

SUMMARY Up to one in four patients infected with human immunodeficiency virus type 1 and given antiretroviral therapy (ART) experiences inflammatory or cellular proliferative disease associated with a preexisting opportunistic infection, which may be subclinical. These immune restoration diseases (IRD) appear to result from the restoration of immunocompetence. IRD associated with intracellular pathogens are characterized by cellular immune responses and/or granulomatous inflammation. Mycobacterial and cryptococcal IRD are attributed to a pathological overproduction of Th1 cytokines. Clinicopathological characteristics of IRD associated with viral infections suggest different pathogenic mechanisms. For example, IRD associated with varicella-zoster virus or JC polyomavirus infection correlate with a CD8 T-cell response in the central nervous system. Exacerbations or de novo presentations of hepatitis associated with hepatitis C virus (HCV) infection following ART may also reflect restoration of pathogen-specific immune responses as titers of HCV-reactive antibodies rise in parallel with liver enzymes and plasma markers of T-cell activation. Correlations between immunological parameters assessed in longitudinal sample sets and clinical presentations are required to illuminate the diverse immunological scenarios described collectively as IRD. Here we present salient clinical features and review progress toward understanding their pathogeneses.

303. Further characterisation of lymphocyte-suppressing activity in gonadal fluids

2005 ◽  
Vol 17 (9) ◽  
pp. 129
Author(s):  
M. Crane ◽  
L. Foulds ◽  
J. Muir ◽  
D. Aridi ◽  
P. Hutchinson ◽  
...  
Keyword(s):  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Transplant Rejection ◽  
Calf Serum ◽  
Autoimmune Response ◽  
T Cell Anergy ◽  
Activation Assay ◽  
Proliferation In Vitro

Protection of the developing gametes from an autoimmune response within the testis and ovary is essential for reproductive success, and autoimmune infertility represents a failure of this protection. The gonads also represent favorable sites for grafts of foreign tissue, that is, they are ‘immunologically privileged’. The actual mechanisms responsible for testicular and ovarian immune privilege are poorly understood. However, it has been well established that testicular interstitial fluid and ovarian fluid have profound inhibitory effects on T-cell activation and proliferation in vitro. We have established previously that a partially purified preparation of the inhibitor, isolated from bovine follicular fluid, suppresses proliferation in an in vitro T-cell activation assay, through induction of T-cell anergy and/or atypical apoptosis. Addition of increasing doses of normal fetal calf serum and/or bovine serum albumin blocks the actions of the inhibitor and progressively increases the ED50 of the assay. It has also been shown that stimulating the T-cells with phorbol-12-myristate-13-acetate (PMA) in place of a polyclonal mitogenic stimulus such as phytohaemagglutinin bypasses the anergic effects of the inhibitor. These results suggest that the activity of the inhibitor may be negatively regulated in the circulation and tissues by serum-derived proteins and other factors. These data also indicate that the inhibitor’s activity is mediated through a specific cellular pathway, most likely involving protein kinase C isotypes, which are activated by PMA. Further work will delineate the molecular pathways and mechanisms of serum regulation of the gonadal lymphocyte-suppressing activity, which may be exploited in the treatment of autoimmune diseases and for prevention of transplant rejection.

scholarly journals CD1d-restricted T cell activation by nonlipidic small molecules

2004 ◽  
Vol 101 (37) ◽  
pp. 13578-13583 ◽  
Author(s):  
I. Van Rhijn ◽  
D. C. Young ◽  
J. S. Im ◽  
S. B. Levery ◽  
P. A. Illarionov ◽  
...  
Keyword(s):  
T Cell ◽  
Small Molecules ◽  
T Cell Activation ◽  
Cell Activation
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