Self-assembled cGAMP-STINGΔTM signaling complex as a bioinspired platform for cGAMP delivery

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). The stimulator of interferon (IFN) genes (STING) pathway constitutes a highly important part of immune responses against various cancers and infections. Consequently, administration of STING agonists such as cyclic GMP-AMP (cGAMP) has been identified as a promising approach to target these diseases. In cancer cells, STING signaling is frequently impaired by epigenetic silencing of STING; hence, conventional delivery of only its agonist cGAMP may be insufficient to trigger STING signaling. In this work, while expression of STING lacking the transmembrane (TM) domain is known to be unresponsive to STING agonists and is dominant negative when coexpressed with the full-length STING inside cells, we observed that the recombinant TM-deficient STING protein complexed with cGAMP could effectively trigger STING signaling when delivered in vitro and in vivo, including in STING-deficient cell lines. Thus, this bioinspired method using TM-deficient STING may present a universally applicable platform for cGAMP delivery

Peptide‐Based Cancer Vaccine Delivery via the STINGΔTM‐cGAMP Complex

With the advent of bioinformatic tools in efficiently predicting neo-antigens, peptide vaccines have gained tremendous attention in cancer immunotherapy. However, the delivery of peptide vaccines remains a major challenge, primarily due to ineffective transport to lymph nodes and low immunogenicity. Here, a strategy for peptide vaccine delivery is reported by first fusing the peptide to the cytosolic domain of the stimulator of interferon genes protein (STINGΔTM), then complexing the peptide-STINGΔTM protein with STING agonist 2'3' cyclic guanosine monophosphate-adenosine monophosphate (cGAMP). The process results in the formation of self-assembled cGAMP-peptide-STINGΔTM tetramers, which enables efficient lymphatic trafficking of the peptide. Moreover, the cGAMP-STINGΔTM complex acts not only as a protein carrier for the peptide, but also as a potent adjuvant capable of triggering STING signaling independent of endogenous STING protein-an especially important attribute considering that certain cancer cells epigenetically silence their endogenous STING expression. With model antigen SIINFEKL, it is demonstrated that the platform elicits effective STING signaling in vitro, draining lymph node targeting in vivo, effective T cell priming in vivo as well as antitumoral immune response in a mouse colon carcinoma model, providing a versatile solution to the challenges faced in peptide vaccine delivery

Synthetic Lift-off Polymer beneath Layer-by-Layer Films for Surface-Mediated Drug Delivery

A broad range of biomaterials coatings and thin film drug delivery systems require a strategy for the immobilization, retention, and release of coatings from surfaces such as patches, inserts, and microneedles under physiological conditions. Here we report a polymer designed to provide a dynamic surface, one that first functions as a platform for electrostatic thin film assembly and releases the film once in an in vivo environment. Atom transfer radical polymerization (ATRP) was used to synthesize this polymer poly­(<i>o</i>-nitrobenzyl-methacrylate-<i>co</i>-hydroxyethyl-methacrylate-<i>co</i>-poly­(ethylene-glycol)-methacrylate) (PNHP), embedded beneath multilayered polyelectrolyte films. Such a base layer is designed to photochemically pattern negative charge onto a solid substrate, assist deposition of smooth layer-by-layer (LbL) polyelectrolyte in mildly acidic buffers and rapidly dissolve at physiological pH, thus lifting off the LbL films. To explore potential uses in the biomedical field, a lysozyme (Lys)/poly­(acrylic acid) (PAA) multilayer film was developed on PNHP-coated silicon wafers to construct prototype antimicrobial shunts. Film thickness was shown to grow exponentially with increasing deposition cycles, and effective drug loading and in vitro release was confirmed by the dose-dependent inhibition of Escherichia coli (E. coli) growth. The efficacy of this approach is further demonstrated in LbL-coated microscale needle arrays ultimately of interest for vaccine applications. Using PNHP as a photoresist, LbL films were confined to the tips of the microneedles, which circumvented drug waste at the patch base. Subsequent confocal images confirmed rapid LbL film implantation of PNHP at microneedle penetration sites on mouse skin. Furthermore, in human skin biopsies, we achieved efficient immune activation demonstrated by a rapid uptake of vaccine adjuvant from microneedle-delivered PNHP LbL film in up to 37% of antigen-presenting cells (APC), providing an unprecedented LbL microneedle platform for human vaccination

Analysis of Outcomes in Ischemic vs Nonischemic Cardiomyopathy in Patients With Atrial Fibrillation A Report From the GARFIELD-AF Registry

IMPORTANCE Congestive heart failure (CHF) is commonly associated with nonvalvular atrial fibrillation (AF), and their combination may affect treatment strategies and outcomes