朱智瑋教授研究團隊發表研究成果於Nature Chemistry

連結網址：https://www.nature.com/articles/s41557-023-01361-4

Abstract

Many peptide-derived natural products are produced by non-ribosomal peptide synthetases (NRPSs) in an assembly-line fashion. Each amino acid is coupled to a designated peptidyl carrier protein (PCP) through two distinct reactions catalysed sequentially by the single active site of the adenylation domain (A-domain). Accumulating evidence suggests that large-amplitude structural changes occur in different NRPS states; yet how these molecular machines orchestrate such biochemical sequences has remained elusive. Here, using single-molecule Förster resonance energy transfer, we show that the A-domain of gramicidin S synthetase I adopts structurally extended and functionally obligatory conformations for alternating between adenylation and thioester-formation structures during enzymatic cycles. Complementary biochemical, computational and small-angle X-ray scattering studies reveal interconversion among these three conformations as intrinsic and hierarchical where intra-A-domain organizations propagate to remodel inter-A–PCP didomain configurations during catalysis. The tight kinetic coupling between structural transitions and enzymatic transformations is quantified, and how the gramicidin S synthetase I A-domain utilizes its inherent conformational dynamics to drive directional biosynthesis with a flexibly linked PCP domain is revealed.

王雲銘教授研究團隊發表研究成果於 Cancer Cell International

連結網址：https://pubmed.ncbi.nlm.nih.gov/38001420/

Abstract

Background: Despite intensive developments of adoptive T cell and NK cell therapies, the efficacy against solid tumors remains elusive. Our study demonstrates that macrophage-based cell therapy could be a potent therapeutic option against solid tumors.

Methods: To this end, we determine the effect of a natural triterpene glycoside, cucumarioside A₂-2 (CA₂-2), on the polarization of mouse macrophages into the M1 phenotype, and explore the antitumor activity of the polarized macrophage. The polarization of CA₂-2-pretreated macrophages was analyzed by flow cytometry and confocal imaging. The anti-cancer activity of CA₂-2 macrophages was evaluated against 4T1 breast cancer cells and EAC cells in vitro and syngeneic mouse model in vivo.

Results: Incubation of murine macrophages with CA₂-2 led to polarization into the M1 phenotype, and the CA₂-2-pretreated macrophages could selectively target and kill various types of cancer in vitro. Notably, loading near-infrared (NIR) fluorochrome-labeled nanoparticles, MnMEIO-mPEG-CyTE777, into macrophages substantiated that M1 macrophages can target and penetrate tumor tissues in vivo efficiently.

Conclusion: In this study, CA₂-2-polarized M1 macrophages significantly attenuated tumor growth and prolonged mice survival in the syngeneic mouse models. Therefore, ex vivo CA₂-2 activation of mouse macrophages can serve as a useful model for subsequent antitumor cellular immunotherapy developments.

Keywords: Anticancer; Cucumarioside A2-2; Holothurian triterpene glycoside; Immunotherapy; M1 macrophage.