Publications by authors named "Ivan Kh Poon"

Article Synopsis
  • There's been a lot of new research on tiny structures called extracellular vesicles (EVs) that cells release, which help us understand how cells work and what goes wrong in diseases.
  • Scientists have had a hard time studying these EVs because they come in different types and can be tough to separate and analyze properly.
  • The International Society for Extracellular Vesicles updated their guidelines, called MISEV2018, to help researchers share clear information about how to study EVs and ensure their findings are accurate and reliable.
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Apoptotic bodies (ApoBDs), microvesicles and exosomes are the key members of the extracellular vesicle family, with ApoBDs being one of the largest type. It has been proposed that ApoBDs can aid cell clearance as well as intercellular communication through trafficking biomolecules. Conventional approaches used for the identification and isolation of ApoBDs are often limited by the lack of accurate quantification and low sample purity.

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NK cells are highly efficient at preventing cancer metastasis but are infrequently found in the core of primary tumors. Here, have we demonstrated that freshly isolated mouse and human NK cells express low levels of the endo-β-D-glucuronidase heparanase that increase upon NK cell activation. Heparanase deficiency did not affect development, differentiation, or tissue localization of NK cells under steady-state conditions.

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Cationic anti-microbial peptides (CAPs) have an important role in host innate defense against pathogens such as bacteria and fungi. Many CAPs including defensins also exhibit selective cytotoxic activity towards mammalian cells via both apoptotic and non-apoptotic processes, and are being investigated as potential anticancer agents. The anti-fungal plant defensin from ornamental tobacco, Defensin 1 (NaD1), was recently shown to induce necrotic-like cell death in a number of tumor cell types within 30 min of treatment, at a concentration of 10 M.

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Cationic antimicrobial peptides (CAPs) such as defensins are ubiquitously found innate immune molecules that often exhibit broad activity against microbial pathogens and mammalian tumor cells. Many CAPs act at the plasma membrane of cells leading to membrane destabilization and permeabilization. In this study, we describe a novel cell lysis mechanism for fungal and tumor cells by the plant defensin NaD1 that acts via direct binding to the plasma membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2).

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