Purcell Sean C, Zhang Michelle H, Honigfort Daniel J, Ng Hans Jefferson C, Michalak Austen L, Godula Kamil
Department of Chemistry and Biochemistry, University of California San Diego 9500 Gilman Drive La Jolla CA 92093 USA
Glycobiology Research and Training Center, University of California San Diego 9500 Gilman Drive La Jolla CA 92093 USA.
Chem Sci. 2022 May 12;13(22):6626-6635. doi: 10.1039/d2sc00524g. eCollection 2022 Jun 7.
The cellular glycocalyx, composed of membrane associated glycoproteins and glycolipids, is a complex and dynamic interface that facilitates interactions between cells and their environment. The glycocalyx composition is continuously changing through biosynthesis of new glycoconjugates and membrane turnover. Various glycocalyx components, such as mucins, can also be rapidly shed from the cell surface in response to acute events, such as pathogenic threat. Mucins, which are large extended glycoproteins, deliver important protective functions against infection by creating a physical barrier at the cell surface and by capturing and clearing pathogens through shedding. Evaluating these mucin functions may provide better understanding of early stages of pathogenesis; however, tools to tailor the composition and dynamics of the glycocalyx with precision are still limited. Here, we report a chemical cell surface engineering strategy to model the shedding behavior of mucins with spatial and temporal control. We generated synthetic mucin mimetic glycopolymers terminated with a photolabile membrane anchor, which could be introduced into the membranes of living cells and, subsequently, released upon exposure to UV light. By tuning the molecular density of the artificial glycocalyx we evaluated lectin crosslinking and its effect on shedding, showing that lectins can stabilize the glycocalyx and limit release of the mucin mimetics from the cell surface. Our findings indicate that endogenous and pathogen-associated lectins, which are known to interact with the host-cell glycocalyx, may alter mucin shedding dynamics and influence the protective properties of the mucosal barrier. More broadly, we present a method which enables photoengineering of the glycocalyx and can be used to facilitate the study of glycocalyx dynamics in other biological contexts.
细胞糖萼由膜相关糖蛋白和糖脂组成，是一个复杂且动态的界面，它促进细胞与其环境之间的相互作用。糖萼的组成通过新糖缀合物的生物合成和膜更新而不断变化。各种糖萼成分，如粘蛋白，也可在应对急性事件（如病原体威胁）时迅速从细胞表面脱落。粘蛋白是大型延伸糖蛋白，通过在细胞表面形成物理屏障以及通过脱落捕获和清除病原体，发挥重要的抗感染保护功能。评估这些粘蛋白功能可能有助于更好地理解发病机制的早期阶段；然而，精确调控糖萼组成和动态的工具仍然有限。在此，我们报告一种化学细胞表面工程策略，用于在空间和时间控制下模拟粘蛋白的脱落行为。我们生成了以光不稳定膜锚定基团终止的合成粘蛋白模拟糖聚合物，其可被引入活细胞膜中，随后在暴露于紫外光时释放。通过调节人工糖萼的分子密度，我们评估了凝集素交联及其对脱落的影响，表明凝集素可稳定糖萼并限制粘蛋白模拟物从细胞表面释放。我们的研究结果表明，已知与宿主细胞糖萼相互作用的内源性和病原体相关凝集素，可能会改变粘蛋白的脱落动态并影响粘膜屏障的保护特性。更广泛地说，我们提出了一种能够对糖萼进行光工程改造的方法，可用于促进在其他生物学背景下对糖萼动态的研究。
