Molecular analysis of hyaluronan and CD44

我们的长期目标是了解免疫细胞如何与其组织环境相互作用，以调节其发育和功能。免疫细胞保护你免受疾病侵袭，并在身体受损时进行修复。巨噬细胞是一种免疫细胞，专门用于修复损伤并保护组织免受疾病侵袭。在肺中，肺泡巨噬细胞生活在空气-肺界面的独特环境中，在那里它们可以保护自己免受损伤和空气传播的疾病。这种环境引导这些巨噬细胞成为能够自我更新的长寿细胞，具有在肺表面活性物质周转和对空气传播病原体的免疫监视方面的特殊功能。它们的一个独特功能是能够结合基质成分透明质酸，这是一种大的吸水分子。我们发现，这种基质-巨噬细胞的相互作用促进了它们的存活。在这项提案中，我们将研究透明质酸如何支持肺泡巨噬细胞的存活和功能。我们将研究肺泡巨噬细胞上透明质酸受体CD44的分子特征，以确定是什么使其能够与透明质酸结合，因为大多数巨噬细胞群不结合透明质酸。我们还将确定透明质酸的大小，哪些细胞制造和分泌它，哪些细胞降解它。我们将确定透明质酸向巨噬细胞发送的信号，以支持生存和长寿。最后，我们将研究当出现肺损伤和修复时，这种相互作用会发生什么。为了回答这些问题，我们将使用动物模型来检查自然环境中的肺泡巨噬细胞和呼吸道中的肺泡巨噬细胞。我们将使用细胞和分子方法，并使用RNA测序和多色流式细胞术等尖端技术。这将提供基础知识和新的见解，了解这种惰性糖分子透明质酸如何提供支持性利基，并向巨噬细胞发出信号，以促进其在这种环境中的生存。它将确定HA的形式和大小，以最好地促进这一功能，并将填补我们知识中的一个重要空白。这一知识将使旨在促进细胞存活和寿命的人造细胞基质的知情开发成为可能。这项工作还具有潜在的意义，超越了巨噬细胞在肺中的存活，因为透明质酸存在于许多组织中，促进细胞的长期存活是衰老过程的基础。这项研究将对免疫学家、生物学家、生物物理学家和生物工程师有用，他们可以利用新信息来设计新的应用程序，并开发促进细胞存活和组织再生的新技术。我们将培养创新思维和创造性科学发现方面的高素质人才，并产生造福于加拿大和国际科学界的新知识。

Our long-term goal is to understand how immune cells interact with their tissue environment to regulate their development and function. Immune cells protect you from disease and repair your body when it gets damaged. Macrophages are a type of immune cell that are specifically designed to repair damage and protect the tissue against disease. In the lung, alveolar macrophages live in the unique environment of the air-lung interface where they protect against damage and air-borne disease. This environment directs these macrophages to become long-lived cells capable of self-renewal with specialized functions in lung surfactant turnover and immunosurveillance of airborne pathogens. One of their unique features is an ability to bind the matrix component, hyaluronan, a large water absorbing molecule. We have found that this matrix-macrophage interaction promotes their survival. In this proposal, we will investigate how hyaluronan supports alveolar macrophage survival and function. We will examine the molecular features of the hyaluronan receptor, CD44, on alveolar macrophages, to determine what enables it to bind to hyaluronan, as most macrophage populations do not bind hyaluronan. We will also determine the size of hyaluronan and which cells make and secrete it, and which cells degrade it. We will determine the signals hyaluronan sends to the macrophage to support survival and longevity. Finally, we will investigate what happens to this interaction when there is lung damage and repair. To answer these questions we will use an animal model to examine alveolar macrophages in their natural environment, in the airways. We will employ cellular and molecular approaches and use cutting edge technologies such as RNA sequencing and multi-color flow cytometry. This will provide fundamental knowledge and new insights into how this inert sugar molecule, hyaluronan provides a supportive niche and signals to the macrophage to promote its survival in this environment. It will characterize the form and size of HA that best promotes this function and will fill an important gap in our knowledge. This knowledge will enable the informed development of artificial cell matrices designed to promote cell survival and longevity. This work also has potential significance beyond macrophage survival in the lung, as hyaluronan is present in many tissues, and promoting long-term cell survival is fundamental to the aging process. This research will be of use to immunologists, biologists, biophysicists and bio-engineers who can use the new information to design new applications and develop new technologies that promote cell-survival and tissue regeneration. We will train highly qualified personnel in innovative thinking and inventive scientific discovery, and generate new knowledge that will benefit the Canadian and International scientific community.