Year: 2017
Type: dissertation
Abstract: As effector cells of the innate immune response, macrophages are capable of recognizing and eliminating pathogens during inflammation. Macrophages achieve maximal immunological potential by undergoing cellular activation. Classical activation of macrophages (M1) with interferon-Îł (IFNÎł) and lipopolysaccharide (LPS) greatly enhances the immune response against intruding pathogens. We have previously revealed that stathmin association with microtubules (MTs) is considerably reduced in M1 macrophages using proteomics approaches. In this thesis, we demonstrate a LPS-dependent stathmin protein reduction in M1 macrophages. We also explored the functional roles of stathmin down-regulation by generating stable cell lines overexpressing stathmin-GFP. Stathmin-GFP overexpression impaired MT integrity and reduced activation-associated phenotypes. Furthermore, overexpressing stathmin-GFP inhibited complement receptor 3 (CR3)-mediated phagocytosis and cellular activation, implicating its pivotal inhibitory role in classical activation of macrophages. We next explored the role of the microenvironment in the classical activation of macrophages. Previous studies were predominately conducted on two-dimensional (2D) platforms. Consequently, we cultured macrophages in a more physiologically relevant microenvironment and examined the cellular activation and morphological changes. Our preliminary data suggested that M1 macrophages within 3D collagen matrices exhibited enhanced activation and unique adhesion complexes when compared to cells cultured on 2D platforms. Overall, our findings suggest that biochemical and physical cues provided by the extracellular matrix (ECM) modulate the morphological changes and immunological functions of macrophages.
Source: TSpace (University of Toronto)
Author: Kewei Xu
Language: English
Topic: Immune cells in cancer
Subfield: Immunology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: green
Award: G9000096646
OpenAlex ID: W2782408852