Confinement-Optimized 3-Dimensional T cell Amoeboid Motility is Modulated via Myosin IIA-Regulated Adhesions

Department of Pathology, University of California San Francisco, San Francisco, California, USA.
Nature Immunology (Impact Factor: 20). 10/2010; 11(10):953-61. DOI: 10.1038/ni.1936
Source: PubMed


During trafficking through tissues, T cells fine-tune their motility to balance the extent and duration of cell-surface contacts versus the need to traverse an entire organ. Here we show that in vivo, myosin IIA-deficient T cells had a triad of defects, including overadherence to high-endothelial venules, less interstitial migration and inefficient completion of recirculation through lymph nodes. Spatiotemporal analysis of three-dimensional motility in microchannels showed that the degree of confinement and myosin IIA function, rather than integrin adhesion (as proposed by the haptokinetic model), optimized motility rate. This motility occurred via a myosin IIA-dependent rapid 'walking' mode with multiple small and simultaneous adhesions to the substrate, which prevented spurious and prolonged adhesions. Adhesion discrimination provided by myosin IIA is thus necessary for the optimization of motility through complex tissues.

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Available from: Matthieu Piel, Feb 17, 2014
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    • "While many cell surface ligands have been shown to be important in regulating T cell migration into lymph nodes and to inflammatory sites, relatively little is known about the intracellular signaling mechanisms that regulate migration. Recent studies have implicated signaling molecules downstream of T cell receptor signaling [11] as well as regulators of the actin cytoskeleton such as Rac GTPases and myosin IIA [12], [13], [14]. PKC proteins are important signaling mediators in many cell types including T cells, leading to changes in cellular proliferation, cytoskeleton organization, and differentiation [15]. "
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    ABSTRACT: Cell motility is a fundamental process crucial for function in many cell types, including T cells. T cell motility is critical for T cell-mediated immune responses, including initiation, activation, and effector function. While many extracellular receptors and cytoskeletal regulators have been shown to control T cell migration, relatively few signaling mediators have been identified that can modulate T cell motility. In this study, we find a previously unknown role for PKCθ in regulating T cell migration to lymph nodes. PKCθ localizes to the migrating T cell uropod and regulates localization of the MTOC, CD43 and ERM proteins to the uropod. Furthermore, PKCθ-deficient T cells are less responsive to chemokine induced migration and are defective in migration to lymph nodes. Our results reveal a novel role for PKCθ in regulating T cell migration and demonstrate that PKCθ signals downstream of CCR7 to regulate protein localization and uropod formation.
    PLoS ONE 11/2013; 8(11):e78940. DOI:10.1371/journal.pone.0078940 · 3.23 Impact Factor
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    • "A growing body of work has been accumulating showing that force transmission by MyoIIA in naïve T cells is important for entry into lymph nodes during recirculation, largely shown by adoptive transfer experiments [5,15]. Intriguingly, however, using genetic ablation of MyoIIA we showed that the long-term effect of MyoIIA loss in naïve T cells is primarily to lower their interstitial motility rate and to restrict their steady-state egress from lymph nodes [5]. "
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    ABSTRACT: Following activation, T cells are released from lymph nodes to traffic via the blood to effector sites. The re-entry of these activated T cells into tissues represents a critical step for them to carry out local effector functions. Here we have assessed defects in effector T cells that are acutely depleted in Myosin-IIA (MyoIIA) and show a T cell intrinsic requirement for this motor to facilitate the diapedesis step of extravasation. We show that MyoIIA accumulates at the rear of T cells undergoing trans-endothelial migration. T cells can extend protrusions and project a substantial portion of their cytoplasm through the endothelial wall in the absence of MyoIIA. However, this motor protein plays a crucial role in allowing T cells to complete the movement of their relatively rigid nucleus through the endothelial junctions. In vivo, this defect manifests as poor entry into lymph nodes, tumors and into the spinal cord, during tissue-specific autoimmunity, but not the spleen. This suggests that therapeutic targeting of this molecule may allow for differential attenuation of tissue-specific inflammatory responses.
    PLoS ONE 09/2013; 8(9):e75151. DOI:10.1371/journal.pone.0075151 · 3.23 Impact Factor
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    • "To address this issue, polydimethylsiloxane (PDMS)-based microfluidic channels have been developed for the study of cellular movement in confined spaces. This technique has been used to examine the locomotion of leukocytes and tumor cells [23], [24], [25], [26], [27], [28]. However, these devices do not incorporate a controlled chemotactic stimulus, and therefore are useful only for the study of spontaneous migration [24], [27], [28]. "
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    ABSTRACT: Cell migration is crucial for both physiological and pathological processes. Current in vitro cell motility assays suffer from various drawbacks, including insufficient temporal and/or optical resolution, or the failure to include a controlled chemotactic stimulus. Here, we address these limitations with a migration chamber that utilizes a self-sustaining chemotactic gradient to induce locomotion through confined environments that emulate physiological settings. Dynamic real-time analysis of both population-scale and single-cell movement are achieved at high resolution. Interior surfaces can be functionalized through adsorption of extracellular matrix components, and pharmacological agents can be administered to cells directly, or indirectly through the chemotactic reservoir. Direct comparison of multiple cell types can be achieved in a single enclosed system to compare inherent migratory potentials. Our novel microfluidic design is therefore a powerful tool for the study of cellular chemotaxis, and is suitable for a wide range of biological and biomedical applications.
    PLoS ONE 01/2012; 7(1):e29211. DOI:10.1371/journal.pone.0029211 · 3.23 Impact Factor
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