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Principal Investigator: Nathan H. Roy
Organization: UPSTATE MEDICAL UNIVERSITY
Fiscal Year: 2024
Award: $407,500
Funding agency: National Institute of Allergy and Infectious Diseases
Project Summary/Abstract
Leukocyte migration out of the vasculature into peripheral tissue is crucial for their role in fighting pathogens,
promoting tissue repair, and attacking solid tumors. This process is a key control point in the inflammatory
response and relies heavily on signaling events downstream of leukocyte integrins and their endothelial
ligands. Manipulating integrin signaling could serve as untapped avenue to control immune cell functions in
inflammatory diseases and cancer, but hindering efforts on this front is a lack of mechanistic understanding of
integrin signaling events. Importantly, integrins are known to be central players in mechanotransduction
(converting mechanical information into a biochemical response), yet very little is known about how immune
cells use integrins to sense and respond to the mechanical cues on the molecular level. This is surprising,
since there is strong evidence that inflammation causes endothelial cells to change their mechanical
properties, driving immune cell infiltration. Our preliminary data show that, indeed, T cells can respond to the
mechanical properties of their substrate through the integrin LFA-1, kicking off cytoskeletal changes that drive
T cell migration. Importantly, we found a signaling scaffold, named CasL, that is mechanically activated and
required for T cell migration downstream of LFA-1. Surprisingly, T cells lacking CasL fail to form an actin-rich
leading edge, but instead display numerous membrane blebs, suggesting CasL may control cytoskeletal
responses and/or cortical integrity. Based on our preliminary data, we hypothesize that CasL is a crucial
mechanosensitive signaling hub governing cytoskeletal responses during T cell migration. Specifically,
we hypothesize CasL controls cytoskeletal organization by regulating the activity of one or more of the Rho
family GTPases, thus coordinating proper cytoskeletal responses and optimum motility. In Aim 1, we will take
a systematic approach to determine how CasL regulates cytoskeletal dynamics and cortex-membrane integrity,
focusing on the Rho GTPases and their downstream effector proteins, and then test the hypothesis that CasL
function is crucial to maintain normal cortex-membrane stiffness. In Aim 2, we will leverage our ability to
introduce mutants into primary T cells lacking CasL to undertake a structure/function analysis of CasL in T cell
migration. We will define how CasL phosphorylation, as well as how each individual domain, contributes to
actin responses, migration, and membrane blebbing. Lastly, in Aim 3, we ask how loss of CasL affects T cell
migration into inflamed tissue in vivo. Taken together, these studies will provide fundamental information on the
mechanisms of T cell migration and mechanotransduction and lay the foundation for future work aimed and
manipulating these pathways in inflammatory diseases and cancer.
Terms: <Actins><Acute><Adoptive Transfer><Affect><Automobile Driving><Binding><Biochemical><Biophysics><Bleb><Blister><Blood leukocyte><Body Tissues><Bulla><Bullous Lesion><CD54 Antigens><Cancers><Cell Body><Cell Communication and Signaling><Cell Function><Cell Locomotion><Cell Migration><Cell Movement><Cell Physiology><Cell Process><Cell Signaling><Cells><Cellular Function><Cellular Matrix><Cellular Mechanotransduction><Cellular Migration><Cellular Motility><Cellular Physiology><Cellular Process><Chronic><Cytoskeletal Modeling><Cytoskeletal Organization><Cytoskeletal Organization Process><Cytoskeletal Reorganization><Cytoskeletal System><Cytoskeleton><Data><Defect><Disease><Disorder><Endothelial Cells><Endothelium><Event><Family><Foundations><Future><GTP Phosphohydrolases><GTPases><Genetic><Goals><Guanosine Triphosphate Phosphohydrolases><Guanosinetriphosphatases><GvHD><Homologous Wasting Disease><ICAM-1><Immune><Immune infiltrates><Immunes><In Vitro><Individual><Inflammation><Inflammatory><Inflammatory Response><Integrin Binding><Integrins><Integrins Extracellular Matrix><Intercellular adhesion molecule 1><Intracellular Communication and Signaling><Knowledge><Leukocytes><Leukocytes Reticuloendothelial System><Ligands><Malignant Neoplasms><Malignant Tumor><Marrow leukocyte><Mechanical Signal Transduction><Mechanics><Mechanosensory Transduction><Membrane><Modeling><Molecular><Molecular Interaction><Motility><Names><Pathway interactions><Peripheral><Phosphorylation><Phosphotyrosine><Physiologic><Physiological><Play><Process><Proliferating><Protein Phosphorylation><Proteins><Role><Runt Disease><Scaffolding Protein><Signal Transduction><Signal Transduction Systems><Signaling><Site><Solid Neoplasm><Solid Tumor><Structure><Subcellular Process><System><T-Cell Activation><T-Cells><T-Lymphocyte><Testing><Tissues><Tyrosine Phosphorylation><Tyrosine-O-phosphate><Vesication><White Blood Cells><White Cell><Work><activate T cells><biological signal transduction><biophysical foundation><biophysical principles><biophysical sciences><cell motility><combat><disease model><disorder model><driving><experiment><experimental research><experimental study><experiments><fighting><graft versus host disease><graft vs host disease><graft vs. host disease><guanosinetriphosphatase><immune cell infiltrate><in vivo><inhibitor><insight><integrin bound><intracellular skeleton><malignancy><mechanic><mechanical><mechanical cue><mechanical properties><mechanical signal><mechanosensing><mechanotransduction><membrane structure><migration><mutant><name><named><naming><neoplasm/cancer><novel><pathogen><pathway><protein protein interaction><response><rho><rho G-Proteins><rho GTP-Binding Proteins><rho GTPases><rho Protein P21><rho Small GTP-Binding Proteins><scaffold><scaffolding><social role><thymus derived lymphocyte><tissue repair><white blood cell><white blood corpuscle>