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Principal Investigator: Jordan Jacobelli
Organization: UNIVERSITY OF COLORADO DENVER
Fiscal Year: 2024
Award: $483,012
Funding agency: National Institute of Allergy and Infectious Diseases
Lymphocytes must correctly localize to mount effective immune responses. To do this, lymphocytes
migrate through tissue environments with very different biophysical characteristics, including extravasation
from blood vessels and crawling through cell-packed or extracellular matrix-rich tissues. To navigate through
these diverse environments, lymphocytes squeeze through constrictions and migrate in low- or high-adhesive
environments. However, there is a key gap in the understanding of how specific cytoskeletal effectors regulate
force generation, shape changes, and cell-cell or cell-matrix interactions during lymphocyte migration in
different settings. Given their relevance to immune function, primary T lymphocytes are a highly significant
model to investigate cytoskeletal regulation of the varying modes of amoeboid cell motility in three-dimensional
(3D) environments. Formin family proteins are cytoskeletal effectors involved in mediating actin network
remodeling. Formin-like-1 (FMNL1) and Diaphanous-homologue-1 (mDia1) are the two most highly expressed
Formins in T cells. We recently determined that FMNL1 is required for T cell transendothelial migration (TEM)
and trafficking to inflamed tissues. Interestingly, our preliminary data support that FMNL1 and mDia1 have
distinct functions in T cell migration through confined environments. Our goal is to achieve a more
comprehensive understanding of the mechanisms by which the cytoskeleton enables migration through diverse
tissue environments by determining the mode of action of Formin proteins in T cell motility. We will investigate
the mechanisms by which Formins generate mechanical forces during T cell migration, the contribution of
Formins in promoting T cell nucleus passage through constrictions, and how Formins regulate T cell motility in
vivo. We will also determine if FMNL1 and mDia1 act independently or in concert with the Arp2/3 complex
and/or Myosin-IIA. Our hypothesis is that to promote migration through complex environments FMNL1
mediates force generation from the back of the T cell while mDia1 creates force and membrane protrusions at
the cell front. To test this hypothesis, we will use a multi-faceted approach, including genetic/mutational
approaches and advanced imaging techniques in complementary model systems in vitro and physiological
environments in vivo. Aim 1: Determine the mechanisms by which FMNL1 and mDia1 promote T cell
transendothelial migration. Aim 2: Determine how FMNL1 and mDia1 regulate T cell motility within 3D
environments with diverse biophysical characteristics. Aim 3: Define how Formins regulate T cell extravasation
and interstitial motility in vivo. Overall, our studies are significant in that they will advance our knowledge of T
cell migration by providing new data to determine the mechanism of action of Formins in T cell motility and if
they cooperate with Myosin-IIA to promote migration through environments with varied biophysical
characteristics. Thus, this work has the potential to provide important insight into novel ways to therapeutically
modulate lymphocyte migration, such as in autoimmune settings and inflammatory diseases.
Terms: <2-photon microscopy><3-D><3-D modeling><3-Dimensional><3D><3D modeling><Actins><Adhesions><Adhesives><Adopted><Autoimmune><Autoimmune Status><Autoimmunity><Back><Biologic Models><Biological Models><Blood Vessels><Body Tissues><C17orf1><C17orf1B><Cancers><Cell Body><Cell Communication><Cell Interaction><Cell Locomotion><Cell Migration><Cell Movement><Cell Nucleus><Cell-Extracellular Matrix><Cell-to-Cell Interaction><Cells><Cellular Immune Function><Cellular Matrix><Cellular Migration><Cellular Motility><Characteristics><Chemotactic Cytokines><Collagen><Complement><Complement Proteins><Complex><Cues><Cytoskeletal Gene><Cytoskeletal Proteins><Cytoskeletal System><Cytoskeleton><Data><Disease><Disorder><Dorsum><ECM><Embryo Development><Embryogenesis><Embryonic Development><Endothelial Cells><Endothelium><Environment><Environmental Factor><Environmental Risk Factor><Extracellular Matrix><Extravasation><FMNL><FMNL1><FMNL1 gene><Face><Family><GeneHomolog><Generations><Genetic><Genetic Alteration><Genetic Change><Genetic defect><Goals><Homolog><Homologous Chemotactic Cytokines><Homologous Gene><Homologue><Imaging Procedures><Imaging Technics><Imaging Techniques><Immune><Immune response><Immune system><Immunes><Immunological response><In Vitro><Inflammatory><Intercrines><Knowledge><Leakage><Ligands><Location><Lymph Node Reticuloendothelial System><Lymph node proper><Lymphatic cell><Lymphatic nodes><Lymphocyte><Lymphocytic><Malignant Cell><Malignant Neoplasms><Malignant Tumor><Mediating><Membrane><Metastasis><Metastasize><Metastatic Lesion><Metastatic Mass><Metastatic Neoplasm><Metastatic Tumor><Methods><Micro-tubule><Microtubules><Model System><Modeling><Motility><Mutation><Myosin A><Myosin IIA><Neoplasm Metastasis><Non-Muscle Myosin Type IIA><Nonmuscle Myosin Type IIA><Nucleus><Organism-Level Process><Organismal Process><Pathologic><Physiologic><Physiologic Processes><Physiological><Physiological Processes><Protein Family><Proteins><Regulation><Role><SIS cytokines><Secondary Neoplasm><Secondary Tumor><Shapes><Spillage><T-Cells><T-Lymphocyte><Testing><Therapeutic><Tissues><Traction Force Microscopy><Vascular Endothelium><Work><Wound Repair><biophysical characteristics><biophysical characterization><biophysical measurement><biophysical parameters><biophysical properties><cancer cell><cancer metastasis><cell motility><cell type><chemoattractant cytokine><chemokine><complementation><constriction><environmental risk><faces><facial><formin-like><formin-like 1><genome mutation><host response><immune function><immune system function><immune system response><immunoresponse><in vivo><insight><interstitial><intracellular skeleton><knowledge integration><lymph cell><lymph gland><lymph nodes><lymphnodes><malignancy><mechanical force><membrane structure><migration><neoplasm/cancer><novel><pathogen><social role><three dimensional><three-dimensional modeling><thymus derived lymphocyte><trafficking><tumor cell metastasis><two photon excitation microscopy><two photon microscopy><vascular><wound healing><wound recovery><wound resolution>