TCR-driven transendothelial migration of human effector memory CD4 T cells involves Vav, Rac, and myosin IIA

Thomas D Manes1, Jordan S Pober

  • 1Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06520, USA

Human effector memory (EM) CD4 T cells may be recruited from the blood into a site of inflammation in response either to inflammatory chemokines displayed on or specific Ag presented by venular endothelial cells (ECs), designated as chemokine-driven or TCR-driven transendothelial migration (TEM), respectively. We have previously described differences in the morphological appearance of transmigrating T cells as well as in the molecules that mediate T cell-EC interactions distinguishing these two pathways. In this study, we report that TCR-driven TEM requires ZAP-70-dependent activation of a pathway involving Vav, Rac, and myosin IIA. Chemokine-driven TEM also uses ZAP-70, albeit in a quantitatively and spatially different manner of activation, and is independent of Vav, Rac, and mysosin IIA, depending instead on an as-yet unidentified GTP exchange factor that activates Cdc42. The differential use of small Rho family GTPases to activate the cytoskeleton is consistent with the morphological differences observed in T cells that undergo TEM in response to these distinct recruitment signals.

Related Concept Videos

T Cell Activation and Clonal Selection01:22

T Cell Activation and Clonal Selection

T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
Role of Myosin in Cell Migration01:18

Role of Myosin in Cell Migration

Myosins are multimeric motor proteins involved in various cellular processes such as migration, adhesion, and proliferation. Myosin II is the most common type in animal cells, which binds and cross-links actin filaments.
Myosin II  is a hexamer comprising two heavy chains with globular heads and coiled-coil tails, two regulatory light chains, and two essential light chains. The ATPase sites on the myosin heads hydrolyze ATP, and the released phosphate generates the force for contraction. It is...
Cytotoxic T Cells-mediated Immune Response01:27

Cytotoxic T Cells-mediated Immune Response

Cytotoxic T cells are a vital component of the immune system. They have the remarkable ability to identify and target antigens on infected or abnormal cells. These antigens often originate from intracellular pathogens such as viruses or abnormal proteins cancer cells produce.
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Cell Polarization by Rho Proteins01:21

Cell Polarization by Rho Proteins

Cell polarity is the asymmetric distribution of cellular and membrane components, making one side of the cell different from the other. This polarity is essential to many processes such as embryogenesis, axon migration, glucose transport across epithelial cells, and directional cell migration. A migrating cell responds to intracellular or extracellular signals via molecular cascades that reorganize the actin cytoskeleton to establish this polarity. In these cells, the Rho family proteins Cdc42,...
T Cell Types and Functions01:24

T Cell Types and Functions

When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Cytoskeletal Coordination in Cell Migration01:32

Cytoskeletal Coordination in Cell Migration

A migrating cell changes its shape during the cyclic events of attachment and detachment from the substratum and repositions the cell organelles correspondingly. These complex events are orchestrated by the dynamic cytoskeletal network comprising actin filaments, intermediate filaments, and microtubules. Cytoskeletal crosstalk — the direct and indirect communication between the different components — is crucial for this coordination. Direct communication involves various linker proteins that...