Forces generated by T cells augment antigen signaling

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Abstract/Contents

Abstract
Activation of T cells through TCR binding to antigen is a highly sensitive process. Recent evidence suggests triggering of the T cell receptor (TCR) integrates both binding kinetics and mechanical forces. To both measure and apply mechanical forces in real-time during T cell activation, I triggered T cells using a novel application of atomic force microscopy (AFM). Using cantilevers coated with antigen, I was able to deliver mechanical and chemical stimulation to T cells. T cells generate patterns of pushing and pulling forces during activation through rapid turnover of actin as well as myosin contractility. I demonstrate how the strength and duration of phases of force generation are regulated by the action of actin capping and severing proteins. In particular, I highlight the role of cofilin in generating pull forces and how it's activity can be regulated by Ca2+ levels. Loss of cell-generated forces through disruption of the cytoskeleton abrogated signaling. Emulation of these lost forces through movement of the AFM cantilever rescued signaling in these F-actin inhibited T cells. In addition, reducing the forces felt by T cells through force clamping of the cantilever decreased the sensitivity of T cells to low antigen concentrations. My work, taken with other findings, show that T cells generate forces during activation and a combination of these mechanical forces and biochemical ligation is required for optimal T cell activation. These studies suggest a mechanical—biochemical feedback loop in which TCR-triggered T cells generate forceful contacts with antigen-presenting cells to amplify signaling through TCR-pMHC engagements.

Description

Type of resource text
Form electronic; electronic resource; remote
Extent 1 online resource.
Publication date 2017
Issuance monographic
Language English

Creators/Contributors

Associated with Hu, Kenneth Hsueh-heng
Associated with Stanford University, Department of Biophysics.
Primary advisor Butte, M. (Manish)
Primary advisor Chaudhuri, Ovijit
Thesis advisor Butte, M. (Manish)
Thesis advisor Chaudhuri, Ovijit
Thesis advisor Bollyky, Paul
Thesis advisor Lewis, Richard
Advisor Bollyky, Paul
Advisor Lewis, Richard

Subjects

Genre Theses

Bibliographic information

Statement of responsibility Kenneth Hsueh-heng Hu.
Note Submitted to the Department of Biophysics.
Thesis Thesis (Ph.D.)--Stanford University, 2017.
Location electronic resource

Access conditions

Copyright
© 2017 by Kenneth Hsueh-heng Hu
License
This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).

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