# Supplement request for Microtubule regulation of actomyosin dynamics and force generation in T lymphocytes

> **NIH NIH R01** · UNIV OF MARYLAND, COLLEGE PARK · 2020 · $150,000

## Abstract

Summary
Cell-cell interactions, mediated by adhesion and signaling receptors, are highly dynamic and subject to
cytoskeletal movements that impart substantial mechanical force at the interface. How cells combine
mechanical and biochemical signals to carry out specific functions is not well understood. Cells of the immune
system present a compelling context for studying force transmission and mechanosensing because they are
structurally dynamic and are sites of biochemical information transfer. T cell signaling is closely linked to the
cytoskeleton, and it is evident that forces applied by the actin cytoskeleton at the T cell receptor are transduced
to biochemical signaling leading to T cell activation. However, the molecular mechanisms by which these
forces are regulated and how they contribute to T cell function remain obscure. In our parent award, we
proposed to dissect the interactions and activities of proteins that reside at the intersection of actin and
microtubule (MT) dynamics to advance our understanding of force generation and mechanosensing in T cells.
We hypothesize that dynamic microtubules modulate the T cell cytoskeleton and proximal signaling both by 1)
regulating actin polymerization dynamics in the lamellipodium and the assembly of structures in the lamella
and 2) regulating RhoA activation leading to myosin contractility and force generation. Ultimately, we
hypothesize that MT/actin interactions contribute to the ability of T cells to adapt their activation and effector
function in response to the stiffness of target cells. Our preliminary studies have shown that there is
considerable cross-talk between the actin and MT cytoskeletons. In our ongoing studies, we are examining
mechanisms by which MT regulate actin dynamics by probing the specific interactions between MT and actin
via +TIP proteins using optogenetic approaches. We are also dissecting the mechanisms that link dynamic
MTs to myosin driven contractile force generation using traction force microscopy and optogenetic
manipulation of myosin contractility. Finally, we will place our in vitro work in a functional context by testing our
hypothesis that contractility tunes the mechanical coordination of cytotoxic T lymphocyte activation and their
killing efficacy using primary cells. Simultaneous imaging of cytoskeletal dynamics and signaling combined with
the measurement of the forces exerted by cells are key experiments for this project. This requires an imaging
system capable of multicolor fluorescence imaging with high signal to noise ratio and low photo-toxicity.
Spinning Disk Confocal Microscopy (SDCM) is an imaging technology that allows for visualization of molecular
events deep within the cell interior and through optically clear substrates with high resolution perpendicular to
the imaging plane. Furthermore, unlike scanning confocal microscopy, SDCM allows for rapid imaging (10s of
Hz) with relatively low light levels and reduced photo-toxicity. Currently, the onl...

## Key facts

- **NIH application ID:** 10135590
- **Project number:** 3R01GM131054-02S1
- **Recipient organization:** UNIV OF MARYLAND, COLLEGE PARK
- **Principal Investigator:** Arpita Upadhyaya
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $150,000
- **Award type:** 3
- **Project period:** 2019-03-15 → 2024-02-29

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10135590

## Citation

> US National Institutes of Health, RePORTER application 10135590, Supplement request for Microtubule regulation of actomyosin dynamics and force generation in T lymphocytes (3R01GM131054-02S1). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10135590. Licensed CC0.

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