# Structural Studies of a T cell Specific Tyrosine Kinase

> **NIH NIH R01** · IOWA STATE UNIVERSITY · 2024 · $562,986

## Abstract

Project Summary
T cell development, activation, and differentiation are all dependent on TCR signaling, along with
important contributions from costimulatory and cytokine receptor pathways. Many lines of
evidence indicate that variations in TCR signal strength have a major impact on the outcome of
these processes. For mature CD8 T cells, TCR signal strength determines proliferative capacity
and effector versus memory potential following infection. We assert that there is a growing need
to develop a more comprehensive understanding of the pathways regulating distinct T cell
functions and differentiation processes. Moreover, manipulation of T cell responses underlies
many therapeutic strategies currently in practice and under development. As this field has
progressed, it has become clear there is a need for more nuanced manipulation of T cell signaling
pathways. To achieve clinical efficacy, we need to understand how to tune T cell responses.
The field presently lacks an understanding of how differences in TCR stimulation strength produce
distinct gene expression patterns that steer T cell responses. We now have a body of data
supporting a key role for the TEC kinase ITK in tuning T-cell signaling. ITK is not required for all
TCR signaling; instead, in its absence, TCR signaling is significantly reduced. From these studies,
the clear function of ITK has been difficult to discern, as some aspects of T cell activation
appeared normal in the absence of ITK, whereas other T cell functions were greatly impaired. Our
data now provide a framework to understand these apparent discrepancies, and suggest that
variations in antigen density and in TCR affinity dictate the magnitude of ITK activity modulating
subsequent gene expression responses.
This proposal will study the contribution of specific ITK activation mechanisms (Aim 1) and
costimulatory interactions (Aim 2) to understand how ITK mediates tunable responses to TCR
stimulation. Biochemical and structural biology insights are directly transferred into primary T cell
experiments to elucidate the molecular mechanisms controlling ITK regulation. We will also study
the role of ITK regulation in human disease (Aim 3). Genetic mutations that activate ITK have
been recently identified in patients with autoimmunity and there is evidence that the ITK-SYK
fusion tyrosine kinase interacts with normal ITK in promoting oncogenesis in peripheral T cell
lymphomas. The results of these studies will provide us with critical information about the nature
of ITK regulation and how ITK activity influences T cell activation in response to TCR signal
strength.

## Key facts

- **NIH application ID:** 10999085
- **Project number:** 2R01AI043957-26
- **Recipient organization:** IOWA STATE UNIVERSITY
- **Principal Investigator:** AMY H ANDREOTTI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $562,986
- **Award type:** 2
- **Project period:** 1999-01-15 → 2029-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10999085

## Citation

> US National Institutes of Health, RePORTER application 10999085, Structural Studies of a T cell Specific Tyrosine Kinase (2R01AI043957-26). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10999085. Licensed CC0.

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