# Biology and structure of pMHC receptors functioning as mechanosensors in the [alpha][beta] T-cell lineage

> **NIH NIH P01** · DANA-FARBER CANCER INST · 2020 · $2,444,290

## Abstract

OVERALL SUMMARY
 T lymphocytes utilized  T cell receptors (TCRs) to distinguish self versus non-self through recognition
of sparse antigenic peptides bound to MHC molecules (pMHC) arrayed on antigen presenting cells (APC).
Through remarkable specificity and digital sensitivity,  T lymphocytes can destroy host cells altered by viruses,
other infectious pathogens or cancerous transformations while leaving normal cellular counterparts intact. Until
recently, it was unclear how TCR discrimination was achieved, given a lack of somatic mutations of TCR
genes to boost receptor-ligand affinity unlike with B cell receptors. Contrary to conventional ligand associations
exemplified by antigen-antibody interactions, however, it is now evident that physical force plays a crucial role in
non-equilibrium TCR-based T cell activation. Here we investigate the overarching hypothesis that  lineage
receptors that recognize pMHC ligands, namely TCRs and preTCRs, function as mechanosensors, transducing
biomechanical forces to impact thymocyte development as well as T cell antigen recognition and activation. Both
TCRs and preTCRs utilize force to induce different receptor conformers associated with energized and non-
energized states. Project 1 shall elucidate biophysical features driving TCR mechanosensing using paired
single molecule and single cell measurements via optical tweezers (OT) to determine non-equilibrium dynamics
and parameterization of energy landscapes under force. In turn, CD8 T cell responses such as antigen-specific
in vitro triggering sensitivity and in vivo cellular proliferation, effector and memory T cell development will be
assessed using TCR retrogenic mice. RNAseq analysis of various populations and single cells shall define the
connection between force-dependent transcriptomes and physical load on TCR-pMHC bonds. Project 2 shall
perform comparable OT biophysical studies on preTCRs and pMHC interactions using high throughput next
generation sequencing (NGS) of DN3, DN4, DP large and DP small subsets to determine TCR repertoire
changes in MHC-sufficient and MHC-deficient animals in vitro and in vivo. By determining  chain clonotypes
that are selected or disallowed during thymocyte developmental progression upon interaction with specific single-
chain pMHC ligands, coupled RNAseq analysis of thymocytes expressing those preTCRs, OT profiling,
Molecular Dynamics (MD) and NMR and X-ray crystallography structural studies, the rules governing early
thymic selection by pMHC shall be defined. Distinctions among  and TCR lineages with respect to
mechanical force shall be similarly analyzed and compared. Project 3 shall develop cutting-edge NMR methods
to reveal allosteric mechanisms of preTCR and TCR receptors upon pMHC ligation, characterizing major and
minor state structures and kinetics of interconversion aided by the MD Core to enhance atomistic detailing. An
Administrative Core (A), a Protein Production Core (B) and a MD Core ...

## Key facts

- **NIH application ID:** 10020596
- **Project number:** 1P01AI143565-01A1
- **Recipient organization:** DANA-FARBER CANCER INST
- **Principal Investigator:** Matthew J. Lang
- **Activity code:** P01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $2,444,290
- **Award type:** 1
- **Project period:** 2020-07-29 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10020596

## Citation

> US National Institutes of Health, RePORTER application 10020596, Biology and structure of pMHC receptors functioning as mechanosensors in the [alpha][beta] T-cell lineage (1P01AI143565-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10020596. Licensed CC0.

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