Programmable DNA-augmented hydrogels for controlled activation of human lymphocytes

Area of Science:

• Biotechnology
• Immunology
• Materials Science

Background:

• Mechanical stimulation of T cell receptors (TCRs) is crucial in mature immune synapses.
• The origin of mechanical forces driving early, microvilli-based TCR activation during immune surveillance is not well understood.
• Novel tools are required to investigate these presynaptic mechanical events.

Purpose of the Study:

• To develop a novel technology for investigating the mechanical forces involved in T cell receptor (TCR) activation.
• To create a platform enabling precise control over mechanical stimuli applied to T cells.
• To elucidate the role of mechanical forces in early T cell activation during immune surveillance.

Main Methods:

• Development of nucleic acid nanoassembly (NAN) technology for hydrogel functionalization.
• Utilizing isothermal toehold-mediated reassociation of RNA/DNA heteroduplexes for NAN construction.
• Employing polyacrylamide gels with varying shear moduli and NAN linkers of different lengths to modulate mechanical forces.
• Assessing T cell capture, activation, spreading, and phosphotyrosine (pY) foci formation.

Main Results:

• Successful functionalization of hydrogels using NAN technology.
• Demonstrated regulation of 3D force momentum along the TCR mechanical axis via NAN linkers.
• Hydrogels modulated 2D shear modulus, contributing to mechanical control.
• Achieved efficient capture of human T lymphocytes and tunable TCR activation, evidenced by T-cell spreading and pY foci.

Conclusions:

• The developed NAN-based hydrogel platform provides a novel tool for studying TCR mechanical stimulation.
• This technology allows for precise control over both 2D and 3D mechanical forces applied to T cells.
• The findings offer new insights into the mechanical underpinnings of early T cell activation and immune surveillance.