Effect of binary mechanical environment on T cell function

Area of Science:

• Immunology
• Biophysics
• Cell Biology

Background:

• T cells (T lymphocytes) are crucial for adaptive immunity, recognizing antigens via T-cell receptors (TCRs).
• Full T cell activation requires biochemical signals and mechanical cues like tissue stiffness.
• Existing ex-vivo platforms offer uniform mechanical environments, unlike heterogeneous in-vivo conditions.

Purpose of the Study:

• To investigate T cell responses to mechanically heterogeneous environments.
• To develop a novel mechanically-biphasic surface mimicking in-vivo mechanical landscapes.
• To understand the role of mechanical heterogeneity in T cell activation and function.

Main Methods:

• Fabrication of a mechanically-biphasic surface with alternating soft and stiff microdomains.
• Culturing T cells on this patterned surface and on uniformly soft/stiff surfaces.
• Quantifying T cell activation, proliferation, and phenotype using flow cytometry and other assays.

Main Results:

• T cells on the biphasic surface responded similarly to those on uniformly soft surfaces, showing lower initial activation than on stiff surfaces.
• Long-term exposure to the biphasic pattern enhanced proliferation of central memory and effector T cell phenotypes.
• T cell mechanosensing demonstrated a non-linear response to mechanical heterogeneity.

Conclusions:

• Mechanical heterogeneity significantly modulates T cell responses, challenging the assumption of signal averaging.
• T cell activation is influenced by the complex interplay of simultaneous mechanical cues.
• Findings provide new insights into T cell biology and potential applications for immunotherapies.