Mechanobiological Regulation of NF-κB in Innate Immunity

Author

Sazid Noor Rabi, Southern Illinois University CarbondaleFollow

Date of Award

8-1-2025

Degree Name

Master of Science

Department

Mechanical Engineering

First Advisor

Chowdhury, Farhan

Abstract

Mechanotransduction is a process through which cells sense and respond to mechanical stimuli, converting them to biochemical signals. The innate immune system plays a role by integrating biochemical signals through cell signaling pathways to safeguard against viral infections. One of these pathways is the mechanosensitive NF-κB signaling pathway. Although this pathway has been widely studied in immunology, its regulation through mechanotransduction has been largely unexplored. Recent work from our group explains the mechanotransduction of the RIG-I pathway upstream of the NF-κB pathway. This study aims to find the role of NF-κB mechanotransduction in innate immune antiviral signaling. We hypothesize that there is a crosstalk between this pathway and the RhoA/ROCK pathway, controlling the immune response based on substrate stiffness. To maintain the mechanical response of the cells, we seeded HeLa cells on polyacrylamide (PAA) hydrogels with stiffness levels of 0.6 kPa and 8.5 kPa. We used Poly (I:C), a synthetic viral mimic, to transfect the cells, triggering the NF-κB and RIG-I pathways. We also used Shikonin (SHK), a suppressor of NF-κB, to study its role in mechanotransduction. A series of traction force microscopy (TFM) experiments were performed. Preliminary data show that SHK suppresses the stress response from the cells, indicating a reduction in viral immune response. This finding, supported by an immunofluorescence study with NF-κB p65 antibody, demonstrates that the NF-κB acts as a mechanotransduction pathway, creating a homeostasis between mechanical and chemical immune responses.