STING couples with PI3K to regulate actin reorganization during BCR activation.

Area of Science:

• Immunology
• Molecular Biology
• Cell Biology

Background:

• The adaptor protein STING (stimulator of interferon genes) is crucial in innate immunity but rarely studied in adaptive immunity.
• Understanding STING's role in B cell biology is essential for comprehending adaptive immune responses.

Purpose of the Study:

• To investigate the impact of STING deficiency on B cell development, differentiation, and B cell receptor (BCR) signaling.
• To elucidate the molecular mechanisms by which STING regulates BCR signaling and actin remodeling.

Main Methods:

• Utilized STING knockout (KO) mice and a patient's mutated STING cells.
• Analyzed B cell development, differentiation, and BCR signaling pathways, including CD19, Btk, SHIP, WASP, and F-actin.

Main Results:

• STING deficiency promoted marginal zone B cell differentiation.
• STING negatively regulated CD19 and Btk activation but positively regulated SHIP activation.
• BCR stimulation in STING KO B cells showed enhanced WASP activation and F-actin accumulation.
• STING mediates actin remodeling via the PI3K-CD19-Btk axis, providing feedback to BCR signaling.

Conclusions:

• STING plays a significant role in regulating BCR signaling through actin reorganization.
• STING positively influences the humoral immune response by modulating B cell activation and differentiation.