Mechanistic Study on SENP6 Regulation of IFN-I Signaling Pathway and Antiviral Activity

Infectious Diseases Rheumatology and Immunology Biochemistry Life Sciences Immunology Medicine Cell Biology
SENP6 Sumoylation USP8 IFNAR2 Antiviral Activity

Academic Background and Research Question

In antiviral efficacy research, type I interferon (IFN-I) has been widely used clinically due to its broad-spectrum antiviral properties. However, the specific signaling mechanism and regulatory modes of IFN-I remain complex and not fully elucidated. In light of this, experts have begun to pay attention to potential deeper regulatory mechanisms, such as SUMOylation modifications and the role of deSUMOylation enzymes. The uniqueness of this study lies in revealing the role of SENP6 in regulating the antiviral activity of IFN-I. SENP6 does not affect the virus-induced production of IFN-I, but rather adjusts the signaling pathway activated by IFN-I, especially by regulating USP8 and its effect on IFNAR2 through deSUMOylation. This study attempts to address whether SENP6 has a regulatory effect on IFN-I signal activation during viral infection, and the biochemical basis of this regulatory mechanism.

Research Source

The study was conducted by Jing Guo, Hui Zheng, and Sidong Xiong, who are affiliated with the Jiangsu Key Laboratory of Infection and Immunity, Institute of Biology and Medical Sciences, Soochow University. The paper was published in the journal “Cellular & Molecular Immunology” on June 21, 2024.

Research Process and Experimental Steps

Interpretation of Research Process

The research mainly consists of the following steps:

  1. Initial verification of SENP6’s deSUMOylation enzyme activity and its impact on viral infection:

    • Using Western blot method to detect changes in SENP6 protein levels in VSV-infected 293T cells and verify its deSUMOylation enzyme activity.
    • Observing the effects of SENP6 knockdown or overexpression on infections of different viruses (including RNA virus SARS-CoV-2 and DNA virus KSHV).

  2. Revealing the mechanism by which SENP6 regulates the IFN-I signaling pathway and host antiviral response:

    • Using MEF cells and JAK-STAT pathway-related small molecule inhibitors to study the effects of SENP6 on the IFN-I signaling pathway under different genetic backgrounds.
    • Utilizing siRNA technology to knock down SENP6 in mice, and detecting its impact on viral infection and IFN-I-induced ISG expression levels in vivo by infecting with VSV virus.

  3. In-depth revelation of how SENP6 affects IFNAR2 stability and signaling pathway by regulating USP8 SUMOylation:

    • Exploring the interaction between USP8 and IFNAR2 and how USP8 SUMOylation affects IFNAR2 protein ubiquitination and degradation through biochemical methods such as immunoprecipitation.
    • Using in vivo and in vitro experiments to verify that SENP6 knockdown regulates IFNAR2 function and its downstream JAK-STAT signaling pathway by affecting USP8 deSUMOylation.

Analysis of Research Results

  1. Positive regulation of SENP6 on viral infection and IFN-I signaling pathway:

    • Knockdown or overexpression of SENP6 significantly affects the infection of various viruses (such as VSV, SARS-CoV-2, etc.). SENP6 knockdown reduced viral infection and increased the expression of antiviral genes.
    • In gene knockout or small molecule inhibitor-treated cells, it was found that SENP6 affected the phosphorylation of downstream signaling molecule STAT1 and ISG expression, indicating its key regulatory role in IFN-I signaling.
    • In vivo experiments showed that mice with SENP6 knockdown were more resistant to VSV virus infection than control mice, and the viral load in the liver was significantly reduced.

  2. SENP6 regulates USP8 through deSUMOylation, thereby affecting IFNAR2 stability:

    • The study found that SENP6 can interact with USP8. After SENP6 knockdown, the SUMOylation level of USP8 increased, enhancing its binding to IFNAR2, thereby reducing IFNAR2 ubiquitination and degradation.
    • The increase in USP8 enzyme activity enhanced downstream JAK-STAT signaling and antiviral gene expression by stabilizing IFNAR2 protein.

Conclusions, Significance, and Value

This study reveals a new molecular mechanism in which SENP6 regulates USP8 through deSUMOylation, thereby affecting IFNAR2 stability and the IFN-I signaling pathway. This discovery not only enriches our understanding of SUMOylation and deSUMOylation regulatory mechanisms but also provides new potential targets for developing antiviral strategies to improve IFN-I efficacy. In particular, in clinical applications, adjustments targeting SENP6 may become a new means to improve the therapeutic effect of IFN-I.

Research Highlights

  • Newly discovered molecular regulatory mechanism: The study first revealed the key regulatory role of SENP6 in the IFN-I signaling pathway and its molecular mechanism of affecting IFNAR2 stability by regulating USP8 SUMOylation.
  • Broad-spectrum antiviral application prospects: The study shows that by regulating SENP6, the antiviral effect against various viral infections can be enhanced, providing a new potential direction for antiviral treatment strategies.
  • Clinical translation value: The research results on SENP6 and its related signaling pathways provide new ideas for improving IFN-I efficacy, potentially enhancing the clinical effect of antiviral therapy through targeted regulation of SENP6 in the future.

Other Application Potential

This study also provides new research clues for the regulation of SUMOylation and deSUMOylation in other biological functions and diseases, which may explore more physiological and pathological mechanisms related to SENP6 and its substrates in the near future.