ISG20L2: an RNA nuclease regulating T cell activation

Area of Science:

• Immunology
• Molecular Biology
• RNA Biology

Background:

• ISG20L2 is a 3' to 5' exoribonuclease previously linked to ribosome biogenesis.
• Its role in activated T cells and immune responses was previously unknown.

Purpose of the Study:

• To investigate the function of ISG20L2 in activated T cells.
• To determine the impact of ISG20L2 on T cell activation and immune regulation.

Main Methods:

• Studied ISG20L2 expression in T lymphocytes upon TCR and IFN type I stimulation.
• Utilized ISG20L2 silencing and knockout models to assess functional consequences.
• Analyzed the expression of T cell activation markers and immunoregulatory molecules.

Main Results:

• ISG20L2 exhibits preferential affinity for uridylated miRNA substrates in T cells.
• ISG20L2 is upregulated in T lymphocytes following TCR and IFN type I stimulation.
• ISG20L2 silencing increased CD69 expression and IL2 secretion but impaired CD25 upregulation and immune synapse formation.
• ISG20L2 absence led to dysregulated expression of key immunoregulatory molecules (AHR, NKG2D, CTLA-4, CD137, TIM-3, PD-L1, PD-1).

Conclusions:

• ISG20L2 acts as a novel RNA-based regulator of T cell function.
• ISG20L2 plays a critical role in modulating T cell activation, cytokine production, and immune synapse formation.
• ISG20L2 influences the expression of crucial molecules governing T cell responses, highlighting its significance in immune regulation.