Efficient CRISPR/Cas9 Disruption of Autoimmune-Associated Genes Reveals Key Signaling Programs in Primary Human T...

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• Genetic variants in phosphatases PTPN22 and PTPN2 are linked to increased autoimmunity risk.
• Previous studies in mouse models and human lymphocytes showed conflicting T cell responses to these genetic variants.

Purpose of the Study:

• To investigate the functional consequences of PTPN22 and PTPN2 loss-of-function in primary human CD4+ T cells.
• To resolve the dichotomy between mouse and human studies regarding T cell responses in autoimmunity.

Main Methods:

• Utilized CRISPR/Cas9 gene editing for efficient disruption of PTPN22 and PTPN2 in human CD4+ T cells.
• Analyzed the impact of gene disruption on T cell signaling pathways and cellular responses.

Main Results:

• Achieved >80% gene disruption efficiency for target phosphatases.
• Observed that loss-of-function in PTPN2 T cells led to initial hyperactive IL-2R signaling followed by hyporesponsiveness.
• Demonstrated dynamic, evolving T cell phenotypes influenced by signaling and experience.

Conclusions:

• Altered phosphatase activity contributes to complex, evolving T cell phenotypes in autoimmunity.
• This gene editing approach effectively models autoimmunity mechanisms in human cells.
• Findings provide insights into genetic risk factors for autoimmune diseases.