An ELF4 hypomorphic variant results in NK cell deficiency.

Area of Science:

• Immunology
• Genetics
• Molecular Biology

Background:

• Natural Killer (NK) cell deficiencies (NKD) are primary immune disorders impacting NK cell number, maturity, or function.
• NK cells are crucial for antiviral defense, and their deficiency increases susceptibility to severe viral infections.

Purpose of the Study:

• To investigate a potential novel genetic cause of NKD in an individual with recurrent viral infections.
• To elucidate the role of the transcription factor gene ELF4 in NK cell development and function.

Main Methods:

• Genetic analysis identified an X-linked variant in the ELF4 gene.
• Functional studies using murine models (Elf4-/-) and a human NK cell line with ELF4 knockdown.
• Characterization of patient NK cells and in vitro human NK cell maturation models.

Main Results:

• The identified ELF4 variant disrupts protein interactions and DNA binding, impairing transcriptional activation.
• ELF4 is essential for normal NK cell development, terminal maturation, and function, as confirmed in murine and human models.
• The ELF4 variant selectively impairs NK cell function, consistent with a role in NKD pathogenesis.

Conclusions:

• A damaging variant in ELF4 is identified as a potential novel cause of X-linked NK cell deficiency.
• This finding underscores the critical role of ELF4 in human NK cell immunity and provides a new avenue for understanding primary immune deficiencies.