Polygenic polymorphism is associated with NKG2A repertoire and influences lymphocyte phenotype and function

Area of Science:

• Immunology
• Cellular and Molecular Immunology
• Genetics and Genomics

Background:

• The CD94/NKG2A receptor complex on NK and T cells mediates inhibitory signaling upon binding HLA-E.
• NKG2A expression levels influence NK cell responsiveness and overall immune repertoire function.
• HLA-E expression is regulated by HLA class I signal peptides and peptide availability.

Purpose of the Study:

• To identify single nucleotide polymorphisms (SNPs) associated with NKG2A expression on immune cells.
• To investigate the relationship between peptide abundance and HLA-E expression.
• To determine the predictive value of NKG2A SNPs and HLA-C epitopes for NK cell phenotype and function.

Main Methods:

• Analysis of killer cell lectin-like receptor C1 (KLR C1) SNPs associated with NKG2A expression.
• Investigation of linkage disequilibrium between KLR C1, KLRC2 (NKG2C), and KLRK1 (NKG2D) polymorphisms.
• Correlation of NKG2A surface expression with NK cell responsiveness and frequency.
• Analysis of the relationship between peptide availability and HLA-E expression levels.
• Identification of HLA-C epitopes as predictive markers for HLA-ABC and HLA-E expression.

Main Results:

• Several KLR C1 (NKG2A) SNPs were associated with NKG2A expression on NK, CD8+, and Vγ9/Vδ2+ T cells.
• Polymorphisms in KLRC2 (NKG2C) and KLRK1 (NKG2D) are linked to NKG2A surface density and frequency.
• Peptide availability strongly correlates with HLA-E expression levels.
• HLA-C1 epitopes are associated with high HLA-E expression, while HLA-C2 epitopes are linked to low HLA-E expression, independent of HLA-E allotypes.
• HLA-E expression impacts NK cell inhibition but not NKG2A-mediated NK education.

Conclusions:

• NKG2A SNPs and HLA-C epitopes serve as important predictive markers for NK cell phenotype and function.
• These genetic factors influence innate immune response and NK cell inhibitability.
• NKG2A SNPs and HLA-C epitopes warrant evaluation as prognostic markers for diseases with high HLA-E expression.