Associations between HLA-II variation and antibody specificity are predicted by antigen properties

Area of Science:

• Immunogenetics
• Molecular Biology
• Human Immunology

Background:

• Human leukocyte antigen class II (HLA-II) genes are highly polymorphic and crucial for T helper cell-dependent antibody responses.
• Genome-wide association studies and high-throughput immunoassays have identified links between HLA-II variants and antibody specificities.
• The underlying factors driving these genetic associations with antibody responses are not fully understood.

Purpose of the Study:

• To identify key determinants linking human genetics and antibody specificity.
• To explore the relationship between HLA-II alleles and immune responses to diverse antigens.

Main Methods:

• Utilized paired SNP array data and functional antibody epitope repertoires against 344,000 peptide antigens.
• Analyzed data from 1940 individuals to uncover genetic associations with antibody specificity.

Main Results:

• Antibody responses against secreted proteins and viral antigens show stronger associations with HLA-II alleles compared to membrane-bound or intracellular proteins.
• A model suggests that antibody responses to single or few protein units dominate HLA-II associations.
• Bacterial antigens, with diverse proteins, dilute potential associations to specific antibody responses.

Conclusions:

• Genetic associations with antibody specificity are influenced by the intrinsic properties of antigens.
• This framework aids in understanding antigen/HLA-II risk factors in diseases like infections, autoimmune disorders, allergies, and cancer.
• Findings can inform the design of improved immunogenetics screens for disease prediction and prevention.