IMMUNOLOGY2026™ Conference Recordings For Attendees-Structural basis of anti-MHC-I antibody blocking of inhibitory NK cell receptors in tumor immunity

Structural basis of anti-MHC-I antibody blocking of inhibitory NK cell receptors in tumor immunity

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Video Summary

Researchers identified a new anti-MHC class I monoclonal antibody, B1.23.2, that binds strongly and specifically to conserved HLA-A, -B, and -C regions. Using cryo-EM at 3 Å resolution, they showed the antibody locks onto the α2 helix of MHC-I without contacting the peptide, allowing it to block inhibitory NK-cell receptor binding. Superimposed structures suggested it competes effectively with receptors like KIR, consistent with its very high affinity. In a humanized mouse tumor model, B1.23.2 reduced tumor growth compared with control antibody. The work extends earlier anti-MHC-I antibodies and supports a general mechanism in which blocking inhibitory NK-cell signaling can enhance anti-tumor immunity, potentially complementing checkpoint inhibitor therapies.

Meta Tag

Date April 16, 2026 1:00 PM - 1:15 PM

Room 153AB

Session Antigen Presentation in Immunity, Pathology, and Tolerance

Speaker Jiansheng Jiang

Track Classical and Non-Classical Antigen Presenting Cells (APC)

Year 2026

Keywords

anti-MHC class I antibody

B1.23.2

cryo-EM structure

NK-cell receptor blockade

anti-tumor immunity

April 16, 2026 1:00 PM - 1:15 PM

153AB

Antigen Presentation in Immunity, Pathology, and Tolerance

Jiansheng Jiang

Classical and Non-Classical Antigen Presenting Cells (APC)

2026