Targeting N-linked Glycosylation for the Therapy of Aggressive Lymphomas

Area of Science:

• Oncology
• Immunology
• Molecular Biology

Background:

• Diffuse large B-cell lymphoma (DLBCL) has two main subtypes: activated B-cell (ABC) and germinal center B cell-like (GCB).
• Chronic active signaling from B-cell receptors (BCR) is crucial for DLBCL pathogenesis, activating pathways like NF-κB and PI3 kinase.

Purpose of the Study:

• To identify regulators of IRF4, a key indicator of BCR signaling in ABC DLBCL, using genome-wide CRISPR-Cas9 screens.
• To explore the role of N-linked protein glycosylation in BCR signaling and its therapeutic potential in DLBCL.

Main Methods:

• Genome-wide CRISPR-Cas9 screening to identify genetic regulators.
• Investigating the impact of oligosaccharyltransferase-B (OST-B) complex inhibition on BCR signaling pathways.
• Assessing the efficacy of OST-B inactivation in DLBCL models.

Main Results:

• Inactivation of the OST-B complex unexpectedly reduced IRF4 expression.
• OST-B inhibition impaired BCR glycosylation, reducing BCR clustering and internalization.
• This inhibition attenuated PI3 kinase and NF-κB activation and promoted BCR association with CD22.
• OST-B inactivation demonstrated efficacy in killing both ABC and GCB DLBCL models.

Conclusions:

• The OST-B complex is a critical regulator of BCR organization and proximal signaling in DLBCL.
• Targeting OST-B-dependent glycosylation presents a novel therapeutic strategy for DLBCL.
• Selective OST-B inhibitors could be developed for treating aggressive DLBCL subtypes.