Tumor-infiltrating plasma cell profiling after PD-1 blockade reveals tumor-specific antibodies.

Tumor-infiltrating plasma cells produce tumor-specific antibodies that can be harnessed for targeted cancer therapy, with some showing strong binding to citrullinated proteins.

• Why it matters: Understanding the role of B cells in anti-tumor immunity is crucial for improving immune checkpoint therapies, as their contribution remains poorly defined in lung cancer.
• What they did: Researchers analyzed resected NSCLC tumors from patients treated with PD-1 blockade, cloning monoclonal antibodies from plasma cells that exhibited somatic hypermutation and class switching, and tested their targeting capabilities.
• The result: The study identified antibodies that bind tumor-associated citrullinated proteins and demonstrated that CAR T cells engineered with these antibodies specifically target tumor and myeloid cells, suggesting a new avenue for cancer immunotherapy.