Non-progressing cancer patients have persistent B cell responses expressing shared antibody paratopes that target public tumor antigens

Publication date: Available online 12 October 2017
Source:Clinical Immunology
Author(s): Jeff DeFalco, Michael Harbell, Amy Manning-Bog, Gilson Baia, Alexander Scholz, Beatriz Millare, May Sumi, Danhui Zhang, Felix Chu, Christine Dowd, Patricia Zuno-Mitchell, Dongkyoon Kim, Yvonne Leung, Shuwei Jiang, Xiaobin Tang, Kevin S. Williamson, Xiaomu Chen, Sean M. Carroll, Gregg Espiritu Santo, Nicole Haaser, Ngan Nguyen, Eldar Giladi, David Minor, Yann Chong Tan, Jeremy B. Sokolove, Lawrence Steinman, Tito A. Serafini, Guy Cavet, Norman M. Greenberg, Jacob Glanville, Wayne Volkmuth, Daniel E. Emerling, William H. Robinson
There is significant debate regarding whether B cells and their antibodies contribute to effective anti-cancer immune responses. Here we show that patients with metastatic but non-progressing melanoma, lung adenocarcinoma, or renal cell carcinoma exhibited increased levels of blood plasmablasts. We used a cell-barcoding technology to sequence their plasmablast antibody repertoires, revealing clonal families of affinity matured B cells that exhibit progressive class switching and persistence over time. Anti-CTLA4 and other treatments were associated with further increases in somatic hypermutation and clonal family size. Recombinant antibodies from clonal families bound non-autologous tumor tissue and cell lines, and families possessing immunoglobulin paratope sequence motifs shared across patients exhibited increased rates of binding. We identified antibodies that caused regression of, and durable immunity toward, heterologous syngeneic tumors in mice. Our findings demonstrate convergent functional anti-tumor antibody responses targeting public tumor antigens, and provide an approach to identify antibodies with diagnostic or therapeutic utility.



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