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

Abstract

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.

Mutation Effects on Remote Epitopes of An Autoantigen Decoded with Simulated B-Factors

“…moANCA518: DNA barcode-enabled sequencing of the antibody repertoire was performed on plasmablasts derived from a PR3-targeting ANCA (PR3-ANCA) positive patient as described elsewhere for rheumatoid arthritis and Sjögren syndrome (16)(17)(18). Phylograms of the antibody repertoires revealed clonal families of affinity matured antibodies with shared heavy and light chain VJ usage.…”

“…The human epithelial kidney cell line 293 used for the expression of recombinant PR3 mutants was obtained from ATCC (Rockville, MD).iPR3-Val 103 and iHm5-Val 103 : The cDNA constructs coding for iPR3-Val 103 and iHm5-Val 103 and their expression in HEK293 cells were described in detail elsewhere (11,12). Both mutants carry a carboxyterminal cmyc-peptide extension and a poly-His peptide extension for purification using nickel columns from GE Healthcare (Chicago, IL) and for anchoring in ELISAs as previously described and specified below (11-15).moANCA518: DNA barcode-enabled sequencing of the antibody repertoire was performed on plasmablasts derived from a PR3-targeting ANCA (PR3-ANCA) positive patient as described elsewhere for rheumatoid arthritis and Sjögren syndrome (16)(17)(18). Phylograms of the antibody repertoires revealed clonal families of affinity matured antibodies with shared heavy and light chain VJ usage.Twenty-five antibodies were selected for recombinant expression (18) and tested for reactivity with recombinant ANCA antigens [including myeloperoxidase (15), human neutrophil elastase (19-21), iPR3-Val 103 , and iHm5-Val 103 ] using the ELISA.…”

AllergoOncology: Microbiota in allergy and cancer—A European Academy for Allergy and Clinical Immunology position paper

“…B cells are known to promote allergy through antigen presentation and class‐switching to IgE, whereas under certain conditions, tumor‐infiltrating B cells can be associated with improved patient survival in cancer . In contrast, Breg‐associated immune tolerance can lead to control of allergy or tumor progression in cancer …”

Functional clustering of B cell receptors using sequence and structural features

“…9313 natively paired, full variable region antibody sequences were generated by applying Immune Repertoire Capture® technology 26 to healthy donor peripheral blood mononuclear cells isolated and cryopreserved 1 week after administration of seasonal flu vaccine. 5743 paired sequences represented plasmablasts sorted as described previously 27 and 3570 represented CD19 + B cells, which were cultured for 4 days in IMDM medium (Invitrogen) in the presence of FBS, Normocin, IL-2 (PeproTech), IL-21 (PeproTech), rCD40 ligand (R&D Systems), and His-Tag antibodies (R&D Systems), prior to single cell sorting. Plasmablasts were grouped into families based on heavy chain V germline, light chain V germline, heavy chain CDR3 length and light chain CDR3 length (a.k.a.…”