A strong B-cell response is part of the immune landscape in human high-grade serous ovarian metastases

A Montfort, O Pearce, E Maniati, BG Vincent… - Clinical Cancer …, 2017 - AACR
A Montfort, O Pearce, E Maniati, BG Vincent, L Bixby, S Böhm, T Dowe, EH Wilkes…
Clinical Cancer Research, 2017AACR
Purpose: In high-grade serous ovarian cancer (HGSOC), higher densities of both B cells and
the CD8+ T-cell infiltrate were associated with a better prognosis. However, the precise role
of B cells in the antitumor response remains unknown. As peritoneal metastases are often
responsible for relapse, our aim was to characterize the role of B cells in the antitumor
immune response in HGSOC metastases. Experimental Design: Unmatched pre and post-
chemotherapy HGSOC metastases were studied. B-cell localization was assessed by …
Abstract
Purpose: In high-grade serous ovarian cancer (HGSOC), higher densities of both B cells and the CD8+ T-cell infiltrate were associated with a better prognosis. However, the precise role of B cells in the antitumor response remains unknown. As peritoneal metastases are often responsible for relapse, our aim was to characterize the role of B cells in the antitumor immune response in HGSOC metastases.
Experimental Design: Unmatched pre and post-chemotherapy HGSOC metastases were studied. B-cell localization was assessed by immunostaining. Their cytokines and chemokines were measured by a multiplex assay, and their phenotype was assessed by flow cytometry. Further in vitro and in vivo assays highlighted the role of B cells and plasma cell IgGs in the development of cytotoxic responses and dendritic cell activation.
Results: B cells mainly infiltrated lymphoid structures in the stroma of HGSOC metastases. There was a strong B-cell memory response directed at a restricted repertoire of antigens and production of tumor-specific IgGs by plasma cells. These responses were enhanced by chemotherapy. Interestingly, transcript levels of CD20 correlated with markers of immune cytolytic responses and immune complexes with tumor-derived IgGs stimulated the expression of the costimulatory molecule CD86 on antigen-presenting cells. A positive role for B cells in the antitumor response was also supported by B-cell depletion in a syngeneic mouse model of peritoneal metastasis.
Conclusions: Our data showed that B cells infiltrating HGSOC omental metastases support the development of an antitumor response. Clin Cancer Res; 23(1); 250–62. ©2016 AACR.
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