Atypical memory B cells acquire Breg phenotypes in hepatocellular carcinoma

• Text
• PDF

Abstract

The functional plasticity of tumor-infiltrating lymphocyte B–cells (TIL-B) spans from antitumor responses to noncanonical immune suppression. Yet, how the tumor microenvironment (TME) influences TIL-B development is still underappreciated. Our current study integrated single-cell transcriptomics and B cell receptor (BCR) sequencing to profile TIL-B phenotypes and clonalities in hepatocellular carcinoma (HCC). Using trajectory and gene regulatory network analysis, we were able to characterize plasma cells and memory and naive B cells within the HCC TME and further revealed a downregulation of BCR signaling genes in plasma cells and a subset of inflammatory TNF+ memory B cells. Within the TME, a nonswitched memory B cell subset acquired an age-associated B cell phenotype (TBET+CD11c+) and expressed higher levels of PD-L1, CD25, and granzyme B. We further demonstrated that the presence of HCC tumor cells could confer suppressive functions on peripheral blood B cells that in turn, dampen T cell costimulation. To the best of our knowledge, these findings represent novel mechanisms of noncanonical immune suppression in HCC. While previous studies identified atypical memory B cells in chronic hepatitis and across several solid cancer types, we further highlighted their potential role as regulatory B cells (Bregs) within both the TME and peripheral blood of HCC patients.

Authors

Shi Yong Neo, Timothy Wai Ho Shuen, Shruti Khare, Joni Chong, Maichan Lau, Niranjan Shirgaonkar, Levene Chua, Junzhe Zhao, Keene Lee, Charmaine Tan, Rebecca Ba, Janice Lim, Joelle Chua, Hui Shi Cheong, Hui Min Chai, Chung Yip Chan, Alexander Yaw Fui Chung, Peng Chung Cheow, Prema Raj Jeyaraj, Jin Yao Teo, Ye Xin Koh, Aik Yong Chok, Pierce Kah Hoe Chow, Brian Goh, Wei Keat Wan, Wei Qiang Leow, Tracy Jie Zhen Loh, Po Yin Tang, Jayanthi Karunanithi, Nye Thane Ngo, Tony Kiat Hon Lim, Shengli Xu, Ramanuj Dasgupta, Han Chong Toh, Kong-Peng Lam