RT Journal Article SR Electronic T1 Interaction between tumour-infiltrating B cells and T cells controls the progression of hepatocellular carcinoma JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 342 OP 351 DO 10.1136/gutjnl-2015-310814 VO 66 IS 2 A1 Marta Garnelo A1 Alex Tan A1 Zhisheng Her A1 Joe Yeong A1 Chun Jye Lim A1 Jinmiao Chen A1 Kiat Hon Lim A1 Achim Weber A1 Pierce Chow A1 Alexander Chung A1 London Lucien PJ Ooi A1 Han Chong Toh A1 Mathias Heikenwalder A1 Irene O L Ng A1 Alessandra Nardin A1 Qingfeng Chen A1 Jean-Pierre Abastado A1 Valerie Chew YR 2017 UL http://gut.bmj.com/content/66/2/342.abstract AB Objective The nature of the tumour-infiltrating leucocytes (TILs) is known to impact clinical outcome in carcinomas, including hepatocellular carcinoma (HCC). However, the role of tumour-infiltrating B cells (TIBs) remains controversial. Here, we investigate the impact of TIBs and their interaction with T cells on HCC patient prognosis.Design Tissue samples were obtained from 112 patients with HCC from Singapore, Hong Kong and Zurich and analysed using immunohistochemistry and immunofluorescence. RNA expression of CD19, CD8A, IFNG was analysed using quantitative PCR. The phenotype of freshly isolated TILs was analysed using flow cytometry. A mouse model depleted of mature B cells was used for functional study.Results Tumour-infiltrating T cells and B cells were observed in close contact with each other and their densities are correlated with superior survival in patients with HCC. Furthermore, the density of TIBs was correlated with an enhanced expression of granzyme B and IFN-γ, as well as with reduced tumour viability defined by low expression of Ki-67, and an enhanced expression of activated caspase-3 on tumour cells. CD27 and CD40 costimulatory molecules and TILs expressing activation marker CD38 in the tumour were also correlated with patient survival. Mice depleted of mature B cells and transplanted with murine hepatoma cells showed reduced tumour control and decreased local T cell activation, further indicating the important role of B cells.Conclusions The close proximity of tumour-infiltrating T cells and B cells indicates a functional interaction between them that is linked to an enhanced local immune activation and contributes to better prognosis for patients with HCC.