Tertiary lymphoid structures (TLSs) are transient ectopic lymphoid aggregates whose formation might be caused by chronic inflammation states, such as cancer. However, how TLSs are induced in the tumor microenvironment (TME) and how they affect patient survival are not well understood. We investigated TLS distribution in relation to tumor infiltrating lymphocytes (TILs) and related gene expression in high grade serous ovarian cancer (HGSC) specimens. CXCL13 gene expression correlated with TLS presence and the infiltration of T cells and B cells, and was a favorable prognostic factor for HGSC patients. Coexistence of CD8+ T cells and B-cell lineages in the TME significantly improved the prognosis of HGSC and was correlated with the presence of TLSs. CXCL13 expression was predominantly coincident with CD4+ T cells in TLSs and CD8+ T cells in TILs, and shifted from CD4+ T cells to CD21+ follicular dendritic cells as TLS matured. In a mouse ovarian cancer model, recombinant CXCL13 induced TLSs and enhanced survival by the infiltration of CD8+ T cells. These results suggest that TLS formation was associated with CXCL13-producing CD4+ T cells and that TLSs facilitated the coordinated antitumor response of cellular and humoral immunity in ovarian cancer.
Masayo Ukita, Junzo Hamanishi, Hiroyuki Yoshitomi, Koji Yamanoi, Shiro Takamatsu, Akihiko Ueda, Haruka Suzuki, Yuko Hosoe, Yoko Furutake, Mana Taki, Kaoru Abiko, Ken Yamaguchi, Hidekatsu Nakai, Tsukasa Baba, Noriomi Matsumura, Akihiko Yoshizawa, Hideki Ueno, Masaki Mandai