Levels of immune responses in tertiary lymphoid structures of non-small cell lung cancer (NSCLC) and association with survival.

Abstract

2627 Background: Tumor-infiltrating tertiary lymphoid structures (TLSs) are thought to have anti-tumor activity and are believed to indicate a favorable prognosis in cancer patients. However, the prognostic value of TLSs in non-small cell lung cancer (NSCLC) is unknown. Methods: RT-qPCR analysis of the reactive Th-cell subsets and fluorescence activated cell sorting (FACS) analysis of the cell composition in tumor and paired controls. Histological evaluation of the co-localization of tumor-associated CD20 + B cells, CD4 + T cells and DC-LAMP + mature dendritic cells (DCs) within TLSs, and statistically analysis of the relationship between TLSs and overall survival. Results: The results indicated high levels of immune responses in tumour microenvironment ofNSCLC, which that high levels of Th-CXCL13, Th1, Tfh and Treg cell immune responses were the main reactions in tumor tissue of NSCLC, followed by weak Th2 and Th17, suggesting high levels of immune responses in tumor microenvironment of NSCLC. Tumor-associated TLS is a complete and mature lymphoid follicle-like structure containing T cells, B cells and APCs in tumor of NSCLC . Six-color MIHC staining indicated tumor-associated TLSs were complete and mature lymphoid follicle-like structures containing T cells, B cells and antigen presenting cells (APCs), and tumor-associated TLSs. Architectural analysis showed that CD20 + B cell clusters were localized in the local tumour microenvironment, and were mainly colocalized with CD4 + T cells, CD68 + macrophages, CD11c + DCs and DC-LAMP + mature DCs, which indicated the formation of mature TLSs. One of the primary functions of TLS is to support the survival of incoming lymphocytes. The vast majority of the evaluated tumour-associated TLSs in NPC represented mature secondary-follicle-like TLSs, as indicated by the presence of both CD21 + FDC and CD23 + GC-B cells. Understanding and analyzing the phenotypes of these TABs was important for interpreting the local immune response. We used six-color MIHC staining (CD10, CD20, CD38, CD138, CD27 and DAPI) to approximate six different TABs in whole tissue sections of NPC. These molecules were expressed to varying degrees in all paraffin sections, and MIHC showing that CD38 + plasmablast cells and CD138 + plasma cells were primarily located at the tumor interstices or margins, which indicated improved survival outcome. In conclusion, this is the first research of applying multiple complementary strategies to map the biological function and clinical relevance of those cells in the TLSs of NSCLC. Conclusions: Our findings provide insights into the potential role of TLSs in the adaptive anti-tumor immune response, with implications for the development of biomarkers and therapeutic targets.