Lung cancer is the leading cause of cancer death in the world, and early lung cancer detection is vital for improving the overall survival. Besides x-ray and CT scan, few genetic tests have been widely used for detecting early lung tumors. We hypothesize that early lung cancer patients have some unique features in the immune repertoires which can be utilized for early cancer detection and profiling disease development. In this study, we performed RNA-seq for paired tumor and tumor-adjacent normal samples from 59 early lung adenocarcinoma patients. We found that early lung tumors have more cytokine activities, higher B cell and CD4+ T cell infiltration, and lower CD8+ T cell infiltration compared to normal lung tissues. We assembled B cell receptors from RNA-seq reads and found more B cell clonal expansion and somatic hypermutations in the tumor than in tumor-adjacent normal tissues, similar to the B cell repertoires in late-stage lung cancer patients. In both early- and late-stage lung tumors, we identified a few cytokines that positively correlated with more IgA isotypes and associated with patient survival. To gain more insights on the B cell binding specificity, we performed motif enrichment analysis for paired tumor and normal samples and validated some tumor-enriched receptor motifs in matched patient blood samples, which implies a new way of early cancer detection. More interesting, we assembled microbial transcripts from RNA-seq data and identified some known lung disease-related species in both tumor and normal samples. The complex interactions between cancer cells, B cells, and microbiota in the early lung tumor development are waiting to be elucidated.

Citation Format: Jin Wang, Xihao Hu, Peng Zhang, Xiaole Shirley Liu. Characteristics of immune repertoires in early lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4966.