Lymphocyte networks are dynamic cellular communities in the immunoregulatory landscape of lung adenocarcinoma

Lymphocytes are key for immune surveillance of tumors, but our understanding of the spatial organization and physical interactions that facilitate lymphocyte anti-cancer functions is limited. We used multiplexed imaging, quantitative spatial analysis, and machine learning to create high-definition maps of lung tumors from a Kras/Trp53-mutant mouse model and human resections. Networks of interacting lymphocytes (“lymphonets”) emerged as a distinctive feature of the anti-cancer immune response. Lymphonets nucleated from small T cell clusters and incorporated B cells with increasing size. CXCR3-mediated trafficking modulated lymphonet size and number, but T cell antigen expression directed intratumoral localization. Lymphonets preferentially harbored TCF1+ PD-1+ progenitor CD8+ T cells involved in responses to immune checkpoint blockade (ICB) therapy. Upon treatment of mice with ICB or an antigen-targeted vaccine, lymphonets retained progenitor and gained cytotoxic CD8+ T cell populations, likely via progenitor differentiation. These data show that lymphonets create a spatial environment supportive of CD8+ T cell anti-tumor responses. [Display omitted] •Interacting networks of lymphocytes (lymphonets) from in the KP GEMM of lung cancer•Small lymphonets have mostly T cells, and B cell fraction rises as networks enlarge•A key feature of lymphonets is that they contain TCF1+PD-1+CD8+ T cell progenitors•Lymphonets gain cytotoxic CD8+ T cells after immunotherapy Gaglia et al. find striking changes in the spatial arrangement of immune cells in response to tumor antigens. T and B cells are recruited in lymphocyte networks (“lymphonets”), which contain progenitor T cells. After immunotherapy, lymphonets gain cytotoxic T cells, likely due to progenitor cell differentiation and activation in this distinct immune environment.