Figure 1.

Overview of possible sites with CXCL13/CXCR5 activity in cutaneous melanoma. (A) At the site of invasive melanomas, tumor infiltration of immune cells may lead to the formation of more or less structured TLS (1). The subsequent tumor-specific immune response includes transfer and migration of tumor antigens, tumor-specific T cells, and tumor antigen-presenting DC to the associated draining lymph nodes. The extent of tumor infiltration of draining lymph nodes may vary (2, 3). Specifically primed anti-tumor immune cells migrate back to the primary tumor site via the efferent lymph and blood vessel. (B) Details regarding tumor-draining lymph nodes and circulating immune cells (black square): tumor antigens, tumor antigen-presenting DC, and anti-tumor effector T cells enter the tumor-infiltrated sentinel lymph node (2), triggering an anti-tumor GC response, associated T cell proliferation, and TLS formation within the affected LN. Tumor antigens, educated B and T cells, and tumor antigen-presenting DC travel via efferent lymphatic vessels to downstream LNs (3) where they further engage in mounting anti-tumor immune responses and education and proliferation of effector cells, which again circulate back to the site of the primary tumor. Abbreviations. TLS: tertiary lymphoid structures, GC: germinal center, DC: dendritic cells, LN: lymph node. We thank Tobias Moser for his support with the figure. Created with BioRender.com.