Characterization of cancer-associated fibroblast populations that promote tertiary lymphoid structure formation in murine melanoma tumors

However, the mechanisms that promote TLS development have remained obscure, largely because of a lack of animal models in which cause and effect studies can be performed. In this study, we used a mouse model in which TLS develop spontaneously in intraperitoneal tumors to address this issue.

Extending earlier studies in which we showed that CXCR5-expressing B cells are essential for TLS development, we found that CXCL13, the ligand for CXCR5, is expressed exclusively by a population of cancer-associated fibroblasts (CAF), and that these CAF are essential to promote B cell accumulation in these tumors. In keeping with earlier work showing that the presence of TLS was associated with smaller tumor size, we also found that the lack of B cell accumulation was associated with larger tumor size.