CXCL12+ Dermal Fibroblasts Promote Neutrophil Recruitment and Host Defense by Recognition of IL-17

The study investigates the role of CXCL12+ fibroblast subsets in the skin's defense against S. aureus infection, highlighting their importance in neutrophil recruitment. These fibroblasts, located in the reticular dermis, express adipocyte lineage markers and respond to IL-17 and TNFα by releasing CXCR2 ligands and CXCL12, which are crucial for neutrophil communication. Deleting Il17ra in mouse fibroblasts significantly reduced neutrophil recruitment and increased infection severity. In humans, similar fibroblast subsets in psoriatic skin express neutrophil chemotactic factors, which decrease with IL-17 targeting therapy. The findings underscore the critical role of CXCL12+ fibroblasts in cutaneous immune response and host defense.