515 Integrated analysis of acne identifies a critical role for immune fibroblastic cells (IFCs) in the pathophysiology of acne and in the action of isotretinoin

To improve understanding of acne we evaluated host cell networks in the pilosebaceous unit and variables associated with C. acnes that promote skin inflammation. Single-cell RNA sequencing uncovered unsuspected activation of specific dermal fibroblast subsets in both human acne and mice challenged by C. acnes. This transcriptional response was characterized by initiation of fat cell differentiation and expression of cathelicidin (Camp) by fibroblasts; responses that were validated by immunostaining of PREF1 and CAMP in these specialized perifollicular immune fibroblastic cells(IFCs).