Hair Follicle Mesenchyme-Associated PD-L1 Regulates T-Cell Activation Induced Apoptosis: A Potential Mechanism of Immune Privilege
September 2013
in “
Journal of Investigative Dermatology
”
TLDR Hair follicle cells help protect against immune attacks by regulating T-cell activity.
The study investigated the immune privilege (IP) properties of cultured hair follicle (HF) cells, specifically focusing on dermal papilla and dermal sheath cup cells (DSCCs). It was found that these cells exhibited preferential expression of IP-associated genes compared to non-follicular fibroblasts (FBs), indicating potential functional IP. A key finding was the significant upregulation of programmed cell death 1 ligand 1 (PD-L1) in DSCCs and dermal papilla cells, which played a role in reducing IFNγ secretion and increasing apoptosis in co-cultured peripheral blood mononuclear cells (PBMCs). The study demonstrated that PD-L1 expression contributed to the IP properties of DSCCs by regulating T-cell activation-induced apoptosis, primarily through the mitochondrial pathway.