Paper

Developing human fetal skin demonstrates a unique lymphocyte signature

Leitner, Elizabeth G, Taravati, Keyon, Scharschmidt, Tiffany C, Karthikeyan, Dhuvarakesh, Lowe, Margaret M, Farhat, Sepideh, Pauli, Mariela, Vasquez, Kimberly S, Rosenblum, Michael D, Dhariwala, Miqdad O

2020

Overview

Lymphocytes in barrier tissues play critical roles in host defense and homeostasis. These cells take up residence in tissues during defined developmental windows, when they may demonstrate distinct phenotypes and functions. Here, we utilized mass and flow cytometry to elucidate early features of human skin immunity, demonstrating a unique fetal skin lymphocyte signature. While most conventional αβ T (Tconv) cells in fetal skin have a naive, proliferative phenotype, a subset of CD4+ Tconv and CD8+ cells demonstrate memory-like features and a propensity for IFNγ production. Skin regulatory T cells dynamically accumulate over the second trimester in temporal and regional association with hair follicle development. These fetal skin Tregs demonstrate an effector memory phenotype while differing from their adult counterparts in expression of key effector molecules. Thus, we identify features of prenatal skin lymphocytes that may have key implications for understanding antigen and allergen encounters in utero and in infancy. Competing Interest Statement MDR is a founder and consultant for TRex Bio and Sitryx Bio. KT is currently an employee of Amgen. EGL is currently an employee of SentiBio. All other authors certify that they have no conflict of interest related to the subject matter or materials discussed in this manuscript.

• Publisher: Cold Spring Harbor Laboratory Press,Cold Spring Harbor Laboratory
• Subject: Allergens / CD4 antigen / CD8 antigen / Fetuses / Flow cytometry / Homeostasis / Immunology / Immunoregulation / Lymphocytes / Lymphocytes T / Memory cells / Phenotypes / Skin / γ-Interferon