αβγδ T cells play a vital role in fetal human skin development and immunity
René Reitermaier, Thomas Krausgruber, Nikolaus Fortelny, Tanya Ayub, Pablo Vieyra-Garcia, Philip Kienzl, Peter Wolf, Anke Scharrer, Christian Fiala, Marita Kölz, Manuela Hiess, Martin Vierhapper, Christopher Schuster, Andreas Spittler, Christof Worda, Wolfgang Weninger, Christoph Bock, W. Eppel, Adelheid Elbe‐Bürger
Abstract
T cells in human skin play an important role in the immune defense against pathogens and tumors. T cells are present already in fetal skin, where little is known about their cellular phenotype and biological function. Using single-cell analyses, we identified a naive T cell population expressing αβ and γδ T cell receptors (TCRs) that was enriched in fetal skin and intestine but not detected in other fetal organs and peripheral blood. TCR sequencing data revealed that double-positive (DP) αβγδ T cells displayed little overlap of CDR3 sequences with single-positive αβ T cells. Gene signatures, cytokine profiles and in silico receptor-ligand interaction studies indicate their contribution to early skin development. DP αβγδ T cells were phosphoantigen responsive, suggesting their participation in the protection of the fetus against pathogens in intrauterine infections. Together, our analyses unveil a unique cutaneous T cell type within the native skin microenvironment and point to fundamental differences in the immune surveillance between fetal and adult human skin.