Research ArticleINNATE IMMUNITY

PD-L1 expression on nonclassical monocytes reveals their origin and immunoregulatory function

See allHide authors and affiliations

Science Immunology  21 Jun 2019:
Vol. 4, Issue 36, eaar3054
DOI: 10.1126/sciimmunol.aar3054

You are currently viewing the editor's summary.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Nonclassical Monocyte Marker

Nonclassical monocytes (NCMs) are a subset of monocytes that act as sentinels in the skin endothelium and lung microvasculature. The origin of NCMs is not well understood, and Bianchini et al. now identify the immune checkpoint molecule PD-L1 as a marker that can track NCMs. Using two-photon microscopy, PD-L1+ NCMs could be tracked within the bone marrow, and contact with endosteal vessels was required for conversion from classical monocytes to NCMs. Under inflammatory conditions, PD-L1+ NCMs were found in tertiary lymphoid organs (TLOs), and expression of PD-L1 by NCMs regulated T cell survival in TLOs. Together, these findings reveal PD-L1 as a valuable tool for studying the origin and functions of NCMs.

View Full Text