AUTHOR=Talker Stephanie C. , Barut G. Tuba , Lischer Heidi E.L. , Rufener Reto , von Münchow Lilly , Bruggmann Rémy , Summerfield Artur 

TITLE=Monocyte biology conserved across species: Functional insights from cattle

JOURNAL=Frontiers in Immunology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.889175

DOI=10.3389/fimmu.2022.889175

ISSN=1664-3224

ABSTRACT=<p>Similar to human monocytes, bovine monocytes can be split into CD14<sup>high</sup>CD16<sup>-</sup> classical, CD14<sup>high</sup>CD16<sup>high</sup> intermediate and CD14<sup>-/dim</sup>CD16<sup>high</sup> nonclassical monocytes (cM, intM, and ncM, respectively). Here, we present an in-depth analysis of their steady-state bulk- and single-cell transcriptomes, highlighting both pronounced functional specializations and transcriptomic relatedness. Bulk gene transcription indicates pro-inflammatory and antibacterial roles of cM, while ncM and intM appear to be specialized in regulatory/anti-inflammatory functions and tissue repair, as well as antiviral responses and T-cell immunomodulation. Notably, intM stood out by high expression of several genes associated with antigen presentation. Anti-inflammatory and antiviral functions of ncM are further supported by dominant oxidative phosphorylation and selective strong responses to TLR7/8 ligands, respectively. Moreover, single-cell RNA-seq revealed previously unappreciated heterogeneity within cM and proposes intM as a transient differentiation intermediate between cM and ncM.</p>