AUTHOR=Le Gallou Simon , Lhomme Faustine , Irish Jonathan M. , Mingam Anna , Pangault Celine , Monvoisin Celine , Ferrant Juliette , Azzaoui Imane , Rossille Delphine , Bouabdallah Krimo , Damaj Gandhi , Cartron Guillaume , Godmer Pascal , Le Gouill Steven , Casasnovas René-Olivier , Molina Thierry Jo , Houot Roch , Lamy Thierry , Tarte Karin , Fest Thierry , Roussel Mikael 

TITLE=Nonclassical Monocytes Are Prone to Migrate Into Tumor in Diffuse Large B-Cell Lymphoma

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.755623

DOI=10.3389/fimmu.2021.755623

ISSN=1664-3224

ABSTRACT=<p>Absolute count of circulating monocytes has been proposed as an independent prognostic factor in diffuse large B-cell lymphoma (DLBCL). However, monocyte nomenclature includes various subsets with pro-, anti-inflammatory, or suppressive functions, and their clinical relevance in DLBCL has been poorly explored. Herein, we broadly assessed circulating monocyte heterogeneity in 91 DLBCL patients. Classical- (cMO, CD14<sup>pos</sup> CD16<sup>neg</sup>) and intermediate- (iMO, CD14<sup>pos</sup> CD16<sup>pos</sup>) monocytes accumulated in DLBCL peripheral blood and exhibited an inflammatory phenotype. On the opposite, nonclassical monocytes (ncMOSlan<sup>pos</sup>, CD14<sup>low</sup> CD16<sup>pos</sup> Slan<sup>neg</sup> and ncMOSlan<sup>neg</sup>, CD14<sup>low</sup> CD16<sup>pos</sup>, Slan<sup>neg</sup>) were decreased in peripheral blood. Tumor-conditioned monocytes presented similarities with ncMO phenotype from DLBCL and were prone to migrate in response to CCL5 and CXCL12, and presented similarities with DLBCL-infiltrated myeloid cells, as defined by mass cytometry. Finally, we demonstrated the adverse value of an accumulation of nonclassical monocytes in 2 independent cohorts of DLBCL.</p>