Unique Subpopulations of CD56+ NK and NK-T Peripheral Blood Lymphocytes Identified by Chemokine Receptor Expression Repertoire

TLDR

CD56 is an immunophenotypic marker for several unique populations of peripheral blood lymphocytes, and CD56+ cells derived from multiple lymphocyte lineages share roles in immunosurveillance and antitumor responses. The study aims to characterize chemokine receptor expression patterns and migratory responses of three distinct CD56+ populations from human peripheral blood. The authors examined chemokine receptor expression and performed functional migration assays on these populations. NK‑T cells differ markedly from NK cells, CD16+ NK cells differ from CD16− NK cells; CD16+ NK cells predominantly respond to IL‑8 and fractalkine, NK‑T cells predominantly respond to the CCR5 ligand macrophage‑inflammatory protein‑1β, and CD16− NK cells uniquely express trafficking molecules for homing into secondary lymphoid organs, indicating diverse trafficking patterns among CD56+ cells.

Abstract

Abstract CD56, an adhesion molecule closely related to neual cell adhesion molecule, is an immunophenotypic marker for several unique populations of PBLs. Although CD56+ cells derive from multiple lymphocyte lineages, they share a role in immunosurveillance and antitumor responses. We have studied the chemokine receptor expression patterns and functional migratory responses of three distinct CD56+ populations from human peripheral blood. NK-T cells were found to differ greatly from NK cells, and CD16+ NK cells from CD16− NK cells. CD16+ NK cells were the predominant population responding to IL-8 and fractalkine, whereas NK-T cells were the predominant population responding to the CCR5 ligand macrophage-inflammatory protein-1β. CD16− NK cells were the only CD56+ population that uniformly expressed trafficking molecules necessary for homing into secondary lymphoid organs through high endothelial venule. These findings describe a diverse population of cells that may have trafficking patterns entirely different from each other, and from other lymphocyte types.