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

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.

Human fractalkine mediates leukocyte adhesion but not capture under physiological shear conditions; a mechanism for selective monocyte recruitment

“…In agreement with previous reports [15,16,30,31], CX 3 CR1 was expressed by a minor population of lymphocytes, by most monocytes but not by granulocytes (Fig. 6A).…”

“…This is best exemplified by the fact that approximately 6 monocytes/mm 2 were recruited by exFKN-AP alone, 55 by VCAM-1 and 147 by VCAM-1 and exFKN-AP. CD56 + /CD16 + NK cells, CD8 + T cells and a subset of activated CD4 + T cells also express functional CX 3 CR1 [15,30] and these likely make up the lymphocyte population recruited by fractalkine.…”

“…Monocytes, CD56 + /CD16 + NK cells and some T cell subsets express CX 3 CR1 and will respond to soluble fractalkine [15,16,19,30,31], yet which of these subsets adhere to membrane-bound fractalkine under flow is completely unknown. It is essential to resolve these issues if we are to understand how fractalkine contributes to inflammatory disease.…”

NK cells from tuberculous pleurisy express high ICAM‐1 levels and exert stimulatory effect on local T cells

“…Two subsets of NK cells have been identified in humans according to CD56 expression differing in phenotype and function, and also in terms of chemokine receptors and adhesion molecules expression [7,8,9]. Functionally, CD56 bright cells are effective cytokine producers, whereas CD56 dim cells are efficient effectors of natural and Ab-dependent target cell lysis.…”

“…NK cells are CD56 1 CD16 1/À /CD3 À CD19 À lymphocytes of the innate immune system whose function is controlled by an array of germline-encoded activator/inhibitory receptors [5,6]. Two subsets of NK cells have been identified in humans according to CD56 expression differing in phenotype and function, and also in terms of chemokine receptors and adhesion molecules expression [7,8,9]. Functionally, CD56 bright cells are effective cytokine producers, whereas CD56 dim cells are efficient effectors of natural and Ab-dependent target cell lysis.…”