title: The CD6 scavenger receptor is differentially expressed on a CD56 natural killer cell subpopulation and contributes to natural killer-derived cytokine and chemokine secretion.
abstract: The CD6 scavenger receptor is known to be expressed on virtually all T cells and is supposed to be involved in costimulation, synapse formation, thymic selection and leukocyte migration. Here, we demonstrate that CD6 is differentially expressed by a subpopulation of peripheral CD56(dim) natural killer (NK) cells and absent on CD56(bright) NK cells. CD56(dim)CD16(+) cells represent the major NK subset in the periphery, and most cells within this group are positive for CD6. Most killer immunoglobulin-like receptor- and immunoglobulin-like transcript-positive cells also belong to the CD6(+) subpopulation, as expected from their restricted expression on CD56(dim) NK cells. In addition, CD6(+) NK cells are similar to the newly identified CD94(low)CD56(dim) NK subpopulation and most distant from the recently defined CD27(+) NK subpopulation based on the reverse correlation of expression between CD6 and CD27, a marker associated primarily with CD56(bright) NK cells. With respect to CD6 function on NK cells, direct CD6 triggering did not result in degranulation but induced secretion of cytokines (interferon-γ and tumor necrosis factor-α) and chemokines [CXCL10 (IP-10), CXCL1 (GRO-α)]. Thus, CD6 expression on peripheral NK cells marks a novel CD56(dim) subpopulation associated with distinct patterns of cytokine and chemokine secretion.
authors.affiliation: Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Monika
authors.initials: M
authors.lastname: Braun
authors.forename: Bernadette
authors.initials: B
authors.lastname: Müller
authors.forename: Dominik
authors.initials: D
authors.lastname: ter Meer
authors.forename: Silke
authors.initials: S
authors.lastname: Raffegerst
authors.forename: Barbara
authors.initials: B
authors.lastname: Simm
authors.forename: Susanne
authors.initials: S
authors.lastname: Wilde
authors.forename: Stefani
authors.initials: S
authors.lastname: Spranger
authors.forename: Joachim
authors.initials: J
authors.lastname: Ellwart
authors.forename: Barbara
authors.initials: B
authors.lastname: Mosetter
authors.forename: Ludmila
authors.initials: L
authors.lastname: Umansky
authors.forename: Tina
authors.initials: T
authors.lastname: Lerchl
authors.forename: Dolores J
authors.initials: DJ
authors.lastname: Schendel
authors.forename: Christine S
authors.initials: CS
authors.lastname: Falk
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D019002:CD56 Antigen / Q000378:metabolism*; D002454:Cell Differentiation; D054360:Chemokine CXCL1 / Q000378:metabolism; D054357:Chemokine CXCL10 / Q000378:metabolism; D018925:Chemokines / Q000378:metabolism*; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D051116:Receptors, Scavenger / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; C062279:CD6 antigen; C475829:CXCL1 protein, human; C114753:CXCL10 protein, human; D054360:Chemokine CXCL1; D054357:Chemokine CXCL10; D018925:Chemokines; D016207:Cytokines; D051116:Receptors, Scavenger; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma