A phenotypic and functional characterization of NK cells in adenoids Academic Article uri icon

abstract

  • Adenoids are part of the MALT. In the present study, we analyzed cell surface markers and cytolytic activity of adenoidal NK (A-NK) cells and compared them with NK cells derived from blood of the same donors (B-NK). NK cells com- prised 0.67% (0.4 -1.2%) of the total lym- phoid population isolated from adenoids. The majority (median92%) of the A-NK cells was CD56 bright CD16 - . A-NK cells were characterized by the increased expression of activation-induced receptors. NKp44 was detected on >60%, CD25 on >40%, and HLA-DR on >50% of freshly iso- lated A-NK cells. Functional assays indicated that the cytotoxic machinery of A-NK is intact, and sensitive target cells are killed via natural cytotox- icity receptors, such as NKG2D. Carcinoembry- onic antigen-related cell adhesion molecule 1 (CEACAM1; CD66) expression was up-regulated in 23% (median) of the A-NK cells by IL-2 activation but unchanged in B-NK cells. CEACAM1 inhibited the A-NK killing of target cells. CXCR4 was ex- pressed on more than 40% A-NK cells prior to activation. Its ligand, CXCL12, was found in endo- thelial cells of the capillaries within the adenoid and in cells of the epithelial lining. In addition, A-NK cells migrated in vitro toward a gradient of CXCL12 in a dose-responsive manner, suggesting a role for this chemokine in A-NK cell recruitment and trafficking. We conclude that the A-NK cells are unique in that they display an activated-like

publication date

  • January 1, 2007