Influence of Hsp70 and HLA-E on the killing of leukemic blasts by cytokine/Hsp70 peptide-activated human natural killer (NK) cells

Abstract This study compared the effects of the human 70-kDa stress protein (Hsp70) peptide, TKDNNLLGRFELSG (TKD), proinflammatory cytokines, or a combination of both on the repertoire of receptors expressed by human natural killer (NK) cells and their capacity to kill human CX colon carcinoma cells, K562 erythroleukemic cells, and leukemic blasts from two patients with acute myelogenous leukemia. Low-dose interleukin (IL) 2/IL-15 and TKD increase the expression density of activatory (NKG2D, NKp30, NKp44, NKp46, CD94/NKG2C) and inhibitory (CD94/NKG2A) receptors on NK cells. Concomitantly, IL-2/TKD treatment enhances the cytotoxicity of NK cells (as reflected by their secretion of granzyme B) against Hsp70 membrane-positive and human leukocyte antigen (HLA)-E membrane-negative ($ Hsp70^{+} $/HLA-$ E^{−} $) $ CX^{+} $ and K562 cells. However, it had no effect on the responsiveness to $ Hsp70^{−} $/HLA-$ E^{−} $ $ CX^{−} $ cells over that induced by IL-2 alone. The cytotoxicity of IL-2/TKD-activated, purified NK cells and peripheral blood mononuclear cells against $ Hsp70^{+} $/HLA-$ E^{+} $ leukemic blasts was weaker than that against $ Hsp70^{+} $/HLA-$ E^{−} $ K562 cells. Hsp70-blocking and HLA-E transfection experiments confirmed membrane-bound Hsp70 as being a recognition/activatory ligand for NK cells, as cytotoxicity was reduced by the presence of the anti-Hsp70 monoclonal antibody cmHsp70.2 and by inhibiting Hsp70 synthesis using short interference ribonucleic acid. HLA-E was confirmed as an inhibitory ligand, as the extent of NK cell-mediated lysis of K562 cell populations that had been transfected with HLA-$ E^{R} $ or HLA-$ E^{G} $ alleles was dependent on the proportion of HLA-E-expressing cells. These findings indicate that Hsp70 (as an activatory molecule) and HLA-E (as an inhibitory ligand) expression influence the susceptibility of leukemic cells to the cytolytic activities of cytokine/TKD-activated NK cells..

Medienart:

E-Artikel

Erscheinungsjahr:

2008

Erschienen:

2008

Enthalten in:

Zur Gesamtaufnahme - volume:13

Enthalten in:

Cell stress & chaperones - 13(2008), 2 vom: 26. Feb., Seite 221-230

Sprache:

Englisch

Beteiligte Personen:

Stangl, Stefan [VerfasserIn]
Gross, Catharina [VerfasserIn]
Pockley, Alan G. [VerfasserIn]
Asea, Alexzander A. [VerfasserIn]
Multhoff, Gabriele [VerfasserIn]

Links:

Volltext [lizenzpflichtig]

Themen:

Cell surface molecules
Cytotoxicity
Human
Natural killer cells
Tumor immunity

Anmerkungen:

© Cell Stress Society International 2008

doi:

10.1007/s12192-007-0008-y

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

SPR025160478