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Generation of a novel regulatory NK cell subset from peripheral blood CD34+ progenitors promoted by membrane-bound IL-15.

Giuliani M, Giron-Michel J, Negrini S, Vacca P, Durali D, Caignard A, Le Bousse-Kerdiles C, Chouaib S, Devocelle A, Bahri R, Durrbach A, Taoufik Y, Ferrini S, Croce M, Mingari MC, Moretta L, Azzarone B - PLoS ONE (2008)

Bottom Line: Through these factors, NK-ireg cells act as effectors of the down-regulation of the immune response: reconverting mature myeloid DC (mDC) into immature/tolerogenic DC, blocking cytolytic functions on conventional NK cells and inducing HLA-G membrane expression on PB-derived monocytes.In conclusion, NK-ireg cells represent a novel truly differentiated non-cytolytic NK subset with a self-sustainable phenotype (CD56(+) CD16(+) NKp30(+) NKp44(+) NKp46(+) CD94(+) CD69(+) CCR7(+)) generated from specific pSTAT6(+) GATA3(+) precursors.In addition, NK-ireg cells can be easily derived from peripheral blood of the patients and could constitute an autologous biotherapic tool to be used combined or in alternative to other immuno-regulatory cells.

View Article: PubMed Central - PubMed

Affiliation: INSERM, UMR 542, Université de Paris XI, Hôpital Paul Brousse, Villejuif, France.

ABSTRACT

Background: NK cells have been long time considered as cytotoxic lymphocytes competent in killing virus-infected cells and tumors. However, NK cells may also play essential immuno-regulatory functions. In this context, the real existence of a defined NK subset with negative regulatory properties has been hypothesized but never clearly demonstrated.

Methodology/principal findings: Herein, we show the in vitro generation from human peripheral blood haematopoietic progenitors (PB-HP), of a novel subset of non-cytolytic NK cells displaying a mature phenotype and remarkable immuno-regulatory functions (NK-ireg). The main functional hallmark of these NK-ireg cells is represented by the surface expression/release of HLA-G, a major immunosuppressive molecule. In addition, NK-ireg cells secrete two powerful immuno-regulatory factors: IL-10 and IL-21. Through these factors, NK-ireg cells act as effectors of the down-regulation of the immune response: reconverting mature myeloid DC (mDC) into immature/tolerogenic DC, blocking cytolytic functions on conventional NK cells and inducing HLA-G membrane expression on PB-derived monocytes. The generation of "NK-ireg" cells is obtained, by default, in culture conditions favouring cell-to-cell contacts, and it is strictly dependent on reciprocal trans-presentation of membrane-bound IL-15 forms constitutively and selectively expressed by human CD34(+) PB-HP. Finally, a small subset of NKp46(+) HLA-G(+) IL-10(+) is detected within freshly isolated decidual NK cells, suggesting that these cells could represent an in vivo counterpart of the NK-ireg cells.

Conclusions/significance: In conclusion, NK-ireg cells represent a novel truly differentiated non-cytolytic NK subset with a self-sustainable phenotype (CD56(+) CD16(+) NKp30(+) NKp44(+) NKp46(+) CD94(+) CD69(+) CCR7(+)) generated from specific pSTAT6(+) GATA3(+) precursors. NK-ireg cells could be employed to develop new immuno-suppressive strategies in autoimmune diseases, transplant rejection or graft versus host diseases. In addition, NK-ireg cells can be easily derived from peripheral blood of the patients and could constitute an autologous biotherapic tool to be used combined or in alternative to other immuno-regulatory cells.

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In vivo detection in freshly isolated decidual NK cells of a NKp46+ HLA-G+ IL-10+ subset.(A) Dot plot analysis of expression of NKp46 and HLA-G (surface labeling) in human freshly isolated decidual (d-NK) and PB-derived NK cells from pregnant woman (p-NK). Data are representative of six independent experiments. (B) Expression of IL-10 (internal labeling) was analyzed on the gated positive NKp46+ HLA-G+ NK cell subset.
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pone-0002241-g010: In vivo detection in freshly isolated decidual NK cells of a NKp46+ HLA-G+ IL-10+ subset.(A) Dot plot analysis of expression of NKp46 and HLA-G (surface labeling) in human freshly isolated decidual (d-NK) and PB-derived NK cells from pregnant woman (p-NK). Data are representative of six independent experiments. (B) Expression of IL-10 (internal labeling) was analyzed on the gated positive NKp46+ HLA-G+ NK cell subset.

Mentions: Finally, we investigated the existence in vivo of NK cell subsets presenting characteristic similar to those of NKPSG cells that we generate in vitro. Thus, we initially focused our study on the pregnancy, a physiological situation where a subset of NK cells, homing in the decidua (d-NK), spontaneously secrete IL-10 [38]. These d-NK display powerful regulatory properties, and low cytolytic activity [39] participating in the development of foetomaternal tolerance [40]. The main functional hallmark of NKPSG cells is the surface expression/release of the HLA-G molecule, on the other hand, both membrane-bound and soluble HLA-G isoforms are expressed in the placenta throughout gestation playing major immunological functions and possibly acting as regulators of chorionic villous angiogenesis [41]. Therefore, we tried to identify, within the d-NK cells, a subset co-expressing NKp46, which at present is considered the most reliable marker for NK cell identification, and HLA-G. In figure 10, Dot plot analysis shows that freshly purified d-NK cells constantly express a small subset of NKp46+ HLA-G+ cells which represent about 3% of the total d-NK population. In addition, this NKp46+ HLA-G+ subset produce IL-10. In contrast this subset is not detected in the peripheral blood of pregnant women.


Generation of a novel regulatory NK cell subset from peripheral blood CD34+ progenitors promoted by membrane-bound IL-15.

Giuliani M, Giron-Michel J, Negrini S, Vacca P, Durali D, Caignard A, Le Bousse-Kerdiles C, Chouaib S, Devocelle A, Bahri R, Durrbach A, Taoufik Y, Ferrini S, Croce M, Mingari MC, Moretta L, Azzarone B - PLoS ONE (2008)

In vivo detection in freshly isolated decidual NK cells of a NKp46+ HLA-G+ IL-10+ subset.(A) Dot plot analysis of expression of NKp46 and HLA-G (surface labeling) in human freshly isolated decidual (d-NK) and PB-derived NK cells from pregnant woman (p-NK). Data are representative of six independent experiments. (B) Expression of IL-10 (internal labeling) was analyzed on the gated positive NKp46+ HLA-G+ NK cell subset.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2376096&req=5

pone-0002241-g010: In vivo detection in freshly isolated decidual NK cells of a NKp46+ HLA-G+ IL-10+ subset.(A) Dot plot analysis of expression of NKp46 and HLA-G (surface labeling) in human freshly isolated decidual (d-NK) and PB-derived NK cells from pregnant woman (p-NK). Data are representative of six independent experiments. (B) Expression of IL-10 (internal labeling) was analyzed on the gated positive NKp46+ HLA-G+ NK cell subset.
Mentions: Finally, we investigated the existence in vivo of NK cell subsets presenting characteristic similar to those of NKPSG cells that we generate in vitro. Thus, we initially focused our study on the pregnancy, a physiological situation where a subset of NK cells, homing in the decidua (d-NK), spontaneously secrete IL-10 [38]. These d-NK display powerful regulatory properties, and low cytolytic activity [39] participating in the development of foetomaternal tolerance [40]. The main functional hallmark of NKPSG cells is the surface expression/release of the HLA-G molecule, on the other hand, both membrane-bound and soluble HLA-G isoforms are expressed in the placenta throughout gestation playing major immunological functions and possibly acting as regulators of chorionic villous angiogenesis [41]. Therefore, we tried to identify, within the d-NK cells, a subset co-expressing NKp46, which at present is considered the most reliable marker for NK cell identification, and HLA-G. In figure 10, Dot plot analysis shows that freshly purified d-NK cells constantly express a small subset of NKp46+ HLA-G+ cells which represent about 3% of the total d-NK population. In addition, this NKp46+ HLA-G+ subset produce IL-10. In contrast this subset is not detected in the peripheral blood of pregnant women.

Bottom Line: Through these factors, NK-ireg cells act as effectors of the down-regulation of the immune response: reconverting mature myeloid DC (mDC) into immature/tolerogenic DC, blocking cytolytic functions on conventional NK cells and inducing HLA-G membrane expression on PB-derived monocytes.In conclusion, NK-ireg cells represent a novel truly differentiated non-cytolytic NK subset with a self-sustainable phenotype (CD56(+) CD16(+) NKp30(+) NKp44(+) NKp46(+) CD94(+) CD69(+) CCR7(+)) generated from specific pSTAT6(+) GATA3(+) precursors.In addition, NK-ireg cells can be easily derived from peripheral blood of the patients and could constitute an autologous biotherapic tool to be used combined or in alternative to other immuno-regulatory cells.

View Article: PubMed Central - PubMed

Affiliation: INSERM, UMR 542, Université de Paris XI, Hôpital Paul Brousse, Villejuif, France.

ABSTRACT

Background: NK cells have been long time considered as cytotoxic lymphocytes competent in killing virus-infected cells and tumors. However, NK cells may also play essential immuno-regulatory functions. In this context, the real existence of a defined NK subset with negative regulatory properties has been hypothesized but never clearly demonstrated.

Methodology/principal findings: Herein, we show the in vitro generation from human peripheral blood haematopoietic progenitors (PB-HP), of a novel subset of non-cytolytic NK cells displaying a mature phenotype and remarkable immuno-regulatory functions (NK-ireg). The main functional hallmark of these NK-ireg cells is represented by the surface expression/release of HLA-G, a major immunosuppressive molecule. In addition, NK-ireg cells secrete two powerful immuno-regulatory factors: IL-10 and IL-21. Through these factors, NK-ireg cells act as effectors of the down-regulation of the immune response: reconverting mature myeloid DC (mDC) into immature/tolerogenic DC, blocking cytolytic functions on conventional NK cells and inducing HLA-G membrane expression on PB-derived monocytes. The generation of "NK-ireg" cells is obtained, by default, in culture conditions favouring cell-to-cell contacts, and it is strictly dependent on reciprocal trans-presentation of membrane-bound IL-15 forms constitutively and selectively expressed by human CD34(+) PB-HP. Finally, a small subset of NKp46(+) HLA-G(+) IL-10(+) is detected within freshly isolated decidual NK cells, suggesting that these cells could represent an in vivo counterpart of the NK-ireg cells.

Conclusions/significance: In conclusion, NK-ireg cells represent a novel truly differentiated non-cytolytic NK subset with a self-sustainable phenotype (CD56(+) CD16(+) NKp30(+) NKp44(+) NKp46(+) CD94(+) CD69(+) CCR7(+)) generated from specific pSTAT6(+) GATA3(+) precursors. NK-ireg cells could be employed to develop new immuno-suppressive strategies in autoimmune diseases, transplant rejection or graft versus host diseases. In addition, NK-ireg cells can be easily derived from peripheral blood of the patients and could constitute an autologous biotherapic tool to be used combined or in alternative to other immuno-regulatory cells.

Show MeSH
Related in: MedlinePlus