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Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation.

Bruno S, Grange C, Tapparo M, Pasquino C, Romagnoli R, Dametto E, Amoroso A, Tetta C, Camussi G - Stem Cells Int (2016)

Bottom Line: At variance with MSCs, HLSCs did not elicit NK degranulation.Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release.This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biotechnology and Health Science, University of Torino, 10126 Torino, Italy.

ABSTRACT
Human liver stem cells (HLSCs) are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs), and dendritic cells (DCs) in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2) and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs), HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

No MeSH data available.


Related in: MedlinePlus

HLSCs used as target for NKs do not elicit NK degranulation. (a) Representative (n = 5) cytofluorimetric analysis of CD107a expression on NKs pretreated for 24 hours with IL-15 and incubated for 4 hours with MSCs or HLSCs, used as target cells in degranulation assay. CD107a expression was used to quantify cytotoxic granule exocytosis. After 4 hours of cocultivation with MSCs, a small percentage of NKs (about 8%) start to express CD107a; instead the NKs incubated with HLSCs did not degranulate and so did not express CD107a. (b) Early and late apoptosis of HLSCs and MSCs were evaluated after 4-hour incubation with NKs. Data are expressed as mean ± SD of percent variation of apoptotic cells. Results were obtained from 3 independent experiments performed in duplicate. Data were analysed by Student's t-test (unpaired, 2-tailed); ∗p < 0.05 MSC cocultured with NKs versus control MSCs.
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fig2: HLSCs used as target for NKs do not elicit NK degranulation. (a) Representative (n = 5) cytofluorimetric analysis of CD107a expression on NKs pretreated for 24 hours with IL-15 and incubated for 4 hours with MSCs or HLSCs, used as target cells in degranulation assay. CD107a expression was used to quantify cytotoxic granule exocytosis. After 4 hours of cocultivation with MSCs, a small percentage of NKs (about 8%) start to express CD107a; instead the NKs incubated with HLSCs did not degranulate and so did not express CD107a. (b) Early and late apoptosis of HLSCs and MSCs were evaluated after 4-hour incubation with NKs. Data are expressed as mean ± SD of percent variation of apoptotic cells. Results were obtained from 3 independent experiments performed in duplicate. Data were analysed by Student's t-test (unpaired, 2-tailed); ∗p < 0.05 MSC cocultured with NKs versus control MSCs.

Mentions: In order to compare the susceptibility of HLSCs to NK cell-mediated lysis, a degranulation assay was performed based on the detection of CD107a surface molecules on NK cell membranes, after NK-HLSC coculture. Allogeneic NKs were stimulated for 24 hours with IL-15 to increase their cytotoxic potential. Both HLSCs and MSCs were used as target cells. Figure 2(a) shows that, after 4 hours of incubation, degranulation of NKs in response to HLSCs was absent (CD56+CD107+: 1 ± 0.5%). In contrast, MSCs induced NK degranulation (CD56+CD107+: 9.3 ± 3.2%), as previously described [8, 10, 11]. Moreover, the viability of HLSCs and MSCs was evaluated after 4 hours of incubation with IL-15 activated NKs. In these conditions, the percentage of early apoptotic HLSCs did not significantly increase, whereas the percentage of early apoptotic MSCs significantly increased (Figure 2(b)), confirming the data obtained by degranulation assay. No significant difference was observed in the percentage of late apoptotic cells between HLSCs and MSCs.


Human Liver Stem Cells Suppress T-Cell Proliferation, NK Activity, and Dendritic Cell Differentiation.

Bruno S, Grange C, Tapparo M, Pasquino C, Romagnoli R, Dametto E, Amoroso A, Tetta C, Camussi G - Stem Cells Int (2016)

HLSCs used as target for NKs do not elicit NK degranulation. (a) Representative (n = 5) cytofluorimetric analysis of CD107a expression on NKs pretreated for 24 hours with IL-15 and incubated for 4 hours with MSCs or HLSCs, used as target cells in degranulation assay. CD107a expression was used to quantify cytotoxic granule exocytosis. After 4 hours of cocultivation with MSCs, a small percentage of NKs (about 8%) start to express CD107a; instead the NKs incubated with HLSCs did not degranulate and so did not express CD107a. (b) Early and late apoptosis of HLSCs and MSCs were evaluated after 4-hour incubation with NKs. Data are expressed as mean ± SD of percent variation of apoptotic cells. Results were obtained from 3 independent experiments performed in duplicate. Data were analysed by Student's t-test (unpaired, 2-tailed); ∗p < 0.05 MSC cocultured with NKs versus control MSCs.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4834412&req=5

fig2: HLSCs used as target for NKs do not elicit NK degranulation. (a) Representative (n = 5) cytofluorimetric analysis of CD107a expression on NKs pretreated for 24 hours with IL-15 and incubated for 4 hours with MSCs or HLSCs, used as target cells in degranulation assay. CD107a expression was used to quantify cytotoxic granule exocytosis. After 4 hours of cocultivation with MSCs, a small percentage of NKs (about 8%) start to express CD107a; instead the NKs incubated with HLSCs did not degranulate and so did not express CD107a. (b) Early and late apoptosis of HLSCs and MSCs were evaluated after 4-hour incubation with NKs. Data are expressed as mean ± SD of percent variation of apoptotic cells. Results were obtained from 3 independent experiments performed in duplicate. Data were analysed by Student's t-test (unpaired, 2-tailed); ∗p < 0.05 MSC cocultured with NKs versus control MSCs.
Mentions: In order to compare the susceptibility of HLSCs to NK cell-mediated lysis, a degranulation assay was performed based on the detection of CD107a surface molecules on NK cell membranes, after NK-HLSC coculture. Allogeneic NKs were stimulated for 24 hours with IL-15 to increase their cytotoxic potential. Both HLSCs and MSCs were used as target cells. Figure 2(a) shows that, after 4 hours of incubation, degranulation of NKs in response to HLSCs was absent (CD56+CD107+: 1 ± 0.5%). In contrast, MSCs induced NK degranulation (CD56+CD107+: 9.3 ± 3.2%), as previously described [8, 10, 11]. Moreover, the viability of HLSCs and MSCs was evaluated after 4 hours of incubation with IL-15 activated NKs. In these conditions, the percentage of early apoptotic HLSCs did not significantly increase, whereas the percentage of early apoptotic MSCs significantly increased (Figure 2(b)), confirming the data obtained by degranulation assay. No significant difference was observed in the percentage of late apoptotic cells between HLSCs and MSCs.

Bottom Line: At variance with MSCs, HLSCs did not elicit NK degranulation.Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release.This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Biotechnology and Health Science, University of Torino, 10126 Torino, Italy.

ABSTRACT
Human liver stem cells (HLSCs) are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs), and dendritic cells (DCs) in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2) and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs), HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.

No MeSH data available.


Related in: MedlinePlus