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NK Cells of Kidney Transplant Recipients Display an Activated Phenotype that Is Influenced by Immunosuppression and Pathological Staging.

Hoffmann U, Neudörfl C, Daemen K, Keil J, Stevanovic-Meyer M, Lehner F, Haller H, Blume C, Falk CS - PLoS ONE (2015)

Bottom Line: Upon in vitro stimulation via Ca++-dependent signals, down-modulation of CD16 was associated with induction of interferon (IFN)-γ expression.However, secretion of other cytokines like IL-13, IL-17, IL-22 and IL-31 was significantly reduced compared to healthy donors.Thus, immunosuppressive treatment affects NK cell function at the level of NFAT-dependent gene expression whereby calcineurin inhibitors primarily impair cytokine secretion while mTOR inhibitors have only marginal effects.

View Article: PubMed Central - PubMed

Affiliation: Institute of Transplant Immunology, IFB-Tx, Hannover Medical School Hannover, Hannover, Germany.

ABSTRACT
To explore phenotype and function of NK cells in kidney transplant recipients, we investigated the peripheral NK cell repertoire, capacity to respond to various stimuli and impact of immunosuppressive drugs on NK cell activity in kidney transplant recipients. CD56dim NK cells of kidney transplanted patients displayed an activated phenotype characterized by significantly decreased surface expression of CD16 (p=0.0003), CD226 (p<0.0001), CD161 (p=0.0139) and simultaneously increased expression of activation markers like HLA-DR (p=0.0011) and CD25 (p=0.0015). Upon in vitro stimulation via Ca++-dependent signals, down-modulation of CD16 was associated with induction of interferon (IFN)-γ expression. CD16 modulation and secretion of NFAT-dependent cytokines such as IFN-γ, TNF-α, IL-10 and IL-31 were significantly suppressed by treatment of isolated NK cells with calcineurin inhibitors but not with mTOR inhibitors. In kidney transplant recipients, IFN-γ production was retained in response to HLA class I-negative target cells and to non-specific stimuli, respectively. However, secretion of other cytokines like IL-13, IL-17, IL-22 and IL-31 was significantly reduced compared to healthy donors. In contrast to suppression of cytokine expression at the transcriptional level, cytotoxin release, i.e. perforin, granzyme A/B, was not affected by immunosuppression in vitro and in vivo in patients as well as in healthy donors. Thus, immunosuppressive treatment affects NK cell function at the level of NFAT-dependent gene expression whereby calcineurin inhibitors primarily impair cytokine secretion while mTOR inhibitors have only marginal effects. Taken together, NK cells may serve as indicators for immunosuppression and may facilitate a personalized adjustment of immunosuppressive medication in kidney transplant recipients.

No MeSH data available.


Related in: MedlinePlus

Surface expression of CD16, CD226 and CD161 is significantly reduced in KTx patients, while CD25, CD69 and HLA-DR surface expression is increased.Phenotypic characterization of peripheral NK cells from healthy individuals (n = 11, circles) and KTx patients (n = 29, triangles) was performed by flow cytometry. (A) CD16, CD226 (DNAM-1), CD161, HLA-DR, CD25 and CD69 expression was determined on CD56dim NK cells, and compared between healthy donors (HD) and KTx patients (left plots). Displayed are mean values using unpaired Student’s t test (* = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown). The impact of immunosuppression (right plots) was determined by grouping patients according to their immunosuppressive regimen: CsA, Tac or combination of Tac and Sir (T/S). Displayed are mean values, D'Agostino & Pearson omnibus normality test was performed to determine Gaussian distribution, subsequently either One-way-ANOVA or Kruskal-Wallis test were used to determine statistical significance. (B) Patients were grouped according to the histopathology of their biopsies (Banff classification): unsuspicious, borderline, T cell-mediated (TCMR) or antibody-mediated (AMR) rejection. (C) The impact of time after Tx was determined by grouping patients according to the time interval after Tx: ≤3, 6 or ≥ 9 months. Data are shown as scatter plots and display mean values. Asterisks indicate p-values * = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown.
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pone.0132484.g001: Surface expression of CD16, CD226 and CD161 is significantly reduced in KTx patients, while CD25, CD69 and HLA-DR surface expression is increased.Phenotypic characterization of peripheral NK cells from healthy individuals (n = 11, circles) and KTx patients (n = 29, triangles) was performed by flow cytometry. (A) CD16, CD226 (DNAM-1), CD161, HLA-DR, CD25 and CD69 expression was determined on CD56dim NK cells, and compared between healthy donors (HD) and KTx patients (left plots). Displayed are mean values using unpaired Student’s t test (* = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown). The impact of immunosuppression (right plots) was determined by grouping patients according to their immunosuppressive regimen: CsA, Tac or combination of Tac and Sir (T/S). Displayed are mean values, D'Agostino & Pearson omnibus normality test was performed to determine Gaussian distribution, subsequently either One-way-ANOVA or Kruskal-Wallis test were used to determine statistical significance. (B) Patients were grouped according to the histopathology of their biopsies (Banff classification): unsuspicious, borderline, T cell-mediated (TCMR) or antibody-mediated (AMR) rejection. (C) The impact of time after Tx was determined by grouping patients according to the time interval after Tx: ≤3, 6 or ≥ 9 months. Data are shown as scatter plots and display mean values. Asterisks indicate p-values * = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown.

Mentions: In our cohort of KTx recipients, we could previously demonstrate that their NK cell phenotype was altered compared to healthy donors with respect to subset composition, especially the CD56dim NK subset [18]. These alterations correlated with the immunosuppressive treatment of KTx patients with CNI and/or mTORi. Here, additional activating and inhibitory receptors were analyzed in PBMC of a larger patient cohort (n = 29) and compared to healthy individuals (n = 11). In contrast to CD16 (FcγRIII), which is expressed by CD56dim NK cells, CD226 and CD161 are expressed by both NK subsets. In KTx recipients, surface expression of these receptors was significantly reduced, in particular in the CD56dim subset (Fig 1A, S1A–S1C Fig) while NKG2D expression was not affected. Receptor down-modulation on NK cells derived from KTx patients appeared to be coordinated because low CD16 density was accompanied by low CD226 (p = 0.016) and CD161 (p = 0.004) expression (S1D Fig, S2 Table). This modified NK cell repertoire was associated with an activated phenotype, since both CD56dim and CD56bright NK cells of KTx patients showed increased expression of three activation markers, i.e. human leukocyte antigen (HLA)-DR, CD25 and CD69. When patients were grouped according to their immunosuppressive regimen, CD56dim NK cells of Tac-treated patients showed stronger reduction of CD16, CD226 and CD161 expression compared to patients treated with CsA or Tac plus sirolimus (Tac/Sir, T/S) reaching statistical significance only for CD16 between CsA- and Tac-treated patients. The HLA-DR+, CD25+, CD69+ activated phenotype was more pronounced in Tac-treated patients without reaching statistical significance (Fig 1A, S1C Fig).


NK Cells of Kidney Transplant Recipients Display an Activated Phenotype that Is Influenced by Immunosuppression and Pathological Staging.

Hoffmann U, Neudörfl C, Daemen K, Keil J, Stevanovic-Meyer M, Lehner F, Haller H, Blume C, Falk CS - PLoS ONE (2015)

Surface expression of CD16, CD226 and CD161 is significantly reduced in KTx patients, while CD25, CD69 and HLA-DR surface expression is increased.Phenotypic characterization of peripheral NK cells from healthy individuals (n = 11, circles) and KTx patients (n = 29, triangles) was performed by flow cytometry. (A) CD16, CD226 (DNAM-1), CD161, HLA-DR, CD25 and CD69 expression was determined on CD56dim NK cells, and compared between healthy donors (HD) and KTx patients (left plots). Displayed are mean values using unpaired Student’s t test (* = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown). The impact of immunosuppression (right plots) was determined by grouping patients according to their immunosuppressive regimen: CsA, Tac or combination of Tac and Sir (T/S). Displayed are mean values, D'Agostino & Pearson omnibus normality test was performed to determine Gaussian distribution, subsequently either One-way-ANOVA or Kruskal-Wallis test were used to determine statistical significance. (B) Patients were grouped according to the histopathology of their biopsies (Banff classification): unsuspicious, borderline, T cell-mediated (TCMR) or antibody-mediated (AMR) rejection. (C) The impact of time after Tx was determined by grouping patients according to the time interval after Tx: ≤3, 6 or ≥ 9 months. Data are shown as scatter plots and display mean values. Asterisks indicate p-values * = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown.
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pone.0132484.g001: Surface expression of CD16, CD226 and CD161 is significantly reduced in KTx patients, while CD25, CD69 and HLA-DR surface expression is increased.Phenotypic characterization of peripheral NK cells from healthy individuals (n = 11, circles) and KTx patients (n = 29, triangles) was performed by flow cytometry. (A) CD16, CD226 (DNAM-1), CD161, HLA-DR, CD25 and CD69 expression was determined on CD56dim NK cells, and compared between healthy donors (HD) and KTx patients (left plots). Displayed are mean values using unpaired Student’s t test (* = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown). The impact of immunosuppression (right plots) was determined by grouping patients according to their immunosuppressive regimen: CsA, Tac or combination of Tac and Sir (T/S). Displayed are mean values, D'Agostino & Pearson omnibus normality test was performed to determine Gaussian distribution, subsequently either One-way-ANOVA or Kruskal-Wallis test were used to determine statistical significance. (B) Patients were grouped according to the histopathology of their biopsies (Banff classification): unsuspicious, borderline, T cell-mediated (TCMR) or antibody-mediated (AMR) rejection. (C) The impact of time after Tx was determined by grouping patients according to the time interval after Tx: ≤3, 6 or ≥ 9 months. Data are shown as scatter plots and display mean values. Asterisks indicate p-values * = p≤0.05, ** = p≤0.01 and *** = p≤0.001, only significant values are shown.
Mentions: In our cohort of KTx recipients, we could previously demonstrate that their NK cell phenotype was altered compared to healthy donors with respect to subset composition, especially the CD56dim NK subset [18]. These alterations correlated with the immunosuppressive treatment of KTx patients with CNI and/or mTORi. Here, additional activating and inhibitory receptors were analyzed in PBMC of a larger patient cohort (n = 29) and compared to healthy individuals (n = 11). In contrast to CD16 (FcγRIII), which is expressed by CD56dim NK cells, CD226 and CD161 are expressed by both NK subsets. In KTx recipients, surface expression of these receptors was significantly reduced, in particular in the CD56dim subset (Fig 1A, S1A–S1C Fig) while NKG2D expression was not affected. Receptor down-modulation on NK cells derived from KTx patients appeared to be coordinated because low CD16 density was accompanied by low CD226 (p = 0.016) and CD161 (p = 0.004) expression (S1D Fig, S2 Table). This modified NK cell repertoire was associated with an activated phenotype, since both CD56dim and CD56bright NK cells of KTx patients showed increased expression of three activation markers, i.e. human leukocyte antigen (HLA)-DR, CD25 and CD69. When patients were grouped according to their immunosuppressive regimen, CD56dim NK cells of Tac-treated patients showed stronger reduction of CD16, CD226 and CD161 expression compared to patients treated with CsA or Tac plus sirolimus (Tac/Sir, T/S) reaching statistical significance only for CD16 between CsA- and Tac-treated patients. The HLA-DR+, CD25+, CD69+ activated phenotype was more pronounced in Tac-treated patients without reaching statistical significance (Fig 1A, S1C Fig).

Bottom Line: Upon in vitro stimulation via Ca++-dependent signals, down-modulation of CD16 was associated with induction of interferon (IFN)-γ expression.However, secretion of other cytokines like IL-13, IL-17, IL-22 and IL-31 was significantly reduced compared to healthy donors.Thus, immunosuppressive treatment affects NK cell function at the level of NFAT-dependent gene expression whereby calcineurin inhibitors primarily impair cytokine secretion while mTOR inhibitors have only marginal effects.

View Article: PubMed Central - PubMed

Affiliation: Institute of Transplant Immunology, IFB-Tx, Hannover Medical School Hannover, Hannover, Germany.

ABSTRACT
To explore phenotype and function of NK cells in kidney transplant recipients, we investigated the peripheral NK cell repertoire, capacity to respond to various stimuli and impact of immunosuppressive drugs on NK cell activity in kidney transplant recipients. CD56dim NK cells of kidney transplanted patients displayed an activated phenotype characterized by significantly decreased surface expression of CD16 (p=0.0003), CD226 (p<0.0001), CD161 (p=0.0139) and simultaneously increased expression of activation markers like HLA-DR (p=0.0011) and CD25 (p=0.0015). Upon in vitro stimulation via Ca++-dependent signals, down-modulation of CD16 was associated with induction of interferon (IFN)-γ expression. CD16 modulation and secretion of NFAT-dependent cytokines such as IFN-γ, TNF-α, IL-10 and IL-31 were significantly suppressed by treatment of isolated NK cells with calcineurin inhibitors but not with mTOR inhibitors. In kidney transplant recipients, IFN-γ production was retained in response to HLA class I-negative target cells and to non-specific stimuli, respectively. However, secretion of other cytokines like IL-13, IL-17, IL-22 and IL-31 was significantly reduced compared to healthy donors. In contrast to suppression of cytokine expression at the transcriptional level, cytotoxin release, i.e. perforin, granzyme A/B, was not affected by immunosuppression in vitro and in vivo in patients as well as in healthy donors. Thus, immunosuppressive treatment affects NK cell function at the level of NFAT-dependent gene expression whereby calcineurin inhibitors primarily impair cytokine secretion while mTOR inhibitors have only marginal effects. Taken together, NK cells may serve as indicators for immunosuppression and may facilitate a personalized adjustment of immunosuppressive medication in kidney transplant recipients.

No MeSH data available.


Related in: MedlinePlus