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Effect of natalizumab treatment on circulating plasmacytoid dendritic cells: a cross-sectional observational study in patients with multiple sclerosis.

Kivisäkk P, Francois K, Mbianda J, Gandhi R, Weiner HL, Khoury SJ - PLoS ONE (2014)

Bottom Line: We observed that NTZ treatment was associated with a 25-50% reduction in PDC frequency in peripheral blood as compared to untreated MS patients, while the frequency of MDCs was unchanged.In contrast, in vitro treatment with NTZ did not increase markers of PDC activation or their ability to induce T cell differentiation.Our study shows that NTZ treatment is associated with a reduced frequency of PDCs in the peripheral circulation, but that PDCs in NTZ-treated individuals display an activated phenotype.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.

ABSTRACT

Objectives: Dendritic cells (DCs) serve a critical role both in promoting and inhibiting adaptive immunity. The goal of this study was to investigate the effect of natalizumab (NTZ) treatment on DC numbers, phenotype, and function in patients with multiple sclerosis (MS).

Methods: Frequency and phenotype of myeloid and plasmacytoid DCs (MDCs and PDCs, respectively) were analyzed in blood from two separate cohorts of untreated, interferon-treated, or NTZ-treated MS patients. In addition, PDCs were stimulated with CpG-containing oligonucleotides or co-cultured with homologous T cells in the presence or absence of NTZ in vitro to determine functional effects of NTZ treatment.

Results: We observed that NTZ treatment was associated with a 25-50% reduction in PDC frequency in peripheral blood as compared to untreated MS patients, while the frequency of MDCs was unchanged. PDCs in NTZ-treated patients displayed a mature, activated phenotype with increased expression of HLA-DR, TLR9, CCR7, IL-6 and IL-12. In contrast, in vitro treatment with NTZ did not increase markers of PDC activation or their ability to induce T cell differentiation.

Conclusion: Our study shows that NTZ treatment is associated with a reduced frequency of PDCs in the peripheral circulation, but that PDCs in NTZ-treated individuals display an activated phenotype. Taken together the data suggests that transmigration of activated PDCs is preferentially affected by blockade of integrin α4 leading to an increased frequency of activated PDCs in blood.

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Frequency of myeloid and plasmacytoid dendritic cells in peripheral blood.Frequency of myeloid and plasmacytoid dendritic cells (MDCs and PDCs) was determined in frozen cells from relapsing-remitting MS patients using flow cytometry. A. Dead cells were excluded using a viability dye (LIVE/DEAD), followed by exclusion of cells expressing mature hematopoietic lineages using a Lineage cocktail (CQ). PDCs and MDCs were identified based on their expression of CD123 and CD11c, respectively. B–C. Frequency of MDCs and PDCs in untreated MS patients (UNT) and MS patients treated with natalizumab (NTZ) or interferon-β (IFN) from Cohort 1 (B) and Cohort 2 (C). Graph shows mean, interquartile range, and min-max range. Frequency of PDCs in NTZ-treated patients in relation to duration of treatment in patients from Cohort 1 (filled) or Cohort 2 (open) (D).
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pone-0103716-g001: Frequency of myeloid and plasmacytoid dendritic cells in peripheral blood.Frequency of myeloid and plasmacytoid dendritic cells (MDCs and PDCs) was determined in frozen cells from relapsing-remitting MS patients using flow cytometry. A. Dead cells were excluded using a viability dye (LIVE/DEAD), followed by exclusion of cells expressing mature hematopoietic lineages using a Lineage cocktail (CQ). PDCs and MDCs were identified based on their expression of CD123 and CD11c, respectively. B–C. Frequency of MDCs and PDCs in untreated MS patients (UNT) and MS patients treated with natalizumab (NTZ) or interferon-β (IFN) from Cohort 1 (B) and Cohort 2 (C). Graph shows mean, interquartile range, and min-max range. Frequency of PDCs in NTZ-treated patients in relation to duration of treatment in patients from Cohort 1 (filled) or Cohort 2 (open) (D).

Mentions: Patients treated with NTZ had roughly 25% less PDCs in peripheral blood (0.72±0.30%) compared to untreated patients (1.04±0.53%) in our first cohort of 75 patients (p = 0.03; Fig. 1A–B). In order to confirm the results, the frequency of PDCs was analyzed in a second cohort of 56 patients, which showed an even more pronounced difference between the groups (NTZ: 0.50±0.22%; UNT: 1.08±0.59%; p<0.0001; Fig. 1C). There was no correlation between the frequency of PDCs in NTZ-treated patients and treatment duration, either in the first (p = 0.21, r2 = 0.07) or second cohort (p = 0.21, r2 = 0.10; Fig. 1D). There was a decrease in the frequency of PDCs in IFN-β-treated patients in the first cohort (0.74±0.33%; p = 0.06), but this was not statistically significant nor reproduced in the second cohort (0.92±0.67%; p = 0.2; Fig. 1B–C). The frequency of MDCs was not affected by NTZ or IFN-β treatment (Fig. 1A–C).


Effect of natalizumab treatment on circulating plasmacytoid dendritic cells: a cross-sectional observational study in patients with multiple sclerosis.

Kivisäkk P, Francois K, Mbianda J, Gandhi R, Weiner HL, Khoury SJ - PLoS ONE (2014)

Frequency of myeloid and plasmacytoid dendritic cells in peripheral blood.Frequency of myeloid and plasmacytoid dendritic cells (MDCs and PDCs) was determined in frozen cells from relapsing-remitting MS patients using flow cytometry. A. Dead cells were excluded using a viability dye (LIVE/DEAD), followed by exclusion of cells expressing mature hematopoietic lineages using a Lineage cocktail (CQ). PDCs and MDCs were identified based on their expression of CD123 and CD11c, respectively. B–C. Frequency of MDCs and PDCs in untreated MS patients (UNT) and MS patients treated with natalizumab (NTZ) or interferon-β (IFN) from Cohort 1 (B) and Cohort 2 (C). Graph shows mean, interquartile range, and min-max range. Frequency of PDCs in NTZ-treated patients in relation to duration of treatment in patients from Cohort 1 (filled) or Cohort 2 (open) (D).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4116240&req=5

pone-0103716-g001: Frequency of myeloid and plasmacytoid dendritic cells in peripheral blood.Frequency of myeloid and plasmacytoid dendritic cells (MDCs and PDCs) was determined in frozen cells from relapsing-remitting MS patients using flow cytometry. A. Dead cells were excluded using a viability dye (LIVE/DEAD), followed by exclusion of cells expressing mature hematopoietic lineages using a Lineage cocktail (CQ). PDCs and MDCs were identified based on their expression of CD123 and CD11c, respectively. B–C. Frequency of MDCs and PDCs in untreated MS patients (UNT) and MS patients treated with natalizumab (NTZ) or interferon-β (IFN) from Cohort 1 (B) and Cohort 2 (C). Graph shows mean, interquartile range, and min-max range. Frequency of PDCs in NTZ-treated patients in relation to duration of treatment in patients from Cohort 1 (filled) or Cohort 2 (open) (D).
Mentions: Patients treated with NTZ had roughly 25% less PDCs in peripheral blood (0.72±0.30%) compared to untreated patients (1.04±0.53%) in our first cohort of 75 patients (p = 0.03; Fig. 1A–B). In order to confirm the results, the frequency of PDCs was analyzed in a second cohort of 56 patients, which showed an even more pronounced difference between the groups (NTZ: 0.50±0.22%; UNT: 1.08±0.59%; p<0.0001; Fig. 1C). There was no correlation between the frequency of PDCs in NTZ-treated patients and treatment duration, either in the first (p = 0.21, r2 = 0.07) or second cohort (p = 0.21, r2 = 0.10; Fig. 1D). There was a decrease in the frequency of PDCs in IFN-β-treated patients in the first cohort (0.74±0.33%; p = 0.06), but this was not statistically significant nor reproduced in the second cohort (0.92±0.67%; p = 0.2; Fig. 1B–C). The frequency of MDCs was not affected by NTZ or IFN-β treatment (Fig. 1A–C).

Bottom Line: We observed that NTZ treatment was associated with a 25-50% reduction in PDC frequency in peripheral blood as compared to untreated MS patients, while the frequency of MDCs was unchanged.In contrast, in vitro treatment with NTZ did not increase markers of PDC activation or their ability to induce T cell differentiation.Our study shows that NTZ treatment is associated with a reduced frequency of PDCs in the peripheral circulation, but that PDCs in NTZ-treated individuals display an activated phenotype.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.

ABSTRACT

Objectives: Dendritic cells (DCs) serve a critical role both in promoting and inhibiting adaptive immunity. The goal of this study was to investigate the effect of natalizumab (NTZ) treatment on DC numbers, phenotype, and function in patients with multiple sclerosis (MS).

Methods: Frequency and phenotype of myeloid and plasmacytoid DCs (MDCs and PDCs, respectively) were analyzed in blood from two separate cohorts of untreated, interferon-treated, or NTZ-treated MS patients. In addition, PDCs were stimulated with CpG-containing oligonucleotides or co-cultured with homologous T cells in the presence or absence of NTZ in vitro to determine functional effects of NTZ treatment.

Results: We observed that NTZ treatment was associated with a 25-50% reduction in PDC frequency in peripheral blood as compared to untreated MS patients, while the frequency of MDCs was unchanged. PDCs in NTZ-treated patients displayed a mature, activated phenotype with increased expression of HLA-DR, TLR9, CCR7, IL-6 and IL-12. In contrast, in vitro treatment with NTZ did not increase markers of PDC activation or their ability to induce T cell differentiation.

Conclusion: Our study shows that NTZ treatment is associated with a reduced frequency of PDCs in the peripheral circulation, but that PDCs in NTZ-treated individuals display an activated phenotype. Taken together the data suggests that transmigration of activated PDCs is preferentially affected by blockade of integrin α4 leading to an increased frequency of activated PDCs in blood.

Show MeSH
Related in: MedlinePlus