Limits...
Depletion of Regulatory T Cells Induces High Numbers of Dendritic Cells and Unmasks a Subset of Anti-Tumour CD8+CD11c+ PD-1lo Effector T Cells.

Goudin N, Chappert P, Mégret J, Gross DA, Rocha B, Azogui O - PLoS ONE (2016)

Bottom Line: These events are concordant with a substantial increase in CD11b+ resident dendritic cells (DCs) subsets in draining lymph nodes followed by CD8+ DCs.These results indicate that Treg depletion leads to tumour regression by unmasking an increase of DC subsets as a part of a program that optimizes the microenvironment by orchestrating the activation, amplification, and migration of high numbers of fully differentiated CD8+CD11c+PD1lo effector T cells to the tumour sites.They also indicate that a critical pattern of DC subsets correlates with the evolution of the anti-tumour response and provide a template for Treg depletion and DC-based therapy.

View Article: PubMed Central - PubMed

Affiliation: Plateau technique de Cytometrie et d'Imagerie Cellulaire, Structure Fédérative de Recherche Necker, INSERM US 24-CNRS, UMS 3633, Paris, France.

ABSTRACT
Natural regulatory T (Treg) cells interfere with multiple functions, which are crucial for the development of strong anti-tumour responses. In a model of 4T1 mammary carcinoma, depletion of CD25+Tregs results in tumour regression in Balb/c mice, but the mechanisms underlying this process are not fully understood. Here, we show that partial Treg depletion leads to the generation of a particular effector CD8 T cell subset expressing CD11c and low level of PD-1 in tumour draining lymph nodes. These cells have the capacity to migrate into the tumour, to kill DCs, and to locally regulate the anti-tumour response. These events are concordant with a substantial increase in CD11b+ resident dendritic cells (DCs) subsets in draining lymph nodes followed by CD8+ DCs. These results indicate that Treg depletion leads to tumour regression by unmasking an increase of DC subsets as a part of a program that optimizes the microenvironment by orchestrating the activation, amplification, and migration of high numbers of fully differentiated CD8+CD11c+PD1lo effector T cells to the tumour sites. They also indicate that a critical pattern of DC subsets correlates with the evolution of the anti-tumour response and provide a template for Treg depletion and DC-based therapy.

No MeSH data available.


Related in: MedlinePlus

DCs from PC61-depleted mice and CD4 T cells reduce the percentages of CD8 T cells expressing high level of PD-1.(A) Histograms show cell surface expression of PD-1 on infiltrating CD8 T cells from treated and untreated tumours resected at day 14 (Left) and mean Fluorescence Intensity (MFI) of PD-1 in each group (Right). (B) CD11chiMHC IIhi tumour DCs were sorted from treated and untreated mice and cultured 3 days with naïve CD8 T cells labelled with CellTrace violet and 0.1μg/ml of anti-CD3 mAb. (C,D) Flow cytometry analysing the expression of PD-1 on dividing cells. CD11chiMHC IIhi DCs from Tumours (C) and CD11chi DCs from DLNs (D) were purified from untreated and PC61-treated mice and co-cultured 3 days with CellTrace violet-labelled CD8 T cells and in the presence or not with anti-CD3 mAb or CD4 T cells. Percentages of cells expressing PD-1 are represented in the middle of the graphs. (E,F) Histograms represent the level of PD-1 expression gated on all dividing cells according to indicated cultures. Results represent two independent experiments.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4920347&req=5

pone.0157822.g005: DCs from PC61-depleted mice and CD4 T cells reduce the percentages of CD8 T cells expressing high level of PD-1.(A) Histograms show cell surface expression of PD-1 on infiltrating CD8 T cells from treated and untreated tumours resected at day 14 (Left) and mean Fluorescence Intensity (MFI) of PD-1 in each group (Right). (B) CD11chiMHC IIhi tumour DCs were sorted from treated and untreated mice and cultured 3 days with naïve CD8 T cells labelled with CellTrace violet and 0.1μg/ml of anti-CD3 mAb. (C,D) Flow cytometry analysing the expression of PD-1 on dividing cells. CD11chiMHC IIhi DCs from Tumours (C) and CD11chi DCs from DLNs (D) were purified from untreated and PC61-treated mice and co-cultured 3 days with CellTrace violet-labelled CD8 T cells and in the presence or not with anti-CD3 mAb or CD4 T cells. Percentages of cells expressing PD-1 are represented in the middle of the graphs. (E,F) Histograms represent the level of PD-1 expression gated on all dividing cells according to indicated cultures. Results represent two independent experiments.

Mentions: Published data identified PD-1 as one of the most overexpressed negative receptors by exhausted CD8 T cells in chronic infections [24] as well as anti-tumour responses [25]. Although functional effector T cells are generated during the early stage of these T cell responses, they gradually lose function during the course of the disease. Because DCs represented the obvious candidates for mediating functional effector cells, we speculate that the increased numbers of DCs observed after Treg depletion could have a positive effect on the generation of non-exhausted anti-tumour effector cells. We therefore studied PD1 expression on tumour infiltrating CD8 T cells from untreated and PC61-treated mice injected with 4T1 tumour cells. In agreement with data reported by others PD-1 was highly expressed on CD8 T cells from untreated mice (Fig 5A). In contrast, we found a marked reduction of PD-1 expression on intra-tumour CD8 T cells from treated mice. To evaluate if these differences in PD1 expression correlated with different tumour DC functional properties we first compared CD8 T cell proliferation of naïve CD8 T cells when cultured in the presence of DCs isolated from untreated and PC61-treated mice. 7 days after tumour inoculation, DCs (CD11chiMHChi) from treated and untreated tumours were sorted and cultured with normal CD8 T cells sorted from LNs, labeled with CellTrace Violet (CTV), division being evaluated by CTV dilutions (Fig 5B). After addition of anti-CD3 mAb, DCs from treated tumours were more efficient at stimulating the proliferation as compared with DCs from untreated tumours.


Depletion of Regulatory T Cells Induces High Numbers of Dendritic Cells and Unmasks a Subset of Anti-Tumour CD8+CD11c+ PD-1lo Effector T Cells.

Goudin N, Chappert P, Mégret J, Gross DA, Rocha B, Azogui O - PLoS ONE (2016)

DCs from PC61-depleted mice and CD4 T cells reduce the percentages of CD8 T cells expressing high level of PD-1.(A) Histograms show cell surface expression of PD-1 on infiltrating CD8 T cells from treated and untreated tumours resected at day 14 (Left) and mean Fluorescence Intensity (MFI) of PD-1 in each group (Right). (B) CD11chiMHC IIhi tumour DCs were sorted from treated and untreated mice and cultured 3 days with naïve CD8 T cells labelled with CellTrace violet and 0.1μg/ml of anti-CD3 mAb. (C,D) Flow cytometry analysing the expression of PD-1 on dividing cells. CD11chiMHC IIhi DCs from Tumours (C) and CD11chi DCs from DLNs (D) were purified from untreated and PC61-treated mice and co-cultured 3 days with CellTrace violet-labelled CD8 T cells and in the presence or not with anti-CD3 mAb or CD4 T cells. Percentages of cells expressing PD-1 are represented in the middle of the graphs. (E,F) Histograms represent the level of PD-1 expression gated on all dividing cells according to indicated cultures. Results represent two independent experiments.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920347&req=5

pone.0157822.g005: DCs from PC61-depleted mice and CD4 T cells reduce the percentages of CD8 T cells expressing high level of PD-1.(A) Histograms show cell surface expression of PD-1 on infiltrating CD8 T cells from treated and untreated tumours resected at day 14 (Left) and mean Fluorescence Intensity (MFI) of PD-1 in each group (Right). (B) CD11chiMHC IIhi tumour DCs were sorted from treated and untreated mice and cultured 3 days with naïve CD8 T cells labelled with CellTrace violet and 0.1μg/ml of anti-CD3 mAb. (C,D) Flow cytometry analysing the expression of PD-1 on dividing cells. CD11chiMHC IIhi DCs from Tumours (C) and CD11chi DCs from DLNs (D) were purified from untreated and PC61-treated mice and co-cultured 3 days with CellTrace violet-labelled CD8 T cells and in the presence or not with anti-CD3 mAb or CD4 T cells. Percentages of cells expressing PD-1 are represented in the middle of the graphs. (E,F) Histograms represent the level of PD-1 expression gated on all dividing cells according to indicated cultures. Results represent two independent experiments.
Mentions: Published data identified PD-1 as one of the most overexpressed negative receptors by exhausted CD8 T cells in chronic infections [24] as well as anti-tumour responses [25]. Although functional effector T cells are generated during the early stage of these T cell responses, they gradually lose function during the course of the disease. Because DCs represented the obvious candidates for mediating functional effector cells, we speculate that the increased numbers of DCs observed after Treg depletion could have a positive effect on the generation of non-exhausted anti-tumour effector cells. We therefore studied PD1 expression on tumour infiltrating CD8 T cells from untreated and PC61-treated mice injected with 4T1 tumour cells. In agreement with data reported by others PD-1 was highly expressed on CD8 T cells from untreated mice (Fig 5A). In contrast, we found a marked reduction of PD-1 expression on intra-tumour CD8 T cells from treated mice. To evaluate if these differences in PD1 expression correlated with different tumour DC functional properties we first compared CD8 T cell proliferation of naïve CD8 T cells when cultured in the presence of DCs isolated from untreated and PC61-treated mice. 7 days after tumour inoculation, DCs (CD11chiMHChi) from treated and untreated tumours were sorted and cultured with normal CD8 T cells sorted from LNs, labeled with CellTrace Violet (CTV), division being evaluated by CTV dilutions (Fig 5B). After addition of anti-CD3 mAb, DCs from treated tumours were more efficient at stimulating the proliferation as compared with DCs from untreated tumours.

Bottom Line: These events are concordant with a substantial increase in CD11b+ resident dendritic cells (DCs) subsets in draining lymph nodes followed by CD8+ DCs.These results indicate that Treg depletion leads to tumour regression by unmasking an increase of DC subsets as a part of a program that optimizes the microenvironment by orchestrating the activation, amplification, and migration of high numbers of fully differentiated CD8+CD11c+PD1lo effector T cells to the tumour sites.They also indicate that a critical pattern of DC subsets correlates with the evolution of the anti-tumour response and provide a template for Treg depletion and DC-based therapy.

View Article: PubMed Central - PubMed

Affiliation: Plateau technique de Cytometrie et d'Imagerie Cellulaire, Structure Fédérative de Recherche Necker, INSERM US 24-CNRS, UMS 3633, Paris, France.

ABSTRACT
Natural regulatory T (Treg) cells interfere with multiple functions, which are crucial for the development of strong anti-tumour responses. In a model of 4T1 mammary carcinoma, depletion of CD25+Tregs results in tumour regression in Balb/c mice, but the mechanisms underlying this process are not fully understood. Here, we show that partial Treg depletion leads to the generation of a particular effector CD8 T cell subset expressing CD11c and low level of PD-1 in tumour draining lymph nodes. These cells have the capacity to migrate into the tumour, to kill DCs, and to locally regulate the anti-tumour response. These events are concordant with a substantial increase in CD11b+ resident dendritic cells (DCs) subsets in draining lymph nodes followed by CD8+ DCs. These results indicate that Treg depletion leads to tumour regression by unmasking an increase of DC subsets as a part of a program that optimizes the microenvironment by orchestrating the activation, amplification, and migration of high numbers of fully differentiated CD8+CD11c+PD1lo effector T cells to the tumour sites. They also indicate that a critical pattern of DC subsets correlates with the evolution of the anti-tumour response and provide a template for Treg depletion and DC-based therapy.

No MeSH data available.


Related in: MedlinePlus