MGL recognises CD45RA on human Tregs and modulates thei

The Macrophage Galactose-Type C-Type Lectin (MGL) Modulates Regulatory T Cell Functions. Zizzari IG, Martufi P, Battisti F, Rahimi H, Caponnetto S, Bellati F, Nuti M, Rughetti A, Napoletano C - PLoS ONE (2015) Bottom Line: In this study, we demonstrate that Treg immunosuppressive activity can be modulated by the cross-linking between the CD45RA expressed by Tregs and the C-type lectin MGL.This effect can be attributed to changes in CD45RA and TCR signalling through the inhibition of Lck and inactivation of Zap-70, an increase in the Foxp3 methylation status and, ultimately, the reduced production of suppressive cytokines.These results indicate a role of MGL as an immunomodulator within the tumour microenvironment interfering with Treg functions, suggesting its possible use in the design of anticancer vaccines. View Article: PubMed Central - PubMed Affiliation: Department of Experimental Medicine, "Sapienza" University, Rome, Italy. ABSTRACT Regulatory T cells (Tregs) are physiologically designed to prevent autoimmune disease and maintain self-tolerance. In tumour microenvironments, their presence is related to a poor prognosis, and they influence the therapeutic outcome due to their capacity to suppress the immune response by cell-cell contact and to release immunosuppressive cytokines. In this study, we demonstrate that Treg immunosuppressive activity can be modulated by the cross-linking between the CD45RA expressed by Tregs and the C-type lectin MGL. This specific interaction strongly decreases the immunosuppressive activity of Tregs, restoring the proliferative capacity of co-cultured T lymphocytes. This effect can be attributed to changes in CD45RA and TCR signalling through the inhibition of Lck and inactivation of Zap-70, an increase in the Foxp3 methylation status and, ultimately, the reduced production of suppressive cytokines. These results indicate a role of MGL as an immunomodulator within the tumour microenvironment interfering with Treg functions, suggesting its possible use in the design of anticancer vaccines. No MeSH data available. Related in: MedlinePlus	© Copyright Policy Related In: Results - Collection License Show All Figures getmorefigures.php?uid=PMC4493043&req=5 pone.0132617.g001: MGL recognises CD45RA on human Tregs and modulates their suppressive capacity.(A) Flow cytometry analysis of purified Treg stained with anti- CD4, CD25, FOXP3 and CD45RA antibodies. (B) Competition studies of rhMGL-Fc binding to CD45RA expressed by Tregs using GalNAc polymer. Filled histograms represent the untreated Tregs, while the open histograms show Tregs treated with rhMGL-Fc or rhMGL-Fc+GalNAc. (C) Western blot analysis of Treg lysate immunoprecipitated with rhMGL-Fc. Samples were run in 4–12% SDS-PAGE gel and were analysed with anti-CD45RA and rhMGL-Fc. These results are representative of one donor out of three. (D) Immunosuppression capacity of Tregs alone and Tregs treated with rhMGL-Fc after four days of co-culture with CD4+ CD25- T cells (ratio 1:5, Treg:CD4+CD25- T cells), in presence of anti-CD3 and anti-CD28. (E) IFNγ spots produced by CD8+ T cells (5×104/well) stimulated with mDCs in presence or not of Tregs ± rhMGL. The results correspond with the mean of three independent experiments ± standard deviation (SD). * corresponds to p<0.05 and to p<0.01. Mentions:** Tregs were isolated from PBMCs and characterised as shown in Fig 1A. After purification, we obtained 92% of Tregs (CD4+CD25+FOXP3+) of which 70% were positive for CD45RA.

The Macrophage Galactose-Type C-Type Lectin (MGL) Modulates Regulatory T Cell Functions.

Zizzari IG, Martufi P, Battisti F, Rahimi H, Caponnetto S, Bellati F, Nuti M, Rughetti A, Napoletano C - PLoS ONE (2015)

Bottom Line: In this study, we demonstrate that Treg immunosuppressive activity can be modulated by the cross-linking between the CD45RA expressed by Tregs and the C-type lectin MGL.This effect can be attributed to changes in CD45RA and TCR signalling through the inhibition of Lck and inactivation of Zap-70, an increase in the Foxp3 methylation status and, ultimately, the reduced production of suppressive cytokines.These results indicate a role of MGL as an immunomodulator within the tumour microenvironment interfering with Treg functions, suggesting its possible use in the design of anticancer vaccines.

View Article: PubMed Central - PubMed

Affiliation: Department of Experimental Medicine, "Sapienza" University, Rome, Italy.

ABSTRACT

Regulatory T cells (Tregs) are physiologically designed to prevent autoimmune disease and maintain self-tolerance. In tumour microenvironments, their presence is related to a poor prognosis, and they influence the therapeutic outcome due to their capacity to suppress the immune response by cell-cell contact and to release immunosuppressive cytokines. In this study, we demonstrate that Treg immunosuppressive activity can be modulated by the cross-linking between the CD45RA expressed by Tregs and the C-type lectin MGL. This specific interaction strongly decreases the immunosuppressive activity of Tregs, restoring the proliferative capacity of co-cultured T lymphocytes. This effect can be attributed to changes in CD45RA and TCR signalling through the inhibition of Lck and inactivation of Zap-70, an increase in the Foxp3 methylation status and, ultimately, the reduced production of suppressive cytokines. These results indicate a role of MGL as an immunomodulator within the tumour microenvironment interfering with Treg functions, suggesting its possible use in the design of anticancer vaccines.

No MeSH data available.

Related in: MedlinePlus

MGL recognises CD45RA on human Tregs and modulates their suppressive capacity.(A) Flow cytometry analysis of purified Treg stained with anti- CD4, CD25, FOXP3 and CD45RA antibodies. (B) Competition studies of rhMGL-Fc binding to CD45RA expressed by Tregs using GalNAc polymer. Filled histograms represent the untreated Tregs, while the open histograms show Tregs treated with rhMGL-Fc or rhMGL-Fc+GalNAc. (C) Western blot analysis of Treg lysate immunoprecipitated with rhMGL-Fc. Samples were run in 4–12% SDS-PAGE gel and were analysed with anti-CD45RA and rhMGL-Fc. These results are representative of one donor out of three. (D) Immunosuppression capacity of Tregs alone and Tregs treated with rhMGL-Fc after four days of co-culture with CD4+ CD25- T cells (ratio 1:5, Treg:CD4+CD25- T cells), in presence of anti-CD3 and anti-CD28. (E) IFNγ spots produced by CD8+ T cells (5×104/well) stimulated with mDCs in presence or not of Tregs ± rhMGL. The results correspond with the mean of three independent experiments ± standard deviation (SD). * corresponds to p<0.05 and ** to p<0.01.

Related In: Results - Collection

License

Show All Figures

getmorefigures.php?uid=PMC4493043&req=5

pone.0132617.g001: MGL recognises CD45RA on human Tregs and modulates their suppressive capacity.(A) Flow cytometry analysis of purified Treg stained with anti- CD4, CD25, FOXP3 and CD45RA antibodies. (B) Competition studies of rhMGL-Fc binding to CD45RA expressed by Tregs using GalNAc polymer. Filled histograms represent the untreated Tregs, while the open histograms show Tregs treated with rhMGL-Fc or rhMGL-Fc+GalNAc. (C) Western blot analysis of Treg lysate immunoprecipitated with rhMGL-Fc. Samples were run in 4–12% SDS-PAGE gel and were analysed with anti-CD45RA and rhMGL-Fc. These results are representative of one donor out of three. (D) Immunosuppression capacity of Tregs alone and Tregs treated with rhMGL-Fc after four days of co-culture with CD4+ CD25- T cells (ratio 1:5, Treg:CD4+CD25- T cells), in presence of anti-CD3 and anti-CD28. (E) IFNγ spots produced by CD8+ T cells (5×104/well) stimulated with mDCs in presence or not of Tregs ± rhMGL. The results correspond with the mean of three independent experiments ± standard deviation (SD). * corresponds to p<0.05 and ** to p<0.01.

Mentions: Tregs were isolated from PBMCs and characterised as shown in Fig 1A. After purification, we obtained 92% of Tregs (CD4+CD25+FOXP3+) of which 70% were positive for CD45RA.