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TLR-4 cooperates with Dectin-1 and mannose receptor to expand Th17 and Tc17 cells induced by Paracoccidioides brasiliensis stimulated dendritic cells.

Loures FV, Araújo EF, Feriotti C, Bazan SB, Calich VL - Front Microbiol (2015)

Bottom Line: The concomitant use of diverse pattern recognition receptors (PRRs) by innate immune cells can result in synergistic or inhibitory activities that profoundly influence anti-microbial immunity.In addition, treatment of WT, TLR-2(-/-), and TLR-4(-/-) DCs by anti-Dectin-1 antibodies or antigen presentation by Dectin-1(-/-) DCs led to decreased lymphoproliferation and impaired Th17 and Tc17 expansion.These responses were also inhibited by anti-MR treatment of DCs, but a synergistic action on Th17/Tc17 differentiation was mediated by TLR-4 and MR.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, Brazil.

ABSTRACT
The concomitant use of diverse pattern recognition receptors (PRRs) by innate immune cells can result in synergistic or inhibitory activities that profoundly influence anti-microbial immunity. Dectin-1 and the mannose receptor (MR) are C-type lectin receptors (CLRs) previously reported to cooperate with toll-like receptors (TLRs) signaling in the initial inflammatory response and in the induction of adaptive Th17 and Tc17 immunity mediated by CD4(+) and CD8(+) T cells, respectively. The protective immunity against paracoccidioidomycosis, the most prevalent fungal infection of Latin America, was previously shown to be influenced by these T cell subsets motivating us to study the contribution of TLRs, Dectin-1, and MR to the development of Th17/Tc17 immunity. First, curdlan a specific Dectin-1 agonist was used to characterize the influence of this receptor in the proliferative response and Th17/Tc17 differentiation of naïve lymphocytes induced by Paracoccidioides brasiliensis activated dendritic cells (DCs) from C57BL/6 mice. Then, wild type (WT), Dectin-1(-/-), TLR-2(-/-), and TLR-4(-/-) DCs treated or untreated with anti-Dectin-1 and anti-MR antibodies were used to investigate the contribution of these receptors in lymphocyte activation and differentiation. We verified that curdlan induces an enhanced lymphocyte proliferation and development of IL-17 producing CD4(+) and CD8(+) T cells. In addition, treatment of WT, TLR-2(-/-), and TLR-4(-/-) DCs by anti-Dectin-1 antibodies or antigen presentation by Dectin-1(-/-) DCs led to decreased lymphoproliferation and impaired Th17 and Tc17 expansion. These responses were also inhibited by anti-MR treatment of DCs, but a synergistic action on Th17/Tc17 differentiation was mediated by TLR-4 and MR. Taken together, our results indicate that diverse TLRs and CLRs are involved in the induction of lymphocyte proliferation and Th17/Tc17 differentiation mediated by P. brasiliensis activated DCs, but a synergist action was restricted to Dectin-1, TLR-4, and MR.

No MeSH data available.


Related in: MedlinePlus

Curdlan regulates the expression of innate immune receptors in P. brasiliensis-stimulated DCs. BMDCs from WT C57BL/6 mice were cultured as previously described. The cells were then treated or not with curdlan (100 μg/ml) for 30 min and infected with viable P. brasiliensis yeasts overnight. The cells were adjusted to 1 × 106, labeled with specific anti-CD11c, Dectin-1, TLR-2, TLR-2, and MR antibodies and analyzed by flow cytometry. The leukocyte population was gated by FSC/SSC analysis and CD11c+ gated cells were analyzed for CD11c+Dectin-1+(A), CD11c+TLR-4+(B), CD11c+TLR-2+(C), and CD11c+MR+ expression (D). The results are expressed as frequency of positive cells. Data are means ± SD of five wells per group from two independent experiments (*P < 0.05; **P < 0.01; ***P < 0.001).
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Figure 3: Curdlan regulates the expression of innate immune receptors in P. brasiliensis-stimulated DCs. BMDCs from WT C57BL/6 mice were cultured as previously described. The cells were then treated or not with curdlan (100 μg/ml) for 30 min and infected with viable P. brasiliensis yeasts overnight. The cells were adjusted to 1 × 106, labeled with specific anti-CD11c, Dectin-1, TLR-2, TLR-2, and MR antibodies and analyzed by flow cytometry. The leukocyte population was gated by FSC/SSC analysis and CD11c+ gated cells were analyzed for CD11c+Dectin-1+(A), CD11c+TLR-4+(B), CD11c+TLR-2+(C), and CD11c+MR+ expression (D). The results are expressed as frequency of positive cells. Data are means ± SD of five wells per group from two independent experiments (*P < 0.05; **P < 0.01; ***P < 0.001).

Mentions: To determine the involvement of curdlan in the modulation of innate immune receptors in DCs, BMDCs from C57BL/6 mice were treated or not with curdlan for 30 min and infected with viable P. brasiliensis yeast cells overnight. The expression of Dectin-1, TLR-2, TLR-4, and MR was then assessed by flow cytometry. Curdlan treatment caused a decreased frequency of Dectin-1 by P. brasiliensis-infected or uninfected DC cultures (Figure 3A). However, an increased frequency of DCs expressing TLR-4 and MR was detected only when the DCs were concomitantly treated with curdlan and P. brasiliensis yeasts (Figures 3B,D). The expression of TLR-2 was not modulated by curdlan in infected or uninfected DCs (Figure 3C).


TLR-4 cooperates with Dectin-1 and mannose receptor to expand Th17 and Tc17 cells induced by Paracoccidioides brasiliensis stimulated dendritic cells.

Loures FV, Araújo EF, Feriotti C, Bazan SB, Calich VL - Front Microbiol (2015)

Curdlan regulates the expression of innate immune receptors in P. brasiliensis-stimulated DCs. BMDCs from WT C57BL/6 mice were cultured as previously described. The cells were then treated or not with curdlan (100 μg/ml) for 30 min and infected with viable P. brasiliensis yeasts overnight. The cells were adjusted to 1 × 106, labeled with specific anti-CD11c, Dectin-1, TLR-2, TLR-2, and MR antibodies and analyzed by flow cytometry. The leukocyte population was gated by FSC/SSC analysis and CD11c+ gated cells were analyzed for CD11c+Dectin-1+(A), CD11c+TLR-4+(B), CD11c+TLR-2+(C), and CD11c+MR+ expression (D). The results are expressed as frequency of positive cells. Data are means ± SD of five wells per group from two independent experiments (*P < 0.05; **P < 0.01; ***P < 0.001).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4379960&req=5

Figure 3: Curdlan regulates the expression of innate immune receptors in P. brasiliensis-stimulated DCs. BMDCs from WT C57BL/6 mice were cultured as previously described. The cells were then treated or not with curdlan (100 μg/ml) for 30 min and infected with viable P. brasiliensis yeasts overnight. The cells were adjusted to 1 × 106, labeled with specific anti-CD11c, Dectin-1, TLR-2, TLR-2, and MR antibodies and analyzed by flow cytometry. The leukocyte population was gated by FSC/SSC analysis and CD11c+ gated cells were analyzed for CD11c+Dectin-1+(A), CD11c+TLR-4+(B), CD11c+TLR-2+(C), and CD11c+MR+ expression (D). The results are expressed as frequency of positive cells. Data are means ± SD of five wells per group from two independent experiments (*P < 0.05; **P < 0.01; ***P < 0.001).
Mentions: To determine the involvement of curdlan in the modulation of innate immune receptors in DCs, BMDCs from C57BL/6 mice were treated or not with curdlan for 30 min and infected with viable P. brasiliensis yeast cells overnight. The expression of Dectin-1, TLR-2, TLR-4, and MR was then assessed by flow cytometry. Curdlan treatment caused a decreased frequency of Dectin-1 by P. brasiliensis-infected or uninfected DC cultures (Figure 3A). However, an increased frequency of DCs expressing TLR-4 and MR was detected only when the DCs were concomitantly treated with curdlan and P. brasiliensis yeasts (Figures 3B,D). The expression of TLR-2 was not modulated by curdlan in infected or uninfected DCs (Figure 3C).

Bottom Line: The concomitant use of diverse pattern recognition receptors (PRRs) by innate immune cells can result in synergistic or inhibitory activities that profoundly influence anti-microbial immunity.In addition, treatment of WT, TLR-2(-/-), and TLR-4(-/-) DCs by anti-Dectin-1 antibodies or antigen presentation by Dectin-1(-/-) DCs led to decreased lymphoproliferation and impaired Th17 and Tc17 expansion.These responses were also inhibited by anti-MR treatment of DCs, but a synergistic action on Th17/Tc17 differentiation was mediated by TLR-4 and MR.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, Brazil.

ABSTRACT
The concomitant use of diverse pattern recognition receptors (PRRs) by innate immune cells can result in synergistic or inhibitory activities that profoundly influence anti-microbial immunity. Dectin-1 and the mannose receptor (MR) are C-type lectin receptors (CLRs) previously reported to cooperate with toll-like receptors (TLRs) signaling in the initial inflammatory response and in the induction of adaptive Th17 and Tc17 immunity mediated by CD4(+) and CD8(+) T cells, respectively. The protective immunity against paracoccidioidomycosis, the most prevalent fungal infection of Latin America, was previously shown to be influenced by these T cell subsets motivating us to study the contribution of TLRs, Dectin-1, and MR to the development of Th17/Tc17 immunity. First, curdlan a specific Dectin-1 agonist was used to characterize the influence of this receptor in the proliferative response and Th17/Tc17 differentiation of naïve lymphocytes induced by Paracoccidioides brasiliensis activated dendritic cells (DCs) from C57BL/6 mice. Then, wild type (WT), Dectin-1(-/-), TLR-2(-/-), and TLR-4(-/-) DCs treated or untreated with anti-Dectin-1 and anti-MR antibodies were used to investigate the contribution of these receptors in lymphocyte activation and differentiation. We verified that curdlan induces an enhanced lymphocyte proliferation and development of IL-17 producing CD4(+) and CD8(+) T cells. In addition, treatment of WT, TLR-2(-/-), and TLR-4(-/-) DCs by anti-Dectin-1 antibodies or antigen presentation by Dectin-1(-/-) DCs led to decreased lymphoproliferation and impaired Th17 and Tc17 expansion. These responses were also inhibited by anti-MR treatment of DCs, but a synergistic action on Th17/Tc17 differentiation was mediated by TLR-4 and MR. Taken together, our results indicate that diverse TLRs and CLRs are involved in the induction of lymphocyte proliferation and Th17/Tc17 differentiation mediated by P. brasiliensis activated DCs, but a synergist action was restricted to Dectin-1, TLR-4, and MR.

No MeSH data available.


Related in: MedlinePlus