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Antigen-Specific Th17 Cells Are Primed by Distinct and Complementary Dendritic Cell Subsets in Oropharyngeal Candidiasis.

Trautwein-Weidner K, Gladiator A, Kirchner FR, Becattini S, Rülicke T, Sallusto F, LeibundGut-Landmann S - PLoS Pathog. (2015)

Bottom Line: The events regulating T cell activation and differentiation toward effector fates in response to fungal invasion in different tissues are poorly understood.This highlights the functional compartmentalization of specific DC subsets in different tissues.These data provide important new insights to our understanding of tissue-specific antifungal immunity.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microbiology, ETH Zürich, Zürich, Switzerland.

ABSTRACT
Candida spp. can cause severe and chronic mucocutaneous and systemic infections in immunocompromised individuals. Protection from mucocutaneous candidiasis depends on T helper cells, in particular those secreting IL-17. The events regulating T cell activation and differentiation toward effector fates in response to fungal invasion in different tissues are poorly understood. Here we generated a Candida-specific TCR transgenic mouse reactive to a novel endogenous antigen that is conserved in multiple distant species of Candida, including the clinically highly relevant C. albicans and C. glabrata. Using TCR transgenic T cells in combination with an experimental model of oropharyngeal candidiasis (OPC) we investigated antigen presentation and Th17 priming by different subsets of dendritic cells (DCs) present in the infected oral mucosa. Candida-derived endogenous antigen accesses the draining lymph nodes and is directly presented by migratory DCs. Tissue-resident Flt3L-dependent DCs and CCR2-dependent monocyte-derived DCs collaborate in antigen presentation and T cell priming during OPC. In contrast, Langerhans cells, which are also present in the oral mucosa and have been shown to prime Th17 cells in the skin, are not required for induction of the Candida-specific T cell response upon oral challenge. This highlights the functional compartmentalization of specific DC subsets in different tissues. These data provide important new insights to our understanding of tissue-specific antifungal immunity.

No MeSH data available.


Related in: MedlinePlus

Hector T cells recognize residues 126–140 of C. albicans ADH1.(A—B) Hybridoma cells were stimulated with DC1940 cells that were pulsed with heat-killed (h.k.) C. albicans, mannoprotein (MP) extract (A) or a pool of overlapping 15-mer peptides covering the entire ADH1 and ENO1 protein sequences (B). IL-2 secretion was quantified with the CTLL2 bioassay. (C) CFSE-labelled CD4+ Hector T cells were stimulated with splenocytes that were pulsed with a pool of overlapping 15-mer peptides covering the entire ADH1 protein sequence or with peptide C2 (pADH1126-140), or that were left unpulsed. Proliferation was analyzed by flow cytometry after 4 days of co-culture. Representative FACS plots are shown on the left, a summary graph with pooled data is shown on the right. (D) CD4+ Hector T cells were adoptively transferred into B6 mice one day before they were immunized subcutaneously in the flank with IFA and 25μg CpG mixed with or without 50μg peptide C2 (pADH1126-140) as indicated. The expansion of Hector T cells in the inguinal lymph nodes (LN, left) and in the spleen (right) was analyzed by flow cytometry on day 7 post-immunization. Each symbol represents one mouse, the mean + SD is indicated. All data are representative of at least 2 independent experiments.
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ppat.1005164.g001: Hector T cells recognize residues 126–140 of C. albicans ADH1.(A—B) Hybridoma cells were stimulated with DC1940 cells that were pulsed with heat-killed (h.k.) C. albicans, mannoprotein (MP) extract (A) or a pool of overlapping 15-mer peptides covering the entire ADH1 and ENO1 protein sequences (B). IL-2 secretion was quantified with the CTLL2 bioassay. (C) CFSE-labelled CD4+ Hector T cells were stimulated with splenocytes that were pulsed with a pool of overlapping 15-mer peptides covering the entire ADH1 protein sequence or with peptide C2 (pADH1126-140), or that were left unpulsed. Proliferation was analyzed by flow cytometry after 4 days of co-culture. Representative FACS plots are shown on the left, a summary graph with pooled data is shown on the right. (D) CD4+ Hector T cells were adoptively transferred into B6 mice one day before they were immunized subcutaneously in the flank with IFA and 25μg CpG mixed with or without 50μg peptide C2 (pADH1126-140) as indicated. The expansion of Hector T cells in the inguinal lymph nodes (LN, left) and in the spleen (right) was analyzed by flow cytometry on day 7 post-immunization. Each symbol represents one mouse, the mean + SD is indicated. All data are representative of at least 2 independent experiments.

Mentions: The antigenic specificity of Hector T cells was determined using the T cell hybridoma 59.8 and different C. albicans antigenic preparations presented by the DC1940 cell line [31]. As positive control, the T cell hybridoma 59.8 exposed to C. albicans-loaded DC1940 cells produced IL-2, which was quantified using the CTLL-2 bioassay (Fig 1A). The hybridoma was found to react against DC1940 cells pulsed with a mannoprotein-enriched fraction (Fig 1A), indicating that the antigenic determinant was present in the C. albicans cell wall. Mass spectrum analysis of the mannoprotein extract revealed the presence of five abundant proteins (yeast wall protein1, YWP1; enolase, ENO1; glyceraldehyde-3-phosphate dehydrogenase, G3PDH; alcohol dehydrogenase, ADH1; fructose bisphosphate 1, FBA1). A peptide pool, consisting of 15-mers overlapping by 10 amino acids covering the entire ADH1 sequence, stimulated IL-2 production from the hybridoma 59.8 in a dose-dependent manner (Fig 1B), while no response was detected against peptide pools covering the sequences of YWP1, ENO1, G3PDH or FBA1. By screening the individual peptides of ADH1, we identified 3 peptides that triggered IL-2 production by the hybridoma (S2 Fig). Of these, peptide C2 induced the strongest when tested for their capacity to induce proliferation of Hector T cells, while peptide C3 induced a much weaker response and peptide D1 failed to induce a response in this assay (S2 Fig). Peptide C2 stimulated proliferation of Hector T cells to an extent that was comparable to that induced by the peptide pool covering the entire ADH1 sequence (Fig 1C). Finally, the specificity of Hector T cells for the ADH1 peptide C2 was confirmed in vivo in mice adoptively transferred with CD4+ Hector T cells and immunized with the peptide admixed with CpG adjuvant (Fig 1D).


Antigen-Specific Th17 Cells Are Primed by Distinct and Complementary Dendritic Cell Subsets in Oropharyngeal Candidiasis.

Trautwein-Weidner K, Gladiator A, Kirchner FR, Becattini S, Rülicke T, Sallusto F, LeibundGut-Landmann S - PLoS Pathog. (2015)

Hector T cells recognize residues 126–140 of C. albicans ADH1.(A—B) Hybridoma cells were stimulated with DC1940 cells that were pulsed with heat-killed (h.k.) C. albicans, mannoprotein (MP) extract (A) or a pool of overlapping 15-mer peptides covering the entire ADH1 and ENO1 protein sequences (B). IL-2 secretion was quantified with the CTLL2 bioassay. (C) CFSE-labelled CD4+ Hector T cells were stimulated with splenocytes that were pulsed with a pool of overlapping 15-mer peptides covering the entire ADH1 protein sequence or with peptide C2 (pADH1126-140), or that were left unpulsed. Proliferation was analyzed by flow cytometry after 4 days of co-culture. Representative FACS plots are shown on the left, a summary graph with pooled data is shown on the right. (D) CD4+ Hector T cells were adoptively transferred into B6 mice one day before they were immunized subcutaneously in the flank with IFA and 25μg CpG mixed with or without 50μg peptide C2 (pADH1126-140) as indicated. The expansion of Hector T cells in the inguinal lymph nodes (LN, left) and in the spleen (right) was analyzed by flow cytometry on day 7 post-immunization. Each symbol represents one mouse, the mean + SD is indicated. All data are representative of at least 2 independent experiments.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591991&req=5

ppat.1005164.g001: Hector T cells recognize residues 126–140 of C. albicans ADH1.(A—B) Hybridoma cells were stimulated with DC1940 cells that were pulsed with heat-killed (h.k.) C. albicans, mannoprotein (MP) extract (A) or a pool of overlapping 15-mer peptides covering the entire ADH1 and ENO1 protein sequences (B). IL-2 secretion was quantified with the CTLL2 bioassay. (C) CFSE-labelled CD4+ Hector T cells were stimulated with splenocytes that were pulsed with a pool of overlapping 15-mer peptides covering the entire ADH1 protein sequence or with peptide C2 (pADH1126-140), or that were left unpulsed. Proliferation was analyzed by flow cytometry after 4 days of co-culture. Representative FACS plots are shown on the left, a summary graph with pooled data is shown on the right. (D) CD4+ Hector T cells were adoptively transferred into B6 mice one day before they were immunized subcutaneously in the flank with IFA and 25μg CpG mixed with or without 50μg peptide C2 (pADH1126-140) as indicated. The expansion of Hector T cells in the inguinal lymph nodes (LN, left) and in the spleen (right) was analyzed by flow cytometry on day 7 post-immunization. Each symbol represents one mouse, the mean + SD is indicated. All data are representative of at least 2 independent experiments.
Mentions: The antigenic specificity of Hector T cells was determined using the T cell hybridoma 59.8 and different C. albicans antigenic preparations presented by the DC1940 cell line [31]. As positive control, the T cell hybridoma 59.8 exposed to C. albicans-loaded DC1940 cells produced IL-2, which was quantified using the CTLL-2 bioassay (Fig 1A). The hybridoma was found to react against DC1940 cells pulsed with a mannoprotein-enriched fraction (Fig 1A), indicating that the antigenic determinant was present in the C. albicans cell wall. Mass spectrum analysis of the mannoprotein extract revealed the presence of five abundant proteins (yeast wall protein1, YWP1; enolase, ENO1; glyceraldehyde-3-phosphate dehydrogenase, G3PDH; alcohol dehydrogenase, ADH1; fructose bisphosphate 1, FBA1). A peptide pool, consisting of 15-mers overlapping by 10 amino acids covering the entire ADH1 sequence, stimulated IL-2 production from the hybridoma 59.8 in a dose-dependent manner (Fig 1B), while no response was detected against peptide pools covering the sequences of YWP1, ENO1, G3PDH or FBA1. By screening the individual peptides of ADH1, we identified 3 peptides that triggered IL-2 production by the hybridoma (S2 Fig). Of these, peptide C2 induced the strongest when tested for their capacity to induce proliferation of Hector T cells, while peptide C3 induced a much weaker response and peptide D1 failed to induce a response in this assay (S2 Fig). Peptide C2 stimulated proliferation of Hector T cells to an extent that was comparable to that induced by the peptide pool covering the entire ADH1 sequence (Fig 1C). Finally, the specificity of Hector T cells for the ADH1 peptide C2 was confirmed in vivo in mice adoptively transferred with CD4+ Hector T cells and immunized with the peptide admixed with CpG adjuvant (Fig 1D).

Bottom Line: The events regulating T cell activation and differentiation toward effector fates in response to fungal invasion in different tissues are poorly understood.This highlights the functional compartmentalization of specific DC subsets in different tissues.These data provide important new insights to our understanding of tissue-specific antifungal immunity.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microbiology, ETH Zürich, Zürich, Switzerland.

ABSTRACT
Candida spp. can cause severe and chronic mucocutaneous and systemic infections in immunocompromised individuals. Protection from mucocutaneous candidiasis depends on T helper cells, in particular those secreting IL-17. The events regulating T cell activation and differentiation toward effector fates in response to fungal invasion in different tissues are poorly understood. Here we generated a Candida-specific TCR transgenic mouse reactive to a novel endogenous antigen that is conserved in multiple distant species of Candida, including the clinically highly relevant C. albicans and C. glabrata. Using TCR transgenic T cells in combination with an experimental model of oropharyngeal candidiasis (OPC) we investigated antigen presentation and Th17 priming by different subsets of dendritic cells (DCs) present in the infected oral mucosa. Candida-derived endogenous antigen accesses the draining lymph nodes and is directly presented by migratory DCs. Tissue-resident Flt3L-dependent DCs and CCR2-dependent monocyte-derived DCs collaborate in antigen presentation and T cell priming during OPC. In contrast, Langerhans cells, which are also present in the oral mucosa and have been shown to prime Th17 cells in the skin, are not required for induction of the Candida-specific T cell response upon oral challenge. This highlights the functional compartmentalization of specific DC subsets in different tissues. These data provide important new insights to our understanding of tissue-specific antifungal immunity.

No MeSH data available.


Related in: MedlinePlus