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CD4(+)CD25(-)Foxp3(-) Th1 cells are the source of IL-10-mediated immune suppression in chronic cutaneous leishmaniasis.

Anderson CF, Oukka M, Kuchroo VJ, Sacks D - J. Exp. Med. (2007)

Bottom Line: Nonhealing forms of leishmaniasis in humans are commonly associated with elevated levels of the deactivating cytokine IL-10, and in the mouse, normally chronic infections can be cleared in the absence of IL-10.IL-10 was produced by innate cells, as well as CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(-) T cells in the chronic lesion.Surprisingly, Rag(-/-) mice reconstituted with naive CD4(+) T cells depleted of natural T regulatory cells developed more severe infections, associated with elevated levels of IL-10 and, especially, Th2 cytokines in the site.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

ABSTRACT
Nonhealing forms of leishmaniasis in humans are commonly associated with elevated levels of the deactivating cytokine IL-10, and in the mouse, normally chronic infections can be cleared in the absence of IL-10. Using a Leishmania major strain that produces nonhealing dermal lesions in a T helper type 1 (Th1) cell-polarized setting, we have analyzed the cellular sources of IL-10 and their relative contribution to immune suppression. IL-10 was produced by innate cells, as well as CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(-) T cells in the chronic lesion. Nonetheless, only IL-10 production by antigen-specific CD4(+)CD25(-)Foxp3(-) T cells, the majority of which also produced IFN-gamma, was necessary for suppression of acquired immunity in Rag(-/-) reconstituted mice. Surprisingly, Rag(-/-) mice reconstituted with naive CD4(+) T cells depleted of natural T regulatory cells developed more severe infections, associated with elevated levels of IL-10 and, especially, Th2 cytokines in the site. The data demonstrate that IL-10-producing Th1 cells, activated early in a strong inflammatory setting as a mechanism of feedback control, are the principal mediators of T cell-derived IL-10-dependent immune suppression in a chronic intracellular infection.

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T cells are the dominant source of IL-10–mediated immune suppression in L. major NIH/Sd infection. 2 × 106 T lymphocytes from lymph nodes of naive C57BL/10 or IL-10−/− mice were adoptively transferred into RAG−/− or RAG−/− × IL-10−/− recipients, followed by intradermal inoculation of L. major NIH/Sd 1 d later. 11 wk after infection, mice were killed for analysis. (A) Draining lymph node cells or ear lesion cells were stimulated in vitro with BMDCs in the absence or presence of L. major antigen for 72 h, followed by IL-10 measurement by ELISA. Groups are labeled with the source of donor T cells specified below either RAG−/− or RAG−/− × IL-10−/− recipient mice. Data are the mean ± SD of triplicate samples from one experiment. The experiment was performed three times with similar results. (B) Real-time PCR was performed on ear lesion tissue for quantification of IL-10. The values are the fold change in gene expression relative to naive controls. Data are the mean ± SD of four ears from one experiment and are representative of three experiments. (C) Ear lesion cells were stimulated in vitro with BMDCs or BMDCs infected with L. major amastigotes. After overnight incubation, monensin was added in the final 4 h, followed by measurement of intracellular IFN-γ. The plots shown are from one experiment, and the values in the upper left quadrants are the total number of IFN-γ+CD4+ cells/ ear × 10−3 and are the mean ± SD of three independent experiments. (D) Parasite burdens in the ear lesions were enumerated by limiting dilution. Unreconstituted RAG−/− and RAG−/− × IL-10−/− mice are also shown as controls. The data points are from six mice from one experiment and are representative of three independent experiments. Horizontal lines represent geometric means.
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fig3: T cells are the dominant source of IL-10–mediated immune suppression in L. major NIH/Sd infection. 2 × 106 T lymphocytes from lymph nodes of naive C57BL/10 or IL-10−/− mice were adoptively transferred into RAG−/− or RAG−/− × IL-10−/− recipients, followed by intradermal inoculation of L. major NIH/Sd 1 d later. 11 wk after infection, mice were killed for analysis. (A) Draining lymph node cells or ear lesion cells were stimulated in vitro with BMDCs in the absence or presence of L. major antigen for 72 h, followed by IL-10 measurement by ELISA. Groups are labeled with the source of donor T cells specified below either RAG−/− or RAG−/− × IL-10−/− recipient mice. Data are the mean ± SD of triplicate samples from one experiment. The experiment was performed three times with similar results. (B) Real-time PCR was performed on ear lesion tissue for quantification of IL-10. The values are the fold change in gene expression relative to naive controls. Data are the mean ± SD of four ears from one experiment and are representative of three experiments. (C) Ear lesion cells were stimulated in vitro with BMDCs or BMDCs infected with L. major amastigotes. After overnight incubation, monensin was added in the final 4 h, followed by measurement of intracellular IFN-γ. The plots shown are from one experiment, and the values in the upper left quadrants are the total number of IFN-γ+CD4+ cells/ ear × 10−3 and are the mean ± SD of three independent experiments. (D) Parasite burdens in the ear lesions were enumerated by limiting dilution. Unreconstituted RAG−/− and RAG−/− × IL-10−/− mice are also shown as controls. The data points are from six mice from one experiment and are representative of three independent experiments. Horizontal lines represent geometric means.

Mentions: Because cell types in addition to CD4+ T cells may produce IL-10 and because macrophages, in particular, have been implicated in IL-10 production in other nonhealing models of cutaneous leishmaniasis (11, 16, 30), experiments were designed to evaluate the relative contribution made by CD4+ T cells versus innate cells to the IL-10–mediated suppression of immunity in L. major NIH/Sd–infected mice. Unfractionated naive T cells from C57BL/10 or IL-10−/− mice were adoptively transferred into RAG−/− or RAG−/− × IL-10−/− recipients, thereby restricting the source of IL-10 to either T cell or non–T cell compartments. 11 wk after transfer and infection, IL-10 was detected by ELISA in draining lymph node cells from RAG−/− and RAG−/− × IL-10−/− recipients of T cells from WT mice and was dependent on the addition of exogenous parasite antigen (Fig. 3 A). IL-10 was not detected in the lymph nodes of recipients of IL-10−/− T cells. In contrast, IL-10 was detectable in the ear lesions from mice that received WT or IL-10−/− T cells and was produced in the absence of exogenous antigen, indicating that there is a non–T cell source of IL-10 in the inflammatory site. Ex vivo analysis by real-time PCR also indicated that IL-10 was being produced in the lesions of mice reconstituted with IL-10−/− T cells (Fig. 3 B). Furthermore, comparison of IL-10 production at the protein and message level suggests that the major source of IL-10 in the ear lesion was innate cells.


CD4(+)CD25(-)Foxp3(-) Th1 cells are the source of IL-10-mediated immune suppression in chronic cutaneous leishmaniasis.

Anderson CF, Oukka M, Kuchroo VJ, Sacks D - J. Exp. Med. (2007)

T cells are the dominant source of IL-10–mediated immune suppression in L. major NIH/Sd infection. 2 × 106 T lymphocytes from lymph nodes of naive C57BL/10 or IL-10−/− mice were adoptively transferred into RAG−/− or RAG−/− × IL-10−/− recipients, followed by intradermal inoculation of L. major NIH/Sd 1 d later. 11 wk after infection, mice were killed for analysis. (A) Draining lymph node cells or ear lesion cells were stimulated in vitro with BMDCs in the absence or presence of L. major antigen for 72 h, followed by IL-10 measurement by ELISA. Groups are labeled with the source of donor T cells specified below either RAG−/− or RAG−/− × IL-10−/− recipient mice. Data are the mean ± SD of triplicate samples from one experiment. The experiment was performed three times with similar results. (B) Real-time PCR was performed on ear lesion tissue for quantification of IL-10. The values are the fold change in gene expression relative to naive controls. Data are the mean ± SD of four ears from one experiment and are representative of three experiments. (C) Ear lesion cells were stimulated in vitro with BMDCs or BMDCs infected with L. major amastigotes. After overnight incubation, monensin was added in the final 4 h, followed by measurement of intracellular IFN-γ. The plots shown are from one experiment, and the values in the upper left quadrants are the total number of IFN-γ+CD4+ cells/ ear × 10−3 and are the mean ± SD of three independent experiments. (D) Parasite burdens in the ear lesions were enumerated by limiting dilution. Unreconstituted RAG−/− and RAG−/− × IL-10−/− mice are also shown as controls. The data points are from six mice from one experiment and are representative of three independent experiments. Horizontal lines represent geometric means.
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Related In: Results  -  Collection

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fig3: T cells are the dominant source of IL-10–mediated immune suppression in L. major NIH/Sd infection. 2 × 106 T lymphocytes from lymph nodes of naive C57BL/10 or IL-10−/− mice were adoptively transferred into RAG−/− or RAG−/− × IL-10−/− recipients, followed by intradermal inoculation of L. major NIH/Sd 1 d later. 11 wk after infection, mice were killed for analysis. (A) Draining lymph node cells or ear lesion cells were stimulated in vitro with BMDCs in the absence or presence of L. major antigen for 72 h, followed by IL-10 measurement by ELISA. Groups are labeled with the source of donor T cells specified below either RAG−/− or RAG−/− × IL-10−/− recipient mice. Data are the mean ± SD of triplicate samples from one experiment. The experiment was performed three times with similar results. (B) Real-time PCR was performed on ear lesion tissue for quantification of IL-10. The values are the fold change in gene expression relative to naive controls. Data are the mean ± SD of four ears from one experiment and are representative of three experiments. (C) Ear lesion cells were stimulated in vitro with BMDCs or BMDCs infected with L. major amastigotes. After overnight incubation, monensin was added in the final 4 h, followed by measurement of intracellular IFN-γ. The plots shown are from one experiment, and the values in the upper left quadrants are the total number of IFN-γ+CD4+ cells/ ear × 10−3 and are the mean ± SD of three independent experiments. (D) Parasite burdens in the ear lesions were enumerated by limiting dilution. Unreconstituted RAG−/− and RAG−/− × IL-10−/− mice are also shown as controls. The data points are from six mice from one experiment and are representative of three independent experiments. Horizontal lines represent geometric means.
Mentions: Because cell types in addition to CD4+ T cells may produce IL-10 and because macrophages, in particular, have been implicated in IL-10 production in other nonhealing models of cutaneous leishmaniasis (11, 16, 30), experiments were designed to evaluate the relative contribution made by CD4+ T cells versus innate cells to the IL-10–mediated suppression of immunity in L. major NIH/Sd–infected mice. Unfractionated naive T cells from C57BL/10 or IL-10−/− mice were adoptively transferred into RAG−/− or RAG−/− × IL-10−/− recipients, thereby restricting the source of IL-10 to either T cell or non–T cell compartments. 11 wk after transfer and infection, IL-10 was detected by ELISA in draining lymph node cells from RAG−/− and RAG−/− × IL-10−/− recipients of T cells from WT mice and was dependent on the addition of exogenous parasite antigen (Fig. 3 A). IL-10 was not detected in the lymph nodes of recipients of IL-10−/− T cells. In contrast, IL-10 was detectable in the ear lesions from mice that received WT or IL-10−/− T cells and was produced in the absence of exogenous antigen, indicating that there is a non–T cell source of IL-10 in the inflammatory site. Ex vivo analysis by real-time PCR also indicated that IL-10 was being produced in the lesions of mice reconstituted with IL-10−/− T cells (Fig. 3 B). Furthermore, comparison of IL-10 production at the protein and message level suggests that the major source of IL-10 in the ear lesion was innate cells.

Bottom Line: Nonhealing forms of leishmaniasis in humans are commonly associated with elevated levels of the deactivating cytokine IL-10, and in the mouse, normally chronic infections can be cleared in the absence of IL-10.IL-10 was produced by innate cells, as well as CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(-) T cells in the chronic lesion.Surprisingly, Rag(-/-) mice reconstituted with naive CD4(+) T cells depleted of natural T regulatory cells developed more severe infections, associated with elevated levels of IL-10 and, especially, Th2 cytokines in the site.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.

ABSTRACT
Nonhealing forms of leishmaniasis in humans are commonly associated with elevated levels of the deactivating cytokine IL-10, and in the mouse, normally chronic infections can be cleared in the absence of IL-10. Using a Leishmania major strain that produces nonhealing dermal lesions in a T helper type 1 (Th1) cell-polarized setting, we have analyzed the cellular sources of IL-10 and their relative contribution to immune suppression. IL-10 was produced by innate cells, as well as CD4(+)CD25(+)Foxp3(+) and CD4(+)CD25(-)Foxp3(-) T cells in the chronic lesion. Nonetheless, only IL-10 production by antigen-specific CD4(+)CD25(-)Foxp3(-) T cells, the majority of which also produced IFN-gamma, was necessary for suppression of acquired immunity in Rag(-/-) reconstituted mice. Surprisingly, Rag(-/-) mice reconstituted with naive CD4(+) T cells depleted of natural T regulatory cells developed more severe infections, associated with elevated levels of IL-10 and, especially, Th2 cytokines in the site. The data demonstrate that IL-10-producing Th1 cells, activated early in a strong inflammatory setting as a mechanism of feedback control, are the principal mediators of T cell-derived IL-10-dependent immune suppression in a chronic intracellular infection.

Show MeSH
Related in: MedlinePlus