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CD40L+ CD4+ memory T cells migrate in a CD62P-dependent fashion into reactive lymph nodes and license dendritic cells for T cell priming.

Martín-Fontecha A, Baumjohann D, Guarda G, Reboldi A, Hons M, Lanzavecchia A, Sallusto F - J. Exp. Med. (2008)

Bottom Line: CD4(+) T(EM) cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules.Antibodies to CD62P, which blocked CD4(+) T(EM) cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE.These results show that T(EM) cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity.

View Article: PubMed Central - PubMed

Affiliation: Institute for Research in Biomedicine, 6500 Bellinzona, Switzerland. alfonso.martin-fontecha@kcl.ac.uk

ABSTRACT
There is growing evidence that the maturation state of dendritic cells (DCs) is a critical parameter determining the balance between tolerance and immunity. We report that mouse CD4(+) effector memory T (T(EM)) cells, but not naive or central memory T cells, constitutively expressed CD40L at levels sufficient to induce DC maturation in vitro and in vivo in the absence of antigenic stimulation. CD4(+) T(EM) cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules. Trafficking of CD4(+) T(EM) cells into chronic reactive lymph nodes maintained resident DCs in a mature state and promoted naive T cell responses and experimental autoimmune encephalomyelitis (EAE) to antigens administered in the absence of adjuvants. Antibodies to CD62P, which blocked CD4(+) T(EM) cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE. These results show that T(EM) cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity.

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CD4+ TEM cells constitutively express CD40L and promote DC maturation in vitro through CD40L–CD40 interaction. (a) Surface expression of CD40L (black lines) in CD4+ T naive (CD44lowCD62L+CD127+), TCM (CD44highCD62L+CD127+), and TEM (CD44highCD62L−CD127+) cells. Gray lines represent control staining with isotype-matched control antibodies. (b) Kinetics of CD40L surface expression on CD4+ T cell subsets sorted as in panel a and stimulated in vitro with anti-CD3 and PdBU. Data are the means ± SD of three separate experiments. Student's t test on values at time 0: TEM versus TCM, P = 0.041; TEM versus T naive, P = 0.023; TCM versus T naive, NS. Unstimulated T cells cultured for the same time had a level of CD40L expression comparable to time 0 (not depicted). (c) Expression of CD40, CD86, and MHC class II (black lines) on DCs that had been cultured for 12 h with the indicated CD4+ T cell subsets or stimulated with LPS. Gray lines represent staining of untreated immature DCs. Results are representative of four independent experiments. (d) Expression of CD86 (black lines) in wild-type DCs (top) or CD40−/− DCs (bottom) cultured for 12 h with live or fixed CD4+ TEM cells or with LPS as control. Gray lines represent staining of untreated immature DCs. Results are representative of three independent experiments.
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fig1: CD4+ TEM cells constitutively express CD40L and promote DC maturation in vitro through CD40L–CD40 interaction. (a) Surface expression of CD40L (black lines) in CD4+ T naive (CD44lowCD62L+CD127+), TCM (CD44highCD62L+CD127+), and TEM (CD44highCD62L−CD127+) cells. Gray lines represent control staining with isotype-matched control antibodies. (b) Kinetics of CD40L surface expression on CD4+ T cell subsets sorted as in panel a and stimulated in vitro with anti-CD3 and PdBU. Data are the means ± SD of three separate experiments. Student's t test on values at time 0: TEM versus TCM, P = 0.041; TEM versus T naive, P = 0.023; TCM versus T naive, NS. Unstimulated T cells cultured for the same time had a level of CD40L expression comparable to time 0 (not depicted). (c) Expression of CD40, CD86, and MHC class II (black lines) on DCs that had been cultured for 12 h with the indicated CD4+ T cell subsets or stimulated with LPS. Gray lines represent staining of untreated immature DCs. Results are representative of four independent experiments. (d) Expression of CD86 (black lines) in wild-type DCs (top) or CD40−/− DCs (bottom) cultured for 12 h with live or fixed CD4+ TEM cells or with LPS as control. Gray lines represent staining of untreated immature DCs. Results are representative of three independent experiments.

Mentions: It has been recently reported that naive CD4+ T cells constitutively express CD40L in amounts that are sufficient to promote autoreactive B cell survival (19). We asked whether constitutive expression of CD40L on naive and memory T cell subsets would be sufficient to induce DC maturation. To generate memory T cells, BALB/c mice were either immunized with KLH in CFA or were adoptively transferred with OVA-specific DO11.10 TCR transgenic naive T cells and immunized with OVA-pulsed mature DCs. At least 4 wk after immunization, CD4+ naive T cells (CD44low, CD62L+, CD127+), TCM cells (CD44high, CD62L+, CD127+), and TEM cells (CD44high, CD62L−, CD127+) were isolated from spleens of BALB/c mice (Fig. S1, available at http://www.jem.org/cgi/content/full/jem.20081212/DC1) and stained with antibodies to CD40L. Naive T and TCM cells isolated from KLH-immunized mice did not express detectable levels of surface CD40L (Fig. 1 a). In contrast, CD4+ TEM cells homogeneously expressed low amounts of surface CD40L, which was significantly higher compared with naive T and TCM cells (Fig. 1 a). Upon in vitro stimulation with CD3 antibodies, CD40L expression increased in all three subsets, although in TEM cells the kinetics were more rapid and the plateau level was ∼10-fold higher than that reached by naive T or TCM cells (Fig. 1 b). CD40L was also expressed on DO11.10 TEM cells but not on DO11.10 naive or TCM cells (unpublished data). CD40L mRNA was found to be expressed in comparable amounts in TCM and TEM cells (unpublished data), suggesting that the difference in protein expression may be caused by differences in translation and/or storage. Consistent with this possibility, previous studies showed the presence of prestored CD40L in memory T cells of both human and mouse origin (16–19).


CD40L+ CD4+ memory T cells migrate in a CD62P-dependent fashion into reactive lymph nodes and license dendritic cells for T cell priming.

Martín-Fontecha A, Baumjohann D, Guarda G, Reboldi A, Hons M, Lanzavecchia A, Sallusto F - J. Exp. Med. (2008)

CD4+ TEM cells constitutively express CD40L and promote DC maturation in vitro through CD40L–CD40 interaction. (a) Surface expression of CD40L (black lines) in CD4+ T naive (CD44lowCD62L+CD127+), TCM (CD44highCD62L+CD127+), and TEM (CD44highCD62L−CD127+) cells. Gray lines represent control staining with isotype-matched control antibodies. (b) Kinetics of CD40L surface expression on CD4+ T cell subsets sorted as in panel a and stimulated in vitro with anti-CD3 and PdBU. Data are the means ± SD of three separate experiments. Student's t test on values at time 0: TEM versus TCM, P = 0.041; TEM versus T naive, P = 0.023; TCM versus T naive, NS. Unstimulated T cells cultured for the same time had a level of CD40L expression comparable to time 0 (not depicted). (c) Expression of CD40, CD86, and MHC class II (black lines) on DCs that had been cultured for 12 h with the indicated CD4+ T cell subsets or stimulated with LPS. Gray lines represent staining of untreated immature DCs. Results are representative of four independent experiments. (d) Expression of CD86 (black lines) in wild-type DCs (top) or CD40−/− DCs (bottom) cultured for 12 h with live or fixed CD4+ TEM cells or with LPS as control. Gray lines represent staining of untreated immature DCs. Results are representative of three independent experiments.
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fig1: CD4+ TEM cells constitutively express CD40L and promote DC maturation in vitro through CD40L–CD40 interaction. (a) Surface expression of CD40L (black lines) in CD4+ T naive (CD44lowCD62L+CD127+), TCM (CD44highCD62L+CD127+), and TEM (CD44highCD62L−CD127+) cells. Gray lines represent control staining with isotype-matched control antibodies. (b) Kinetics of CD40L surface expression on CD4+ T cell subsets sorted as in panel a and stimulated in vitro with anti-CD3 and PdBU. Data are the means ± SD of three separate experiments. Student's t test on values at time 0: TEM versus TCM, P = 0.041; TEM versus T naive, P = 0.023; TCM versus T naive, NS. Unstimulated T cells cultured for the same time had a level of CD40L expression comparable to time 0 (not depicted). (c) Expression of CD40, CD86, and MHC class II (black lines) on DCs that had been cultured for 12 h with the indicated CD4+ T cell subsets or stimulated with LPS. Gray lines represent staining of untreated immature DCs. Results are representative of four independent experiments. (d) Expression of CD86 (black lines) in wild-type DCs (top) or CD40−/− DCs (bottom) cultured for 12 h with live or fixed CD4+ TEM cells or with LPS as control. Gray lines represent staining of untreated immature DCs. Results are representative of three independent experiments.
Mentions: It has been recently reported that naive CD4+ T cells constitutively express CD40L in amounts that are sufficient to promote autoreactive B cell survival (19). We asked whether constitutive expression of CD40L on naive and memory T cell subsets would be sufficient to induce DC maturation. To generate memory T cells, BALB/c mice were either immunized with KLH in CFA or were adoptively transferred with OVA-specific DO11.10 TCR transgenic naive T cells and immunized with OVA-pulsed mature DCs. At least 4 wk after immunization, CD4+ naive T cells (CD44low, CD62L+, CD127+), TCM cells (CD44high, CD62L+, CD127+), and TEM cells (CD44high, CD62L−, CD127+) were isolated from spleens of BALB/c mice (Fig. S1, available at http://www.jem.org/cgi/content/full/jem.20081212/DC1) and stained with antibodies to CD40L. Naive T and TCM cells isolated from KLH-immunized mice did not express detectable levels of surface CD40L (Fig. 1 a). In contrast, CD4+ TEM cells homogeneously expressed low amounts of surface CD40L, which was significantly higher compared with naive T and TCM cells (Fig. 1 a). Upon in vitro stimulation with CD3 antibodies, CD40L expression increased in all three subsets, although in TEM cells the kinetics were more rapid and the plateau level was ∼10-fold higher than that reached by naive T or TCM cells (Fig. 1 b). CD40L was also expressed on DO11.10 TEM cells but not on DO11.10 naive or TCM cells (unpublished data). CD40L mRNA was found to be expressed in comparable amounts in TCM and TEM cells (unpublished data), suggesting that the difference in protein expression may be caused by differences in translation and/or storage. Consistent with this possibility, previous studies showed the presence of prestored CD40L in memory T cells of both human and mouse origin (16–19).

Bottom Line: CD4(+) T(EM) cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules.Antibodies to CD62P, which blocked CD4(+) T(EM) cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE.These results show that T(EM) cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity.

View Article: PubMed Central - PubMed

Affiliation: Institute for Research in Biomedicine, 6500 Bellinzona, Switzerland. alfonso.martin-fontecha@kcl.ac.uk

ABSTRACT
There is growing evidence that the maturation state of dendritic cells (DCs) is a critical parameter determining the balance between tolerance and immunity. We report that mouse CD4(+) effector memory T (T(EM)) cells, but not naive or central memory T cells, constitutively expressed CD40L at levels sufficient to induce DC maturation in vitro and in vivo in the absence of antigenic stimulation. CD4(+) T(EM) cells were excluded from resting lymph nodes but migrated in a CD62P-dependent fashion into reactive lymph nodes that were induced to express CD62P, in a transient or sustained fashion, on high endothelial venules. Trafficking of CD4(+) T(EM) cells into chronic reactive lymph nodes maintained resident DCs in a mature state and promoted naive T cell responses and experimental autoimmune encephalomyelitis (EAE) to antigens administered in the absence of adjuvants. Antibodies to CD62P, which blocked CD4(+) T(EM) cell migration into reactive lymph nodes, inhibited DC maturation, T cell priming, and induction of EAE. These results show that T(EM) cells can behave as endogenous adjuvants and suggest a mechanistic link between lymphocyte traffic in lymph nodes and induction of autoimmunity.

Show MeSH
Related in: MedlinePlus