Cutting edge: human latency-associated peptide+ T cells: a novel regulatory T cell subset - PubMed (original) (raw)

Cutting edge: human latency-associated peptide+ T cells: a novel regulatory T cell subset

Roopali Gandhi et al. J Immunol. 2010.

Abstract

Regulatory T cells (Tregs) play an important role in the maintenance of peripheral tolerance. Several molecules including TGF-beta have been linked to the function and differentiation of Tregs. In this study, we describe a unique population of T cells expressing a membrane bound form of TGF-beta, the latency-associated peptide (LAP), and having regulatory properties in human peripheral blood. These CD4(+)LAP(+) T cells lack Foxp3 but express TGF-betaR type II and the activation marker CD69. CD4(+)LAP(+) T cells are hypoproliferative compared with CD4(+)LAP(-) T cells, secrete IL-8, IL-9, IL-10, IFN-gamma, and TGF-beta upon activation, and exhibit TGF-beta- and IL-10-dependent suppressive activity in vitro. The in vitro activation of CD4(+)LAP(-) T cells results in the generation of LAP(+) Tregs, which is further amplified by IL-8. In conclusion, we have characterized a novel population of human LAP(+) Tregs that is different from classic CD4(+)Foxp3(+)CD25(high) natural Tregs.

PubMed Disclaimer

Conflict of interest statement

Disclosures: The authors have no financial conflicts of interest.

Figures

FIGURE 1

FIGURE 1

Identification of LAP+CD4+ T cells in human peripheral blood. Human PBMCs were isolated and analyzed by FACS. A, Left panel shows annexin−AAD−CD3+CD4+ T cells stained with anti-LAP Ab. Right panels show T cells stained with anti-LAP Ab in presence of rLAP. B, Percentage of CD4+LAP+, CD4+LAP−, and CD4+CD25high T cells among different individuals. C, Left panel shows gating criteria based on CD25 expression into CD25high, CD25int, and CD25low subpopulations. Right panels indicate overlay histogram plots representing the LAP+ T cell subpopulation in respective CD25high, CD25int, and CD25low T cell subpopulations. The isotype control is the filled profile, and anti-LAP staining is the empty profile. The percentages of LAP+ T cells are indicated in each plot. Results are representative of five independent experiments.

FIGURE 2

FIGURE 2

Selective expression of activation and regulatory markers on CD4+LAP+ T cells. A, Foxp3 staining of CD25high, CD25int, CD25low LAP+, and LAP- T cells. Cells were stained with AAD, annexin, CD3, CD4, CD25, and LAP followed by intracellular staining for Foxp3. B, RT-PCR analysis to determine Foxp3 expression in respective FACS-sorted populations. C, Human PBMCs were stained with AAD, annexin, CD3, CD4, CD25, LAP, and specific markers including TGF-βRII, CD69, CD103, HLA-DR, and CD3. Filled blue profiles represent isotype control; empty profiles represent specific staining for different Abs on selected populations. The percentage of positive cells are indicated in each plot. Results are representative of five independent experiments.

FIGURE 3

FIGURE 3

Proliferation and in vitro regulatory activity of CD4+LAP+ T cells. A, CD4+LAP−, CD4+LAP+, and CD4+LAP−CD25high T cells were sorted and stimulated with anti-CD3 and anti-CD28 for 5 d. Proliferation of respective T cell subpopulations is represented as a mean (±SD) of three independent experiments. B, Responder T cells were cocultured with Treg subpopulations in presence of anti-CD3− and anti-CD28−coated beads. Percent suppression for each population is represented as mean (±SD) of three independent experiments. C, Suppressive activity of CD4+LAP+ T cells and CD4+LAP−CD25high T cells reversed by blocking TGF-β (rLAP, 25 μg/ml) and anti–IL-10 (20 μg/ml). Results are representative of three independent experiments.

FIGURE 4

FIGURE 4

Signaling events in CD4+LAP+ T cells and activation-induced generation of CD4+LAP+ T cells. A, CD4+LAP+ and CD4+LAP− T cells were analyzed by reverse-phase protein array to identify specific cytokine signaling pathways active in CD4+LAP+ T cells. B, CD4+LAP− T cells were cultured in presence of anti-CD3, anti-CD28, and IL-2 in addition to either no cytokine (control) or IL-8 or IL-17 for 6 d. Percentage of CD4+LAP+ T cells post-activation was calculated, assigning the control condition as 100%. C, Activation-induced CD4+LAP+ T cells are more suppressive compared with activation-induced CD4+LAP− T cell population and ex vivo-isolated CD4+LAP+ T cells. Percent suppression for each population is represented as mean (±SD) of three independent experiments. D, Activation-induced CD4+LAP+ T cell suppression is reversed by anti–IL-10 and rLAP. In C and D, a representative experiment of three independent experiments is shown.

Similar articles

Cited by

References

    1. Hogquist KA, Baldwin TA, Jameson SC. Central tolerance: learning self-control in the thymus. Nat Rev Immunol. 2005;5:772–782. - PubMed
    1. Josefowicz SZ, Rudensky A. Control of regulatory T cell lineage commitment and maintenance. Immunity. 2009;30:616–625. - PMC - PubMed
    1. Sakaguchi S, Yamaguchi T, Nomura T, Ono M. Regulatory T cells and immune tolerance. Cell. 2008;133:775–787. - PubMed
    1. Bennett CL, Christie J, Ramsdell F, Brunkow ME, Ferguson PJ, Whitesell L, Kelly TE, Saulsbury FT, Chance PF, Ochs HD. The immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) is caused by mutations of FOXP3. Nat Genet. 2001;27:20–21. - PubMed
    1. Fife BT, Bluestone JA. Control of peripheral T-cell tolerance and autoimmunity via the CTLA-4 and PD-1 pathways. Immunol Rev. 2008;224:166–182. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources