-
[show abstract]
[hide abstract]
ABSTRACT: Here we present a microfluidic method for the analysis of single cell secretions. The method co-encapsulates cells with microspheres conjugated with capture antibodies and detection fluorescence-labeled antibodies. The secreted substance captured on the microsphere surface and detected via detection antibodies generating a localized fluorescent signal on a microsphere surface. Using this method, CD4+CD25+ regulatory T cells were encapsulated and assayed to detect IL-10 secreting cell in population.
Biosensors & bioelectronics 09/2010; 26(5):2707-10. · 5.43 Impact Factor
-
Gaëlle Beriou,
Elizabeth M Bradshaw,
Ester Lozano,
Cristina M Costantino,
William D Hastings,
Tihamer Orban,
Wassim Elyaman,
Samia J Khoury,
Vijay K Kuchroo, Clare Baecher-Allan,
David A Hafler
[show abstract]
[hide abstract]
ABSTRACT: The secretion of IL-9, initially recognized as a Th2 cytokine, was recently attributed to a novel CD4 T cell subset termed Th9 in the murine system. However, IL-9 can also be secreted by mouse Th17 cells and may mediate aspects of the proinflammatory activities of Th17 cells. Here we report that IL-9 is secreted by human naive CD4 T cells in response to differentiation by Th9 (TGF-beta and IL-4) or Th17 polarizing conditions. Yet, these differentiated naive cells did not coexpress IL-17 and IL-9, unless they were repeatedly stimulated under Th17 differentiation-inducing conditions. In contrast to the naive cells, memory CD4 T cells were induced to secrete IL-9 by simply providing TGF-beta during stimulation, as neither IL-4 nor proinflammatory cytokines were required. Furthermore, the addition of TGF-beta to the Th17-inducing cytokines (IL-1beta, IL-6, IL-21, IL-23) that induce memory cells to secrete IL-17, resulted in the marked coexpression of IL-9 in IL-17 producing memory cells. The proinflammatory cytokine mediating TGF-beta-dependent coexpression of IL-9 and IL-17 was identified to be IL-1beta. Moreover, circulating monocytes were potent costimulators of IL-9 production by Th17 cells via their capacity to secrete IL-1beta. Finally, to determine whether IL-9/IL-17 coproducing CD4 cells were altered in an inflammatory condition, we examined patients with autoimmune diabetes and demonstrated that these subjects exhibit a higher frequency of memory CD4 cells with the capacity to transition into IL-9(+)IL-17(+) cells. These data demonstrate the presence of IL-17(+)IL-9(+) CD4 cells induced by IL-1beta that may play a role in human autoimmune disease.
The Journal of Immunology 07/2010; 185(1):46-54. · 5.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: MHC class II expression identifies an effector subset of human CD4(+)CD25(high)FoxP3(high) natural regulatory T cells (DR(+) Tregs) that induces more rapid suppression and exhibits higher FoxP3 expression than the remaining Treg population. Although Tregs are known to be highly sensitive to apoptosis, in this study we demonstrate that this sensitivity is primarily a feature of DR(+) Tregs. Granzyme B (GzmB) is strongly expressed by nonregulatory responder CD4 T cells, whereas effector DR(+) Tregs express little GzmB. Strong TCR stimulation markedly increases the expression of GzmB in all dividing responder CD4 T cells and mitigates the suppression by DR(+) Tregs. DR(+) Treg suppressive activity reemerges if GzmB is neutralized. We show that responder cells actively kill effector Tregs by producing GzmB in response to strong TCR stimulation. Thus, the production of GzmB by strongly activated CD4 T cells represents a mechanism by which CD4 T cells resist Treg suppression.
The Journal of Immunology 10/2009; 183(8):4843-7. · 5.79 Impact Factor
-
Saumyadipta Pyne,
Xinli Hu,
Kui Wang,
Elizabeth Rossin,
Tsung-I Lin,
Lisa M Maier, Clare Baecher-Allan,
Geoffrey J McLachlan,
Pablo Tamayo,
David A Hafler,
Philip L De Jager,
Jill P Mesirov
[show abstract]
[hide abstract]
ABSTRACT: Flow cytometric analysis allows rapid single cell interrogation of surface and intracellular determinants by measuring fluorescence intensity of fluorophore-conjugated reagents. The availability of new platforms, allowing detection of increasing numbers of cell surface markers, has challenged the traditional technique of identifying cell populations by manual gating and resulted in a growing need for the development of automated, high-dimensional analytical methods. We present a direct multivariate finite mixture modeling approach, using skew and heavy-tailed distributions, to address the complexities of flow cytometric analysis and to deal with high-dimensional cytometric data without the need for projection or transformation. We demonstrate its ability to detect rare populations, to model robustly in the presence of outliers and skew, and to perform the critical task of matching cell populations across samples that enables downstream analysis. This advance will facilitate the application of flow cytometry to new, complex biological and clinical problems.
Proceedings of the National Academy of Sciences 06/2009; 106(21):8519-24. · 9.68 Impact Factor
-
Philip L De Jager, Clare Baecher-Allan,
Lisa M Maier,
Ariel T Arthur,
Linda Ottoboni,
Lisa Barcellos,
Jacob L McCauley,
Stephen Sawcer,
An Goris,
Janna Saarela, [......],
Leena Peltonen,
Bénédicte Dubois,
Jonathan L Haines,
Howard L Weiner,
Alastair Compston,
Stephen L Hauser,
Mark J Daly,
David Reich,
Jorge R Oksenberg,
David A Hafler
[show abstract]
[hide abstract]
ABSTRACT: Multiple sclerosis (MS) is an inflammatory disease of the central nervous system associated with demyelination and axonal loss. A whole genome association scan suggested that allelic variants in the CD58 gene region, encoding the costimulatory molecule LFA-3, are associated with risk of developing MS. We now report additional genetic evidence, as well as resequencing and fine mapping of the CD58 locus in patients with MS and control subjects. These efforts identify a CD58 variant that provides further evidence of association with MS (P = 1.1 x 10(-6), OR 0.82) and the single protective effect within the CD58 locus is captured by the rs2300747(G) allele. This protective rs2300747(G) allele is associated with a dose-dependent increase in CD58 mRNA expression in lymphoblastic cell lines (P = 1.1 x 10(-10)) and in peripheral blood mononuclear cells from MS subjects (P = 0.0037). This protective effect of enhanced CD58 expression on circulating mononuclear cells in patients with MS is supported by finding that CD58 mRNA expression is higher in MS subjects during clinical remission. Functional investigations suggest a potential mechanism whereby increases in CD58 expression, mediated by the protective allele, up-regulate the expression of transcription factor FoxP3 through engagement of the CD58 receptor, CD2, leading to the enhanced function of CD4(+)CD25(high) regulatory T cells that are defective in subjects with MS.
Proceedings of the National Academy of Sciences 03/2009; 106(13):5264-9. · 9.68 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Multiple sclerosis (MS) is an organ-specific autoimmune disorder that is in part genetically determined. The gene encoding the alpha-chain of the IL-2 receptor, IL2RA, harbors alleles associated with risk to MS and other autoimmune diseases. In addition, IL2RA genetic variants correlate with the levels of a soluble form of the IL-2 receptor in subjects with type 1 diabetes and multiple sclerosis. Here, we show that the IL2RA genotypes differentially affects soluble IL-2RA (sIL-2RA) levels in MS cases vs healthy controls; the two variants associated with MS (rs12722489 and rs2104286) account for 15 and 18% of the total variance in log(10)-transformed sIL-2RA concentration in control subjects but less so in subjects with MS (2 and 5%), suggesting that perturbations associated with disease or treatment may influence sIL-2RA levels in subjects with MS. Whereas analyses demonstrate that sIL-2RA serum concentrations are a remarkably stable phenotype in both healthy controls and untreated MS subjects, a difference is observed between benign and malignant MS. These data indicate that, in addition to specific allelic variants at IL2RA, immunological perturbations associated with aggressive forms of the disease can influence sIL-2RA levels in serum of MS subjects. We also demonstrate, functionally, that sIL-2RA can inhibit IL-2 signaling, yet enhance T cell proliferation and expansion. In summary, we propose that before disease onset, strong genetic factors associated with disease risk dictate sIL-2RA levels that may be further modulated with onset of chronic systemic inflammation associated with MS.
The Journal of Immunology 03/2009; 182(3):1541-7. · 5.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although implicated in antagonistic functions, both regulatory T cells (Tregs) and Th17 effector cells play an important role in controlling autoimmune pathogenesis. Paradoxically, recent studies indicate that Tregs have the capacity to produce interleukin-17 (IL-17), although the ability of these cells to retain their suppressive function remains unknown. Here we report that human Tregs within the CD4(+)CD45RA(-)CD25(high)CCR6(+)HLA-DR(-)FoxP3(+) population produce IL-17 when activated in the presence of the proinflammatory cytokines IL-1beta and IL-6, whereas IL-17 secretion was inhibited by TGFbeta. To assess the ability of a single Treg to secrete IL-17 and to suppress in vitro immune function, we isolated clones from this population. We found that IL-17(+)/FoxP3(+) Treg clones retain suppressive function and exhibit the plasticity to secrete IL-17 or suppress depending on the nature of the stimulus provided. IL-17 production by these Treg clones was accompanied by sustained FoxP3 expression and concomitant, but reversible, loss of suppressive activity. Our data demonstrate that at the single cell level a subset of in vitro suppressive FoxP3(+) cells can be driven to secrete IL-17 under inflammatory conditions. These findings suggest a new mechanism by which inflammation can drive Tregs to secrete IL-17, thereby dampening suppression and promoting an inflammatory milieu.
Blood 02/2009; 113(18):4240-9. · 9.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: INTRODUCTION: Multiple sclerosis (MS) is a complex genetic disease characterized by chronic inflammation of the central nervous system (CNS). The pathology of MS is largely attributed to autoreactive effector T cells that penetrate the blood-brain barrier and become activated within the CNS. As autoreactive T cells are present in the blood of both patients with MS and healthy individuals, other regulatory mechanisms exist to prevent autoreactive T cells from causing immune disorders. Active suppression by regulatory T (Treg) cells plays a key role in the control of self-antigen-reactive T cells and the induction of peripheral tolerance in vivo. In particular, the importance of antigen-specific Treg cells in conferring genetic resistance to organ-specific autoimmunity and in limiting autoimmune tissue damage has been documented in many disease models including MS. RESULTS: We have found that the frequency of Tregs in MS patients is unchanged from controls, but their function measured in vitro may be diminished, correlating with impaired inhibitory activity in vivo. This review discusses the immunopathology of MS with particular focus given to regulatory T cells and their potential for the development of new therapies to treat this disease.
Journal of Clinical Immunology 10/2008; 28(6):697-706. · 3.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The recent discovery of CD4(+) T cells characterized by secretion of interleukin (IL)-17 (T(H)17 cells) and the naturally occurring regulatory FOXP3(+) CD4 T cell (nT(reg)) has had a major impact on our understanding of immune processes not readily explained by the T(H)1/T(H)2 paradigm. T(H)17 and nT(reg) cells have been implicated in the pathogenesis of human autoimmune diseases, including multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease and psoriasis. Our recent data and the work of others demonstrated that transforming growth factor-beta (TGF-beta) and IL-6 are responsible for the differentiation of naive mouse T cells into T(H)17 cells, and it has been proposed that IL-23 may have a critical role in stabilization of the T(H)17 phenotype. A second pathway has been discovered in which a combination of TGF-beta and IL-21 is capable of inducing differentiation of mouse T(H)17 cells in the absence of IL-6 (refs 6-8). However, TGF-beta and IL-6 are not capable of differentiating human T(H)17 cells and it has been suggested that TGF-beta may in fact suppress the generation of human T(H)17 cells. Instead, it has been recently shown that the cytokines IL-1beta, IL-6 and IL-23 are capable of driving IL-17 secretion in short-term CD4(+) T cell lines isolated from human peripheral blood, although the factors required for differentiation of naive human CD4 to T(H)17 cells are still unknown. Here we confirm that whereas IL-1beta and IL-6 induce IL-17A secretion from human central memory CD4(+) T cells, TGF-beta and IL-21 uniquely promote the differentiation of human naive CD4(+) T cells into T(H)17 cells accompanied by expression of the transcription factor RORC2. These data will allow the investigation of this new population of T(H)17 cells in human inflammatory disease.
Nature 08/2008; 454(7202):350-2. · 36.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Multiple sclerosis (MS) is a complex genetic disease associated with inflammation in the central nervous system (CNS) white
matter. This disease thought to be mediated by an autoimmune processes, involves autoreactive T cells and the clonal expansion
of B cells and their antibody products. Consistent with this hypothesis, MS is associated with major histocompatibility complex
genes, the occurrence of inflammatory white matter infiltrates, and can be treated with immunomodulatory and immunosuppressive
therapies. The underlying disease pathology is thought to be caused by autoreactive myelin-specific effector T cells that
enter into the CNS. Whilst autoreactive T cells are present in the periphery of healthy individuals, other regulatory mechanisms
exist to prevent autoreactive T cells from causing immune disorders. Active suppression by regulatory T (Treg) cells plays
a key role in the control of self-antigen-reactive T cells and the induction of peripheral tolerance in vivo. In particular,
the importance of antigen-specific Treg cells in conferring genetic resistance to organ specific autoimmunity and in limiting
autoimmune tissue damage has been documented in many disease models including MS. The current consensus suggests that the
frequency of Tregs in MS patients is unchanged from controls, but their function measured in vitro may be diminished, correlating
with impaired inhibitory activity in vivo. This chapter discusses the immunopathology of MS with particular focus given to
regulatory T cells and their potential for the development of new therapies to treat this disease.
12/2007: pages 265-277;
-
[show abstract]
[hide abstract]
ABSTRACT: A growing body of literature indicates that the Notch pathway can influence the activation and differentiation of peripheral murine T cells, though comparatively little is known about the effects of Notch signaling in human T cells. In the present report we demonstrate that Jagged-1-induced Notch signaling (using immobilized Jagged-1 fusion protein) during stimulation of purified human CD4+ and CD8+ T cells potently inhibits T cell proliferation and effector function, including both Th1- and Th2-associated cytokines. Inhibition of T cell activation is not due to apoptosis or disruption of proximal TCR signaling, but is associated with up-regulation of GRAIL (gene related to anergy in lymphocytes) in CD4+ T cells, with modest effects on other E3 ubiquitin ligases such as c-Cbl and Itch. When evaluated for its effects on CD4+ T cell differentiation, Jagged-1-mediated signaling inhibits T cell cytokine secretion with no significant effect on proliferative responses. Collectively, these data demonstrate that Notch signaling in human T cells induced by Jagged-1 promotes a novel form of T cell hyporesponsiveness that differs from anergy, whereby primary T cell proliferation and cytokine secretion are potently inhibited, and effector function but not proliferative capacity are ameliorated upon secondary stimulation.
The Journal of Immunology 06/2007; 178(10):6158-63. · 5.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: As self-recognition is fundamental to the efficient operation of the immune system, a number of mechanisms have evolved to keep this potential pathologic self-reactivity in check. Thus, even though the majority of strongly self-reactive T cells are deleted in the thymus during T-cell maturation, a number of mature T cells that recognize self-antigens can be found in the peripheral circulation in healthy individuals as well as in patients with autoimmune disease. These self-reactive cells are kept in a non-responsive state in healthy individuals while they appear to be involved in the etiology of a number of autoimmune diseases in patients. The primary role of a relatively recently identified T-cell population, referred to as natural CD4+ CD25+ regulatory T cells, is to modulate the activity of these self-reactive cells. Although it is still unclear how these regulatory cells function, they can inhibit the activation of other potentially pathologic T cells in in vitro assays. Using such assays, regulatory T cells isolated from patients with a number of autoimmune diseases have been shown to exhibit reduced inhibitory function as compared with those isolated from healthy individuals. In this review, we discuss human natural regulatory T cells, what is known about their function, and their associations with specific autoimmune diseases.
Immunological Reviews 09/2006; 212:203-16. · 11.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: While there is now little debate about the existence or relevance of regulatory populations of T cells to a variety of human diseases, including cancer, there is considerable debate about the ontogeny, phenotype, and mechanisms of action of given regulatory T cell populations. This review will limit itself to discussion to two distinct populations of CD4+ regulatory T cells: T cells co-expressing the CD25 receptor (Tregs), and type 1 regulatory (Tr1) T cells. Attention will be focused on the definition and role of these regulatory T cell populations in human cancers.
Seminars in Cancer Biology 05/2006; 16(2):98-105. · 6.47 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A wealth of data indicates that tumor immunity directed against a wide variety of malignancies is suppressed in cancer patients. Recent studies have explored the role of 'natural' CD4(+)CD25(+) regulatory T cells (Tregs) in the suppression of tumor immunity in cancer patients. It is now clear, using multiple phenotypic and functional criteria, that the frequency of Tregs is increased in the peripheral blood of cancer patients as well as within the tumor microenvironment. Human Tregs with specificity for tumor-associated antigens have recently been identified, and murine studies have demonstrated that vaccination with tumor-associated antigens can expand Tregs, posing a challenge to cancer vaccine strategies. However, a variety of approaches, including depletion of Tregs or modulation of their activity in vivo, might soon enhance the efficacy of existing cancer vaccines directed against a variety of malignancies.
Current Opinion in Immunology 05/2006; 18(2):214-9. · 9.52 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: It has been known for decades that circulating human CD4 cells can express functional MHC class II molecules that induce T cell nonresponsiveness with Ag presentation. Because there is significant expression of MHC class II (MHC-II) determinants (DR) on a subpopulation CD4+ CD25(high) regulatory T cells (Treg), we examined the function of CD4 cells expressing MHC-DR. We demonstrate that MHC-II expression on human CD4+ CD25(high) T cells identifies a functionally distinct population of Treg that induces early contact-dependent suppression that is associated with high Foxp3 expression. In striking contrast, MHC-II- CD4+ CD25(high) Treg induce early IL-4 and IL-10 secretion and a late Foxp3-associated contact-dependent suppression. The DR expressing CD25(high) Treg express higher levels of Foxp3 message and protein, compared with the DR- CD25(high) Treg population. Direct single-cell cloning of CD4+ CD25(high) Treg revealed that, regardless of initial DR expression, ex vivo expression of CD25(high), and not DR, predicted which clones would exhibit contact-dependent suppression, high levels of Foxp3 message, and an increased propensity to become constitutive for DR expression. Thus, the direct ex vivo expression of MHC-II in the context of CD25(high) identifies a mature, functionally distinct regulatory T cell population involved in contact-dependent in vitro suppression.
The Journal of Immunology 05/2006; 176(8):4622-31. · 5.79 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Multiple sclerosis (MS) is a complex genetic disease associated with inflammation in the central nervous system (CNS) white matter and is thought to be mediated by autoimmune processes. Clonal expansion of B cells, their antibody products, and T cells, hallmarks of inflammation in the CNS, are found in MS. The association of the disease with major histocompatibility complex genes, the inflammatory white matter infiltrates, similarities with animal models, and the observation that MS can be treated with immunomodulatory and immunosuppressive therapies support the hypothesis that autoimmunity plays a major role in the disease pathology. This review discusses the immunopathology of MS with particular focus given to regulatory T cells and the role of B cells and antibodies, immunomodulatory therapeutics, and finally new directions in MS research, particularly new methods to define the molecular pathology of human disease with high-throughput examination of germline DNA haplotypes, RNA expression, and protein structures that will allow the generation of a new series of hypotheses that can be tested to develop better understandings and therapies for this disease.
Immunological Reviews 05/2005; 204:208-31. · 11.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The importance of CD4+ CD25+ regulatory T cells (Treg) in maintaining immune homeostasis has been directly demonstrated in vivo by their manipulation in a number of autoimmune disease models in the mouse. In the study of human regulatory cells, we have found that the cells that consistently demonstrate the in vitro regulatory activity most similar to that described for murine cells in vitro are best identified by restricting the isolation of CD25+ CD4 T cells to those cells expressing only the highest levels of CD25, representing approximately 2-3% of total CD4 T cells. Thus, it is the CD4+ CD25high subset that exhibits the in vitro characteristics that are identical to the CD4+ CD25+ regulatory cells initially characterized in mice. Furthermore, the cells expressing medium to low levels of CD25 not only do not exhibit suppressive activity directly ex vivo, but also actually contain a significant proportion of CD62L- CD4 T cells which are believed to be in vivo activated T cells. Due to the inherent difficulties in using CD25 as a marker for the purification of Treg cells, the finding that selection of the CD25high subset of CD4+ CD25+ T cells minimizes the co-isolation of contaminating activated CD4 T cells is important for future studies of these Treg cells in human disease. In order to perform these studies, we first had to establish a highly reproducible 'micro in vitro co-culture' assay system to enable the functional analysis of high-purity, but low-yield regulatory populations derived from FACS sorting. With this system in place, we are poised to dissect the potential heterogeneity of mechanisms employed by highly specific subpopulations of CD4+ CD25+ cells.
Clinical Immunology 05/2005; 115(1):10-8. · 4.05 Impact Factor
-
12/2004: pages 133-151;
-
[show abstract]
[hide abstract]
ABSTRACT: Although central and peripheral tolerance are important for the regulation of human immune responses to self- and microbial antigens, an important role of suppressor CD4(+) CD25(+) T cells is suggested from the recent investigations of human autoimmune diseases and HIV. These new data provide increasing evidence that altered function of CD4(+) CD25(+) T cells may be an important factor in a wide range of human inflammatory and infectious diseases.
Journal of Experimental Medicine 09/2004; 200(3):273-6. · 13.85 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: CD4+CD25+ regulatory T cells contribute to the maintenance of peripheral tolerance by active suppression because their deletion causes spontaneous autoimmune diseases in mice. Human CD4+ regulatory T cells expressing high levels of CD25 are suppressive in vitro and mimic the activity of murine CD4+CD25+ regulatory T cells. Multiple sclerosis (MS) is an inflammatory disease thought to be mediated by T cells recognizing myelin protein peptides. We hypothesized that altered functions of CD4+CD25hi regulatory T cells play a role in the breakdown of immunologic self-tolerance in patients with MS. Here, we report a significant decrease in the effector function of CD4+CD25hi regulatory T cells from peripheral blood of patients with MS as compared with healthy donors. Differences were also apparent in single cell cloning experiments in which the cloning frequency of CD4+CD25hi T cells was significantly reduced in patients as compared with normal controls. These data are the first to demonstrate alterations of CD4+CD25hi regulatory T cell function in patients with MS.
Journal of Experimental Medicine 05/2004; 199(7):971-9. · 13.85 Impact Factor
