scholarly journals Suppression of allergic airway inflammation by helminth-induced regulatory T cells

2005 ◽  
Vol 202 (9) ◽  
pp. 1199-1212 ◽  
Author(s):  
Mark S. Wilson ◽  
Matthew D. Taylor ◽  
Adam Balic ◽  
Constance A.M. Finney ◽  
Jonathan R. Lamb ◽  
...  

Allergic diseases mediated by T helper type (Th) 2 cell immune responses are rising dramatically in most developed countries. Exaggerated Th2 cell reactivity could result, for example, from diminished exposure to Th1 cell–inducing microbial infections. Epidemiological studies, however, indicate that Th2 cell–stimulating helminth parasites may also counteract allergies, possibly by generating regulatory T cells which suppress both Th1 and Th2 arms of immunity. We therefore tested the ability of the Th2 cell–inducing gastrointestinal nematode Heligmosomoides polygyrus to influence experimentally induced airway allergy to ovalbumin and the house dust mite allergen Der p 1. Inflammatory cell infiltrates in the lung were suppressed in infected mice compared with uninfected controls. Suppression was reversed in mice treated with antibodies to CD25. Most notably, suppression was transferable with mesenteric lymph node cells (MLNC) from infected animals to uninfected sensitized mice, demonstrating that the effector phase was targeted. MLNC from infected animals contained elevated numbers of CD4+CD25+Foxp3+ T cells, higher TGF-β expression, and produced strong interleukin (IL)-10 responses to parasite antigen. However, MLNC from IL-10–deficient animals transferred suppression to sensitized hosts, indicating that IL-10 is not the primary modulator of the allergic response. Suppression was associated with CD4+ T cells from MLNC, with the CD4+CD25+ marker defining the most active population. These data support the contention that helminth infections elicit a regulatory T cell population able to down-regulate allergen induced lung pathology in vivo.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 812-812 ◽  
Author(s):  
Emanuela I Sega ◽  
Dennis Leveson-Gower ◽  
Vu H. Nguyen ◽  
Robert Negrin

Abstract Graft versus host disease (GVHD) is a major complication of hematopoietic stem cell transplantation resulting from donor T cell reactivity against host tissue antigens. CD4+CD25+Foxp3+ regulatory T cells (Treg) are known to be important in maintaining self tolerance and preventing autoimmunity. Using murine models of acute GVHD in which allogeneic bone marrow cells are transplanted into lethally irradiated hosts, we and others have shown that donor Treg are able to suppress GVHD induced by donor allogeneic T cells and dramatically improve survival. Treg are rare and suppression of GVHD requires adequate numbers of Treg in relation to the number of conventional T cells (Tcon). To overcome this problem, expansion of Treg has been performed, however there has not been a head to head comparison of the function of expanded vs fresh Treg. Highly purified CD4+CD25+Foxp3+ T cells (>98% purity) were expanded using anti-CD3/anti-CD28 dynabeads and 1000 U/ml IL-2. Under these conditions, after five days Treg expanded up to 13 fold while maintaining high Foxp3 expression levels (85–90%). Longer expansion periods result in more T cell expansion but an overgrowth of Foxp3 negative T cells. In a mixed lymphocyte reaction assay, the ex-vivo expanded Treg efficiently suppressed the proliferation of alloreactive T cells. The expanded Treg were evaluated in an in vivo acute GVHD mouse model in direct comparison with freshly isolated Treg using a novel bioluminescent imaging assay that allowed for assessment of Tcon proliferation in addition to traditional metrics of GVHD severity including weight gain, survival and GVHD score. Initial experiments show that, similar to freshly isolated Treg, the ex-vivo expanded Treg suppress GVHD symptoms and improve survival, although a greater number of expanded Treg were required comparable to freshly isolated Treg. The mean GVHD score for the Tcon alone group was 5.8±1.02. Fresh Treg added at 1:1 ratio decreased the GVHD score to 0.75±0.25 (p=0.0036). Ex-vivo expanded Treg demonstrated a dose-dependent decrease in GVHD score, although four times more expanded Treg were needed to obtain a similar reduction in GVHD score (0.50±0.5, p=0.0036). This observed difference in potency was not due to the ex-vivo expanded Treg being short-lived when infused in mice. Bioluminescence imaging of luciferase positive (luc+) cultured Treg showed the same in vivo persistence as freshly isolated Treg. The ability to expand ex-vivo generated Treg is greater than the difference in potency, making ex-vivo expanded Treg potentially a viable option for treatment of GVHD, however, increased ratios of Treg:Tcon are likely to be required.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 349-349 ◽  
Author(s):  
Tuna Mutis ◽  
Henk Rozemuller ◽  
Maarten E. Emmelot ◽  
Tineke Aarts-Riemens ◽  
Vivienne Verweij ◽  
...  

Abstract The curative Graft-vs-Tumor effect (GvT) of allogeneic Stem cell transplantation (SCT) is frequently complicated with life threatening Graft-vs-Host Disease (GvHD). In mice, prevention of GvHD, without abrogation of GvT is possible by co-transplantation of naturally occurring regulatory T cells (Tregs) with SC grafts. Consistent with these murine studies, we recently demonstrated that also human Tregs possess potent GvHD-downregulatory capacities in a xenogeneic(x) model, where x-GvHD is induced by infusion of autologous human T cells in RAG2−/−γc−/− mice (Mutis et al. Clin. Cancer Res.2006, 12: 5520–5525). Towards clinical application of Tregs, we now explored the impact of human Treg-administration on GvT in a bioluminescence imaging (BLI) based human-GvT model in the RAG2−/−γc−/− mice. In this model, mice inoculated with luciferase (LUC)-transduced human myeloma (MM) cell lines developed BLI-detectable, progressive, MM-like multifocal tumors exclusively in the bone marrow (BM). Full blown tumors were effectively eliminated by infusion of allogeneic human PBMC. This treatment also caused lethal x-GvHD as expected. In this setting, co-infusion of human PBMC with autologous, in vitro cultured Tregs at a 1:1 Treg: T effector cell ratio had no adverse effects on the development of GvT while significantly reducing the lethality of x-GvHD. In vitro analyses of sacrificed mice at day 21 revealed that administered Tregs homed to BM and spleen, significantly downregulated the total numbers of IFN-γ-producing CD4+ and CD8+ T cells responding to CD3 mediated signals, but had no downregulatory effect on the frequencies of IFN-γ-producing T cells responding to tumor cells. There was also no downregulation of cytotoxic activity against tumor cells in Treg-treated mice. Conclusively, these results showed that Tregs, at doses which are inhibitory for x-GvHD-inducing T cells, could maintain the GvT effect by allowing T cell reactivity against tumor cells. Human Tregs thus still hold promise as attractive cellular tools for separating GvT from GvHD.


2005 ◽  
Vol 202 (11) ◽  
pp. 1539-1547 ◽  
Author(s):  
Jennifer Kearley ◽  
Jane E. Barker ◽  
Douglas S. Robinson ◽  
Clare M. Lloyd

Deficient suppression of T cell responses to allergen by CD4+CD25+ regulatory T cells has been observed in patients with allergic disease. Our current experiments used a mouse model of airway inflammation to examine the suppressive activity of allergen-specific CD4+CD25+ T cells in vivo. Transfer of ovalbumin (OVA) peptide–specific CD4+CD25+ T cells to OVA-sensitized mice reduced airway hyperreactivity (AHR), recruitment of eosinophils, and T helper type 2 (Th2) cytokine expression in the lung after allergen challenge. This suppression was dependent on interleukin (IL) 10 because increased lung expression of IL-10 was detected after transfer of CD4+CD25+ T cells, and regulation was reversed by anti–IL-10R antibody. However, suppression of AHR, airway inflammation, and increased expression of IL-10 were still observed when CD4+CD25+ T cells from IL-10 gene–deficient mice were transferred. Intracellular cytokine staining confirmed that transfer of CD4+CD25+ T cells induced IL-10 expression in recipient CD4+ T cells, but no increase in IL-10 expression was detected in airway macrophages, dendritic cells, or B cells. These data suggest that CD4+CD25+ T cells can suppress the Th2 cell–driven response to allergen in vivo by an IL-10–dependent mechanism but that IL-10 production by the regulatory T cells themselves is not required for such suppression.


2019 ◽  
Vol 202 (12) ◽  
pp. 3447-3457 ◽  
Author(s):  
Yi Xu ◽  
Yanmei Cheng ◽  
David J. Baylink ◽  
Samiksha Wasnik ◽  
Gati Goel ◽  
...  
Keyword(s):  
T Cells ◽  

2021 ◽  
Vol 22 (16) ◽  
pp. 8366
Author(s):  
Ignacio Relaño-Rodríguez ◽  
María de la Sierra Espinar-Buitrago ◽  
Vanessa Martín-Cañadilla ◽  
Rafael Gómez-Ramírez ◽  
María Ángeles Muñoz-Fernández

Human immunodeficiency virus (HIV-1) is still a major problem, not only in developing countries but is also re-emerging in several developed countries, thus the development of new compounds able to inhibit the virus, either for prophylaxis or treatment, is still needed. Nanotechnology has provided the science community with several new tools for biomedical applications. G2-S16 is a polyanionic carbosilane dendrimer capable of inhibiting HIV-1 in vitro and in vivo by interacting directly with viral particles. One of the main barriers for HIV-1 eradication is the reservoirs created in primoinfection. These reservoirs, mainly in T cells, are untargetable by actual drugs or immune system. Thus, one approach is inhibiting HIV-1 from reaching these reservoir cells. In this context, macrophages play a main role as they can deliver viral particles to T cells establishing reservoirs. We showed that G2-S16 dendrimer is capable of inhibiting the infection from infected macrophages to healthy T CD4/CD8 lymphocytes by eliminating HIV-1 infectivity inside macrophages, so they are not able to carry infectious particles to other body locations, thus preventing the reservoirs from forming.


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