Oral tolerance induction with antigen conjugated to cholera toxin B subunit generates both Foxp3+CD25+ and Foxp3-CD25- CD4+ regulatory T cells.
ABSTRACT Oral administration of Ag coupled to cholera toxin B subunit (CTB) efficiently induces peripheral immunological tolerance. We investigated the extent to which this oral tolerance is mediated by CD25+CD4+ regulatory T cells (T(reg)). We found that total T(reg), KJ1-26+ T(reg) and CTLA-4+ T(reg) were all increased in Peyer's patches, mesenteric lymph nodes, and, to a lesser extent, in spleen of mice after intragastric administration of OVA/CTB conjugate, which also increased TGF-beta in serum. This could be abolished by co-administering cholera toxin or by treatment with anti-TGF-beta mAb. CD25+ T(reg), but also CD25-CD4+ T cells from OVA/CTB-treated BALB/c or DO11.10 mice efficiently suppressed effector T cell proliferation and IL-2 production in vitro. Following adoptive transfer, both T cell populations also suppressed OVA-specific T cell and delayed-type hypersensitivity responses in vivo. Foxp3 was strongly expressed by CD25+ T(reg) from OVA/CTB-treated mice, and treatment also markedly expanded CD25+Foxp3+ T(reg). Furthermore, in Rag1(-/-) mice that had adoptively received highly purified Foxp3-CD25-CD4+ OT-II T cells OVA/CTB feeding efficiently induced CD25+ T(reg) cells, which expressed Foxp3 more strongly than naturally developing T(reg) and also had stronger ability to suppress effector OT-II T cell proliferation. A remaining CD25- T cell population, which also became suppressive in response to OVA/CTB treatment, did not express Foxp3. Our results demonstrate that oral tolerance induced by CTB-conjugated Ag is associated with increase in TGF-beta and in both the frequency and suppressive capacity of Foxp3+ and CTLA-4+ CD25+ T(reg) together with the generation of both Foxp3+ and Foxp3-CD25- CD4+ T(reg).
SourceAvailable from: Janneke N Samsom[Show abstract] [Hide abstract]
ABSTRACT: Celiac disease (CD) is an intestinal inflammation driven by gluten-reactive CD4(+) T cells. Due to lack of selective markers it has not been determined whether defects in inducible regulatory T cell (Treg) differentiation are associated with CD. This is of importance as changes in numbers of induced Treg could be indicative of defects in mucosal tolerance development in CD. Recently, we have shown that, after encounter of retinoic acid during differentiation, circulating gut-imprinted T cells express CD62L(neg)CD38(+). Using this new phenotype, we now determined whether alterations occur in the frequency of natural CD62L(+)Foxp3(+) Treg or mucosally-imprinted CD62L(neg)CD38(+)Foxp3(+) Treg in peripheral blood of CD patients. In particular, we compared pediatric CD, aiming to select for disease at onset, with adult CD. Cell surface markers, intracellular Foxp3 and Helios were determined by flow cytometry. Foxp3 expression was also detected by immunohistochemistry in duodenal tissue of CD patients. In children, the percentages of peripheral blood CD4(+)Foxp3(+) Treg were comparable between CD patients and healthy age-matched controls. Differentiation between natural and mucosally-imprinted Treg on the basis of CD62L and CD38 did not uncover differences in Foxp3. In adult patients on gluten-free diet and in refractory CD increased percentages of circulating natural CD62L(+)Foxp3(+) Treg, but normal mucosally-imprinted CD62L(neg)CD38(+)Foxp3(+) Treg frequencies were observed. Our data exclude that significant numeric deficiency of mucosally-imprinted or natural Foxp3(+) Treg explains exuberant effector responses in CD. Changes in natural Foxp3(+) Treg occur in a subset of adult patients on a gluten-free diet and in refractory CD patients.PLoS ONE 07/2013; 8(7):e68432. DOI:10.1371/journal.pone.0068432 · 3.53 Impact Factor
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ABSTRACT: Abstract In the 1950s, the discovery of autoantibodies produced by B cells seemed to provide a compelling mechanism underlying autoimmune diseases. The discovery of T regulatory cells and other T helper cell subsets shifted the field back towards a T cell central view. The success of rituxan, a chimeric mAb targeting CD20 on B cells, in the treatment of rheumatoid arthritis forced a review of the role of B cells in autoimmunity. Rituxan was first developed to treat lymphomas, and it also proved effective in treating rheumatoid arthritis, a disease not previously associated with B cells. One of the side effects of rituxan is a pronounced depletion of peripheral blood B cells, an effect that seemed to correlate with effectiveness in preclinical and clinical models of autoimmune diseases. B cell depletion was also shown to affect T cell populations, suggesting an antibody-independent mechanism through which B cells influenced rheumatic disease. Most recently, the identification of cytokine producing B cells (B regulatory and B effector cells) that modulate tolerance has added to our understanding of human health and disease and the mechanisms that break tolerance, as the B cell cytokine network produced by B cell subsets were shown to influence T cell numbers, as well as the polarization of T cell subsets (Tregs/Th1/Th2). Therefore, B cells have once again taken the center stage in tolerance and autoimmunity. Here, we review the role of B cells in autoimmunity, mainly through their ability to produce cytokines.Autoimmunity 11/2013; DOI:10.3109/08916934.2013.856006 · 2.75 Impact Factor
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ABSTRACT: Multiple sclerosis and its animal model, EAE, are crucially dependent on the invasion of activated autoreactive lymphocytes and blood macrophages into the central nervous system. Proinflammatory mononuclear cells and activated local microglia mediate inflammation, demyelination and axonal damage at the target organ. Previously, we observed that the administration of a hybrid between the synapsin ABC domains and the B subunit of E. coli heat labile-enterotoxin (LTBABC) to rats with EAE ameliorated disease by modulating the peripheral Th1 response to myelin basic protein (MBP). In the present study, we investigated the effect of LTBABC administration on proinflammatory cell frequency into the central nervous system of rats with EAE. Treatment with the hybrid in the inductive phase of EAE attenuated disease severity and diminished histological inflammatory infiltrates and demyelination in the spinal cord of rats with acute EAE. Lower frequencies of infiltrating and local macrophages as well as CD4+ T cells that produce the proinflammatory cytokines IFN-γ and IL-17 were found at the target organ. Concomitantly, low levels of INF-γ and IL-17 and increased levels of IL-10 were measured in cultures of CNS infiltrating cells and spinal cord tissue. An increased frequency of CD4+CD25+Foxp3 cells was observed at the disease peak and at the beginning of the recovery stage. These results provide further evidence for the immunomodulatory properties of the fusion protein LTBABC in autoimmune demyelinating disease affecting the central nervous system.Neuroscience 07/2014; 277. DOI:10.1016/j.neuroscience.2014.06.070 · 3.33 Impact Factor