| 1. |
- Cardell, Susanna, 1959, et al.
(författare)
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Tolerization of diabetogenic CD4+T cells by intranasal treatment with CTA1R7K-DD containing specific peptide through the induction of FoxP3+Treg cells
- 2012
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Ingår i: Journal of Immunology. - 0022-1767. ; 188
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Type I diabetes (T1D) results from immune destruction of insulin producing β-cells in the pancreas islets. Diabetogenic CD4+ T cells are key cells in the autoimmune process. To achieve tolerization of diabetogenic CD4+ T cells would therefore be an important advancement in the development of treatments of T1D. We previously described that a mutated (R7K), enzyme killed, form of the cholera toxin A1 subunit based adjuvant CTA1-DD induces specific tolerance rather than enhancement of immunity. Intranasal (i n) treatment with CTA1R7K-DD containing a type II collagen peptide reduced in vitro recall responses to the peptide, and moreover, ameliorated collagen induced arthritis in mice. Here, we use CTA1R7K-DD to investigate tolerization of diabetogenic CD4+ T cells of the non-obese diabetic (NOD) mouse, exploring diabetogenic TCR transgenic BDC2.5 CD4+ T cells. I n treatment of BDC2.5 NOD mice with CTA1R7K-DD containing a peptide specific for the BDC2.5 TCR reduced proliferation and IFN-{gamma} production to in vitro peptide stimulation. Transfer of CD4+ BDC2.5 T cells to NOD.scid mice results in T1D development in 80-100% of recipient mice. In contrast, recipients of cells from BDC2.5 NOD mice treated with the CTA1R7K-DD peptide construct remained healthy. The i n treatment resulted in systemic increase in the frequency of CD4+ BDC2.5 transgenic T cells expressing FoxP3, suggesting that CTA1R7K-peptide-DD induces specific CD4+ Treg cells preventing T1D development.
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| 2. |
- Fahlén-Yrlid, Linda, 1973, et al.
(författare)
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CD11c(high )dendritic cells are essential for activation of CD4+ T cells and generation of specific antibodies following mucosal immunization.
- 2009
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 183:8, s. 5032-41
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Tidskriftsartikel (refereegranskat)abstract
- To generate vaccines that protect mucosal surfaces, a better understanding of the cells required in vivo for activation of the adaptive immune response following mucosal immunization is required. CD11c(high) conventional dendritic cells (cDCs) have been shown to be necessary for activation of naive CD8(+) T cells in vivo, but the role of cDCs in CD4(+) T cell activation is still unclear, especially at mucosal surfaces. The activation of naive Ag-specific CD4(+) T cells and the generation of Abs following mucosal administration of Ag with or without the potent mucosal adjuvant cholera toxin were therefore analyzed in mice depleted of CD11c(high) cDCs. Our results show that cDCs are absolutely required for activation of CD4(+) T cells after oral and nasal immunization. Ag-specific IgG titers in serum, as well as Ag-specific intestinal IgA, were completely abrogated after feeding mice OVA and cholera toxin. However, giving a very high dose of Ag, 30-fold more than required to detect T cell proliferation, to cDC-ablated mice resulted in proliferation of Ag-specific CD4(+) T cells. This proliferation was not inhibited by additional depletion of plasmacytoid DCs or in cDC-depleted mice whose B cells were MHC-II deficient. This study therefore demonstrates that cDCs are required for successful mucosal immunization, unless a very high dose of Ag is administered.
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| 3. |
- Mattsson, Johan, et al.
(författare)
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Cholera toxin adjuvant promotes a balanced Th1/Th2/Th17 response independently of IL-12 and IL-17 by acting on Gsα in CD11b(+) DCs.
- 2015
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Ingår i: Mucosal immunology. - : Elsevier BV. - 1935-3456 .- 1933-0219. ; 8:4, s. 815-827
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Tidskriftsartikel (refereegranskat)abstract
- Despite an extensive literature on the mechanism of action of cholera toxin (CT), we still lack critical information about how the toxin acts as an adjuvant and, especially, which dendritic cells (DCs) are the target cells. Although a T helper type 2 (Th2)-skewing effect of CT is most commonly reported, effective priming of Th17 cells as well as suppression of Th1 responses are well documented. However, the ability of CT to block interferon regulatory factor 8 (IRF8) function and interleukin (IL)-12 production in DCs, which blocks CD8α DC and Th1 cell development, is inconsistent with priming of Th1 and CD8 T cells in many other reports. This prompted us to investigate the adjuvant effect of CT in wild-type, IL-12p40-/-, Batf3-/-, and IL-17A-/- mice and in mice that selectively lack the Gsα target protein for CT adenosine diphosphate (ADP)-ribosylation in DCs. We found that CT promoted Th1 priming independently of IL-12, and whereas Th2 and also Th17 responses were augmented, the gut IgA responses did not require IL-17A. Adjuvanticity was intact in Batf3-/- mice, lacking CD8α(+) DCs, but completely lost in mice with Gsα-deficient CD11c cells. Thus, our data demonstrate that the adjuvant effect requires Gsα expression in CD11b(+) DCs, and that priming of mucosal IgA and CD4 T cells appears unbiased and is independent of IL-12 and IL-17A.Mucosal Immunology advance online publication, 26 November 2014; doi:10.1038/mi.2014.111.
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| 4. |
- Westlund, Jessica, et al.
(författare)
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CD47-deficient mice have decreased production of intestinal IgA following oral immunization but a maintained capacity to induce oral tolerance.
- 2012
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Ingår i: Immunology. - Malden : Wiley. - 1365-2567 .- 0019-2805. ; 135:3, s. 236-44
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Tidskriftsartikel (refereegranskat)abstract
- Signal regulatory protein α (SIRPα/CD172a), expressed by myeloid cells including CD11b(+) dendritic cells, interacts with ubiquitously expressed CD47 to mediate cell-cell signalling and therefore, may be pivotal in the development of tolerance or immunity. We show that in mice deficient in CD47 (CD47(-/-) ) the cellularity in gut-associated lymphoid tissues is reduced by 50%. In addition, the frequency of CD11b(+) CD172a(+) dendritic cells is significantly reduced in the gut and mesenteric lymph nodes, but not in Peyer's patches. Activation of ovalbumin (OVA)-specific CD4(+) T cells in the mesenteric lymph nodes after feeding OVA is reduced in CD47(-/-) mice compared with wild-type however, induction of oral tolerance is maintained. The addition of cholera toxin generated normal serum anti-OVA IgG and IgA titres but resulted in reduced intestinal anti-OVA IgA in CD47(-/-) mice. Replacing the haematopoietic compartment in CD47(-/-) mice with wild-type cells restored neither the cellularity in gut-associated lymphoid tissues nor the capacity to produce intestinal anti-OVA IgA following immunization. This study demonstrates that CD47 signalling is dispensable for oral tolerance induction, whereas the expression of CD47 by non-haematopoietic cells is required for intestinal IgA B-cell responses. This suggests that differential CD4 T cell functions control tolerance and enterotoxin-induced IgA immunity in the gut.
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| 5. |
- Hasselberg, Annemarie, 1973, et al.
(författare)
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ADP-ribosylation control the outcome of tolerance or enhanced priming following mucosal immunization.
- 2010
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 184:6, s. 2776-2784
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating evidence suggests that the dichotomy between tolerance and active IgA immunity in mucosal immune responses is regulated at the APC level. Therefore, immunomodulation of the APC could be an effective mechanism to control the two response patterns. In this study, we demonstrate that ADP-ribosylation controls the outcome of tolerance or active effector T cell immunity to an internal peptide p323–339 from OVA inserted into the cholera toxin (CT)-derived CTA1-OVA-DD adjuvant. We found that a single point mutation, CTA1R7K-OVA-DD, resulting in lack of enzymatic activity, promoted peptide-specific tolerance in TCR transgenic CD4+ T cells following a single intranasal (i.n.) treatment. The CTA1R7K-OVA-DD–induced tolerance was strong, long-lasting, and impaired the ability of adoptively transferred naive peptide-specific CD4+ T cells to respond to Ag-challenge, irrespective if this was given i.p or i.n. The tolerance correlated with induction of regulatory T cells of the regulatory T type 1 characterized by CD25−Foxp3−CD4+ T cells producing IL-10. In contrast, in IL-10–deficient mice, no peptide-specific tolerance was observed, and these mice exhibited unimpaired CD4+ T cell responsiveness to recall Ag irrespective of if they were untreated (PBS) or treated i.n. with CTA1R7K-OVA-DD. Thus, for the first time, we can provide unequivocal proof that ADP-ribosylation can control the outcome of mucosal Ag exposure from tolerance to an enhanced effector CD4+ T cell response. The exploitation of this system for clinical treatment of autoimmune diseases is discussed.
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| 6. |
- Odqvist, Lina, et al.
(författare)
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Genetic variations in A20 DUB domain provide a genetic link to citrullination and neutrophil extracellular traps in systemic lupus erythematosus
- 2019
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 78:10, s. 1363-1370
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Genetic variations in TNFAIP3 (A20) de-ubiquitinase (DUB) domain increase the risk of systemic lupus erythematosus (SLE) and rheumatoid arthritis. A20 is a negative regulator of NF-κB but the role of its DUB domain and related genetic variants remain unclear. We aimed to study the functional effects of A20 DUB-domain alterations in immune cells and understand its link to SLE pathogenesis. Methods: CRISPR/Cas9 was used to generate human U937 monocytes with A20 DUB-inactivating C103A knock-in (KI) mutation. Whole genome RNA-sequencing was used to identify differentially expressed genes between WT and C103A KI cells. Functional studies were performed in A20 C103A U937 cells and in immune cells from A20 C103A mice and genotyped healthy individuals with A20 DUB polymorphism rs2230926. Neutrophil extracellular trap (NET) formation was addressed ex vivo in neutrophils from A20 C103A mice and SLE-patients with rs2230926. Results: Genetic disruption of A20 DUB domain in human and murine myeloid cells did not give rise to enhanced NF-κB signalling. Instead, cells with C103A mutation or rs2230926 polymorphism presented an upregulated expression of PADI4, an enzyme regulating protein citrullination and NET formation, two key mechanisms in autoimmune pathology. A20 C103A cells exhibited enhanced protein citrullination and extracellular trap formation, which could be suppressed by selective PAD4 inhibition. Moreover, SLE-patients with rs2230926 showed increased NETs and increased frequency of autoantibodies to citrullinated epitopes. Conclusions: We propose that genetic alterations disrupting the A20 DUB domain mediate increased susceptibility to SLE through the upregulation of PADI4 with resultant protein citrullination and extracellular trap formation.
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| 7. |
- Sedimbi, Sai Kiran, 1982, et al.
(författare)
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PAMP mediated activation of type II NKT cells
- 2011
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Ingår i: 6th International Symposium on CD1d and NK T cells, September 23-27, 2011, Chicago, IL, USA.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Type 2 NK T cells are known to have immuno-stimulatory/regulatory effects on innate and adaptive immune responses to infections, tumors and autoimmunity. However, there is a paucity of information regarding the mechanism of activation of type 2 NK T cells in various immune responses. We aim to identify the signals required for activation of type 2 NK T cells by pathogen associated molecular patterns (PAMPs). Using type 2 NK T cells from a transgenic mouse model (24αβ B6: over expressing Vα3.2/Vβ9 type 2 NK T cells), we performed co-culture experiments with enriched primary type 2 NK T cells and bone marrow derived dendritic cells (DC) from mice that were WT or harbouring various gene deletions. Several TLR ligands activated the type 2 NK T cells in the co-cultures. The experiments revealed that type 2 NK T cells were not activated directly by PAMPs, but required the presence of antigen presenting cells such as DC. Transwell experiments suggest that activation occurred in a cell-contact dependent fashion. Further, we find that IL12 was absolutely essential for activation, while type I interferons appear to be dispensible. Surprisingly, CD1d was not required for type 2 NK T cell activation by PAMPs. Our results suggest that in addition to IL-12, other DC mediated signals were required for the CD1d-independent activation of type 2 NK T cells by PAMPs. Ongoing studies are investigating further which signals are required for NKT cell activation and the type of immune response induced.
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| 8. |
- Sjökvist Ottsjö, Louise, 1986, et al.
(författare)
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Induction of mucosal immune responses against Helicobacter pylori infection after sublingual and intragastric route of immunization
- 2017
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Ingår i: Immunology. - : Wiley. - 0019-2805. ; 150:2, s. 172-183
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Tidskriftsartikel (refereegranskat)abstract
- There is a current lack of effective mucosal vaccines against major gastroenteric pathogens and particularly against Helicobacter pylori, which causes a chronic infection that can lead to peptic ulcers and gastric cancer in a subpopulation of infected individuals. Mucosal CD4(+) T-cell responses have been shown to be essential for vaccine-induced protection against H. pylori infection. The current study addresses the influence of the adjuvant and site of mucosal immunization on early CD4(+) T-cell priming to H. pylori antigens. The vaccine formulation consisted of H. pylori lysate antigens and mucosal adjuvants, cholera toxin (CT) or a detoxified double-mutant heat-labile enterotoxin from Escherichia coli (dmLT), which were administered by either the sublingual or intragastric route. We report that in vitro, adjuvants CT and dmLT induce up-regulation of pro-inflammatory gene expression in purified dendritic cells and enhance the H. pylori-specific CD4(+) T-cell response including interleukin-17A (IL-17A), interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha) secretion. In vivo, sublingual immunization led to an increased frequency of IL-17A(+), IFN-gamma(+) and TNF-alpha(+) secreting CD4(+) T cells in the cervical lymph nodes compared with in the mesenteric lymph nodes after intragastric immunization. Subsequently, IL-17A(+) cells were visualized in the stomach of sublingually immunized and challenged mice. In summary, our results suggest that addition of an adjuvant to the vaccine clearly activated dendritic cells, which in turn, enhanced CD4(+) T-cell cytokines IL-17A, IFN-gamma and TNF-alpha responses, particularly in the cervical lymph nodes after sublingual vaccination.
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| 9. |
- Tripathi, Prabhanshu, et al.
(författare)
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Innate and adaptive stimulation of murine diverse NKT cells result in distinct cellular responses.
- 2019
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Ingår i: European journal of immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 49:3, s. 443-453
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Tidskriftsartikel (refereegranskat)abstract
- Natural killer T (NKT) cells recognize glycolipids presented on CD1d. They share features of adaptive T lymphocytes and innate NK cells, and mediate immunoregulatory functions via rapid production of cytokines. Invariant (iNKT) and diverse (dNKT) NKT cell subsets are defined by their TCR. The immunological role of dNKT cells, that do not express the invariant TCRα-chain used by iNKT cells, is less well explored than that of iNKT cells. Here, we investigated signals driving Toll-like receptor (TLR) ligand activation of TCR-transgenic murine dNKT cells. IFN-γ production by dNKT cells required dendritic cells (DC), cell-to-cell contact and presence of TLR ligands. TLR-stimulated DC activated dNKT cells to secrete IFN-γ in a CD1d-, CD80/86- and type I IFN-independent manner. In contrast, a requirement for IL-12p40, and a TLR ligand-selective dependence on IL-18 or IL-15 was observed. TLR ligand/DC stimulation provoked early secretion of pro-inflammatory cytokines by both CD62L+ and CD62L- dNKT cells. However, proliferation was limited. In contrast, TCR/co-receptor-mediated activation resulted in proliferation and delayed production of a broader cytokine spectrum preferentially in CD62L- dNKT cells. Thus, innate (TLR ligand/DC) and adaptive (TCR/co-receptor) stimulation of dNKT cells resulted in distinct cellular responses that may contribute differently to the formation of immune memory.
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| 10. |
- Yrlid, Ulf, 1971, et al.
(författare)
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A distinct subset of intestinal dendritic cells responds selectively to oral TLR7/8 stimulation.
- 2006
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Ingår i: European journal of immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 36:10, s. 2639-48
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Tidskriftsartikel (refereegranskat)abstract
- The intestinal innate immune system continually interacts with commensal bacteria, thus oral vaccines should induce extra/alternative activation of DC, potentially through TLR. To examine this we collected intestinal lymph DC (iL-DC) under steady-state conditions and after feeding resiquimod (R-848), a synthetic TLR7/8 ligand, which we showed induces complete emptying of gut DC into lymph. iL-DC are heterogeneous with subset-specific functions. In this study we determined the kinetics of iL-DC subset release, activation and cytokine secretion induced by R-848. We show that L-DC comprise three distinct subsets (CD172ahigh, CD172aint and CD172alow) present with similar frequencies in intestinal but not hepatic lymph. No iL-DC express TLR7 mRNA, and only CD172a+ iL-DC express TLR8. However, after oral R-848 administration, output of all three subsets increases dramatically. CD172ahigh DC release precedes that of CD172alow DC, and the increased frequency of CD25high iL-DC is restricted to the two CD172a+ subsets. After feeding R-848 only CD172ahigh iL-DC secrete IL-6 and IL-12p40. However, CD172aint and CD172ahigh DC secrete similar but markedly lower amounts when stimulated in vitro. These results highlight the importance of in vivo approaches to assess adjuvant effects on DC and give novel insights into the subset-specific effects of an oral TLR ligand on intestinal DC.
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| 11. |
- Yrlid, Ulf, 1971, et al.
(författare)
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Plasmacytoid dendritic cells do not migrate in intestinal or hepatic lymph.
- 2006
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Ingår i: Journal of immunology (Baltimore, Md. : 1950). - 0022-1767. ; 177:9, s. 6115-21
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Tidskriftsartikel (refereegranskat)abstract
- Plasmacytoid dendritic cells (pDCs) recognize pathogen-associated molecules, particularly viral, and represent an important mechanism in innate defense. They may however, also have roles in steady-state tolerogenic responses at mucosal sites. pDCs can be isolated from blood, mucosa, and lymph nodes (LNs). Although pDCs can express peripherally derived Ags in LNs and at mucosal sites, it is not clear whether pDCs actually migrate from the periphery in lymph or whether LN pDCs acquire Ags by other mechanisms. To determine whether pDCs migrate in lymph, intestine or liver-draining LNs were removed and thoracic duct leukocytes (TDLs) were collected. TDLs expressing MHC-II and CD45R, but not TCRalphabeta or CD45RA, were then analyzed. These enriched TDLs neither transcribe type I IFNs nor secrete inflammatory cytokines in response to viral stimuli in vitro or after a TLR7/8 stimulus in vivo. In addition, these TDLs do not express CD5, CD90, CD200, or Siglec-H, but do express Ig, and therefore represent B cells, despite their lack of CD45RA expression. Intestinal and hepatic lymph are hence devoid of bona fide pDCs under both steady-state conditions and after TLR7/8 stimulation. This shows that any role for pDCs in Ag-specific T cell activation or tolerance must differ from the roles of classical dendritic cells, because it cannot result from peripheral Ag capture, followed by migration of pDCs via lymph to the LN.
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