1.
Agrawal, Smriti, et al.
(författare)
Dystroglycan is selectively cleaved at the parenchymal basement membrane at sites of leukocyte extravasation in experimental autoimmune encephalomyelitis.
2006
Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 203:4, s. 1007-1019
Tidskriftsartikel (refereegranskat) abstract
The endothelial cell monolayer of cerebral vessels and its basement membrane (BM) are ensheathed by the astrocyte endfeet, the leptomeningeal cells, and their associated parenchymal BM, all of which contribute to establishment of the blood–brain barrier (BBB). As a consequence of this unique structure, leukocyte penetration of cerebral vessels is a multistep event. In mouse experimental autoimmune encephalomyelitis (EAE), a widely used central nervous system inflammatory model, leukocytes first penetrate the endothelial cell monolayer and underlying BM using integrin β1-mediated processes, but mechanisms used to penetrate the second barrier defined by the parenchymal BM and glia limitans remain uninvestigated. We show here that macrophage-derived gelatinase (matrix metalloproteinase [MMP]-2 and MMP-9) activity is crucial for leukocyte penetration of the parenchymal BM. Dystroglycan, a transmembrane receptor that anchors astrocyte endfeet to the parenchymal BM via high affinity interactions with laminins 1 and 2, perlecan and agrin, is identified as a specific substrate of MMP-2 and MMP-9. Ablation of both MMP-2 and MMP-9 in double knockout mice confers resistance to EAE by inhibiting dystroglycan cleavage and preventing leukocyte infiltration. This is the first description of selective in situ proteolytic damage of a BBB-specific molecule at sites of leukocyte infiltration.
2.
Rizk, John, et al.
(författare)
SMAC mimetics promote NIK-dependent inhibition of CD4+ TH17 cell differentiation
2019
Ingår i: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 12:596
Tidskriftsartikel (refereegranskat) abstract
Second mitochondria-derived activator of caspase (SMAC) mimetics (SMs) are selective antagonists of the inhibitor of apoptosis proteins (IAPs), which activate noncanonical NF-B signaling and promote tumor cell death. Through gene expression analysis, we found that treatment of CD4+ T cells with SMs during T helper 17 (TH17) cell differentiation disrupted the balance between two antagonistic transcription factor modules. Moreover, proteomics analysis revealed that SMs altered the abundance of proteins associated with cell cycle, mitochondrial activity, and the balance between canonical and noncanonical NF-B signaling. Whereas SMs inhibited interleukin-17 (IL-17) production and ameliorated TH17 cell-driven inflammation, they stimulated IL-22 secretion. Mechanistically, SM-mediated activation of NF-B-inducing kinase (NIK) and the transcription factors RelB and p52 directly suppressed Il17a expression and IL-17A protein production, as well as the expression of a number of other immune genes. Induction of IL-22 production correlated with the NIK-dependent reduction in cMAF protein abundance and the enhanced activity of the aryl hydrocarbon receptor. Last, SMs also increased IL-9 and IL-13 production and, under competing conditions, favored the differentiation of naïve CD4+ T cells into TH2 cells rather than TH17 cells. These results demonstrate that SMs shape the gene expression and protein profiles of TH17 cells and inhibit TH17 cell-driven autoimmunity.
3.
Björkman, Per, et al.
(författare)
Common Interactions between S100A4 and S100A9 Defined by a Novel Chemical Probe.
2013
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:5
Tidskriftsartikel (refereegranskat) abstract
S100A4 and S100A9 proteins have been described as playing roles in the control of tumor growth and metastasis. We show here that a chemical probe, oxyclozanide (OX), selected for inhibiting the interaction between S100A9 and the receptor for advanced glycation end-products (RAGE) interacts with both S100A9 and S100A4. Furthermore, we show that S100A9 and S100A4 interact with RAGE and TLR4; interactions that can be inhibited by OX. Hence, S100A4 and S100A9 display similar functional elements despite their primary sequence diversity. This was further confirmed by showing that S100A4 and S100A9 dimerize both in vitro and in vivo. All of these interactions required levels of Zn(++) that are found in the extracellular space but not intracellularly. Interestingly, S100A4 and S100A9 are expressed by distinct CD11b(+) subpopulations both in healthy animals and in animals with either inflammatory disease or tumor burden. The functions of S100A9 and S100A4 described in this paper, including heterodimerization, may therefore reflect S100A9 and S100A4 that are released into the extra-cellular milieu.
4.
Deronic, Adnan, et al.
(författare)
The anti-tumor effect of the quinoline-3-carboxamide tasquinimod : Blockade of recruitment of CD11b+ Ly6Chi cells to tumor tissue reduces tumor growth
2016
Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 16:1
Tidskriftsartikel (refereegranskat) abstract
Background: Previous work has demonstrated immunomodulatory, anti-tumor, anti-metastatic and anti-angiogenic effects of the small molecule quinoline-3-carboxamide tasquinimod in pre-clinical cancer models. To better understand the anti-tumor effects of tasquinimod in transplantable tumor models, we have evaluated the impact of the compound both on recruitment of myeloid cells to tumor tissue and on tumor-induced myeloid cell expansion as these cells are known to promote tumor development. Methods: Mice bearing subcutaneous 4 T1 mammary carcinoma tumors were treated with tasquinimod in the drinking water. A BrdU-based flow cytometry assay was utilized to assess the impact of short-term tasquinimod treatment on myeloid cell recruitment to tumors. Additionally, long-term treatment was performed to study the anti-tumor effect of tasquinimod as well as its effects on splenic myeloid cells and their progenitors. Myeloid cell populations were also immune-depleted by in vivo antibody treatment. Results: Short-term tasquinimod treatment did not influence the proliferation of splenic Ly6Chi and Ly6Ghi cells, but instead reduced the influx of Ly6Chi cells to the tumor. Treatment with tasquinimod for various periods of time after tumor inoculation revealed that the anti-tumor effect of this compound mainly operated during the first few days of tumor growth. Similar to tasquinimod treatment, antibody-mediated depletion of Ly6Chi cells within that same time frame, caused reduced tumor growth, thereby confirming a significant role for these cells in tumor development. Additionally, long-term tasquinimod treatment reduced the splenomegaly and expansion of splenic myeloid cells during a later phase of tumor development. In this phase, tasquinimod normalized the tumor-induced alterations in myeloerythroid progenitor cells in the spleen but had only limited impact on the same populations in the bone marrow. Conclusions: Our results indicate that tasquinimod treatment reduces tumor growth by operating early after tumor inoculation and that this effect is at least partially caused by reduced recruitment of Ly6Chi cells to tumor tissue. Long-term treatment also reduces the number of splenic myeloid cells and myeloerythroid progenitors, but these effects did not influence established rapidly growing tumors.
5.
Eroukhmanoff, Lena, et al.
(författare)
T-cell tolerance induced by repeated antigen stimulation: Selective loss of Foxp3(-) conventional CD4 T cells and induction of CD4 T-cell anergy.
2009
Ingår i: European Journal of Immunology. - : Wiley. - 1521-4141 .- 0014-2980. ; 39:4, s. 1078-1087
Tidskriftsartikel (refereegranskat) abstract
Repeated immunization of mice with bacterial superantigens induces extensive deletion and anergy of reactive CD4 T cells. Here we report that the in vitro proliferation anergy of CD4 T cells from TCR transgenic mice immunized three times with staphylococcal enterotoxin B (SEB) (3x SEB) is partially due to an increased frequency of Foxp3(+) CD4 T cells. Importantly, reduced number of conventional CD25(-) Foxp3(-) cells, rather than conversion of such cells to Foxp3(+) cells, was the cause of that increase and was also seen in mice repeatedly immunized with OVA (3x OVA) and OVA-peptide (OVAp) (3x OVAp). Cell-transfer experiments revealed profound but transient anergy of CD4 T cells isolated from 3x OVAp and 3x SEB mice. However, the in vivo anergy was CD4 T-cell autonomous and independent of Foxp3(+) Treg. Finally, proliferation of transferred CD4 T cells was inhibited in repeatedly immunized mice but inhibition was lost when transfer was delayed, despite the maintenance of elevated frequency of Foxp3(+) cells. These data provide important implications for Foxp3(+) cell-mediated tolerance in situations of repeated antigen exposure such as human persistent infections.
6.
Fransén-Pettersson, Nina, et al.
(författare)
A New Mouse Model That Spontaneously Develops Chronic Liver Inflammation and Fibrosis
2016
Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:7
Tidskriftsartikel (refereegranskat) abstract
Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF) mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT) induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders.
7.
Fransén Pettersson, Nina, et al.
(författare)
The immunomodulatory quinoline-3-carboxamide paquinimod reverses established fibrosis in a novel mouse model for liver fibrosis
2018
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 13:9
Tidskriftsartikel (refereegranskat) abstract
Quinoline-3-carboxamides (Q substances) are small molecule compounds with anti-inflammatory properties. In this study, we used one of these substances, Paquinimod, to treat a novel model for chronic liver inflammation and liver fibrosis, the NOD-Inflammation Fibrosis (N-IF) mouse. We show that treatment of N-IF mice significantly reduced inflammation and resulted in the regression of fibrosis, even when the treatment was initiated after onset of disease. The reduced disease phenotype was associated with a systemic decrease in the number and reduced activation of disease-promoting transgenic natural killer T (NKT)-II cells and their type 2-cytokine expression profile. Paquinimod treatment also led to a reduction of CD115+ Ly6Chi monocytes and CD11b+ F4/80+ CD206+ macrophages.
8.
Fritsch, Maria, et al.
(författare)
A TCR alpha chain transgene induces maturation of CD4- CD8- alpha beta+ T cells from gamma delta T cell precursors
1998
Ingår i: European Journal of Immunology. - 1521-4141. ; 28:3, s. 828-837
Tidskriftsartikel (refereegranskat) abstract
The proportion of CD4- CD8- double-negative (DN) alpha beta T cells is increased both in the thymus and in peripheral lymphoid organs of TCR alpha chain-transgenic mice. In this report we have characterized this T cell population to elucidate its relationship to alpha beta and gamma delta T cells. We show that the transgenic DN cells are phenotypically similar to gamma delta T cells but distinct from DN NK T cells. The precursors of DN cells have neither rearranged endogenous TCR alpha genes nor been negatively selected by the MIsa antigen, suggesting that they originate from a differentiation stage before the onset of TCR alpha chain rearrangements and CD4/CD8 gene expression. Neither in-frame V delta D delta J delta nor V gamma J gamma rearrangements are over-represented in this population. However, since peripheral gamma delta T cells with functional TCR beta gene rearrangements have been depleted in the transgenics, we propose that the transgenic DN population, at least partially, originates from the precursors of those cells. The present data lend support to the view that maturation signals to gamma delta lineage-committed precursors can be delivered via TCR alpha beta heterodimers.
9.
Grundström, Susanna, et al.
(författare)
Superantigen-Induced Regulatory T Cells Display Different Suppressive Functions in the Presence or Absence of Natural CD4(+)CD25(+) Regulatory T Cells In Vivo.
2003
Ingår i: Journal of Immunology. - 1550-6606. ; 170:10, s. 5008-5017
Tidskriftsartikel (refereegranskat) abstract
Repeated exposures to both microbial and innocuous Ags in vivo have been reported to both eliminate and tolerize T cells after their initial activation and expansion. The remaining tolerant T cells have been shown to suppress the response of naive T cells in vitro. This feature is reminiscent of natural CD4+CD25+ regulatory T cells. However, it is not known whether the regulatory function of in vivo-tolerized T cells is similar to the function of natural CD4+CD25+ regulatory T cells. In this study, we demonstrate that CD4+CD25+ as well as CD4+CD25- T cells isolated from mice treated with superantigen three consecutive times to induce tolerance were functionally comparable to natural CD4+CD25+ regulatory T cells, albeit more potent. The different subpopulations of in vivo-tolerized CD4+ T cells efficiently down-modulated costimulatory molecules on dendritic cells, and their suppressive functions were strictly cell contact dependent. Importantly, we demonstrate that conventional CD4+CD25- T cells could also be induced to acquire regulatory functions by the same regimen in the absence of natural regulatory T cells in vivo, but that such regulatory cells were functionally different.
10.
He, Zhifei, et al.
(författare)
CD14 is a co-receptor for TLR4 in the S100A9-induced pro-inflammatory response in monocytes
2016
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 11:5
Tidskriftsartikel (refereegranskat) abstract
The cytosolic Ca2+-binding S100A9 and S100A8 proteins form heterodimers that are primarily expressed in human neutrophils and monocytes. We have recently shown that S100A9 binds to TLR4 in vitro and induces TLR4-dependent NF-κB activation and a pro-inflammatory cytokine response in monocytes. In the present report we have further investigated the S100A9-mediated stimulation of TLR4 in monocytes. Using transmission immunoelectron microscopy, we detected focal binding of S100A9 to monocyte membrane subdomains containing the caveolin-1 protein and TLR4. Furthermore, the S100A9 protein was detected in early endosomes of the stimulated cells, indicating that the protein could be internalized by endocytosis. Although stimulation of monocytes with S100A9 was strictly TLR4-dependent, binding of S100A9 to the plasma membrane and endocytosis of S100A9 was still detectable and coincided with CD14 expression in TLR4-deficient cells. We therefore investigated whether CD14 would be involved in the TLR4-dependent stimulation and could show that the S100A9-induced cytokine response was inhibited both in CD14-deficient cells and in cells exposed to CD14 blocking antibodies. Further, S100A9 was not internalized into CD14-deficient cells suggesting a direct role of CD14 in endocytosis of S100A9. Finally, we could detect satiable binding of S100A9 to CD14 in surface plasmon resonance experiments. Taken together, these results indicate that CD14 is a co-receptor of TLR4 in the S100A9-induced cytokine response.
