Publications by authors named "Michaela Blanfeld"

4 Publications

  • Page 1 of 1

IL-17 controls central nervous system autoimmunity through the intestinal microbiome.

Sci Immunol 2021 Feb;6(56)

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.

Interleukin-17A- (IL-17A) and IL-17F-producing CD4 T helper cells (T17 cells) are implicated in the development of chronic inflammatory diseases, such as multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). T17 cells also orchestrate leukocyte invasion of the central nervous system (CNS) and subsequent tissue damage. However, the role of IL-17A and IL-17F as effector cytokines is still confused with the encephalitogenic function of the cells that produce these cytokines, namely, T17 cells, fueling a long-standing debate in the neuroimmunology field. Here, we demonstrated that mice deficient for IL-17A/F lose their susceptibility to EAE, which correlated with an altered composition of their gut microbiota. However, loss of IL-17A/F in T cells did not diminish their encephalitogenic capacity. Reconstitution of a wild-type-like intestinal microbiota or reintroduction of IL-17A specifically into the gut epithelium of IL-17A/F-deficient mice reestablished their susceptibility to EAE. Thus, our data demonstrated that IL-17A and IL-17F are not encephalitogenic mediators but rather modulators of intestinal homeostasis that indirectly alter CNS-directed autoimmunity.
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http://dx.doi.org/10.1126/sciimmunol.aaz6563DOI Listing
February 2021

Cutting Edge: IL-6-Driven Immune Dysregulation Is Strictly Dependent on IL-6R α-Chain Expression.

J Immunol 2020 02 10;204(4):747-751. Epub 2020 Jan 10.

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, 55131 Mainz, Germany.

IL-6 binds to the IL-6R α-chain (IL-6Rα) and signals via the signal transducer gp130. Recently, IL-6 was found to also bind to the cell surface glycoprotein CD5, which would then engage gp130 in the absence of IL-6Rα. However, the biological relevance of this alternative pathway is under debate. In this study, we developed a mouse model, in which murine IL-6 is overexpressed in a CD11c-Cre-dependent manner. Transgenic mice developed a lethal immune dysregulation syndrome with increased numbers of Ly-6G neutrophils and Ly-6C monocytes/macrophages. IL-6 overexpression promoted activation of CD4 T cells while suppressing CD5 B-1a cell development. However, additional ablation of IL-6Rα protected IL-6-overexpressing mice from IL-6-triggered inflammation and fully phenocopied IL-6Rα-deficient mice without IL-6 overexpression. Mechanistically, IL-6Rα deficiency completely prevented downstream activation of STAT3 in response to IL-6. Altogether, our data clarify that IL-6Rα is the only biologically relevant receptor for IL-6 in mice.
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http://dx.doi.org/10.4049/jimmunol.1900876DOI Listing
February 2020

Oligodendrocyte ablation triggers central pain independently of innate or adaptive immune responses in mice.

Nat Commun 2014 Dec 1;5:5472. Epub 2014 Dec 1.

Institute for Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany.

Mechanisms underlying central neuropathic pain are poorly understood. Although glial dysfunction has been functionally linked with neuropathic pain, very little is known about modulation of pain by oligodendrocytes. Here we report that genetic ablation of oligodendrocytes rapidly triggers a pattern of sensory changes that closely resemble central neuropathic pain, which are manifest before overt demyelination. Primary oligodendrocyte loss is not associated with autoreactive T- and B-cell infiltration in the spinal cord and neither activation of microglia nor reactive astrogliosis contribute functionally to central pain evoked by ablation of oligodendrocytes. Instead, light and electron microscopic analyses reveal axonal pathology in the spinal dorsal horn and spinothalamic tract concurrent with the induction and maintenance of nociceptive hypersensitivity. These data reveal a role for oligodendrocytes in modulating pain and suggest that perturbation of oligodendrocyte functions that maintain axonal integrity can lead to central neuropathic pain independent of immune contributions.
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http://dx.doi.org/10.1038/ncomms6472DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4268702PMC
December 2014

Targeting transcription factor Stat4 uncovers a role for interleukin-18 in the pathogenesis of severe lupus nephritis in mice.

Kidney Int 2011 Feb 27;79(4):452-63. Epub 2010 Oct 27.

Department of Internal Medicine, Division of Rheumatology and Clinical Immunology, Johannes Gutenberg University, Mainz, Germany.

Polymorphisms in the transcription factor Stat4 gene have been implicated as risk factors for systemic lupus erythematosus. Although some polymorphisms have a strong association with autoantibodies and nephritis, their impact on pathophysiology is still unknown. To explore this further we used signal transducers and activators of transcription 4 (Stat4) knockout MRL/MpJ-Fas(lpr)/Fas(lpr) (MRL-Fas(lpr)) mice and found that they did not differ in survival or renal function from Stat4-intact MRL-Fas(lpr) mice. Circulating interleukin (IL)-18 levels, however, were elevated in Stat4-deficient compared to Stat4-intact mice, suggesting that this interleukin might contribute to the progression of lupus nephritis independent of Stat4. In a second approach, Stat4 antisense or missense oligonucleotides or vehicle were given to MRL-Fas(lpr) mice with advanced nephritis. Each of these treatments temporarily ameliorated disease, although IL-18 was increased in each setting. Based on these findings, studies using gene transfer to overexpress IL-18 in MRL-Fas(lpr) and IL-12p40/IL-23 knockout MRL-Fas(lpr) mice reveal a critical role for IL-18 in mediating disease. Thus, the Stat4 and IL-12 (an activator of Stat4)-independent factor, IL-18, can drive autoimmune lupus nephritis in MRL-Fas(lpr) mice. Temporarily blocking Stat4 during advanced nephritis ameliorates disease, suggesting a time-dependent compensatory proinflammatory mechanism.
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http://dx.doi.org/10.1038/ki.2010.438DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3197226PMC
February 2011