Biology subjects

Zaiss, M. M.

Publications and source records attributed to Zaiss, M. M..

4 recordsLinked to original sources

bioRxiv2026

Microbiota-specific serum IgG links gut and joints through immune-endothelial crosstalk in arthritis

Rheumatoid arthritis (RA) pathogenesis involves early gut immune alterations that precede clinical onset and systemic bone involvement. Using mouse and human imaging mass cytometry (IMC) and tissue sequencing, this study shows that intestinal endothelial and immune changes emerge before or coincide with arthritis symptom development. In the collagen-induced arthritis (CIA) model, intestinal vascular permeability and endothelial gene activation promoting leukocyte trafficking appeared prior to synovial inflammation. Spatial mapping of murine and human ileal tissues predicted enhanced epithelial-immune interactions and lymphoid activation, suggesting mucosal immune priming before joint pathology. Both gut-selective 4{beta}7 integrin blockade with vedolizumab and endothelial barrier enhancement by imatinib significantly reduced arthritis severity in CIA mice. After clinical onset, microbiota-specific IgG responses expanded to recognize rare gut bacteria, reflecting increased microbial exposure. Bone marrow endothelium exhibited interferon-I-driven inflammation and vascular activation, indicating tissue-specific endothelial dysfunction. Microbiota-reactive IgG increased during CIA - likely a response to translocating gut bacteria and immune cell activation. Integrating mouse and human data, these findings define a mechanistic framework where endothelial barrier impairment, microbial translocation, and systemic endothelial activation initiate RA autoimmunity, revealing endothelial and mucosal pathways as targets for early intervention. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/702529v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@1ef2f41org.highwire.dtl.DTLVardef@77d66org.highwire.dtl.DTLVardef@1b9e4cborg.highwire.dtl.DTLVardef@15bd170_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2025

Mucosal innate immune activation as the trigger to Prevotella species-induced arthritis in genetically resistant mice

An altered gut microbiota, particularly the expansion of Prevotellaceae members, is increasingly implicated in the pathogenesis of rheumatoid arthritis (RA), yet the mechanisms hind this phenomenon remain unclear. Here, we demonstrate that Palleniella intestinalis, a member of the Prevotellaceae family, induces a 100% arthritis incidence in genetically resistant C57BL/6 mice. Inoculation with P. intestinalis modifies gut microbiota ecology, increases intestinal permeability, and selectively activates colonic CD11bCD11c myeloid cells, facilitating Th17 differentiation and driving joint inflammation. In vitro, outer membrane vesicles (OMV) from P. intestinalis and Segatella copri (formerly known as Prevotella copri) prime bone marrow-derived dendritic cells (BMDCs) to drive Th17 differentiation in an IL-6-dependent manner. Similar changes with increase in innate immune cell activation and IL-6 levels were shown in gut biopsies from new-onset RA patients. The transfer of Prevotellaceae-derived OMVs or Prevotellaeae-primed BMDCs replicates the hightened arthritis incidence in resistant mice, highlighting the critical role of intestinal immune activation in RA. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=130 SRC="FIGDIR/small/643707v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1ce227corg.highwire.dtl.DTLVardef@3a2d0eorg.highwire.dtl.DTLVardef@16404b6org.highwire.dtl.DTLVardef@1717dc1_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIColonization with Paleniella intestinalis bypasses genetic resistance, consistently inducing arthritis incidence in non-susceptible C57BL/6 mice C_LIO_LIP. intestinalis activates colonic CD11b+CD11c+ myeloid cells, driving systemic Th17 cell differentiation C_LIO_LIIn vitro, outer membrane vesicles from P. intestinalis or RA-derived S. copri RPC01 primed DCs that drive Th17 differentiation in an IL-6-dependent manner C_LIO_LITransfer of P. intestinalis-primed DCs or its outer membrane vesicles alone increases arthritis incidence in non-susceptible C57BL/6 mice C_LI

immunology↗

bioRxiv2024

Gut-specific H3R signaling orchestrates microglia-dependent resolution of peripheral inflammation

Chronic inflammatory diseases, like rheumatoid arthritis (RA) have been described to cause central nervous system (CNS) activation. Less is known about environmental factors that enable the CNS to suppress peripheral inflammation in RA. Here, we identified gut microbiota-derived histamine as such factor. We show that low levels of histamine activate the enteric nervous system, increase inhibitory neurotransmitter concentrations in the spinal cord and restore homeostatic microglia, thereby reducing inflammation in the joints. Selective histamine 3 receptor (H3R) signaling in the intestine is critical for this effect, as systemic and intrathecal application did not show effects. Microglia depletion or pharmacological silencing of local nerve fibers impaired oral H3R agonist-induced pro-resolving effects on arthritis. Moreover, therapeutic supplementation of the SCFA propionate identified one way to expand local intestinal histamine concentrations in mice and humans. Thus, we define a gut-CNS-joint axis pathway where microbiota-derived histamine initiates the resolution of arthritis via the CNS. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=109 HEIGHT=200 SRC="FIGDIR/small/603031v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@c217b8org.highwire.dtl.DTLVardef@a340ceorg.highwire.dtl.DTLVardef@1f3c1d8org.highwire.dtl.DTLVardef@3b6fc9_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIGut microbiota-derived histamine activates enteric neurons via H3R C_LIO_LILocal intestinal H3R activation induces shift to homeostatic microglia in the spinal cord C_LIO_LICNS controlled decrease in endothelial leakiness resolves synovial inflammation C_LI

immunology↗

bioRxiv2022

Alcohol-sourced acetate reduces T cell filamentous actin branching and migration

Alcohol is among the most widely consumed dietary substances. Excessive alcohol consumption damages the liver, heart and brain. Alcohol also has strong immunoregulatory properties. Here we report how alcohol impairs T cell function via acetylation of cortactin, a protein that binds filamentous actin and facilitates branching. Upon alcohol consumption, acetate, the metabolite of alcohol, accumulates in lymphoid organs. T cells exposed to acetate, exhibit increased acetylation of cortactin. Acetylation of cortactin inhibits filamentous actin binding and hence reduces T cell migration, immune synapse formation and activation. While mutated, acetylation-resistant cortactin rescued the acetate-induced inhibition of T cell migration, primary mouse cortactin knock-out T cells exhibited impaired migration. Furthermore, acetate-induced cytoskeletal changes effectively inhibited activation, proliferation, and immune synapse formation in T cells in vitro and in vivo in an influenza infection model in mice. Together these findings reveal cortactin as a possible target for mitigation of T cell driven autoimmune diseases.

immunology↗