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Biology subjects

Neumann, P.-A.

Publications and source records attributed to Neumann, P.-A..

2 recordsLinked to original sources

Orally delivered biodegradable targeted inflammation resolving pectin-coated nanoparticles induce anastomotic healing post intestinal surgery

Although medical treatment is sucessful in most cases in patients with inflammatory bowel diseases (IBD), a percentage of patients require surgical resection of diseased bowel segments at least once in their lifetime. Healing success of the intestinal anastomosis is at high risk, especially in presence of acute inflammation. Failure of anastomotic healing is a life-threatening complication and causes high socioeconomic costs. Common anti-inflammatory medications can have detrimental effects on wound healing. Thus, targeted perioperative therapeutics supporting anastomotic healing during colitis are an urgent medical need. Here, we develop a novel basal membrane targeted controlled release, pectin-coated polymeric nanoparticle (NP) encapsulating a highly potent inflammation resolving mediator, the peptide Ac2-26. These NPs can undergo gastric passage and facilitate localized release of the therapeutic peptide in the colon via degradation of their pectin-chitosan coating by microbial pectinases, which subsequently exposes a collagen IV targeted NP surface, allowing for further binding and retention of the NPs at the intestinal wound. To test these NPs, we used a murine surgical model combining the formation of an intestinal anastomosis with the induction of a preoperative colitis by dextran sodium sulfate. In this model, perioperative administration of pectin-chitosan coated NPs containing Ac2-26 (P-C-Col IV-Ac2-26-NP) led to the reduction of colitis activity in the postoperative phase. Macroscopic wound closure was improved by P-C-Col IV-Ac2-26-NP treatment as evaluated by endoscopy and intraabdominal adhesion scoring. Microscopic analysis of the healing process showed an improved semiquantitative healing score in the treatment group. In this proof-of-concept study we demonstrate that novel P-C-Col IV-Ac2-26-NP could be a promising and clinically feasible perioperative treatment strategy for IBD patients. TOC graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=135 SRC="FIGDIR/small/569918v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@14f726dorg.highwire.dtl.DTLVardef@e1739aorg.highwire.dtl.DTLVardef@16ca7d0org.highwire.dtl.DTLVardef@7d87fe_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

B/T cell crosstalk and aberrant inflammatory IgG exacerbate autoimmune intestinal inflammation

Dysregulated B cell responses have been described in inflammatory-bowel disease (IBD) patients; however, the role of B cells in IBD pathology remained incompletely understood. We here described Wiskott-Aldrich Syndrome interacting protein deficient (Wipf1-/-) mice as novel mouse model of spontaneous, chronic colitis modelling human IBD. Concomitant with aberrant IgG production in colonic tissue of Wipf1-/- mice, we identified systemic, hypo-sialylated IgG as drivers of IL-1{beta} production in monocytes. Pathological antibody production was promoted by the hyper-reactivity of Wipf1-/- B cells in response to LPS stimulation, resulting in efficient activation of the MAPK/Erk and mTOR/Akt/4E-BP1 pathways and heightened metabolic activity. In addition to abundant inflammatory IgG, we found that B cells directly promoted the production of pro-inflammatory cytokines by intestinal CD4+ T cells. B/T co-culture assays defined the co-stimulatory molecule CD86 as driver of IFN-{gamma} and GM-CSF production by CD4+ T cells. CD86 expression was further enhanced by the presence of sCD40L, which was elevated in sera of Wipf1-/- mice. Similarly, colonic B cells of IBD patients expressed increased mRNA levels of CD86 correlating with enhanced levels of systemic sCD40L. Together, B cell-mediated pro-inflammatory cytokine secretion and B cell-derived inflammatory antibody production contributed to exacerbated pathogenesis during intestinal inflammation. O_FIG O_LINKSMALLFIG WIDTH=168 HEIGHT=200 SRC="FIGDIR/small/507066v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1449ae8org.highwire.dtl.DTLVardef@116045borg.highwire.dtl.DTLVardef@77f3f2org.highwire.dtl.DTLVardef@130a271_HPS_FORMAT_FIGEXP M_FIG C_FIG One Sentence SummaryB cells fuel intestinal inflammation

immunology↗