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Wullaert, A.

Publications and source records attributed to Wullaert, A..

3 recordsLinked to original sources

Neonatal microbiota colonization drives maturation of primary and secondary goblet cell mediated protection in the pre-weaning colon

In the distal colon, mucus secreting goblet cells primarily confer protection from luminal microorganisms via generation of a sterile inner mucus layer barrier structure. Bacteria-sensing sentinel goblet cells provide a secondary defensive mechanism that orchestrates mucus secretion in response to microbes that breach the mucus barrier. Previous reports have identified mucus barrier deficiencies in adult germ-free mice, thus implicating a fundamental role for the microbiota in programming mucus barrier generation. In this study, we have investigated the natural neonatal development of the mucus barrier and sentinel goblet cell-dependent secretory responses upon postnatal colonization. Combined in vivo and ex vivo analyses of pre- and post-weaning colonic mucus barrier and sentinel goblet cell maturation demonstrated a sequential microbiota-dependent development of these primary and secondary goblet cell-intrinsic protective functions, with dynamic changes in mucus processing dependent on innate immune signalling via MyD88, and development of functional sentinel goblet cells dependent on the NADPH/Dual oxidase family member Duox2. Our findings therefore identify new mechanisms of microbiota-goblet cell regulatory interaction and highlight the critical importance of the pre-weaning period for the normal development of colonic barrier function.

immunology↗

Myeloid A20 is critical for type-2 immune mediated helminth resistance

Protective immunity against intestinal helminths requires induction of robust Type-2 immunity orchestrated by various cellular and soluble effectors which promote goblet cell hyperplasia, mucus production, epithelial proliferation and smooth muscle contractions to expel worms and reestablish immune homeostasis. Conversely, defects in type-2 immunity result in ineffective helminth clearance, persistent infection and chronic inflammation. We identify A20 as an essential myeloid factor for the induction of type-2 immune responses against the intestinal parasite Trichuris muris. Myeloid cell-specific loss of A20 in mice (A20myel-KO) results in chronic Trichuris muris infection and intestinal inflammation. Myeloid A20 deficient mice are not able to induce anti-helmith type-2 immune responses while instead mount detrimental Th1/Th17 polarized immune responses. Antibody-mediated neutralization of the type-1 cytokines IFN{gamma}, IL18 and IL12 prevents Th1/Th17 polarization and reestablishes Type-2 mediated protective immunity against Trichuris muris in A20myel-KO mice. In contrast, the strong Th1/Th17 biased immunity in A20myel-KO mice offers protection against Salmonella infection. We hereby identify A20 as an essential myeloid factor to initiate approriate adaptive immunity in response to infection, and to induce a balanced type-2 immune response against the intestinal parasite Trichuris muris. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/556360v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@632052org.highwire.dtl.DTLVardef@1def1f2org.highwire.dtl.DTLVardef@1de8459org.highwire.dtl.DTLVardef@1c316ff_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical abstractThe clearance of gastrointestinal helmiths depends on type-2 immunity. Helminths interact with and damage intestinal tissue, which leads to the release of intracellular DAMPs and cytokines such as TSLP and IL33, and IL25 produced by epithelial cells. These factors may activate myeloid cells and ILCs, which further activate T and B cells to mount effective Th2 responses and the secretion of IL4, IL5 and IL13 cytokines, as well as helminth-specific IgG1 immunoglobulins, leading to effective expulsion of the helminths. Deletion of A20 in the myeloid cells leads to enhanced secretion of type-1 cytokines, including IL12, IL18 and IFN{gamma}, which impede type-2 immune-mediated helminth clearance and promotes chronic intestinal inflammation.

immunology↗

Inflammasome- and gasdermin D-independent IL-1β production mobilizes neutrophils to inhibit antitumor immunity

Interleukin-1{beta} (IL-1{beta}) is a central mediator of inflammation whose secretion typically requires proteolytic maturation by the inflammasome and formation of membrane pores by gasdermin D (GSDMD). Emerging evidence suggests an important role for IL-1{beta} in promoting cancer progression in patients, but the underlying mechanisms are little understood. Here, we show a key role for IL-1{beta} in driving tumor progression in two distinct mouse tumor models. Notably, inflammasome activation and GSDMD were dispensable for the production of intratumoral bioactive IL-1{beta}, which promoted systemic mobilization and infiltration of neutrophils into tumors. Neutrophils recruited via IL-1{beta} suppressed the acquisition of an effector T-cell phenotype and subsequent antitumor immune response. Moreover, IL-1{beta} was essential for neutrophil accumulation upon antiangiogenic therapy, thereby contributing to therapy-induced immunosuppression. Antitumor immunity in the absence of IL-1{beta}-dependent neutrophil recruitment relied on immunostimulatory macrophages which promoted the infiltration and activation of cytotoxic T-cells. Overall, these results support a tumor-promoting role for IL-1{beta} through establishing an immunosuppressive microenvironment and show that inflammasome activation is not essential for its release in tumors.

immunology↗