In vivo regulation of the monocyte phenotype by Mycobacterium marinum and the ESX-1 type VII secretion system.

Pathogenic mycobacteria require the conserved ESX-1 type VII secretion system to cause disease. In a murine Mycobacterium marinum infection model we previously demonstrated that infiltrating monocytes and neutrophils represent the major bacteria-harbouring cell populations in infected tissue. In the current study we use this model, in combination with scRNA sequencing, to assess the impact of M.

Guidelines for preparation and flow cytometry analysis of human nonlymphoid tissue DC.

This article is part of the Dendritic Cell Guidelines article series, which provides a collection of state-of-the-art protocols for the preparation, phenotype analysis by flow cytometry, generation, fluorescence microscopy, and functional characterization of mouse and human dendritic cells (DC) from lymphoid organs, and various nonlymphoid tissues. Within this article, detailed protocols are presented that allow for the generation of single-cell suspensions from human nonlymphoid tissues including lung, skin, gingiva, intestine as well as from tumors and tumor-draining lymph nodes with a subsequent analysis of dendritic cells by flow cytometry. Further, prepared single-cell suspensions can be subjected to other applications including cellular enrichment procedures, RNA sequencing, functional assays, etc.

Identification and characterization of murine glycoprotein 2-expressing intestinal dendritic cells.

The intestinal lamina propria (LP) contains distinct subsets of classical dendritic cells (cDC), each playing key non-redundant roles in intestinal immune homeostasis. Here, we show that glycoprotein 2 (GP2), a GPI-anchored protein and receptor for bacterial type-I fimbriae, is selectively expressed by CD103CD11b cDC in the murine small intestine (SI). GP2 expression was induced on CD103CD11b cDC within the SI-LP and was regulated by IRF4, TGFβR1- and retinoic acid signalling.

The small and large intestine contain related mesenchymal subsets that derive from embryonic Gli1 precursors.

The intestinal lamina propria contains a diverse network of fibroblasts that provide key support functions to cells within their local environment. Despite this, our understanding of the diversity, location and ontogeny of fibroblasts within and along the length of the intestine remains incomplete. Here we show that the small and large intestinal lamina propria contain similar fibroblast subsets that locate in specific anatomical niches.

Intragranuloma Accumulation and Inflammatory Differentiation of Neutrophils Underlie Mycobacterial ESX-1-Dependent Immunopathology.

The conserved ESX-1 type VII secretion system is a major virulence determinant of pathogenic mycobacteria, including Mycobacterium tuberculosis and Mycobacterium marinum. ESX-1 is known to interact with infected macrophages, but its potential roles in regulating other host cells and immunopathology have remained largely unexplored. Using a murine M.