Article

Opening the crypt: current facts and hypotheses on the function of cryptopatches.

CNRS URA1961, Paris 75724, France. <>
Trends in Immunology (Impact Factor: 12.03). 12/2009; 31(2):50-5. DOI: 10.1016/j.it.2009.11.004
Source: PubMed

ABSTRACT Cryptopatches, small aggregates of lymphoid cells found in the intestinal lamina propria, have been assigned many functions specific to gut immunity. Populated with seemingly immature lymphoid cells and dendritic cells, it has been suggested that cryptopatches maturate intraepithelial lymphocytes, Th17 cells, IL-22-producing NKp46(+) cells, and lymphoid tissues in response to the gut microbiota. Some of these issues, however, remain hotly debated. Therefore, cryptopatches are coming to the forefront of gut immunology and warrant a comprehensive discussion of their role in the development of the immune system.

0 Bookmarks
 · 
100 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Innate lymphoid cells (ILCs) are a heterogeneous group of lymphocytes, which play an important role in tissue homeostasis at epithelial surfaces. They are scarce in spleen and lymph nodes, but substantial numbers can be found in the intestinal mucosa even at steady state. There, they represent the first line of defence against invading pathogens and contribute to lymphorganogenesis, tissue repair and, when inappropriately activated, immune pathology. Lineage-specific development, function and maintenance of these cells depend on a restricted set of transcription factors that partially emerged as a result of diversification and selection during vertebrate evolution. The differential expression of transcription factors regulates unique developmental programs, which endow the different ILC subsets with specific effector functions. Despite this division of labour, ILCs are considered to share a common origin, as they all are progeny of the common lymphoid progenitor, rely on the common γ-chain (γc) used by various cytokine receptors and show a developmental requirement for the transcriptional regulator Id2 (inhibitor of DNA binding 2). Here, we review the transcriptional programs required for the development and function of ILCs and give an overview of the evolution of transcription factors and cytokines expressed by ILCs.
    International Immunology 03/2014; 26(3):119-28. DOI:10.1093/intimm/dxt063 · 3.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 18β-glycyrrhetinic acid (GRA) is a pharmacologically active component of licorice root with documented immunomodulatory properties. We reported that GRA administered orally to mice induces B cell recruitment to isolated lymphoid follicles (ILF) in the small intestine and shortens the duration of rotavirus antigen shedding. ILF are dynamic lymphoid tissues in the gut acquired post-natally upon colonization with commensal bacteria and mature through B cell recruitment to the follicles, resulting in up-regulation of IgA synthesis in response to changes in the composition of microbiota. In this study, we investigated potential mechanisms by which GRA induces ILF maturation in the ileum and the colon using mice depleted of enteric bacteria and a select group of mice genetically deficient in pattern recognition receptors. The data show GRA was unable to induce ILF maturation in ileums of mice devoid of commensal bacteria, MyD88-/- or NOD2-/- mice, but differentially induced ILF in colons. Increased expression of chemokine and chemokine receptor genes that modulate B and T cell recruitment to the mucosa were in part dependent on NOD2, TLR, and signaling adaptor protein MyD88. Together the results suggest GRA induces ILF through cooperative signals provided by bacterial ligands under normal conditions to induce B cell recruitment to ILF to the gut, but that the relative contribution of these signals differ between ileum and colon.
    PLoS ONE 07/2014; 9(7):e100878. DOI:10.1371/journal.pone.0100878 · 3.53 Impact Factor
    This article is viewable in ResearchGate's enriched format
  • [Show abstract] [Hide abstract]
    ABSTRACT: Secondary lymphoid organs (SLO) are crucial structures for immune-surveillance and rapid immune responses allowing resident lymphocytes to encounter antigen-presenting cells that carry antigens from peripheral tissues. These structures develop during embryonic life through a tightly regulated process that involves interactions between haematopoietic and mesenchymal cells [1,2]. Importantly, this morphogenesis potential is maintained throughout life since in chronic inflammatory conditions novel "tertiary lymphoid organs" can be generated by processes that are reminiscent of embryonic SLO development. In this review we will discuss early events in SLO morphogenesis, focusing on haematopoietic and mesenchymal cell subsets implicated on the development of lymphoid organs.
    Immunology letters 08/2013; DOI:10.1016/j.imlet.2013.08.001 · 2.91 Impact Factor