Search results for "Langerin"

2015

Dendritic cells (DC) are a heterogeneous family of professional antigen-presenting cells classically recognized as most potent inducers of adaptive immune responses. In this respect, Langerhans cells have long been considered to be prototypic immunogenic DC in the skin. More recently this view has considerably changed. The generation of in vivo cell ablation and lineage tracing models revealed the complexity of the skin DC network and, in particular, established the existence of a number of phenotypically distinct Langerin(+) and negative DC populations in the dermis. Moreover, by now we appreciate that DC also exert important regulatory functions and are required for the maintenance of tol…

Classical Flt3L-dependent dendritic cells control immunity to protein vaccine

2014

DCs are critical for initiating immunity. The current paradigm in vaccine biology is that DCs migrating from peripheral tissue and classical lymphoid-resident DCs (cDCs) cooperate in the draining LNs to initiate priming and proliferation of T cells. Here, we observe subcutaneous immunity is Fms-like tyrosine kinase 3 ligand (Flt3L) dependent. Flt3L is rapidly secreted after immunization; Flt3 deletion reduces T cell responses by 50%. Flt3L enhances global T cell and humoral immunity as well as both the numbers and antigen capture capacity of migratory DCs (migDCs) and LN-resident cDCs. Surprisingly, however, we find immunity is controlled by cDCs and actively tempered in vivo by migDCs. Del…

Posttranslational modifications by ADAM10 shape myeloid antigen-presenting cell homeostasis in the splenic marginal zone

2021

The spleen contains phenotypically and functionally distinct conventional dendritic cell (cDC) subpopulations, termed cDC1 and cDC2, which each can be divided into several smaller and less well-characterized subsets. Despite advances in understanding the complexity of cDC ontogeny by transcriptional programming, the significance of posttranslational modifications in controlling tissue-specific cDC subset immunobiology remains elusive. Here, we identified the cell-surface–expressed A-disintegrin-and-metalloproteinase 10 (ADAM10) as an essential regulator of cDC1 and cDC2 homeostasis in the splenic marginal zone (MZ). Mice with a CD11c-specific deletion of ADAM10 (ADAM10(ΔCD11c)) exhibited a …

Langerin+ DCs regulate innate IL-17 production in the oral mucosa during Candida albicans-mediated infection

2018

The opportunistic fungal pathogen Candida albicans frequently causes diseases such as oropharyngeal candidiasis (OPC) in immunocompromised individuals. Although it is well appreciated that the cytokine IL-17 is crucial for protective immunity against OPC, the cellular source and the regulation of this cytokine during infection are still a matter of debate. Here, we directly visualized IL-17 production in the tongue of experimentally infected mice, thereby demonstrating that this key cytokine is expressed by three complementary subsets of CD90+ leukocytes: RAG-dependent αβ and γδ T cells, as well as RAG-independent ILCs. To determine the regulation of IL-17 production at the onset of OPC, we…

Langerhans's cell histiocytosis in old subjects: two rare case reports and review of the literature

2012

Background: Langerhans cell histiocytosis (LCH) is a proliferative disease of histiocyte-like cells that generally affects children; LCH onset is rare in adults; immunohistochemistry is essential to obtain the correct diagnosis, and treatment protocols are controversial. Objective: To describe two new cases of adult onset oral LCH. Case reports: Case 1: a 71-year-old woman, complaining of diffuse oral pain, presented with erythematous mucosal lesions; the panoramic radiograph and CT scan showed multiple mandible radiolucent areas. Immunohistochemical assay for S-100, CD1a and langerin test was essential in reaching the correct diagnosis. Case 2: a 77-year-old female patient presented with a…

Histiocytosis with mixed cell populations

2016

Langerhans cell histiocytosis (LCH) and juvenile xanthogranuloma (JXG) are thought to originate from a common stem cell precursor, with divergent differentiation under different microenvironmental conditions. We describe an exceptional case of multiple cutaneous lesions in a 10-year-old boy, in which the coexistence of both LCH and JXG cell populations is found in every single lesion. The presence of Birbeck granules and CD207 (langerin) immunostaining in the LCH component would argue against the diagnosis of indeterminate cell histiocytosis (ICH). This unique case gives additional support to the hypothesis of a potentially common histogenesis for LCH and JXG.

Langerhans’s cell histiocytosis in old subjects: two rare case reports and review of the literature

2012

doi: 10.1111/j.1741-2358.2012.00629.x Langerhans’s cell histiocytosis in old subjects: two rare case reports and review of the literature Background:  Langerhans cell histiocytosis (LCH) is a proliferative disease of histiocyte-like cells that generally affects children; LCH onset is rare in adults; immunohistochemistry is essential to obtain the correct diagnosis, and treatment protocols are controversial. Objective:  To describe two new cases of adult onset oral LCH. Case reports:  Case 1: a 71-year-old woman, complaining of diffuse oral pain, presented with erythematous mucosal lesions; the panoramic radiograph and CT scan showed multiple mandible radiolucent areas. Immunohistochemical a…

Skin response to a carcinogen involves the xenobiotic receptor pregnane X receptor.

2015

Skin is in daily contact with potentially harmful molecules from the environment such as cigarette smoke, automobile emissions, industrial soot and groundwater. Pregnane X receptor (PXR) is a transcription factor expressed in liver and intestine that is activated by xenobiotic chemicals including drugs and environmental pollutants. Topical application of the tumor initiator 7,12-dimethylbenz(a)anthracene (DMBA) enhances Pxr, Cyp1a1, Cyp1b1 and Cyp3a11, but not Ahr expression in the skin. Surprisingly, DMBA-induced Pxr upregulation is largely impaired in Langerin(+) cell-depleted skin, suggesting that DMBA mainly triggers Pxr in Langerin(+) cells. Furthermore, PXR deficiency protects from DN…