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Hils, M.

Publications and source records attributed to Hils, M..

3 recordsLinked to original sources

Kidins220 regulates the development of B cells bearing the {lambda} light chain

The ratio between Ig{kappa} and Ig{lambda} light chain (LC)-expressing B cells varies considerably between species. We recently identified Kinase D-interacting substrate of 220 kDa (Kidins220) as an interaction partner of the BCR. In vivo ablation of Kidins220 in B cells resulted in a marked reduction of {lambda}LC-expressing B cells. Kidins220 knockout B cells fail to open and recombine the genes of the{lambda} LC locus, even in genetic scenarios where the{kappa} LC genes cannot be rearranged or where the {kappa}LC confers autoreactivity.{kappa} LC gene recombination and expression in Kidins220-deficient B cells is normal. Kidins220 regulates the development of {lambda}LC B cells by enhancing the survival of developing B cells and thereby extending the time-window in which the{lambda} LC locus opens and the genes are rearranged and transcribed. Further, our data suggest that Kidins220 guarantees optimal pre-BCR and BCR signaling to induce{lambda} LC locus opening and gene recombination during B cell development and receptor editing. One Sentence SummaryWe demonstrate that the scaffold protein Kidins220 regulates the development of {lambda}LC B cells by supporting B cell precursor survival and optimizing pre-BCR and BCR signaling to open, recombine, and transcribe the genes of the{lambda} LC locus.

immunology↗

Lung epithelial CYP1 activity regulates aryl hydrocarbon receptor dependent allergic airway inflammation

The lung epithelial barrier serves as a guardian towards environmental insults and responds to allergen encounter with a cascade of immune reactions that can possibly lead to inflammation. Whether the environmental sensor aryl hydrocarbon receptor (AhR) together with its downstream targets cytochrome P450 (CYP1) family members contribute to the regulation of allergic airway inflammation remains unexplored. By employing knockout mice for AhR and for single CYP1 family members, we found that AhR-/- and CYP1B1-/- but not CYP1A1-/- or CYP1A2-/- animals display enhanced allergic airway inflammation compared to WT. Expression analysis, immunofluorescence staining of murine and human lung sections and bone marrow chimeras suggest an important role of CYP1B1 in non-hematopoietic lung epithelial cells to prevent exacerbation of allergic airway inflammation. Transcriptional analysis of murine and human lung epithelial cells indicates a functional link of AhR to barrier protection/inflammatory mediator signaling upon allergen challenge. In contrast, CYP1B1 deficiency leads to enhanced expression and activity of CYP1A1 in lung epithelial cells and to an increased availability of the AhR ligand kynurenic acid following allergen challenge. Thus, differential CYP1 family member expression and signaling via the AhR in epithelial cells represents an immunoregulatory layer protecting the lung from exacerbation of allergic airway inflammation.

immunology↗

The concerted action of E2-2 and HEB is critical for early lymphoid specification

The apparition of adaptive immunity in Gnathostomata correlates with the expansion of the E-protein family to encompass E2-2, HEB and E2A. Within the family, E2-2 and HEB are more closely evolutionarily related but their concerted action in hematopoiesis remains to be explored. Here we show that the combined disruption of E2-2 and HEB results in failure to express the early lymphoid program in CLPs and a near complete block in B-cell development. In the thymus, ETPs were reduced and T-cell development perturbed, resulting in reduced CD4 T- and increased {gamma}{delta} T-cell numbers. In contrast, HSCs, erythro-myeloid progenitors and innate immune cells were unaffected showing that E2-2 and HEB are dispensable for the ancestral hematopoietic lineages. Taken together, this E-protein dependence suggests that the appearance of the full Gnathostomata E-protein repertoire was critical to reinforce the gene regulatory circuits that drove the emergence and expansion of the lineages constituting humoral immunity.

immunology↗