Cell type–specific actions of Bcl11b in early T-lineage and group 2 innate lymphoid cells

The zinc finger transcription factor, Bcl11b, is expressed in T cells and group 2 innate lymphoid cells (ILC2s) among hematopoietic cells. In early T-lineage cells, Bcl11b directly binds and represses the gene encoding the E protein antagonist, Id2, preventing pro-T cells from adopting innate-like fates. In contrast, ILC2s co-express both Bcl11b and Id2. To address this contradiction, we have directly compared Bcl11b action mechanisms in pro-T cells and ILC2s. We found that Bcl11b binding to regions across the genome shows distinct cell type–specific motif preferences. Bcl11b occupies functionally different sites in lineage-specific patterns and controls totally different sets of target genes in these cell types. In addition, Bcl11b bears cell type–specific post-translational modifications and organizes different cell type–specific protein complexes. However, both cell types use the same distal enhancer region to control timing of Bcl11b activation. Therefore, although pro-T cells and ILC2s both need Bcl11b for optimal development and function, Bcl11b works substantially differently in these two cell types

Cell type–specific actions of Bcl11b in early T-lineage and group 2 innate lymphoid cells

The zinc finger transcription factor, Bcl11b, is expressed in T cells and group 2 innate lymphoid cells (ILC2s) among hematopoietic cells. In early T-lineage cells, Bcl11b directly binds and represses the gene encoding the E protein antagonist, Id2, preventing pro-T cells from adopting innate-like fates. In contrast, ILC2s co-express both Bcl11b and Id2. To address this contradiction, we have directly compared Bcl11b action mechanisms in pro-T cells and ILC2s. We found that Bcl11b binding to regions across the genome shows distinct cell type–specific motif preferences. Bcl11b occupies functionally different sites in lineage-specific patterns and controls totally different sets of target genes in these cell types. In addition, Bcl11b bears cell type–specific post-translational modifications and organizes different cell type–specific protein complexes. However, both cell types use the same distal enhancer region to control timing of Bcl11b activation. Therefore, although pro-T cells and ILC2s both need Bcl11b for optimal development and function, Bcl11b works substantially differently in these two cell types

Group 2 innate lymphoid cells support hematopoietic recovery under stress conditions

The cell-cycle status of hematopoietic stem and progenitor cells (HSPCs) becomes activated following chemotherapy-induced stress, promoting bone marrow (BM) regeneration; however, the underlying molecular mechanism remains elusive. Here we show that BM-resident group 2 innate lymphoid cells (ILC2s) support the recovery of HSPCs from 5-fluorouracil (5-FU)-induced stress by secreting granulocyte-macrophage colony-stimulating factor (GM-CSF). Mechanistically, IL-33 released from chemosensitive B cell progenitors activates MyD88-mediated secretion of GM-CSF in ILC2, suggesting the existence of a B cell-ILC2 axis for maintaining hematopoietic homeostasis. GM-CSF knockout mice treated with 5-FU showed severe loss of myeloid lineage cells, causing lethality, which was rescued by transferring BM ILC2s from wild-type mice. Further, the adoptive transfer of ILC2s to 5-FU-treated mice accelerates hematopoietic recovery, while the reduction of ILC2s results in the opposite effect. Thus, ILC2s may function by "sensing" the damaged BM spaces and subsequently support hematopoietic recovery under stress conditions.Sudo T., Motomura Y., Okuzaki D., et al. Group 2 innate lymphoid cells support hematopoietic recovery under stress conditions. Journal of Experimental Medicine 218, e20200817 (2021); https://doi.org/10.1084/jem.20200817

Annual report by The Japanese Association for Thoracic Surgery

All data regarding cardiovascular surgery and thoracic surgery were obtained from NCD, whereas data regarding esophageal surgery were collected from survey questionnaire by The Japanese Association for Thoracic Surgery forms because NCD of esophageal surgery does not include non-surgical cases (i.e., patients with adjuvant chemotherapy or radiation alone). Based on the change in data aggregation, there are several differences between this 2015 annual report and previous annual reports: the number of institutions decreased in each category from 578 (2014) to 568 (2015) in cardiovascular, from 762 to 714 in general thoracic and from 626 to 571 in esophageal surgery. Because more than two departments in the same institute registered their data to NCD individually, we cannot calculate correct number of institutes in this survey. Then, the response rate is not indicated in the category of cardiovascular surgery (Table 1), and the number of institutions classified by the operation number is also not calculated in the category of cardiovascular surgery (Table 2)

Development and Function of Invariant Natural Killer T Cells Producing TH2- and TH17-Cytokines

Four distinct subsets of invariant natural killer T (NKT) cells are shown to differentiate in the thymus, then migrate to peripheral tissues where they retain their phenotypic and functional characteristics

Regulation of the Il4 Gene Is Independently Controlled by Proximal and Distal 3′ Enhancers in Mast Cells and Basophils▿

Mast cells and basophils are known to be a critical interleukin 4 (IL-4) source for establishing Th2 protective responses to parasitic infections. Chromatin structure and histone modification patterns in the Il13/Il4 locus of mast cells were similar to those of IL-4-producing type 2 helper T cells. However, using a transgenic approach, we found that Il4 gene expression was distinctly regulated by individual cis regulatory elements in cell types of different lineages. The distal 3′ element contained conserved noncoding sequence 2 (CNS-2), which was a common enhancer for memory phenotype T cells, NKT cells, mast cells, and basophils. Targeted deletion of CNS-2 compromised production of IL-4 and several Th2 cytokines in connective-tissue-type and immature-type mast cells but not in basophils. Interestingly, the proximal 3′ element containing DNase I-hypersensitive site 4 (HS4), which controls Il4 gene silencing in T-lineage cells, exhibited selective enhancer activity in basophils. These results indicate that CNS-2 is an essential enhancer for Il4 gene transcription in mast cell but not in basophils. The transcription of the Il4 gene in mast cells and basophils is independently regulated by CNS-2 and HS4 elements that may be critical for lineage-specific Il4 gene regulation in these cell types