We report the direct observation of dioxygen molecules physisorbed in the nanochannels of a microporous copper coordination polymer by the MEM (maximum entropy method)/Rietveld method, using in situ high-resolution synchrotron x-ray powder diffraction measurements. The obtained MEM electron density revealed that van der Waals dimers of physisorbed O2 locate in the middle of nanochannels and form a one-dimensional ladder structure aligned to the host channel structure. The observed O-O stretching Raman band and magnetic susceptibilities are characteristic of the confined O2 molecules in one-dimensional nanochannels of CPL-1 (coordination polymer 1 with pillared layer structure).

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Summary Lineage-committed αβ and γδ T cells are thought to originate from common intrathymic multipotent progenitors following instructive T cell receptor (TCR) signals. A subset of lymph node and mucosal Vγ2+ γδ T cells is progγδTCR in development of these cells remains controversial. Here we generated reporter mice for the rammed intrathymically to produce IL-17 (Tγδ17 cells), however the role of the Tγδ17 lineage-defining transcription factor SOX13 and identified fetal-origin, intrathymic Sox13+ progenitors. In organ culture developmental assays, Tγδ17 cells derived primarily from Sox13+ progenitors, and not from other known lymphoid progenitors. Single cell transcriptome assays of the progenitors found in TCR-deficient mice demonstrated that Tγδ17 lineage programming was independent of γδTCR. Instead, generation of the lineage committed progenitors and Tγδ17 cells was controlled by TCF1 and SOX13. Thus, T lymphocyte lineage fate can be prewired cell-intrinsically and is not necessarily specified by clonal antigen receptor signals.

Significance All lymphoid cells are considered to be products of hematopoietic stem cells (HSCs); however, it has been suggested, but not proven, that innate immune B-1 progenitor cells develop independently of HSCs in the fetal liver. B-1 cells, especially B-1a cells, are not replaced by adult bone marrow transplantation. Thus, it is critical to understand the origin and mechanisms required to sustain these cells in vivo because B-1 cells play important roles in the first line of defense against microbial infection and in preventing organ damage in autoimmune patients and infections in some patients after bone-marrow transplantation. We demonstrate that B-1 progenitor cells can develop independently of HSCs in the fetal liver and that their development relies critically on the expression of core-binding factor beta.