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Background Unprofessional behaviour undermines organizational trust and negatively affects patient safety, the clinical learning environment, and clinician well-being. Improving professionalism in healthcare organizations requires insight into the frequency, types, sources, and targets of unprofessional behaviour in order to refine organizational programs and strategies to prevent and address unprofessional behaviours. Objective To investigate the types and frequency of perceived unprofessional behaviours among health care professionals and to identify the sources and targets of these behaviours. Methods Data was collected from 2017–2019 based on a convenience sample survey administered to all participants at the start of a mandatory professionalism course for health care professionals including attending physicians, residents and advanced practice providers (APPs) working at one academic hospital in the United States. Results Out of the 388 participants in this study, 63% experienced unprofessional behaviour at least once a month, including failing to respond to calls/pages/requests (44.3%), exclusion from decision-making (43.0%) and blaming behaviour (39.9%). Other monthly experienced subtypes ranged from 31.7% for dismissive behaviour to 4.6% for sexual harassment. Residents were more than twice as likely (OR 2.25, p<0.001)) the targets of unprofessional behaviour compared to attending physicians. Female respondents experienced more discriminating behaviours (OR 2.52, p<0.01). Nurses were identified as the most common source of unprofessional behaviours (28.1%), followed by residents from other departments (21%). Conclusions Unprofessional behaviour was experienced frequently by all groups, mostly inflicted on these groups by those outside of the own discipline or department. Residents were most frequently identified to be the target and nurses the source of the behaviours. This study highlights that unprofessional behaviour is varied, both regarding typ

Tuft cells are an epithelial cell type critical for initiating type 2 immune responses to parasites and protozoa in the small intestine. To respond to these stimuli, intestinal tuft cells use taste chemosensory signaling pathways, but the role of taste receptors in type 2 immunity is poorly understood. In this study, we show that the taste receptor TAS1R3, which detects sweet and umami in the tongue, also regulates tuft cell responses in the distal small intestine. BALB/c mice, which have an inactive form of TAS1R3, as well as Tas1r3-deficient C57BL6/J mice both have severely impaired responses to tuft cell-inducing signals in the ileum, including the protozoa Tritrichomonas muris and succinate. In contrast, TAS1R3 is not required to mount an immune response to the helminth Heligmosomoides polygyrus, which infects the proximal small intestine. Examination of uninfected Tas1r3-/- mice revealed a modest reduction in the number of tuft cells in the proximal small intestine but a severe decrease in the distal small intestine at homeostasis. Together, these results suggest that TAS1R3 influences intestinal immunity by shaping the epithelial cell landscape at steady-state.

© 2019 Myers et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc. Proteomic profiling describes the molecular landscape of proteins in cells immediately available to sense, transduce, and enact the appropriate responses to extracellular queues. Transcriptional profiling has proven invaluable to our understanding of cellular responses; however, insights may be lost as mounting evidence suggests transcript levels only moderately correlate with protein levels in steady state cells. Mass spectrometry-based quantitative proteomics is a well-suited and widely used analytical tool for studying global protein abundances. Typical proteomic workflows are often limited by the amount of sample input that is required for deep and quantitative proteome profiling. This is especially true if the cells of interest need to be purified by fluorescence-activated cell sorting (FACS) and one wants to avoid ex vivo culturing. To address this need, we developed an easy to implement, streamlined workflow that enables quantitative proteome profiling from roughly 2 g of protein input per experimental condition. Utilizing a combination of facile cell collection from cell sorting, solid-state isobaric labeling and multiplexing of peptides, and small-scale fractionation, we profiled the proteomes of 12 freshly isolated, primary murine immune cell types. Analyzing half of the 3e5 cells collected per cell type, we quantified over 7000 proteins across 12 key immune cell populations directly from their resident tissues. We show that low input proteomics is precise, and the data generated accurately reflects many aspects of known immunology, while expanding the list of cell-type specific proteins across the cell types profiled. The low input proteomics methods we developed are readily adaptable and broadly applicable to any cell or sample types and should enable proteome profiling in systems previously unattainable.

The clear role of autophagy in human inflammatory diseases such as Crohn disease was first identified by genome-wide association studies and subsequently dissected in multiple mechanistic studies. ATG16L1 has been particularly well studied in knockout and hypomorph settings as well as models recapitulating the Crohn disease–associated T300A polymorphism. Interestingly, ATG16L1 has a single homolog, ATG16L2, which is independently implicated in diseases, including Crohn disease and systemic lupus erythematosus. However, the contribution of ATG16L2 to canonical autophagy pathways and other cellular functions is poorly understood. To better understand its role, we generated and analyzed the first, to our knowledge, ATG16L2 knockout mouse. Our results show that ATG16L1 and ATG16L2 contribute very distinctly to autophagy and cellular ontogeny in myeloid, lymphoid, and epithelial lineages. Dysregulation of any of these lineages could contribute to complex diseases like Crohn disease and systemic lupus erythematosus, highlighting the value of examining cell-specific effects. We also identify a novel genetic interaction between ATG16L2 and epithelial ATG16L1. These findings are discussed in the context of how these genes may contribute distinctly to human disease.

In the small intestine, a niche of accessory cell types supports the generation of mature epithelial cell types from intestinal stem cells (ISCs). It is unclear, however, if and how immune cells in the niche affect ISC fate or the balance between self-renewal and differentiation. Here, we use single-cell RNA sequencing (scRNA-seq) to identify MHC class II (MHCII) machinery enrichment in two subsets of Lgr5⁺ ISCs. We show that MHCII⁺ Lgr5⁺ ISCs are non-conventional antigen-presenting cells in co-cultures with CD4⁺ T helper (Th) cells. Stimulation of intestinal organoids with key Th cytokines affects Lgr5⁺ ISC renewal and differentiation in opposing ways: pro-inflammatory signals promote differentiation, while regulatory cells and cytokines reduce it. In vivo genetic perturbation of Th cells or MHCII expression on Lgr5⁺ ISCs impacts epithelial cell differentiation and IEC fate during infection. These interactions between Th cells and Lgr5⁺ ISCs, thus, orchestrate tissue-wide responses to external signals. Intestinal stem cells act as non-conventional antigen presenting cells, and these interactions with T helper cells modulate ISC renewal and differentiation to shape the intestine. Keywords: gut biology; intestinal stem cells; ISCs; T helper; Th; mucosal immunity; MHC class II; MHCII; tuft cells; T regulatory; Treg; single cell RNA-seq; scRNA-seq; epithelial differentiation; stem cell renewal, National Institute of Health (U.S.) (Award 1DP2OD020839), National Institute of Health (U.S.) (Grant CA211184), National Institute of Health (U.S.) (Grant AG045144)

Intestinal epithelial cells absorb nutrients, respond to microbes, function as a barrier and help to coordinate immune responses. Here we report profiling of 53,193 individual epithelial cells from the small intestine and organoids of mice, which enabled the identification and characterization of previously unknown subtypes of intestinal epithelial cell and their gene signatures. We found unexpected diversity in hormone-secreting enteroendocrine cells and constructed the taxonomy of newly identified subtypes, and distinguished between two subtypes of tuft cell, one of which expresses the epithelial cytokine Tslp and the pan-immune marker CD45, which was not previously associated with non-haematopoietic cells. We also characterized the ways in which cell-intrinsic states and the proportions of different cell types respond to bacterial and helminth infections: Salmonella infection caused an increase in the abundance of Paneth cells and enterocytes, and broad activation of an antimicrobial program; Heligmosomoides polygyrus caused an increase in the abundance of goblet and tuft cells. Our survey highlights previously unidentified markers and programs, associates sensory molecules with cell types, and uncovers principles of gut homeostasis and response to pathogens.