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Scheible, K.

Publications and source records attributed to Scheible, K..

4 recordsLinked to original sources

Single cell analysis of neonatal naïve CD8α+ T cells reveals novel subsets bridging the innate-adaptive spectrum

There is growing evidence that neonates harbor innate-like CD8a+ T cell subsets that contribute to both protection and hyper-inflammatory states. It remains unclear, however, where these innate-like features are found among the many conventional and unconventional T cell populations that can upregulate the CD8 receptor. Further delineation of these unique populations and functions, with a focus on CD8ab co-expression, will enable studies that seek to understand the unique immune features in conventional T cell populations that are present during fetal and early postnatal life. We used cord blood from infants across the full viable gestational age range to examine phenotypic and transcriptional heterogeneity, with a particular focus on the naive T cell pool. We report a set of fetally-derived and innate-like naive CD8{beta}+ T cells ( FITs) that are marked by their KLRG1+CD161+ phenotype, unique transcriptomic features and which are sparsely detected in adult peripheral blood. Additionally, using T cell receptor repertoire profiling, we can distinguish FITs from well-described and semi-invariant unconventional T cell populations such as mucosa-associated invariant T cells. Our delineation of FITs unique features will enable future investigation into their ontogeny and tissue distribution, and ultimately their role in immune-related outcomes in preterm infants.

immunology↗

A semi-parametric multiple imputation method for high-sparse, high-dimensional, compositional data

High sparsity (i.e., excessive zeros) in microbiome data, which are high-dimensional and compositional, is unavoidable and can significantly alter analysis results. However, efforts to address this high sparsity have been very limited because, in part, it is impossible to justify the validity of any such methods, as zeros in microbiome data arise from multiple sources (e.g., true absence, stochastic nature of sampling). The most common approach is to treat all zeros as structural zeros (i.e., true absence) or rounded zeros (i.e., undetected due to detection limit). However, this approach can underestimate the mean abundance while overestimating its variance because many zeros can arise from the stochastic nature of sampling and/or functional redundancy (i.e., different microbes can perform the same functions), thus losing power. In this manuscript, we argue that treating all zeros as missing values would not significantly alter analysis results if the proportion of structural zeros is similar for all taxa, and we propose a semi-parametric multiple imputation method for high-sparse, high-dimensional, compositional data. We demonstrate the merits of the proposed method and its beneficial effects on downstream analyses in extensive simulation studies. We reanalyzed a type II diabetes (T2D) dataset to determine differentially abundant species between T2D patients and non-diabetic controls.

bioinformatics↗

Affective Symptoms in Pregnancy are Associated with the Vaginal Microbiome

Composition of the vaginal microbiome in pregnancy is associated with adverse maternal, obstetric, and child health outcomes. Identifying the sources of individual differences in the vaginal microbiome is therefore of considerable clinical and public health interest. The current study tested the hypothesis that vaginal microbiome composition during pregnancy is associated with an individuals experience of affective symptoms and stress exposure. Data were based on a prospective longitudinal study of a diverse and medically healthy community sample of 275 mother-infant pairs. Affective symptoms and stress exposure and select measures of associated biomarkers (diurnal salivary cortisol, serum measures of sex hormones) were collected at each trimester; self-report, clinical, and medical records were used to collect detailed data on socio-demographic factors and health behavior, including diet and sleep. Vaginal microbiome samples were collected in the third trimester (34-40 weeks) and characterized by 16S rRNA sequencing. Identified taxa were clustered into three community state types (CST1-3) based on dissimilarity of vaginal microbiota composition. Results indicate that depressive symptoms during pregnancy were reliably associated with individual taxa and CST3 in the third trimester. Prediction of functional potential from 16S taxonomy revealed a differential abundance of metabolic pathways in CST1-3 and individual taxa, including biosynthetic pathways for the neuroactive metabolites, serotonin and dopamine. With the exception of bioavailable testosterone, no significant associations were found between symptoms- and stress-related biomarkers and CSTs. Our results provide further evidence of how prenatal psychological distress during pregnancy alters the maternal-fetal microbiome ecosystem that may be important for understanding maternal and child health outcomes. ImportancePrenatal affective symptoms and stress are associated with maternal, obstetric, and child health outcomes, but the mechanisms underlying these links and their application to intervention remain unclear. The findings from this investigation extend prior microbiome-oriented research by demonstrating that the maternal vaginal microbiome composition has a biologically plausible mechanistic link with affective symptoms that also suggest additional clinical applications for assessment and intervention.

microbiology↗

Lin28b specifies an innate-like lineage of CD8+ T cells in early life

The immune system is stratified into layers of specialized cells with distinct functions. Recently, Lin28b was shown to serve as a master regulator of fetal lymphopoiesis, programming the development of more innate-like lymphocytes in early life. However, it remains unclear whether Lin28b specifies innate functions in more conventional adaptive lymphocytes. In this report, we discovered that Lin28b promotes the development of a more innate-like lineage of CD8+ T cells that is capable of protecting the host against a wide variety of pathogens in the absence of TCR stimulation. Using RNA-seq and ATAC-seq, we found that Lin28b transcriptionally and epigenetically programs CD8+ T cells to be highly responsive to innate cytokines. We also performed scRNAseq and found that the shift from innate-like CD8+ T cells in early life to adaptive CD8+ T cells in adulthood is mediated by changes in the abundance of distinct subsets of cells. Remarkably, the innate CD8+ T cell subset predominates in early life but is also present in adult mice and humans. Collectively, our findings demonstrate that neonatal CD8+ T cells are a distinct lineage of lymphocytes that provide the host with innate defense in early life. One sentence SummaryHigh-dimensional analysis reveals how Lin28b programs neonatal CD8+ T cells for innate defense.

immunology↗