ABSTRACT: Three innate (B1-B, NKT, CD8aaT cells) and adaptive (B2-B, CD4T, CD8abT cells) cell-types were sorted by FACS. Three biological replicates for NKT, CD4T, CD8aaT, CD8abT cells and two biological replicates for B1 and B2 cells were generated and the expression profiles were determined using Affymetrix Mu74Av2 chip. Comparisons between the sample groups allow the identification of genes differentially expressed between the innate and adaptive cell-types. Keywords: cell type comparison, innate vs. adaptive
Project description:Three innate (B1-B, NKT, CD8aaT cells) and adaptive (B2-B, CD4T, CD8abT cells) cell-types were sorted by FACS. Three biological replicates for NKT, CD4T, CD8aaT, CD8abT cells and two biological replicates for B1 and B2 cells were generated and the expression profiles were determined using Affymetrix Mu74Av2 chip. Comparisons between the sample groups allow the identification of genes differentially expressed between the innate and adaptive cell-types. Experiment Overall Design: 3 biological replicates for NKT, CD4T, CD8aaT, CD8abT cells and 2 biological replicates for B1, B2 cells were analyzed
Project description:Humoral immunity in mammals relies on the function of two developmentally and functionally distinct B cell subsets - B1 and B2 cells. While B2 cells are responsible for the adaptive response to environmental antigens, B1 cells regulate the production of polyreactive and low affinity antibodies for innate humoral immunity. The molecular mechanism of B cell specification into different subsets is understudied. We identified lysine methyltransferase NSD2 (MMSET/WHSC1) as a critical regulator of B1 cell development. In contrast to its minor impact on B2 cells, deletion of the catalytic domain of NSD2 in primary B cells impairs the generation of B1 lineage. Thus, NSD2, a histone H3 K36 dimethylase, is the first-in-class epigenetic regulator of a B cell lineage in mice.
Project description:miR-181a1/b1, miR-181a2/b2, and miR-181c/d belong to a highly conserved family of microRNA clusters, yet their role in vivo is poorly understood. Here we show that the miR-181a1/b1 cluster is absolutely essential for NKT development and is a critical determinant of thymocyte proliferation, survival and T-cell receptor α locus rearrangement. Furthermore, while individual ablation of miR-181a2/b2 and miR-181c/d revealed no overt phenotypes, compound mutant mice lacking both miR-181a1/b1 and miR-181a2/b2 display decreased survival, reduced body weight, and abnormal B cell development. Mechanistically, we reveal that miR-181 regulates PTEN, a key tumor suppressor whose abundance determines key metabolic adaptations required to meet the biosynthetic demands of highly proliferative tissues. These results provide important insights into the physiological function of this family of microRNAs in vivo; moreover, it places miR-181 as a central regulator of the PI3K signaling pathway and cellular metabolism. Three sorted populations of double positive (DP) thymocytes from each of two conditions (WT and miR181a1/b1 -/- mice)
Project description:Natural killer T (NKT) cells are a distinct lymphocyte lineage thought to operate primarily at the interface between the innate and adaptive immune response. Yet, their unique role in the immune system remains elusive. Whilst NKT cells show high similarities to other cells of the innate and adaptive immune system, they express unique functional features such as rapid, concomitant production of Th1 and Th2 cytokines upon TCR ligation. In order to portray gene expression of NKT cells and to analyze their complete functional potential, we performed comparative microarray analyses of naive NKT cells, naive NK cells as well as naive conventional CD4+ T cells (Th, CD4+CD25–) and naive regulatory CD4+CD25+ T cells (Treg ). Furthermore, we compared the gene expression profiles of naive versus alpha-galactosylceramide activated NKT cells to elucidate the gene set rapidly expressed upon activation. We describe profound gene expression differences between the different cell types as well as between naive and activated NKT cells allowing the identification of a unique gene expression profile of NKT cells. In addition to known NKT cell specific markers, a high number of genes were expressed and detected which had not been attributed to NKT cells. Notably, our analyses reveals that NKT cells are not only of Th1 and Th2 type but also fulfil criteria of Th17 cells. Hence, our data provide new insight into the genetic décor of NKT cells which will facilitate a better understanding of their versatile role during the immune response. Keywords: NKT, NK, Th and Treg cell type comparison
Project description:miR-181a1/b1, miR-181a2/b2, and miR-181c/d belong to a highly conserved family of microRNA clusters, yet their role in vivo is poorly understood. Here we show that the miR-181a1/b1 cluster is absolutely essential for NKT development and is a critical determinant of thymocyte proliferation, survival and T-cell receptor α locus rearrangement. Furthermore, while individual ablation of miR-181a2/b2 and miR-181c/d revealed no overt phenotypes, compound mutant mice lacking both miR-181a1/b1 and miR-181a2/b2 display decreased survival, reduced body weight, and abnormal B cell development. Mechanistically, we reveal that miR-181 regulates PTEN, a key tumor suppressor whose abundance determines key metabolic adaptations required to meet the biosynthetic demands of highly proliferative tissues. These results provide important insights into the physiological function of this family of microRNAs in vivo; moreover, it places miR-181 as a central regulator of the PI3K signaling pathway and cellular metabolism.
Project description:Neurogenesis and gliogenesis continue in the Ventricular-Subventricular Zone (V-SVZ) of the adult rodent brain. B1 cells are radial glia-derived astroglial cells that function as primary progenitors or neural stem cells (NSCs) in the V-SVZ. B1 cells, which have an apical contact with the ventricle, decline during early postnatal life, yet neurogenesis continues into adulthood. We found that a second population of V-SVZ astroglial cells (B2 cells), that do not contact the ventricle, function as NSCs in the adult brain. B2 cell numbers increase postnatally, remain constant in 12-month-old mice, and decrease by 18 months. Transcriptomic analysis revealed differences between B1 and B2 cells and shows that like B1 cells, B2 cells can be quiescent or activated. Transplantation and lineage tracing of B2 cells demonstrate their function as primary progenitors for adult neurogenesis. This study reveals that NSC function is relayed from B1 to B2 progenitors to maintain adult neurogenesis.
Project description:Type 1 NKT cells play a critical role in controlling the strength and character of adaptive and innate immune responses. Their functional characteristics are distinct from conventional T cells, and are induced by a transcriptional program initiated by positive selection on CD4+CD8+ (double positive, DP) thymocytes. Here we examined transcriptional events in four immature thymic NKT cell subsets in a novel Vα14 TCR transgenic strain bearing greatly expanded numbers of CD24+CD44- NKT cells. We used a transcriptional regulatory network approach to map TCR validation to the transition from DP T to DP NKT cells, and positive selection and lineage commitment to the transition from DP NKT to CD4 NKT
Project description:CD1d-dependent type I NKT cells, which are activated by lipid antigen, are known to play important roles in innate and adaptive immunity, as are a portion of type II NKT cells. However, the heterogeneity of NKT cells, especially NKT-like cells, remains largely unknown. Here, we report the profiling of NKT (NK1.1+CD3e+) cells in livers from wild type (WT), Jα18-deficient and CD1d- deficient mice by single-cell RNA sequencing. Unbiased transcriptional clustering revealed distinct cell subsets. The transcriptomic profiles identified the well-known CD1d-dependent NKT cells and defined two CD1d-independent NKT cell subsets. In addition, validation of marker genes revealed the differential organ distribution and landscape of NKT cell subsets during liver tumor progression. More importantly, we found that CD1d-independent Sca-1−CD62L+ NKT cells showed a strong ability to secrete IFN-γ after costimulation with IL-2, IL-12 and IL-18 in vitro. Collectively, our findings provide a comprehensive characterization of NKT cell heterogeneity and unveil a previously undefined functional NKT cell subset.
Project description:Semi-invariant natural killer T (NKT) cells are thymus-derived innate lymphocytes that modulate microbial and tumour immunity as well as autoimmune diseases. These immunoregulatory properties of NKT cells are acquired during their development. Much has been learnt regarding the molecular and cellular cues that promote NKT cell development, yet how these cells are maintained in the thymus and the periphery and how they acquire functional competence are incompletely understood. We found that IL-15 induced several Bcl-2 family survival factors in thymic and splenic NKT cells in vitro. Yet, IL15-mediated thymic and peripheral NKT cell survival critically depended on Bcl-xL expression. Additionally, IL-15 regulated thymic developmental stage 2 (ST2) to ST3 lineage progression and terminal NKT cell differentiation. Global gene expression analyses and validation revealed that IL-15 regulated Tbx21 (T-bet) expression in thymic ST3 NKT cells. The loss of IL15-dependent T-bet expression resulted in poor expression of IFN-γ and several NK cell receptors in NKT cells. Taken together, our findings reveal a critical role for IL-15 in NKT cell survival, which is mediated by Bcl-xL, and effector differentiation, which is regulated by T-bet. Gene expression was measured in NKT cells sorted from pooled thymi of wild-type (3 replicates) or IL-15 deficient (2 replicates) mice.
Project description:Plants of a “Hana-type” landrace (B1) were taller, flowered earlier and produced heavier, larger and more vigorous seeds that resisted ageing longer compared to a semi-dwarf breeding line (B2). Drought significantly reduced seed yield in both genotypes, and elevated temperature reduced seed size. Genotype B2 showed partial thermodormancy that was alleviated by drought and elevated temperature, in line with lower abundance of the TF ABI5, a key regulator of seed dormancy and vigour. Metabolite profiling revealed clear differences between the embryos of B1 and B2. Drought, but not elevated temperature, affected the metabolism of amino acids, organic acids, osmolytes and nitrogen assimilation, in the seeds of both genotypes.