Analysis of in vivo antigen-specific (LCMV-specific, SMARTA TCR transgenic) follicular helper CD4 T cells (CXCR5high),versus non-follicular helper CD4 T cells (CXCR5low), eight days after viral infection. A paper including data analysis of these experiments has been accepted for publication (Robert J. Johnston et al. Bcl6 and Blimp-1 are reciprocal and antagonistic regulators of follicular helper CD4 T cell differentiation).
Bcl6 and Blimp-1 are reciprocal and antagonistic regulators of T follicular helper cell differentiation.
Specimen part
View SamplesThe cellular ontogeny of hematopoietic stem cells (HSCs) remains poorly understood because their isolation from and their identification in early developing small embryos are difficult. We attempted to dissect early developmental stages of HSCs using an in vitro mouse embryonic stem cell (ESC) differentiation system combined with inducible HOXB4 expression. Here we report the identification of pre-HSCs and an embryonic type of HSCs (embryonic HSCs) as intermediate cells between ESCs and HSCs. Both pre-HSCs and embryonic HSCs were isolated by their c-Kit+CD41+CD45- phenotype. Pre-HSCs did not engraft in irradiated adult mice. After co-culture with OP9 stromal cells and conditional expression of HOXB4, pre-HSCs gave rise to embryonic HSCs capable of engraftment and long-term reconstitution in irradiated adult mice. Blast colony assays revealed that most hemangioblast activity was detected apart from the pre-HSC population, implying the early divergence of pre-HSCs from hemangioblasts. Gene expression profiling suggests that a particular set of transcripts closely associated with adult HSCs is involved in the transition of pre-HSC to embryonic HSCs.
Stepwise development of hematopoietic stem cells from embryonic stem cells.
Treatment
View SamplesMRL/Faslpr mice is a lupus prone strain that exhibits lupus disease features at 12-16 weeks of age, including high-titer circulating anti-DNA antibodies, splenomegaly, lymphadnopathy, skin lesions, and IgG deposits in the kidney. At 16-24 weeks of age, CD4+ B220- CD44+ T cells were sorted into three populations based on the expression of two cell surface molecules, CD62L and PSGL1. CD62Lhi PSGL1hi, CD62Llo PSGL1hi, and CD62Llo PSGL1lo CD4+ T cells were isolated directly ex vivo. There was no treatment given to the animals. Naive (CD62Lhi CD44lo) CD4+ B220- T cells were isolated from young 6-8 week old female mice for comparison.
In vivo regulation of Bcl6 and T follicular helper cell development.
Specimen part
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