Effective anti-tumor immunity is driven by cytotoxic CD8 T cells with specificity for tumor antigens. However, the factors that control successful tumor rejection are not well understood. Here we identify a subpopulation of CD8 T cells that are tumor-antigen-specific and can be identified by KIR expression but paradoxically impair anti-tumor immunity in patients with melanoma.
View Article and Find Full Text PDFA fertilized egg is initially transcriptionally silent and relies on maternally provided factors to initiate development. For embryonic development to proceed, the oocyte-inherited cytoplasm and the nuclear chromatin need to be reprogrammed to create a permissive environment for zygotic genome activation (ZGA). During this maternal-to-zygotic transition (MZT), which is conserved in metazoans, transient totipotency is induced and zygotic transcription is initiated to form the blueprint for future development.
View Article and Find Full Text PDFEffective anti-tumor immunity is largely driven by cytotoxic CD8 T cells that can specifically recognize tumor antigens. However, the factors which ultimately dictate successful tumor rejection remain poorly understood. Here we identify a subpopulation of CD8 T cells which are tumor antigen-specific in patients with melanoma but resemble KIRCD8 T cells with a regulatory function (Tregs).
View Article and Find Full Text PDFUpon fertilization, embryos undergo chromatin reprogramming and genome activation; however, the mechanisms that regulate these processes are poorly understood. Here, we generated a triple mutant for Nanog, Pou5f3, and Sox19b (NPS) in zebrafish and found that NPS pioneer chromatin opening at >50% of active enhancers. NPS regulate acetylation across core histones at enhancers and promoters, and their function in gene activation can be bypassed by recruiting histone acetyltransferase to individual genes.
View Article and Find Full Text PDFThe germ line provides the cellular link between generations of multicellular organisms, its cells entering the meiotic cell cycle only once each generation. However, the mechanisms governing this initiation of meiosis remain poorly understood. Here, we examined cells undergoing meiotic initiation in mice, and we found that initiation involves the dramatic upregulation of a transcriptional network of thousands of genes whose expression is not limited to meiosis.
View Article and Find Full Text PDFIsolating discrete populations of germ cells from the mouse testis is challenging, because the adult testis contains germ cells at every step of spermatogenesis, in addition to somatic cells. We present a novel method for isolating precise, high-purity populations of male germ cells. We first synchronize germ cell development in vivo by manipulating retinoic acid metabolism, and perform histological staging to verify synchronization.
View Article and Find Full Text PDFThe meiosis-specific chromosomal events of homolog pairing, synapsis, and recombination occur over an extended meiotic prophase I that is many times longer than prophase of mitosis. Here we show that, in mice, maintenance of an extended meiotic prophase I requires the gene Meioc, a germ-cell specific factor conserved in most metazoans. In mice, Meioc is expressed in male and female germ cells upon initiation of and throughout meiotic prophase I.
View Article and Find Full Text PDFLow-moisture foods (LMF) are increasingly implicated in outbreaks of foodborne illness, resulting in a significant public health burden. To inform the development of a new Codex Alimentarius code of hygienic practice for LMF, we applied a rapid knowledge synthesis and transfer approach to review global research on the burden of illness, prevalence, and interventions to control nine selected microbial hazards in eight categories of LMF. Knowledge synthesis methods included an integrated scoping review (search strategy, relevance screening and confirmation, and evidence mapping), systematic review (detailed data extraction), and meta-analysis of prevalence data.
View Article and Find Full Text PDFThe Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO) conducted an international expert meeting on the potential food safety implications of the application of nanotechnologies in the food and agriculture sectors in June 2009. The present report reviews national, regional and international activities on the risk assessment and risk management of nanomaterials in the food and agriculture sectors that have been carried out between 2009 and 2012. The full report of the work is presented in a FAO/WHO paper available at http://www.
View Article and Find Full Text PDFWhole-genome sequencing, particularly in fungi, has progressed at a tremendous rate. More difficult, however, is experimental testing of the inferences about gene function that can be drawn from comparative sequence analysis alone. We present a genome-wide functional characterization of a sequenced but experimentally understudied budding yeast, Saccharomyces bayanus var.
View Article and Find Full Text PDFBackground: Although quiescence (reversible cell cycle arrest) is a key part in the life history and fate of many mammalian cell types, the mechanisms of gene regulation in quiescent cells are poorly understood. We sought to clarify the role of microRNAs as regulators of the cellular functions of quiescent human fibroblasts.
Results: Using microarrays, we discovered that the expression of the majority of profiled microRNAs differed between proliferating and quiescent fibroblasts.
Quiescence is a state of reversible cell cycle arrest that can grant protection against many environmental insults. In some systems, cellular quiescence is associated with a low metabolic state characterized by a decrease in glucose uptake and glycolysis, reduced translation rates and activation of autophagy as a means to provide nutrients for survival. For cells in multiple different quiescence model systems, including Saccharomyces cerevisiae, mammalian lymphocytes and hematopoietic stem cells, the PI3Kinase/TOR signaling pathway helps to integrate information about nutrient availability with cell growth rates.
View Article and Find Full Text PDF