Cytokines produced in association with tumors can impair antitumor immune responses by reducing the abundance of type 1 conventional dendritic cells (cDC1), but the mechanism remains unclear. Here, we show that tumor-derived IL-6 generally reduces cDC development but selectively impairs cDC1 development in both murine and human systems through the induction of C/EBPβ in the common dendritic cell progenitor (CDP). C/EBPβ and NFIL3 compete for binding to sites in the Zeb2 −165 kb enhancer and support or repress Zeb2 expression, respectively. At homeostasis, pre-cDC1 specification occurs upon Nfil3 induction and consequent Zeb2 suppression. However, IL-6 strongly induces C/EBPβ expression in CDPs. Importantly, the ability of IL-6 to impair cDC development is dependent on the presence of C/EBPβ binding sites in the Zeb2 −165 kb enhancer, as this effect is lost in Δ1+2+3 mutant mice in which these binding sites are mutated. These results explain how tumor-associated IL-6 suppresses cDC1 development and suggest therapeutic approaches preventing abnormal C/EBPβ induction in CDPs may help reestablish cDC1 development to enhance antitumor immunity.
Individual elements within a superenhancer can act in a cooperative or temporal manner, but the underlying mechanisms remain obscure. We recently identified an Irf8 superenhancer, within which different elements act at distinct stages of type 1 classical dendritic cell (cDC1) development. The +41-kb Irf8 enhancer is required for pre-cDC1 specification, while the +32-kb Irf8 enhancer acts to support subsequent cDC1 maturation. Here, we found that compound heterozygous Δ32/Δ41 mice, lacking the +32- and +41-kb enhancers on different chromosomes, show normal pre-cDC1 specification but, surprisingly, completely lack mature cDC1 development, suggesting cis dependence of the +32-kb enhancer on the +41-kb enhancer. Transcription of the +32-kb Irf8 enhancer-associated long noncoding RNA (lncRNA) Gm39266 is also dependent on the +41-kb enhancer. However, cDC1 development in mice remained intact when Gm39266 transcripts were eliminated by CRISPR/Cas9-mediated deletion of lncRNA promoters and when transcription across the +32-kb enhancer was blocked by premature polyadenylation. We showed that chromatin accessibility and BATF3 binding at the +32-kb enhancer were dependent on a functional +41-kb enhancer located in cis . Thus, the +41-kb Irf8 enhancer controls the subsequent activation of the +32-kb Irf8 enhancer in a manner that is independent of associated lncRNA transcription.
Climate change-driven coral disease outbreaks have led to widespread declines in coral populations. Early work on coral genomics established that corals have a complex innate immune system, and whole-transcriptome gene expression studies have revealed mechanisms by which the coral immune system responds to stress and disease. The present investigation expands bioinformatic data available to study coral molecular physiology through the assembly and annotation of a reference transcriptome of the Caribbean reef-building coral, Orbicella faveolata . Samples were collected during a warm water thermal anomaly, coral bleaching event and Caribbean yellow band disease outbreak in 2010 in Puerto Rico. Multiplex sequencing of RNA on the Illumina GAIIx platform and de novo transcriptome assembly by Trinity produced 70,745,177 raw short-sequence reads and 32,463 O. faveolata transcripts, respectively. The reference transcriptome was annotated with gene ontologies, mapped to KEGG pathways, and a predicted proteome of 20,488 sequences was generated. Protein families and signaling pathways that are essential in the regulation of innate immunity across Phyla were investigated in-depth. Results were used to develop models of evolutionarily conserved Wnt, Notch, Rig-like receptor, Nod-like receptor, and Dicer signaling. O. faveolata is a coral species that has been studied widely under climate-driven stress and disease, and the present investigation provides new data on the genes that putatively regulate its immune system.
Disposal of municipal sewage sludge is a problem of national importance (U.S. Environmental Protection Agency 1972, Cairns 1978, Stearns and Ross 1978). Commonly used disposal methods (incineration, wetland filling, freshwater dumping, and ocean dumping) have widely recognized negative environmental impacts. Because sludges contain high levels of nitrogen and plant macronutrients, it may be possible to defray disposal costs by fertilizing agricultural, range, and forest lands with sludge. In 1973 the College of Forest Resources, University of Washington, began a cooperative effort with metropolitan Seattle to examine the feasibility of fertilizing soils of the Tsuga heterophylla Zone of western Washington with sludge for silvicultural purposes. Because glacial soils of this region are typically nitrogen-poor, the growth rate of economically important conifers can be substantially increased by sludge amendment (Edmonds and Cole 1977). This increased wood yield may defray disposal costs (Taggart and Schroeder 1980). Incidental to the impact of sludge fertilization on wood yield is the potential for altering wildlife habitat through the fertilization of understory vegetation. The game animal of particular interest in western Washington is the Columbian black-tailed deer (Odocoileus hemionus columbianus). Because diet quality has frequently been associated with reproductive success in Odocoileus (Cheatum and Severinghaus 1950, Taber 1956, Forbes 963, Verme 1965, Murphy and Coates 1966, Dechert 1968), it was hypothesized that forest fertilization with sewage sludge would increase herd productivity. The objective of this paper is to document that sludge application increased the crude protein content of key deer forage items and that female deer exploiting sludge-amended areas recruited more fawns to the 6-month age-class than did controls.
