The prefrontal cortex is a critical neuroanatomical hub for controlling motivated behaviours across mammalian species. In addition to intra-cortical connectivity, prefrontal projection neurons ...innervate subcortical structures that contribute to reward-seeking behaviours, such as the ventral striatum and midline thalamus. While connectivity among these structures contributes to appetitive behaviours, how projection-specific prefrontal neurons encode reward-relevant information to guide reward seeking is unknown. Here we use in vivo two-photon calcium imaging to monitor the activity of dorsomedial prefrontal neurons in mice during an appetitive Pavlovian conditioning task. At the population level, these neurons display diverse activity patterns during the presentation of reward-predictive cues. However, recordings from prefrontal neurons with resolved projection targets reveal that individual corticostriatal neurons show response tuning to reward-predictive cues, such that excitatory cue responses are amplified across learning. By contrast, corticothalamic neurons gradually develop new, primarily inhibitory responses to reward-predictive cues across learning. Furthermore, bidirectional optogenetic manipulation of these neurons reveals that stimulation of corticostriatal neurons promotes conditioned reward-seeking behaviour after learning, while activity in corticothalamic neurons suppresses both the acquisition and expression of conditioned reward seeking. These data show how prefrontal circuitry can dynamically control reward-seeking behaviour through the opposing activities of projection-specific cell populations.
The paraventricular thalamus (PVT) is an interface for brain reward circuits, with input signals arising from structures, such as prefrontal cortex and hypothalamus, that are broadcast to downstream ...limbic targets. However, the precise synaptic connectivity, activity, and function of PVT circuitry for reward processing are unclear. Here, using in vivo two-photon calcium imaging, we find that PVT neurons projecting to the nucleus accumbens (PVT-NAc) develop inhibitory responses to reward-predictive cues coding for both cue-reward associative information and behavior. The multiplexed activity in PVT-NAc neurons is directed by opposing activity patterns in prefrontal and lateral hypothalamic afferent axons. Further, we find that prefrontal cue encoding may maintain accurate cue-reward processing, as optogenetic disruption of this encoding induced long-lasting effects on downstream PVT-NAc cue responses and behavioral cue discrimination. Together, these data reveal that PVT-NAc neurons act as an interface for reward processing by integrating relevant inputs to accurately inform reward-seeking behavior.
•PVT-NAc neurons develop inhibitory responses to reward-predictive cues•Glutamatergic PFC axons to PVT show reductions in activity to cues•GABAergic LHA axons to PVT show increases in activity during licking•Optogenetic stimulation of PFC axons disrupts PVT-NAc cue encoding and behavior
The paraventricular nucleus of the thalamus is a substrate underlying reward seeking. Otis, Zhu, et al. demonstrate that projection-defined thalamic neurons are controlled by dissociable response features in cortical and hypothalamic inputs during reward processing.
Immune responses to cancer are highly variable, with mismatch repair-deficient (MMRd) tumors exhibiting more anti-tumor immunity than mismatch repair-proficient (MMRp) tumors. To understand the rules ...governing these varied responses, we transcriptionally profiled 371,223 cells from colorectal tumors and adjacent normal tissues of 28 MMRp and 34 MMRd individuals. Analysis of 88 cell subsets and their 204 associated gene expression programs revealed extensive transcriptional and spatial remodeling across tumors. To discover hubs of interacting malignant and immune cells, we identified expression programs in different cell types that co-varied across tumors from affected individuals and used spatial profiling to localize coordinated programs. We discovered a myeloid cell-attracting hub at the tumor-luminal interface associated with tissue damage and an MMRd-enriched immune hub within the tumor, with activated T cells together with malignant and myeloid cells expressing T cell-attracting chemokines. By identifying interacting cellular programs, we reveal the logic underlying spatially organized immune-malignant cell networks.
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•A scRNA-seq study reveals shared and distinct features of human MMRd and MMRp CRC•Co-variation of single-cell transcriptional programs across specimens predicts immune hubs•A myeloid-rich inflammatory hub is identified below the colonic lumen in human CRC•CXCR3-ligand+ cells form foci with activated T cells in human MMRd CRC
Single-cell transcriptomics-based co-variation analysis of human colorectal cancer identifies a spatially resolved myeloid-rich inflammatory hub that is shared by mismatch repair-deficient (MMRd) and mismatch repair-proficient (MMRp) tumors and CXCR3-ligand+ multicellular foci distinct for MMRd tumors.
Colorectal cancers (CRCs) arise from precursor polyps whose cellular origins, molecular heterogeneity, and immunogenic potential may reveal diagnostic and therapeutic insights when analyzed at high ...resolution. We present a single-cell transcriptomic and imaging atlas of the two most common human colorectal polyps, conventional adenomas and serrated polyps, and their resulting CRC counterparts. Integrative analysis of 128 datasets from 62 participants reveals adenomas arise from WNT-driven expansion of stem cells, while serrated polyps derive from differentiated cells through gastric metaplasia. Metaplasia-associated damage is coupled to a cytotoxic immune microenvironment preceding hypermutation, driven partly by antigen-presentation differences associated with tumor cell-differentiation status. Microsatellite unstable CRCs contain distinct non-metaplastic regions where tumor cells acquire stem cell properties and cytotoxic immune cells are depleted. Our multi-omic atlas provides insights into malignant progression of colorectal polyps and their microenvironment, serving as a framework for precision surveillance and prevention of CRC.
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•A single-cell resolution atlas of human adenomas and serrated polyps•Serrated polyps arise from metaplasia as opposed to stem cell expansion•Cytotoxic immunity in serrated polyps occurs independently of hypermutation•Distinct immune microenvironments track tumor cell-differentiation states
A single-cell resolution atlas of human colorectal polyps maps out distinct paths for pre-cancer to cancer transformation, accompanied by differential immune microenvironment features.
T cells engineered to express chimeric antigen receptors (CARs) targeting CD19 have produced impressive outcomes for the treatment of B cell malignancies, but different products vary in kinetics, ...persistence, and toxicity profiles based on the co-stimulatory domains included in the CAR. In this study, we performed transcriptional profiling of bulk CAR T cell populations and single cells to characterize the transcriptional states of human T cells transduced with CD3ζ, 4-1BB-CD3ζ (BBζ), or CD28-CD3ζ (28ζ) co-stimulatory domains at rest and after activation by triggering their CAR or their endogenous T cell receptor (TCR). We identified a transcriptional signature common across CARs with the CD3ζ signaling domain, as well as a distinct program associated with the 4-1BB co-stimulatory domain at rest and after activation. CAR T cells bearing BBζ had increased expression of human leukocyte antigen (HLA) class II genes, ENPP2, and interleukin (IL)-21 axis genes, and decreased PD1 compared to 28ζ CAR T cells. Similar to previous studies, we also found BBζ CAR CD8 T cells to be enriched in a central memory cell phenotype and fatty acid metabolism genes. Our data uncovered transcriptional signatures related to costimulatory domains and demonstrated that signaling domains included in CARs uniquely shape the transcriptional programs of T cells.
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Maus, Regev, and colleagues performed a deep transcriptional analysis of CAR T cells bearing different signaling domains, at rest and after activation. Findings include CAR-specific signatures and a distinct program activated in CARs with 4-1BB domains that was characterized by expression of central memory markers, MHC class II, and IL-21, among others.
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