Brain, behavior, and immunity
Reinl, EL;Blanchard, AC;Graham, EL;Edwards, S;Dionisos, C;McCarthy, MM;
PMID: 36049705 | DOI: 10.1016/j.bbi.2022.08.012
Little is known about the peripheral immune cell (PIC) profile of the developing brain despite growing appreciation for these cells in the mature nervous system. To address this gap, the PIC profile, defined as which cells are present, where they are located, and for how long, was examined in the developing rat using spectral flow cytometry. Select regions of the rat brain (cerebellum, hippocampus, and hypothalamus) were examined at embryonic day 20, and postnatal days 0, 7 and 16. At their peak (E20), PICs were most abundant in the cerebellum, then the hippocampus and hypothalamus. Within the PIC pool, monocytes were most prevalent in all regions and time points, and shifted from being majority classical at E20 to non-classical by PN7. T cells increased over time, and shifted from majority cytotoxic to T-helper cells by PN7. This suggests the PIC profile transitions from reactive to adaptive and surveilling in the second postnatal week. NK cells and mast cells increased temporarily, and mast cells were restricted to the hippocampus and hypothalamus, suggesting they may play a specific role in the development of those regions. Mimicking a viral infection by administration of Poly I:C increased the influx of PICs into the neonatal brain, particularly of NK cells and in the case of males only, non-classical monocytes. This work provides a map for researchers as they study immune cell contributions to healthy and pathological brain development.
Pitter, KL;Grbovic-Huezo, O;Joost, S;Singhal, A;Blum, M;Wu, K;Holm, M;Ferrena, A;Bhutkar, A;Hudson, A;Lecomte, N;de Stanchina, E;Chaligne, R;Iacobuzio-Donahue, CA;Pe'er, D;Tammela, T;
PMID: 35952360 | DOI: 10.1158/0008-5472.CAN-22-1742
Intra-tumoral heterogeneity and cellular plasticity have emerged as hallmarks of cancer, including pancreatic ductal adenocarcinoma (PDAC). As PDAC portends a dire prognosis, a better understanding of the mechanisms underpinning cellular diversity in PDAC is crucial. Here, we investigated the cellular heterogeneity of PDAC cancer cells across a range of in vitro and in vivo growth conditions using single-cell genomics. Heterogeneity contracted significantly in 2D and 3D cell culture models but was restored upon orthotopic transplantation. Orthotopic transplants reproducibly acquired cell states identified in autochthonous PDAC tumors, including a basal state exhibiting co-expression and co-accessibility of epithelial and mesenchymal genes. Lineage-tracing combined with single-cell transcriptomics revealed that basal cells display high plasticity in situ. This work defines the impact of cellular growth conditions on phenotypic diversity and uncovers a highly plastic cell state with the capacity to facilitate state transitions and promote intra-tumoral heterogeneity in PDAC.
Guerrero-Juarez, CF;Lee, GH;Liu, Y;Wang, S;Karikomi, M;Sha, Y;Chow, RY;Nguyen, TTL;Iglesias, VS;Aasi, S;Drummond, ML;Nie, Q;Sarin, K;Atwood, SX;
PMID: 35687691 | DOI: 10.1126/sciadv.abm7981
How basal cell carcinoma (BCC) interacts with its tumor microenvironment to promote growth is unclear. We use singe-cell RNA sequencing to define the human BCC ecosystem and discriminate between normal and malignant epithelial cells. We identify spatial biomarkers of tumors and their surrounding stroma that reinforce the heterogeneity of each tissue type. Combining pseudotime, RNA velocity-PAGA, cellular entropy, and regulon analysis in stromal cells reveals a cancer-specific rewiring of fibroblasts, where STAT1, TGF-β, and inflammatory signals induce a noncanonical WNT5A program that maintains the stromal inflammatory state. Cell-cell communication modeling suggests that tumors respond to the sudden burst of fibroblast-specific inflammatory signaling pathways by producing heat shock proteins, whose expression we validated in situ. Last, dose-dependent treatment with an HSP70 inhibitor suppresses in vitro vismodegib-resistant BCC cell growth, Hedgehog signaling, and in vivo tumor growth in a BCC mouse model, validating HSP70's essential role in tumor growth and reinforcing the critical nature of tumor microenvironment cross-talk in BCC progression.
Liu, Y;Guerrero-Juarez, C;Xiao, F;Shettigar, N;Ramos, R;Kuan, C;Lin, Y;de Jesus Martinez Lomeli, L;Park, J;Oh, J;Liu, R;Lin, S;Tartaglia, M;Yang, R;Yu, Z;Nie, Q;Li, J;Plikus, M;
| DOI: 10.1016/j.devcel.2022.06.005
Hair follicle stem cells are regulated by dermal papilla fibroblasts, their principal signaling niche. Overactivation of Hedgehog signaling in the niche dramatically accelerates hair growth and induces follicle multiplication in mice. On single-cell RNA sequencing, dermal papilla fibroblasts increase heterogeneity to include new Wnt5ahigh states. Transcriptionally, mutant fibroblasts activate regulatory networks for Gli1, Alx3, Ebf1, Hoxc8, Sox18, and Zfp239. These networks jointly upregulate secreted factors for multiple hair morphogenesis and hair-growth-related pathways. Among these is non-conventional TGF-β ligand Scube3. We show that in normal mouse skin, Scube3 is expressed only in dermal papillae of growing, but not in resting follicles. SCUBE3 protein microinjection is sufficient to induce new hair growth, and pharmacological TGF-β inhibition rescues mutant hair hyper-activation phenotype. Moreover, dermal-papilla-enriched expression of SCUBE3 and its growth-activating effect are partially conserved in human scalp hair follicles. Thus, Hedgehog regulates mesenchymal niche function in the hair follicle via SCUBE3/TGF-β mechanism.
Journal of Swine Health and Production
Buckley, A;Lager, K;
| DOI: 10.54846/jshap/1270
Senecavirus A (SVA) has been demonstrated to be a causative agent for vesicular disease in swine. It is clinically indistinguishable from other agents that cause vesicular disease such as foot-and-mouth disease virus (FMDV), which is a reportable foreign animal disease (FAD). Thus, an investigation is initiated to rule out FMDV every time a vesicle is observed. Senecavirus A has now been reported across the Americas and Asia, and it appears the ecology of this virus has changed from sporadic infections to an endemic disease in some areas. In addition to vesicular disease, there have also been reports of increased neonatal mortality on affected sow farms. Knowledge about the pathogenesis of SVA in swine can provide many benefits to the swine industry. Understanding how long the virus can be detected in various sample types after infection can aide in choosing the correct samples to collect for diagnosis. In addition, the duration of virus shedding can help determine measures to control virus spread between animals. Prevention of SVA infection and disease with an efficacious vaccine could improve swine welfare, minimize SVA transmission, and reduce the burden of FAD investigations.
Zhang, JY;Du, Y;Gong, LP;Shao, YT;Pan, LJ;Feng, ZY;Pan, YH;Huang, JT;Wen, JY;Sun, LP;Chen, GF;Chen, JN;Shao, CK;
PMID: 35304258 | DOI: 10.1016/j.canlet.2022.215646
Epstein-Barr virus (EBV) is a tumor virus that is associated with a variety of neoplasms, including EBV-associated gastric carcinoma (EBVaGC). Recently, EBV was reported to generate various circular RNAs (circRNAs). CircRNAs are important regulators of tumorigenesis by modulating the malignant behaviors of tumor cells. However, to date, the functions of ebv-circRNAs in EBVaGC remain poorly understood. In the present study, we observed high ebv-circRPMS1 expression in EBVaGC and showed that ebv-circRPMS1 promoted the proliferation, migration, and invasion and inhibited the apoptosis of EBVaGC cells. In addition, METTL3 was upregulated in GC cells overexpressing ebv-circRPMS1. Mechanistically, ebv-circRPMS1 bound to Sam68 to facilitate its physical interaction with the METTL3 promotor, resulting in the transactivation of METTL3 and cancer progression. In clinical EBVaGC samples, ebv-circRPMS1 was associated with distant metastasis and a poor prognosis. Based on these findings, ebv-circRPMS1 contributed to EBVaGC progression by recruiting Sam68 to the METTL3 promoter to induce METTL3 expression. ebv-circRPMS1, Sam68, and METTL3 might serve as therapeutic targets for EBVaGC.
Ye, M;Wang, M;Feng, Y;Shang, H;Yang, Y;Hu, L;Wang, M;Vakal, S;Lin, X;Chen, J;Zheng, W;
PMID: 35167016 | DOI: 10.1007/s11302-022-09847-5
The choroid plexus (CP) is one of the key gateways regulating the entry of peripheral immune cells into the CNS. However, the neuromodulatory mechanisms of maintaining its gateway activity are not fully understood. Here, we identified adenosine A2A receptor (A2AR) activity as a regulatory signal for the activity of CP gateway under physiological conditions. In association with a tightly closed CP gateway, we found that A2AR was present at low density in the CP. The RNA-seq analysis revealed that the A2AR antagonist KW6002 affected the expression of the cell adhesion molecules' (CAMs) pathway and cell response to IFN-γ in the CP. Furthermore, blocking or activating A2AR signaling in the CP resulted in a decreased and an increased, respectively, expression of lymphocyte trafficking determinants and disruption of the tight junctions (TJs). Furthermore, A2AR signaling regulates the CP permeability. Thus, A2AR activity in the CP may serve as a therapeutic target for remodeling the immune homeostasis in the CNS with implications for the treatment of neuroimmunological disorders.
Webb, A;Schindell, B;Griffin, B;Soule, G;Siddik, A;Abrenica, B;Memon, H;Su, R;Kobasa, D;Safronetz, D;Kindrachuk, J;
| DOI: 10.2139/ssrn.4000892
Recent outbreaks of Ebola virus linked to chains of transmission from the 2014-2016 West African Ebola virus epidemic suggest a new paradigm for persistent Ebola virus infections as a lasting concern to public health. Cases of Ebola virus disease linked to sexual transmission and detection of Ebola virus in the male reproductive tract long after patients have recovered suggests that Ebola virus persistence occurs in this immune privileged area. However, little is known about Ebola virus cell tropism, viral kinetics, and host response to infection in the testis. In this study, we challenged immunocompromised mice and testicular tissue cultures with wild type Ebola virus. We utilized RT-qPCR and ISH to detect and quantify Ebola virus in the testis. We also employed RNAseq analysis to measure the transcriptomic response of specific testicular cell types to Ebola virus infection. Our results indicate that Ebola virus productively infects the cells at the blood-testis barrier, and that the interstitial space is more susceptible to infection compared to blood-testis barrier itself. In addition, the Sertoli cells that make up the physical structure of the blood-testis barrier maintain greater viability during Ebola virus infection, and this results from nonstandard immune response that prioritizes inhibited viral entry/replication and increased cell homeostatic activity. Our findings reinforce the need to further investigate viral persistence in the male reproductive tract as a reservoir for ongoing and future outbreaks of Ebola virus disease.
Tan, Y;Tey, HL;Chong, SZ;Ng, LG;
PMID: 34859448 | DOI: 10.1111/imr.13049
As the largest organ of the body, the skin is a key barrier tissue with specialized structures where ongoing immune surveillance is critical for protecting the body from external insults. The innate immune system acts as first-responders in a coordinated manner to react to injury or infections, and recent developments in intravital imaging techniques have made it possible to delineate dynamic immune cell responses in a spatiotemporal manner. We review here key studies involved in understanding neutrophil, dendritic cell and macrophage behavior in skin and further discuss how this knowledge collectively highlights the importance of interactions and cellular functions in a systems biology manner. Furthermore, we will review emerging imaging technologies such as high-content proteomic screening, spatial transcriptomics and three-dimensional volumetric imaging and how these techniques can be integrated to provide a systems overview of the immune system that will further our current knowledge and lead to potential exciting discoveries in the upcoming decades.
Borrajo, A;Svicher, V;Salpini, R;Pellegrino, M;Aquaro, S;
PMID: 34946138 | DOI: 10.3390/microorganisms9122537
The chronic infection established by the human immunodeficiency virus 1 (HIV-1) produces serious CD4+ T cell immunodeficiency despite the decrease in HIV-1 ribonucleic acid (RNA) levels and the raised life expectancy of people living with HIV-1 (PLWH) through treatment with combined antiretroviral therapies (cART). HIV-1 enters the central nervous system (CNS), where perivascular macrophages and microglia are infected. Serious neurodegenerative symptoms related to HIV-associated neurocognitive disorders (HAND) are produced by infection of the CNS. Despite advances in the treatment of this infection, HAND significantly contribute to morbidity and mortality globally. The pathogenesis and the role of inflammation in HAND are still incompletely understood. Principally, growing evidence shows that the CNS is an anatomical reservoir for viral infection and replication, and that its compartmentalization can trigger the evolution of neurological damage and thus make virus eradication more difficult. In this review, important concepts for understanding HAND and neuropathogenesis as well as the viral proteins involved in the CNS as an anatomical reservoir for HIV infection are discussed. In addition, an overview of the recent advancements towards therapeutic strategies for the treatment of HAND is presented. Further neurological research is needed to address neurodegenerative difficulties in people living with HIV, specifically regarding CNS viral reservoirs and their effects on eradication.
Hu, L;Chen, X;Narwade, N;Lim, MGL;Chen, Z;Tennakoon, C;Guan, P;Chan, UI;Zhao, Z;Deng, M;Xu, X;Sung, WK;Cheung, E;
PMID: 34611310 | DOI: 10.1038/s41388-021-02026-7
Androgen receptor (AR) plays a central role in driving prostate cancer (PCa) progression. How AR promotes this process is still not completely clear. Herein, we used single-cell transcriptome analysis to reconstruct the transcriptional network of AR in PCa. Our work shows AR directly regulates a set of signature genes in the ER-to-Golgi protein vesicle-mediated transport pathway. The expression of these genes is required for maximum androgen-dependent ER-to-Golgi trafficking, cell growth, and survival. Our analyses also reveal the signature genes are associated with PCa progression and prognosis. Moreover, we find inhibition of the ER-to-Golgi transport process with a small molecule enhanced antiandrogen-mediated tumor suppression of hormone-sensitive and insensitive PCa. Finally, we demonstrate AR collaborates with CREB3L2 in mediating ER-to-Golgi trafficking in PCa. In summary, our findings uncover a critical role for dysregulation of ER-to-Golgi trafficking expression and function in PCa progression, provide detailed mechanistic insights for how AR tightly controls this process, and highlight the prospect of targeting the ER-to-Golgi pathway as a therapeutic strategy for advanced PCa.
Subcellular localization of biomolecules and drug distribution by high-definition ion beam imaging
Rovira-Clavé, X;Jiang, S;Bai, Y;Zhu, B;Barlow, G;Bhate, S;Coskun, AF;Han, G;Ho, CK;Hitzman, C;Chen, SY;Bava, FA;Nolan, GP;
PMID: 34330905 | DOI: 10.1038/s41467-021-24822-1
Simultaneous visualization of the relationship between multiple biomolecules and their ligands or small molecules at the nanometer scale in cells will enable greater understanding of how biological processes operate. We present here high-definition multiplex ion beam imaging (HD-MIBI), a secondary ion mass spectrometry approach capable of high-parameter imaging in 3D of targeted biological entities and exogenously added structurally-unmodified small molecules. With this technology, the atomic constituents of the biomolecules themselves can be used in our system as the "tag" and we demonstrate measurements down to ~30 nm lateral resolution. We correlated the subcellular localization of the chemotherapy drug cisplatin simultaneously with five subnuclear structures. Cisplatin was preferentially enriched in nuclear speckles and excluded from closed-chromatin regions, indicative of a role for cisplatin in active regions of chromatin. Unexpectedly, cells surviving multi-drug treatment with cisplatin and the BET inhibitor JQ1 demonstrated near total cisplatin exclusion from the nucleus, suggesting that selective subcellular drug relocalization may modulate resistance to this important chemotherapeutic treatment. Multiplexed high-resolution imaging techniques, such as HD-MIBI, will enable studies of biomolecules and drug distributions in biologically relevant subcellular microenvironments by visualizing the processes themselves in concert, rather than inferring mechanism through surrogate analyses.