The development of human prenatal adaptive immunity progresses faster than previously appreciated, with the emergence of memory CD4+ T cells alongside regulatory T (Treg) cells by mid-gestation. We previously identified a prenatal-specific population of PLZF+ CD4+ T cells with heightened effector potential that were enriched in the developing intestine and accumulated in the cord blood of infants exposed to prenatal inflammation. However, the signals that drive their tissue distribution and effector maturation are unknown. Here we define the transcriptional and functional heterogeneity of human prenatal PLZF+ CD4+ T cells and identify the compartmentalization of T helper (Th)-like effector function across the small intestine (SI) and mesenteric lymph nodes (MLN). IL-7 was more abundant in the SI relative to the MLN and drove the preferential expansion of naïve PLZF+ CD4+ T cells via enhanced STAT5 and MEK/ERK signaling. Exposure to IL-7 was sufficient to induce the acquisition of CD45RO expression and rapid effector function in a subset of PLZF+ CD4+ T cells, identifying a human analog of memory-phenotype CD4+ T cells. Further, IL-7 modulated the differentiation of Th1- and Th17-like PLZF+ CD4+ T cells, and thus likely contributes to the anatomic compartmentalization of human prenatal CD4+ T cell effector function.
Veronica Locher, Sara Park, Daniel G. Bunis, Stephanie Makredes, Margareta Mayer, Trevor D. Burt, Gabriela K. Fragiadakis, Joanna Halkias
Thyroid hormone (TH) levels are low during development, and the deiodinases control TH signaling through tissue-specific activation or inactivation of TH. Here we studied human iPSC-derived hepatic organoids and identified a robust induction in DIO2 expression (the deiodinase that activates T4 to T3) that occurs in hepatoblasts. The surge in D2-T3 per-sists until the hepatoblasts differentiate into hepatocytes- or cholangiocytes-like cells, nei-ther of which express DIO2. Preventing the induction of the D2-T3 signaling modified the expression of key transcription factors, decreased the number of hepatocyte-like cells by 60%, and increased the number of cholangiocyte-like cells by 55% without affecting the growth or the size of the mature liver organoid. Physiological levels of T3 could not ful-ly restore the transition from hepatoblasts to mature cells. This indicates that the timed surge in D2-T3 signaling critically determines the fate of developing human hepatoblasts and the transcriptome of the maturing hepatocytes, with physiological and clinical implica-tions for how the liver handles energy substrates.
Jorge Hidalgo-Álvarez, Federico Salas-Lucia, Diana Vera Cruz, Tatiana L. Fonseca, Antonio C. Bianco
In youth with obesity, the gut hormone potentiation of insulin secretion - the incretin effect - is blunted. We explored the longitudinal impact of the incretin effect during pubertal transition on beta cell function and insulin sensitivity. Youths with obesity and 2-h glucose≥120mg/dL underwent a 3-h OGTT and an isoglycemic intravenous glucose infusion to quantify the incretin effect. After 2 years, 30/39 participants had a repeated OGTT and were stratified into three tertiles according to the baseline incretin effect. Thirty participants completed the baseline and follow-up tests. The high-incretin effect group demonstrated a longitudinal increase in beta cell function (DIMM) (p=0.034), with greater insulin sensitivity at follow-up (p=0.034) and stable insulin secretion (φtotal) (p=0.077). A lower incretin effect at baseline was associated with a higher 1-h and 2-h glucose at follow-up (r = -0.558, p=0.001 and r = -0.533, p=0.004). The high-incretin effect group displayed a greater increase of GLP-17-36 than the moderate- and low-incretin group at baseline (p=0.008 and p=0.029), while such a difference did not persist after 2 years. Glucagon suppression was reduced at follow-up in those with low-baseline incretin respect to the high-incretin group (p=0.049).
Alfonso Galderisi, Domenico Tricò, Jessica O. Lat, Stephanie L. Samuels, Ram Weiss, Michelle Van Name, Bridget Pierpont, Nicola Santoro, Sonia Caprio
Approximately 30% of breast cancer survivors deemed ‘free of disease’ will experience locoregional or metastatic recurrence even up to 30 years post initial diagnosis, yet how residual/dormant tumor cells escape immunity elicited by the primary tumor remains unclear. We demonstrate that intrinsically dormant tumor cells are indeed recognized and lysed by antigen-specific T cells in vitro and elicit robust immune responses in vivo. However, despite close proximity to CD8+ killer T cells, dormant tumor cells themselves support early accumulation of protective FoxP3+ T regulatory cells (Tregs), which can be targeted to reduce tumor burden. These intrinsically dormant tumor cells maintain a hybrid epithelial/mesenchymal state which is associated with immune dysfunction, and we find the tumor-derived stem/basal gene Dickkopf WNT Signaling Pathway Inhibitor 3 (DKK3) is critical for Treg inhibition of CD8+ T cells. We also demonstrate that DKK3 promotes immune-mediated progression of proliferative tumors and is significantly associated with poor survival and immune suppression in human breast cancers. Together, these findings reveal that latent tumors can use fundamental mechanisms of tolerance to alter the T cell microenvironment and subvert immune detection. Thus, targeting these pathways, such as DKK3, may help render dormant tumors susceptible to immunotherapies.
Timothy N. Trotter, Carina E. Dagotto, Delila Serra, Tao Wang, Xiao Yang, Chaitanya R. Acharya, Junping Wei, Gangjun Lei, Herbert Kim Lyerly, Zachary C. Hartman
Use of autologous cells isolated from elderly patients with multiple co-morbidities may account for the modest efficacy of cell therapy in patients with chronic limb threatening ischemia (CLTI). We aimed to determine whether pro-arteriogenic monocyte/macrophages (Mo/MΦs) from CLTI patients were functionally impaired and to demonstrate the mechanisms related to any impairment. Pro-arteriogenic Mo/MΦs isolated from CLTI patients were found to have an impaired capacity to promote neovascularization in vitro and in vivo compared with those isolated from healthy controls. This was associated with increased expression of human HIV-1 TAT interactive protein-2 (HTATIP2), a transcription factor known to suppress angiogenesis/arteriogenesis. Silencing HTATIP2 restored the functional capacity of CLTI Mo/MΦs which was associated with increased expression of arteriogenic regulators neuropilin-1 and angiopoietin-1, and their ability to enhance angiogenic (endothelial tubule formation) and arteriogenic (smooth muscle proliferation) processes in vitro. In support of the translational relevance of our findings, silencing HTATIP2 in pro-arteriogenic Mo/MΦs isolated from CLTI patients rescued their capacity to enhance limb perfusion in the ischemic hindlimb by effecting greater angiogenesis and arteriogenesis. Ex-vivo modulation of HTATIP2 may offer a strategy for rescuing the functional impairment of pro-angio/arteriogenic Mo/MΦs prior to autologous delivery and increase the likelihood of clinical efficacy.
Ashish S. Patel, Francesca E. Ludwinski, Angeles Mondragon, Katherine Nuthall, Prakash Saha, Oliver Lyons, Mario Leonardo Squadrito, Richard C. Siow, Michele De Palma, Alberto Smith, Bijan Modarai
Neuropeptide Y targets the Y1 receptor (Y1) in the spinal dorsal horn (DH) to produce endogenous and exogenous analgesia. DH interneurons that express Y1 (Y1-INs; encoded by Npy1r) are necessary and sufficient for neuropathic hypersensitivity after peripheral nerve injury. However, as Y1-INs are heterogenous in composition in terms of morphology, neurophysiological characteristics, and gene expression, we hypothesized that a more precisely defined subpopulation mediates neuropathic hypersensitivity. Using fluorescence in situ hybridization, we found that Y1-INs segregate into three largely non-overlapping subpopulations defined by the co-expression of Npy1r with gastrin-releasing peptide (Grp/Npy1r), neuropeptide FF (Npff/Npy1r), and cholecystokinin (Cck/Npy1r) in the superficial DH of mouse, non-human primate, and human. Next, we analyzed the functional significance of Grp/Npy1r, Npff/Npy1r, and Cck/Npy1r INs to neuropathic pain using a mouse model of peripheral nerve injury. We found that chemogenetic inhibition of Npff/Npy1r-INs did not change the behavioral signs of neuropathic pain. Further, inhibition of Y1-INs with an intrathecal Y1 agonist, [Leu31, Pro34]-NPY, reduced neuropathic hypersensitivity in mice with conditional deletion of Npy1r from CCK-INs but not from GRP-INs. We conclude that Grp/Npy1r-INs are conserved in higher order mammalian species and represent a promising and precise pharmacotherapeutic target for the treatment of neuropathic pain.
Tyler S. Nelson, Heather N. Allen, Paramita Basu, Pranav Prasoon, Eileen K. Nguyen, Cynthia M. Arokiaraj, Diogo F.S. Santos, Rebecca P. Seal, Sarah E. Ross, Andrew J. Todd, Bradley K. Taylor
Aberrant fibroblast function plays a key role in the pathogenesis of Idiopathic Pulmonary Fibrosis, a devastating disease of unrelenting extracellular matrix deposition in response to lung injury. Platelet-derived growth factor alpha-positive (PDGFRα+) lipofibroblasts (LipoFBs) are essential for lung injury response and maintenance of a functional alveolar stem cell niche. Little is known about the effects of lung injury on LipoFB function. Here, we used scRNA-Seq technology and PDGFRαGFP lineage tracing to generate a transcriptomic profile of PDGFRα+ fibroblasts in normal and injured mouse lungs 14 days after bleomycin exposure, generating eleven unique transcriptomic clusters that segregated according to treatment. While normal and injured LipoFBs shared a common gene signature, injured LipoFBs acquired fibrogenic pathway activity with an attenuation of lipogenic pathways. In a 3D organoid model, injured PDGFRα+ fibroblast- supported organoids were morphologically distinct from those cultured with normal FBs, and scRNA-Seq analysis suggested distinct transcriptomic changes in alveolar epithelia supported by injured PDGFRα+ fibroblasts. In summary, while LipoFBs in injured lung have not migrated from their niche and retain their lipogenic identity, they acquire a potentially reversible fibrogenic profile, which may alter the kinetics of epithelial regeneration and potentially contribute to dysregulated repair, leading to fibrosis.
Carol S. Trempus, Brian N. Papas, Maria I. Sifre, Carl D. Bortner, Erica Scappini, Charles J. Tucker, Xin Xu, Katina L. Johnson, Leesa J. Deterding, Jason G Williams, Dylan J. Johnson, Jian-Liang Li, Deloris Sutton, Charan K. Ganta, Debabrata Mahapatra, Muhammad Arif, Abhishek Basu, Lenny Pommerolle, Resat Cinar, Anne-Karina T. Perl, Stavros Garantziotis
Overactive fibroblast growth factor receptor 3 (FGFR3) signaling drives pathogenesis in a variety of cancers and a spectrum of short-limbed bone dysplasias, including the most common form of human dwarfism, achondroplasia (ACH). Targeting FGFR3 activity holds great promise as a therapeutic approach for treatment of these diseases. Here, we established a receptor/adaptor translocation assay system that can specifically monitor FGFR3 activation, and we applied it to identify FGFR3 modulators from complex natural mixtures. An FGFR3-suppressing plant extract of Amaranthus viridis was identified from the screen, and two bioactive porphyrins, pheophorbide a (Pa) and pyropheophorbide a (PyroPa) were sequentially isolated from the extract and functionally characterized. Further analysis showed that Pa reduced excessive FGFR3 signaling by decreasing its half-life in FGFR3-overactivated multiple myeloma (MM) cells and chondrocytes. In an ex vivo culture system, Pa alleviated defective long bone growth in humanized ACH mice (FGFR3ACH mice). Overall, our study presents a novel approach to discovery and validation of plant extracts or drug candidates that target FGFR3 activation. The compounds identified by this approach may have potential applications as therapeutics for FGFR3-associated cancers and skeletal dysplasias.
Yun-Wen Lin, Hsiao-Jung Kao, Wei-Ting Chen, Cheng-Fu Kao, Jer-Yuarn Wu, Yuan-Tsong Chen, Yi-Ching Lee
The penetration of allergens through the epithelial layer is the initial step in the development of allergic conjunctivitis. Although the pollinosis patients manifest symptoms in minutes after pollen exposure, the mechanisms of the rapid allergen transport remain unclear. In the present study, we found that the instillation of pollen shells rapidly induces a large number of goblet cell-associated antigen passages (GAPs) in the conjunctiva. Antigen acquisition by the stromal cells including macrophages and CD11b+ dendritic cells correlated with the surface GAP formation. Furthermore, a substantial amount of antigen was transported to the stroma during the first 10 minutes of the pollen exposure, which was sufficient for the full induction of an allergic conjunctivitis mouse model. This inducible rapid GAP formation and antigen acquisition was suppressed by topical lidocaine or trigeminal ablation, indicating that the sensory nervous system plays an essential role. Interestingly, pollen shell-stimulated GAP formation was not suppressed by topical atropine, suggesting that the conjunctival GAPs and intestinal GAPs are differentially regulated. These results identify pollen shell-induced GAP as a novel therapeutic target for allergic conjunctivitis.
Meiko Kimura, Tomoaki Ando, Yasuharu Kume, Saaya Fukase, Moe Matsuzawa, Kosuke Kashiwagi, Kumi Izawa, Ayako Kaitani, Nobuhiro Nakano, Keiko Maeda, Hideoki Ogawa, Ko Okumura, Shintaro Nakao, Akira Murakami, Nobuyuki Ebihara, Jiro Kitaura
CXCR4 is a key regulator of the development of NK cells and dendritic cells, both of which play an important role in early placental development and immune tolerance at the maternal-fetal interface. However, the role of CXCR4 in pregnancy is not well understood. Our study demonstrates that adult-induced global genetic CXCR4 deletion, but not uterine-specific CXCR4 deletion, was associated with increased pregnancy resorptions and decreased litter size. CXCR4-deficient mice had decreased NK cells and increased granulocytes in the decidua, and increased leukocyte numbers in peripheral blood. We found that CXCR4-deficient mice had abnormal decidual NK cell aggregates and NK cell infiltration into trophoblast areas beyond the giant cell layer. This was associated with low NK cell expression of granzyme B, a NK cell granule effector, indicative of NK cell dysfunction. Pregnancy failure in these mice was associated with abnormalities in placental vascular development and increased placental expression of inflammatory genes. Importantly, adoptive bone marrow transfer of wild type CXCR4+ bone marrow cells into CXCR4-deficient mice rescued the reproductive deficits by normalizing NK cell function and mediating normal placental vascular development. Collectively, our study found an important role for maternal CXCR4 expression in immune cell function, placental development and pregnancy maintenance.
Fang Lyu, Chase A. Burzynski, Yuan yuan Fang, Aya Tal, Alice Y. Chen, Jacqueline Kisa, Kriti Agrawal, Yuval Kluger, Hugh S. Taylor, Reshef Tal
No posts were found with this tag.