The heterogeneity of human hematopoietic stem (HSCs) and progenitor cells (HPCs) under stress conditions such as ex vivo expansion is poorly understood. Here we report that the frequencies of SCID repopulating cells (SRCs) were greatly decreased in cord blood（CB）CD34+ HSCs and HPCs upon ex vivo culture. Transcriptome analysis and metabolic profiling demonstrated that mitochondrial oxidative stress of human CB HSCs and HPCs notably increased along with loss of stemness. Limiting dilution analysis (LDA) revealed that functional human HSCs were enriched in cell populations with low levels of mitochondrial reactive oxygen species (mitoROS) during ex vivo culture. Using single cell RNA sequencing (scRNA-seq) analysis of mitoROS low cell population, we demonstrated that functional HSCs were substantially enriched in the Adhesion G protein-coupled receptor G1 positive (ADGRG1+) population of CD34+CD133+ CB cells upon ex vivo expansion stress. GSEA analysis revealed that HSC signature genes including MSI2 and MLLT3 are enriched in CD34+CD133+ ADGRG1+ CB HSCs. Our study reveals that ADGRG1 enriches for functional human HSCs under oxidative stress during ex vivo culture, which can be a reliable target for drug screening of agonists of HSC expansion.
Yandan Chen, Shuyi Fang, Qingwei Ding, Rongzhen Jiang, Jiefeng He, Qin Wang, Yuting Jin, Xinxin Huang, Sheng Liu, Maegan Capitano, Thao Trinh, Yincheng Teng, Qingyou Meng, Jun Wan, Hal Broxmeyer, Bin Guo
Dementia resulting from small vessel diseases of the brain (SVDs) is an emerging epidemic for which there is no treatment. Hypertension is the major risk factor for SVDs, but how hypertension damages the brain microcirculation is unclear. Here, we show that chronic hypertension in a mouse model progressively disrupts on-demand delivery of blood to metabolically active areas of the brain (functional hyperemia) through diminished activity of the capillary endothelial cell inward-rectifier potassium channel, Kir2.1. Despite similar efficacy in reducing blood pressure, amlodipine, a voltage-dependent calcium-channel blocker, prevented hypertension-related damage to functional hyperemia whereas losartan, an angiotensin II type-1 receptor blocker, did not. We attribute this drug class effect to losartan-induced ‘aldosterone breakthrough’, a phenomenon triggered by pharmacological interruption of the renin-angiotensin pathway leading to elevated plasma aldosterone levels. This hypothesis is supported by the finding that combining losartan with the aldosterone receptor antagonist eplerenone prevented the hypertension-related decline in functional hyperemia. Collectively, these data suggest Kir2.1 as a possible therapeutic target in vascular dementia and indicate that concurrent mineralocorticoid aldosterone receptor blockade may aid in protecting against late-life cognitive decline in hypertensive patients treated with angiotensin II type-1 receptor blockers.
Masayo Koide, Osama F. Harraz, Fabrice Dabertrand, Thomas A. Longden, Hannah R. Ferris, George C. Wellman, David C. Hill-Eubanks, Adam S. Greenstein, Mark Nelson
Natural killer (NK) cell suppression of T cells is a key determinant of viral pathogenesis and vaccine efficacy. This process involves perforin-dependent elimination of activated CD4 T cells during the first three days of infection. Although this mechanism requires cell-cell contact, NK cells and T cells typically reside in different compartments of lymphoid tissues at steady state. Here, we showed that NK-cell suppression of T cells is associated with transient accumulation of NK cells within T cell-rich sites of the spleen during lymphocytic choriomeningitis virus infection. The chemokine receptor CXCR3 was required for this relocation and suppression of antiviral T cells. Accordingly, NK-cell migration was mediated by type I interferon (IFN)-dependent promotion of CXCR3 ligand expression. In contrast, adenoviral vectors that weakly induced type I IFN and did not stimulate NK-cell inhibition of T cells also did not promote measurable redistribution of NK cells to T-cell zones. Exogenous IFN rescued NK-cell migration during adenoviral vector immunization. Thus, type I IFN and CXCR3 were critical for properly positioning NK cells to constrain antiviral T-cell responses. Development of strategies to curtail migration of NK cells between lymphoid compartments may enhance vaccine-elicited immune responses.
Ayad Ali, Laura M. Canaday, H. Alex Feldman, Hilal Cevik, Michael T. Moran, Sanjeeth Rajaram, Nora Lakes, Jasmine A. Tuazon, Harsha Seelamneni, Durga Krishnamurthy, Eryn Blass, Dan H. Barouch, Stephen N. Waggoner
Intratumoral T cells that might otherwise control tumors are often identified in an ‘exhausted’ state, defined by specific epigenetic modifications and upregulation of genes such as CD38, CTLA-4 and PD-1. While the term might imply inactivity, there has been little study of this state at the phenotypic level in tumors to understand the extent of their incapacitation. Starting with the observation that T cells move more quickly through mouse tumors as residence time increases and they progress towards exhaustion, we elaborated a non-stimulatory live-biopsy method for real-time study of T cell behaviors within individual patient tumors. Using two-photon microscopy, we studied native CD8 T cells interacting with APCs and cancer cells in different micro-niches of human tumors, finding that T cell speed was variable by region and by patient and was inversely correlated with local tumor density. Across a range of tumor types, we found a strong relationship between CD8 T cell motility and exhausted T cell state that corresponds to observations made in mouse models where exhausted T cells move faster. Our study demonstrates T cell dynamic states in individual human tumors and supports the existence of an active program in ‘exhausted’ T cells that extends beyond incapacitating them.
Ran You, Jordan Artichoker, Adam Fries, Austin W. Edwards, Alexis J. Combes, Gabriella C. Reeder, Bushra Samad, Matthew F. Krummel
A recent report found that rare predicted loss-of-function (pLOF) variants across 13 candidate genes in TLR3- and IRF7-dependent type I IFN pathways explain up to 3.5% of severe COVID-19 cases. We performed whole-exome or whole-genome sequencing of 1,934 COVID-19 cases (713 with severe and 1,221 with mild disease) and 15,251 ancestry-matched population controls across four independent COVID-19 biobanks. We then tested if rare pLOF variants in these 13 genes were associated with severe COVID-19. We identified only one rare pLOF mutation across these genes amongst 713 cases with severe COVID-19 and observed no enrichment of pLOFs in severe cases compared to population controls or mild COVID-19 cases. We find no evidence of association of rare loss-of-function variants in the proposed 13 candidate genes with severe COVID-19 outcomes.
Gundula Povysil, Guillaume Butler-Laporte, Ning Shang, Chen Wang, Atlas Khan, Manal Alaamery, Tomoko Nakanishi, Sirui Zhou, Vincenzo Forgetta, Robert J. M. Eveleigh, Mathieu Bourgey, Naveed Aziz, Steven J.M. Jones, Bartha Knoppers, Stephen W. Scherer, Lisa J. Strug, Pierre Lepage, Jiannis Ragoussis, Guillaume Bourque, Jahad Alghamdi, Nora Aljawini, Nour Albesher, Hani M. Al-Afghani, Bader Alghamdi, Mansour S. Almutair, Ebrahim Sabri Mahmoud, Leen Abu-Safieh, Hadeel El Bardisy, Fawz S. Al Harthi, Abdulraheem Alshareef, Bandar Ali Suliman, Saleh A. Alqahtani, Abdulaziz Almalik, May M. Alrashed, Salam Massadeh, Vincent Mooser, Mark Lathrop, Mohamed Fawzy, Yaseen M. Arabi, Hamdi Mbarek, Chadi Saad, Wadha Al-Muftah, Junghyun Jung, Serghei Mangul, Radja Badji, Asma Al Thani, Said I. Ismail, Ali G. Gharavi, Malak S. Abedalthagafi, J Brent Richards, David B. Goldstein, Krzysztof Kiryluk
Autoantibodies to interferon(IFN)-α and IFN-ω (type I IFNs) were recently reported as causative for severe COVID-19 in the general population. Autoantibodies against IFN-α and IFN-ω are present in almost all patients with Autoimmune-Polyendocrine-Syndrome Type 1 (APS-1) caused by biallelic deleterious or heterozygous dominant mutations in AIRE. We therefore hypothesized that autoantibodies against type I IFNs also predispose patients with APS-1 to severe COVID-19. We prospectively studied six patients with APS-1 between April 1st, 2020 and April 1st, 2021. Biobanked pre-COVID-19 sera of APS-1 subjects were tested for neutralizing autoantibodies to IFN-αand IFN-ω. The patients ́ sera ability to block recombinant human IFN-α and IFN-ω was assessed by assays quantifying phosphorylation of signal transducer and activator of transcription 1 (STAT1) as well as infection-based IFN-neutralization assays. We describe four patients with APS-1 and pre-existing high titers of neutralizing autoantibodies to IFN-α and IFN-ω who contracted SARS-CoV-2, yet developed only mild symptoms of COVID-19. None of the patients developed dyspnoea, oxygen requirement or high temperature. All infected patients with APS-1 shared female sex and age younger than 26 years. Clinical penetrance of neutralizing autoantibodies against type I IFNs for severe COVID-19 is not complete.
Christian Meisel, Bengisu Akbil, Tim Meyer, Erwin Lankes, Victor M. Corman, Olga Staudacher, Nadine Unterwalder, Uwe Kölsch, Christian Drosten, Marcus A. Mall, Tilmann Kallinich, Dirk Schnabel, Christine Goffinet, Horst von Bernuth
The four serotypes of dengue virus (DENV1-4) are mosquito-borne flaviviruses that infect humans. Live attenuated tetravalent DENV vaccines are at different phases of clinical testing. DENV vaccine developers have relied on neutralizing antibodies (NAbs) as a correlate of protection. A leading tetravalent vaccine (Dengvaxia) stimulated NAbs to the 4 DENV serotypes, yet overall vaccine efficacy was low in children who were DENV seronegative at baseline before vaccination. We compared the properties of 1) NAbs induced by wild type DENV1 or 3 infections, which are strongly correlated with protection from repeat infections, and 2) NAbs induced by Dengvaxia in individuals who subsequently experienced DENV1 or DENV3 breakthrough infections. Wild type infections induced NAbs that recognized epitopes unique (type-specific) to each serotype, whereas the vaccine stimulated qualitatively different NAbs that recognized epitopes conserved (cross-reactive) between serotypes. Our results indicate that among children who were DENV seronegative at baseline, unbalanced replication of the DENV type 4 vaccine component in the tetravalent vaccine stimulates Abs capable of cross neutralizing DENV1 and 3 in vitro but not protect in vivo. In DENV seronegative individuals who are vaccinated, we propose that type specific NAbs are a better correlate of protection than total levels of NAbs.
Sandra Henein, Cameron Adams, Matthew Bonaparte, Janice M. Moser, Alina Munteanu, Ralph Baric, Aravinda M. Desilva
The characterization of the adaptive immune response to COVID-19 vaccination in individuals who recovered from SARS-CoV-2 infection may define current and future clinical practice. To determine the effect of two doses BNT162b2 mRNA COVID-19 vaccination schedule in individuals who recovered from COVID-19 (COVID-19 recovered) compared to naïve subjects, we evaluated SARS-CoV-2 Spike-specific T and B cell responses, as well as specific IgA, IgG, IgM and neutralizing antibodies titers in 22 individuals who received BNT162b2 mRNA COVID-19 vaccine, 11 of which had a previous history of SARS-CoV-2 infection. Evaluations were performed before vaccination and then weekly until 7 days post second injection. Data obtained clearly showed that one vaccine dose is sufficient to increase both cellular and humoral immune response in COVID-19 recovered subjects without any additional improvement after the second dose. On the contrary, the second dose is proved mandatory in naïve ones to further enhance the immune response. These findings were further confirmed at serological level in a larger cohort of naïve (68) and COVID-19 recovered (29) subjects, tested up to 50 days post vaccination. These results question whether a second vaccine injection in COVID-19 recovered subjects is required and indicate that millions of vaccine doses may be redirected to naïve individuals, thus shortening the time to reach herd immunity.
Alessio Mazzoni, Nicoletta Di Lauria, Laura Maggi, Lorenzo Salvati, Anna Vanni, Manuela Capone, Giulia Lamacchia, Elisabetta Mantengoli, Michele Spinicci, Lorenzo Zammarchi, Seble Tekle Kiros, Arianna Rocca, Filippo Lagi, Maria Grazia Colao, Paola Parronchi, Cristina Scaletti, Lucia Turco, Francesco Liotta, Gian Maria Rossolini, Lorenzo Cosmi, Alessandro Bartoloni, Francesco Annunziato
Recent studies have shown T cell cross-recognition of SARS-CoV-2 and common cold coronavirus spike proteins. However, the effect of SARS-CoV-2 vaccines on T cell responses to common cold coronaviruses remain unknown. In this study, we analyzed CD4+ T cell responses to spike peptides from SARS-CoV-2 and 3 common cold coronaviruses (HCoV-229E, HCoV-NL63, and HCoV-OC43) before and after study participants received Pfizer-BioNTech (BNT162b2) or Moderna (mRNA-1273) mRNA-based COVID-19 vaccines. Vaccine recipients made broad T cell responses to the SARS-CoV-2 spike protein and we identified 23 distinct targeted peptides in 9 participants including one peptide that was targeted by 6 individuals. Only 4 out of these 23 targeted peptides would potentially be affected by mutations in the UK (B.1.1.7) and South African (B.1.351) variants and CD4+ T cells from vaccine recipients recognized the 2 variant spike proteins as effectively as the spike protein from the ancestral virus. Interestingly, we saw a 3-fold increase in the CD4+ T cell responses to HCoV-NL63 spike peptides post-vaccination. Our results suggest that T cell responses elicited or enhanced by SARS-CoV-2 mRNA vaccines may be able to control SARS-CoV-2 variants and lead to cross-protection from some endemic coronaviruses.
Bezawit A. Woldemeskel, Caroline C. Garliss, Joel N. Blankson
In rheumatoid arthritis (RA), osteoclastic bone resorption causes structural joint damage as well as periarticular and systemic bone loss. Periarticular bone loss is one of the earliest indices of RA, often preceding the onset of clinical symptoms via largely unknown mechanisms. Excessive osteoclastogenesis induced by receptor activator of NF-κB ligand (RANKL) expressed by synovial fibroblasts causes joint erosion, whereas the role of RANKL expressed by lymphocytes in various types of bone damage has yet to be elucidated. In the bone marrow of arthritic mice, we found an increase in the number of RANKL-expressing plasma cells, which displayed an ability to induce osteoclastogenesis in vitro. Genetic ablation of RANKL in B-lineage cells resulted in amelioration of periarticular bone loss, but not of articular erosion or systemic bone loss, in autoimmune arthritis. We also show conclusive evidence for the critical contribution of synovial fibroblast RANKL to joint erosion in collagen-induced arthritis on the arthritogenic DBA/1J background. This study highlights the importance of plasma-cell RANKL in periarticular bone loss in arthritis and provides mechanistic insight into the early manifestation of bone lesion induced by autoimmunity.
Noriko Komatsu, Stephanie Win, Minglu Yan, Nam Cong-Nhat Huynh, Shinichiro Sawa, Masayuki Tsukasaki, Asuka Terashima, Warunee Pluemsakunthai, George Kollias, Tomoki Nakashima, Hiroshi Takayanagi
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