Browsing by Author "Sempowski, Gregory D"
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Item Open Access Breadth of SARS-CoV-2 Neutralization and Protection Induced by a Nanoparticle VaccineLi, Dapeng; Martinez, David R; Martinez, David R; Schäfer, Alexandra; Chen, Haiyan; Barr, Maggie; Sutherland, Laura L; Lee, Esther; Parks, Robert; Mielke, Dieter; Edwards, Whitney; Newman, Amanda; Bock, Kevin W; Minai, Mahnaz; Nagata, Bianca M; Gagne, Matthew; Douek, Daniel C; DeMarco, C Todd; Denny, Thomas N; Oguin, Thomas H; Brown, Alecia; Rountree, Wes; Wang, Yunfei; Mansouri, Katayoun; Edwards, Robert J; Ferrari, Guido; Sempowski, Gregory D; Eaton, Amanda; Tang, Juanjie; Cain, Derek W; Santra, Sampa; Pardi, Norbert; Weissman, Drew; Tomai, Mark A; Fox, Christopher B; Moore, Ian N; Andersen, Hanne; Lewis, Mark G; Golding, Hana; Seder, Robert; Khurana, Surender; Baric, Ralph S; Montefiori, David C; Saunders, Kevin O; Haynes, Barton FItem Open Access Breadth of SARS-CoV-2 Neutralization and Protection Induced by a Nanoparticle Vaccine.(bioRxiv, 2022-02-14) Li, Dapeng; Martinez, David R; Schäfer, Alexandra; Chen, Haiyan; Barr, Maggie; Sutherland, Laura L; Lee, Esther; Parks, Robert; Mielke, Dieter; Edwards, Whitney; Newman, Amanda; Bock, Kevin W; Minai, Mahnaz; Nagata, Bianca M; Gagne, Matthew; Douek, Daniel C; DeMarco, C Todd; Denny, Thomas N; Oguin, Thomas H; Brown, Alecia; Rountree, Wes; Wang, Yunfei; Mansouri, Katayoun; Edwards, Robert J; Ferrari, Guido; Sempowski, Gregory D; Eaton, Amanda; Tang, Juanjie; Cain, Derek W; Santra, Sampa; Pardi, Norbert; Weissman, Drew; Tomai, Mark A; Fox, Christopher B; Moore, Ian N; Andersen, Hanne; Lewis, Mark G; Golding, Hana; Seder, Robert; Khurana, Surender; Baric, Ralph S; Montefiori, David C; Saunders, Kevin O; Haynes, Barton FCoronavirus vaccines that are highly effective against SARS-CoV-2 variants are needed to control the current pandemic. We previously reported a receptor-binding domain (RBD) sortase A-conjugated ferritin nanoparticle (RBD-scNP) vaccine that induced neutralizing antibodies against SARS-CoV-2 and pre-emergent sarbecoviruses and protected monkeys from SARS-CoV-2 WA-1 infection. Here, we demonstrate SARS-CoV-2 RBD-scNP immunization induces potent neutralizing antibodies in non-human primates (NHPs) against all eight SARS-CoV-2 variants tested including the Beta, Delta, and Omicron variants. The Omicron variant was neutralized by RBD-scNP-induced serum antibodies with a mean of 10.6-fold reduction of ID50 titers compared to SARS-CoV-2 D614G. Immunization with RBD-scNPs protected NHPs from SARS-CoV-2 WA-1, Beta, and Delta variant challenge, and protected mice from challenges of SARS-CoV-2 Beta variant and two other heterologous sarbecoviruses. These results demonstrate the ability of RBD-scNPs to induce broad neutralization of SARS-CoV-2 variants and to protect NHPs and mice from multiple different SARS-related viruses. Such a vaccine could provide the needed immunity to slow the spread of and reduce disease caused by SARS-CoV-2 variants such as Delta and Omicron.Item Open Access Chromatin remodeling in peripheral blood cells reflects COVID-19 symptom severity.(bioRxiv, 2020-12-05) Giroux, Nicholas S; Ding, Shengli; McClain, Micah T; Burke, Thomas W; Petzold, Elizabeth; Chung, Hong A; Palomino, Grecia R; Wang, Ergang; Xi, Rui; Bose, Shree; Rotstein, Tomer; Nicholson, Bradly P; Chen, Tianyi; Henao, Ricardo; Sempowski, Gregory D; Denny, Thomas N; Ko, Emily R; Ginsburg, Geoffrey S; Kraft, Bryan D; Tsalik, Ephraim L; Woods, Christopher W; Shen, XilingSARS-CoV-2 infection triggers highly variable host responses and causes varying degrees of illness in humans. We sought to harness the peripheral blood mononuclear cell (PBMC) response over the course of illness to provide insight into COVID-19 physiology. We analyzed PBMCs from subjects with variable symptom severity at different stages of clinical illness before and after IgG seroconversion to SARS-CoV-2. Prior to seroconversion, PBMC transcriptomes did not distinguish symptom severity. In contrast, changes in chromatin accessibility were associated with symptom severity. Furthermore, single-cell analyses revealed evolution of the chromatin accessibility landscape and transcription factor motif occupancy for individual PBMC cell types. The most extensive remodeling occurred in CD14+ monocytes where sub-populations with distinct chromatin accessibility profiles were associated with disease severity. Our findings indicate that pre-seroconversion chromatin remodeling in certain innate immune populations is associated with divergence in symptom severity, and the identified transcription factors, regulatory elements, and downstream pathways provide potential prognostic markers for COVID-19 subjects.Item Open Access COVID-19 Diagnosis and SARS-CoV-2 Strain Identification by a Rapid, Multiplexed, Point-of-Care Antibody Microarray.(Analytical chemistry, 2023-03) Heggestad, Jacob T; Britton, Rhett J; Kinnamon, David S; Liu, Jason; Anderson, Jack G; Joh, Daniel Y; Quinn, Zachary; Fontes, Cassio M; Hucknall, Angus M; Parks, Robert; Sempowski, Gregory D; Denny, Thomas N; Burke, Thomas W; Haynes, Barton F; Woods, Christopher W; Chilkoti, AshutoshAntigen tests to detect SARS-CoV-2 have emerged as a promising rapid diagnostic method for COVID-19, but they are unable to differentiate between variants of concern (VOCs). Here, we report a rapid point-of-care test (POC-T), termed CoVariant-SPOT, that uses a set of antibodies that are either tolerant or intolerant to spike protein mutations to identify the likely SARS-CoV-2 strain concurrent with COVID-19 diagnosis using antibodies targeting the nucleocapsid protein. All reagents are incorporated into a portable, multiplexed, and sensitive diagnostic platform built upon a nonfouling polymer brush. To validate CoVariant-SPOT, we tested recombinant SARS-CoV-2 proteins, inactivated viruses, and nasopharyngeal swab samples from COVID-19 positive and negative individuals and showed that CoVariant-SPOT can readily distinguish between two VOCs: Delta and Omicron. We believe that CoVariant-SPOT can serve as a valuable adjunct to next-generation sequencing to rapidly identify variants using a scalable and deployable POC-T, thereby enhancing community surveillance efforts worldwide and informing treatment selection.Item Open Access Decontamination and Reuse of N95 Respirators with Hydrogen Peroxide Vapor to Address Worldwide Personal Protective Equipment Shortages During the SARS-CoV-2 (COVID-19) Pandemic(Applied Biosafety, 2020-01-01) Schwartz, Antony; Stiegel, Matthew; Greeson, Nicole; Vogel, Andrea; Thomann, Wayne; Brown, Monte; Sempowski, Gregory D; Alderman, Thomas Scott; Condreay, James Patrick; Burch, James; Wolfe, Cameron; Smith, Becky; Lewis, SarahItem Open Access Development and implementation of a proficiency testing program for Luminex bead-based cytokine assays.(Journal of Immunological Methods, 2014-07) Lynch, Heather E; Sanchez, Ana M; D'Souza, M Patricia; Rountree, Wes; Denny, Thomas N; Kalos, Michael; Sempowski, Gregory DLuminex bead array assays are widely used for rapid biomarker quantification due to the ability to measure up to 100 unique analytes in a single well of a 96-well plate. There has been, however, no comprehensive analysis of variables impacting assay performance, nor development of a standardized proficiency testing program for laboratories performing these assays. To meet this need, the NIH/NIAID and the Cancer Immunotherapy Consortium of the Cancer Research Institute collaborated to develop and implement a Luminex assay proficiency testing program as part of the NIH/NIAID-sponsored External Quality Assurance Program Oversight Laboratory (EQAPOL) at Duke University. The program currently monitors 25 domestic and international sites with two external proficiency panels per year. Each panel includes a de-identified commercial Luminex assay kit with standards to quantify human IFNγ, TNFα, IL-6, IL-10 and IL-2, and a series of recombinant cytokine-spiked human serum samples. All aspects of panel development, testing and shipping are performed under GCLP by EQAPOL support teams. Following development testing, a comprehensive site proficiency scoring system comprised of timeliness, protocol adherence, accuracy and precision was implemented. The overall mean proficiency score across three rounds of testing has remained stable (EP3: 76%, EP4: 75%, EP5: 77%); however, a more detailed analysis of site reported results indicates a significant improvement of intra- (within) and inter- (between) site variation, suggesting that training and remediation for poor performing sites may be having a positive impact on proficiency. Through continued proficiency testing, identification of variables affecting Luminex assay outcomes will strengthen efforts to bring standardization to the field.Item Open Access Development of mRNA manufacturing for vaccines and therapeutics: mRNA platform requirements and development of a scalable production process to support early phase clinical trials.(Translational research : the journal of laboratory and clinical medicine, 2022-04) Whitley, Jill; Zwolinski, Christopher; Denis, Christian; Maughan, Maureen; Hayles, Leonie; Clarke, David; Snare, Meghan; Liao, Hong; Chiou, Sean; Marmura, Tina; Zoeller, Holly; Hudson, Ben; Peart, John; Johnson, Monica; Karlsson, Amelia; Wang, Yunfei; Nagle, Cynthia; Harris, Cherell; Tonkin, Daniel; Fraser, Stephanie; Capiz, Lieza; Zeno, Christina L; Meli, Yvonne; Martik, Diana; Ozaki, Daniel A; Caparoni, Amy; Dickens, Jason E; Weissman, Drew; Saunders, Kevin O; Haynes, Barton F; Sempowski, Gregory D; Denny, Thomas N; Johnson, Matthew RThe remarkable success of SARS CoV-2 mRNA-based vaccines and the ensuing interest in mRNA vaccines and therapeutics have highlighted the need for a scalable clinical-enabling manufacturing process to produce such products, and robust analytical methods to demonstrate safety, potency, and purity. To date, production processes have either not been disclosed or are bench-scale in nature and cannot be readily adapted to clinical and commercial scale production. To address these needs, we have advanced an aqueous-based scalable process that is readily adaptable to GMP-compliant manufacturing, and developed the required analytical methods for product characterization, quality control release, and stability testing. We also have demonstrated the products produced at manufacturing scale under such approaches display good potency and protection in relevant animal models with mRNA products encoding both vaccine immunogens and antibodies. Finally, we discuss continued challenges in raw material identification, sourcing and supply, and the cold chain requirements for mRNA therapeutic and vaccine products. While ultimate solutions have yet to be elucidated, we discuss approaches that can be taken that are aligned with regulatory guidance.Item Open Access Differential chromatin accessibility in peripheral blood mononuclear cells underlies COVID-19 disease severity prior to seroconversion.(Res Sq, 2022-04-07) Giroux, Nicholas S; Ding, Shengli; McClain, Micah T; Burke, Thomas W; Petzold, Elizabeth; Chung, Hong A; Rivera, Grecia O; Wang, Ergang; Xi, Rui; Bose, Shree; Rotstein, Tomer; Nicholson, Bradly P; Chen, Tianyi; Henao, Ricardo; Sempowski, Gregory D; Denny, Thomas N; De Ussel, Maria Iglesias; Satterwhite, Lisa L; Ko, Emily R; Ginsburg, Geoffrey S; Kraft, Bryan D; Tsalik, Ephraim L; Shen, Xiling; Woods, ChristopherSARS-CoV-2 infection triggers profound and variable immune responses in human hosts. Chromatin remodeling has been observed in individuals severely ill or convalescing with COVID-19, but chromatin remodeling early in disease prior to anti-spike protein IgG seroconversion has not been defined. We performed the Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) and RNA-seq on peripheral blood mononuclear cells (PBMCs) from outpatients with mild or moderate symptom severity at different stages of clinical illness. Early in the disease course prior to IgG seroconversion, modifications in chromatin accessibility associate with mild or moderate symptoms are already robust and include severity-associated changes in accessibility of genes in interleukin signaling, regulation of cell differentiation and cell morphology. Furthermore, single-cell analyses revealed evolution of the chromatin accessibility landscape and transcription factor motif accessibility for individual PBMC cell types over time. The most extensive remodeling occurred in CD14+ monocytes, where sub-populations with distinct chromatin accessibility profiles were observed prior to seroconversion. Mild symptom severity is marked by upregulation classical antiviral pathways including those regulating IRF1 and IRF7, whereas in moderate disease these classical antiviral signals diminish suggesting dysregulated and less effective responses. Together, these observations offer novel insight into the epigenome of early mild SARS-CoV-2 infection and suggest that detection of chromatin remodeling in early disease may offer promise for a new class of diagnostic tools for COVID-19.Item Open Access Differential chromatin accessibility in peripheral blood mononuclear cells underlies COVID-19 disease severity prior to seroconversion.(Scientific reports, 2022-07-09) Giroux, Nicholas S; Ding, Shengli; McClain, Micah T; Burke, Thomas W; Petzold, Elizabeth; Chung, Hong A; Rivera, Grecia O; Wang, Ergang; Xi, Rui; Bose, Shree; Rotstein, Tomer; Nicholson, Bradly P; Chen, Tianyi; Henao, Ricardo; Sempowski, Gregory D; Denny, Thomas N; De Ussel, Maria Iglesias; Satterwhite, Lisa L; Ko, Emily R; Ginsburg, Geoffrey S; Kraft, Bryan D; Tsalik, Ephraim L; Shen, Xiling; Woods, Christopher WSARS-CoV-2 infection triggers profound and variable immune responses in human hosts. Chromatin remodeling has been observed in individuals severely ill or convalescing with COVID-19, but chromatin remodeling early in disease prior to anti-spike protein IgG seroconversion has not been defined. We performed the Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) and RNA-seq on peripheral blood mononuclear cells (PBMCs) from outpatients with mild or moderate symptom severity at different stages of clinical illness. Early in the disease course prior to IgG seroconversion, modifications in chromatin accessibility associated with mild or moderate symptoms were already robust and included severity-associated changes in accessibility of genes in interleukin signaling, regulation of cell differentiation and cell morphology. Furthermore, single-cell analyses revealed evolution of the chromatin accessibility landscape and transcription factor motif accessibility for individual PBMC cell types over time. The most extensive remodeling occurred in CD14+ monocytes, where sub-populations with distinct chromatin accessibility profiles were observed prior to seroconversion. Mild symptom severity was marked by upregulation of classical antiviral pathways, including those regulating IRF1 and IRF7, whereas in moderate disease, these classical antiviral signals diminished, suggesting dysregulated and less effective responses. Together, these observations offer novel insight into the epigenome of early mild SARS-CoV-2 infection and suggest that detection of chromatin remodeling in early disease may offer promise for a new class of diagnostic tools for COVID-19.Item Open Access Dusp3 and Psme3 are associated with murine susceptibility to Staphylococcus aureus infection and human sepsis.(PLoS Pathog, 2014-06) Yan, Qin; Sharma-Kuinkel, Batu K; Deshmukh, Hitesh; Tsalik, Ephraim L; Cyr, Derek D; Lucas, Joseph; Woods, Christopher W; Scott, William K; Sempowski, Gregory D; Thaden, Joshua T; Rude, Thomas H; Ahn, Sun Hee; Fowler, Vance GUsing A/J mice, which are susceptible to Staphylococcus aureus, we sought to identify genetic determinants of susceptibility to S. aureus, and evaluate their function with regard to S. aureus infection. One QTL region on chromosome 11 containing 422 genes was found to be significantly associated with susceptibility to S. aureus infection. Of these 422 genes, whole genome transcription profiling identified five genes (Dcaf7, Dusp3, Fam134c, Psme3, and Slc4a1) that were significantly differentially expressed in a) S. aureus -infected susceptible (A/J) vs. resistant (C57BL/6J) mice and b) humans with S. aureus blood stream infection vs. healthy subjects. Three of these genes (Dcaf7, Dusp3, and Psme3) were down-regulated in susceptible vs. resistant mice at both pre- and post-infection time points by qPCR. siRNA-mediated knockdown of Dusp3 and Psme3 induced significant increases of cytokine production in S. aureus-challenged RAW264.7 macrophages and bone marrow derived macrophages (BMDMs) through enhancing NF-κB signaling activity. Similar increases in cytokine production and NF-κB activity were also seen in BMDMs from CSS11 (C57BL/6J background with chromosome 11 from A/J), but not C57BL/6J. These findings suggest that Dusp3 and Psme3 contribute to S. aureus infection susceptibility in A/J mice and play a role in human S. aureus infection.Item Unknown Dysregulated transcriptional responses to SARS-CoV-2 in the periphery support novel diagnostic approaches.(medRxiv, 2020-07-26) McClain, Micah T; Constantine, Florica J; Henao, Ricardo; Liu, Yiling; Tsalik, Ephraim L; Burke, Thomas W; Steinbrink, Julie M; Petzold, Elizabeth; Nicholson, Bradly P; Rolfe, Robert; Kraft, Bryan D; Kelly, Matthew S; Sempowski, Gregory D; Denny, Thomas N; Ginsburg, Geoffrey S; Woods, Christopher WIn order to elucidate novel aspects of the host response to SARS-CoV-2 we performed RNA sequencing on peripheral blood samples across 77 timepoints from 46 subjects with COVID-19 and compared them to subjects with seasonal coronavirus, influenza, bacterial pneumonia, and healthy controls. Early SARS-CoV-2 infection triggers a conserved transcriptomic response in peripheral blood that is heavily interferon-driven but also marked by indicators of early B-cell activation and antibody production. Interferon responses during SARS-CoV-2 infection demonstrate unique patterns of dysregulated expression compared to other infectious and healthy states. Heterogeneous activation of coagulation and fibrinolytic pathways are present in early COVID-19, as are IL1 and JAK/STAT signaling pathways, that persist into late disease. Classifiers based on differentially expressed genes accurately distinguished SARS-CoV-2 infection from other acute illnesses (auROC 0.95). The transcriptome in peripheral blood reveals unique aspects of the immune response in COVID-19 and provides for novel biomarker-based approaches to diagnosis.Item Unknown Dysregulated transcriptional responses to SARS-CoV-2 in the periphery.(Nature communications, 2021-02-17) McClain, Micah T; Constantine, Florica J; Henao, Ricardo; Liu, Yiling; Tsalik, Ephraim L; Burke, Thomas W; Steinbrink, Julie M; Petzold, Elizabeth; Nicholson, Bradly P; Rolfe, Robert; Kraft, Bryan D; Kelly, Matthew S; Saban, Daniel R; Yu, Chen; Shen, Xiling; Ko, Emily M; Sempowski, Gregory D; Denny, Thomas N; Ginsburg, Geoffrey S; Woods, Christopher WSARS-CoV-2 infection has been shown to trigger a wide spectrum of immune responses and clinical manifestations in human hosts. Here, we sought to elucidate novel aspects of the host response to SARS-CoV-2 infection through RNA sequencing of peripheral blood samples from 46 subjects with COVID-19 and directly comparing them to subjects with seasonal coronavirus, influenza, bacterial pneumonia, and healthy controls. Early SARS-CoV-2 infection triggers a powerful transcriptomic response in peripheral blood with conserved components that are heavily interferon-driven but also marked by indicators of early B-cell activation and antibody production. Interferon responses during SARS-CoV-2 infection demonstrate unique patterns of dysregulated expression compared to other infectious and healthy states. Heterogeneous activation of coagulation and fibrinolytic pathways are present in early COVID-19, as are IL1 and JAK/STAT signaling pathways, which persist into late disease. Classifiers based on differentially expressed genes accurately distinguished SARS-CoV-2 infection from other acute illnesses (auROC 0.95 [95% CI 0.92-0.98]). The transcriptome in peripheral blood reveals both diverse and conserved components of the immune response in COVID-19 and provides for potential biomarker-based approaches to diagnosis.Item Unknown Evaluation of SARS-CoV-2 identification methods through surveillance of companion animals in SARS-CoV-2-positive homes in North Carolina, March to December 2020(PeerJ) Gin, Taylor E; Petzold, Elizabeth A; Uthappa, Diya M; Neighbors, Coralei E; Borough, Anna R; Gin, Craig; Lashnits, Erin; Sempowski, Gregory D; Denny, Thomas; Bienzle, Dorothee; Weese, J Scott; Callahan, Benjamin J; Woods, Christopher WWe collected oral and/or rectal swabs and serum from dogs and cats living in homes with SARS-CoV-2-PCR-positive persons for SARS-CoV-2 PCR and serology testing. Pre-COVID-19 serum samples from dogs and cats were used as negative controls, and samples were tested in duplicate at different timepoints. Raw ELISA results scrutinized relative to known negative samples suggested that cut-offs for IgG seropositivity may require adjustment relative to previously proposed values, while proposed cut-offs for IgM require more extensive validation. A small number of pet dogs (2/43, 4.7%) and one cat (1/21, 4.8%) were positive for SARS-CoV-2 RNA, and 28.6 and 37.5% of cats and dogs were positive for anti-SARS-CoV-2 IgG, respectively.Item Unknown Fab-dimerized glycan-reactive antibodies are a structural category of natural antibodies.(Cell, 2021-05-18) Williams, Wilton B; Meyerhoff, R Ryan; Edwards, RJ; Li, Hui; Manne, Kartik; Nicely, Nathan I; Henderson, Rory; Zhou, Ye; Janowska, Katarzyna; Mansouri, Katayoun; Gobeil, Sophie; Evangelous, Tyler; Hora, Bhavna; Berry, Madison; Abuahmad, A Yousef; Sprenz, Jordan; Deyton, Margaret; Stalls, Victoria; Kopp, Megan; Hsu, Allen L; Borgnia, Mario J; Stewart-Jones, Guillaume BE; Lee, Matthew S; Bronkema, Naomi; Moody, M Anthony; Wiehe, Kevin; Bradley, Todd; Alam, S Munir; Parks, Robert J; Foulger, Andrew; Oguin, Thomas; Sempowski, Gregory D; Bonsignori, Mattia; LaBranche, Celia C; Montefiori, David C; Seaman, Michael; Santra, Sampa; Perfect, John; Francica, Joseph R; Lynn, Geoffrey M; Aussedat, Baptiste; Walkowicz, William E; Laga, Richard; Kelsoe, Garnett; Saunders, Kevin O; Fera, Daniela; Kwong, Peter D; Seder, Robert A; Bartesaghi, Alberto; Shaw, George M; Acharya, Priyamvada; Haynes, Barton FNatural antibodies (Abs) can target host glycans on the surface of pathogens. We studied the evolution of glycan-reactive B cells of rhesus macaques and humans using glycosylated HIV-1 envelope (Env) as a model antigen. 2G12 is a broadly neutralizing Ab (bnAb) that targets a conserved glycan patch on Env of geographically diverse HIV-1 strains using a unique heavy-chain (VH) domain-swapped architecture that results in fragment antigen-binding (Fab) dimerization. Here, we describe HIV-1 Env Fab-dimerized glycan (FDG)-reactive bnAbs without VH-swapped domains from simian-human immunodeficiency virus (SHIV)-infected macaques. FDG Abs also recognized cell-surface glycans on diverse pathogens, including yeast and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike. FDG precursors were expanded by glycan-bearing immunogens in macaques and were abundant in HIV-1-naive humans. Moreover, FDG precursors were predominately mutated IgM+IgD+CD27+, thus suggesting that they originated from a pool of antigen-experienced IgM+ or marginal zone B cells.Item Unknown Growth hormone mitigates against lethal irradiation and enhances hematologic and immune recovery in mice and nonhuman primates.(PLoS One, 2010-06-16) Chen, Benny J; Deoliveira, Divino; Spasojevic, Ivan; Sempowski, Gregory D; Jiang, Chen; Owzar, Kouros; Wang, Xiaojuan; Gesty-Palmer, Diane; Cline, J Mark; Bourland, J Daniel; Dugan, Greg; Meadows, Sarah K; Daher, Pamela; Muramoto, Garrett; Chute, John P; Chao, Nelson JMedications that can mitigate against radiation injury are limited. In this study, we investigated the ability of recombinant human growth hormone (rhGH) to mitigate against radiation injury in mice and nonhuman primates. BALB/c mice were irradiated with 7.5 Gy and treated post-irradiation with rhGH intravenously at a once daily dose of 20 microg/dose for 35 days. rhGH protected 17 out of 28 mice (60.7%) from lethal irradiation while only 3 out of 28 mice (10.7%) survived in the saline control group. A shorter course of 5 days of rhGH post-irradiation produced similar results. Compared with the saline control group, treatment with rhGH on irradiated BALB/c mice significantly accelerated overall hematopoietic recovery. Specifically, the recovery of total white cells, CD4 and CD8 T cell subsets, B cells, NK cells and especially platelets post radiation exposure were significantly accelerated in the rhGH-treated mice. Moreover, treatment with rhGH increased the frequency of hematopoietic stem/progenitor cells as measured by flow cytometry and colony forming unit assays in bone marrow harvested at day 14 after irradiation, suggesting the effects of rhGH are at the hematopoietic stem/progenitor level. rhGH mediated the hematopoietic effects primarily through their niches. Similar data with rhGH were also observed following 2 Gy sublethal irradiation of nonhuman primates. Our data demonstrate that rhGH promotes hematopoietic engraftment and immune recovery post the exposure of ionizing radiation and mitigates against the mortality from lethal irradiation even when administered after exposure.Item Unknown Inflammation triggers emergency granulopoiesis through a density-dependent feedback mechanism.(PLoS One, 2011) Cain, Derek W; Snowden, Pilar B; Sempowski, Gregory D; Kelsoe, GarnettNormally, neutrophil pools are maintained by homeostatic mechanisms that require the transcription factor C/EBPα. Inflammation, however, induces neutrophilia through a distinct pathway of "emergency" granulopoiesis that is dependent on C/EBPβ. Here, we show in mice that alum triggers emergency granulopoiesis through the IL-1RI-dependent induction of G-CSF. G-CSF/G-CSF-R neutralization impairs proliferative responses of hematopoietic stem and progenitor cells (HSPC) to alum, but also abrogates the acute mobilization of BM neutrophils, raising the possibility that HSPC responses to inflammation are an indirect result of the exhaustion of BM neutrophil stores. The induction of neutropenia, via depletion with Gr-1 mAb or myeloid-specific ablation of Mcl-1, elicits G-CSF via an IL-1RI-independent pathway, stimulating granulopoietic responses indistinguishable from those induced by adjuvant. Notably, C/EBPβ, thought to be necessary for enhanced generative capacity of BM, is dispensable for increased proliferation of HSPC to alum or neutropenia, but plays a role in terminal neutrophil differentiation during granulopoietic recovery. We conclude that alum elicits a transient increase in G-CSF production via IL-1RI for the mobilization of BM neutrophils, but density-dependent feedback sustains G-CSF for accelerated granulopoiesis.Item Unknown Leptin Regulation of Thymopoiesis During Endotoxin-Induced Acute Thymic Atrophy(2009) Gruver, Amanda LouiseThymus atrophy is highly inducible by stress and prolonged thymus atrophy can contribute to T cell deficiency or inhibit immune recovery after acute peripheral T cell depletion. Little is known regarding the mechanisms driving thymic involution or thymic reconstitution after acute stress. Leptin deficiency in mice results in chronic thymic atrophy, suppressed cell-mediated immunity, and decreased numbers of total lymphocytes, suggesting a role for leptin in regulating thymopoiesis and overall immune homeostasis. Exogenous leptin administration during stress has been shown to protect against thymic damage, yet the mechanisms governing these thymostimulatory effects are currently undefined. Studies herein define the impact of endotoxin-induced thymic damage in the stromal and lymphoid compartment of the thymus and systemic glucocorticoid and cytokine responses in the animal. We report here the novel finding that leptin receptor expression is restricted to medullary thymic epithelial cells in the normal thymus. Using a model of endotoxin-induced acute thymic involution and recovery, we have demonstrated a role for the metabolic hormone leptin in protection of medullary thymic epithelial cells from acute endotoxin-induced damage. We also demonstrated that systemic leptin treatment decreased endotoxin-induced apoptosis of double positive thymocytes and promoted proliferation of double negative thymocytes in vivo through a leptin receptor isoform b-specific mechanism. Leptin treatment increased thymic expression of IL-7, an important soluble thymocyte growth factor produced by medullary thymic epithelial cells. We also found leptin to inhibit systemic glucocorticoid and pro-inflammatory cytokine responses. Using leptin-deficient and leptin receptor-deficient mice in our stress model, we found that endotoxin-induced thymic atrophy was exacerbated in the absence of leptin, despite an inability to mount a proper pro-inflammatory cytokine response. Together, these data support a model in which leptin can function to protect the thymus gland from stress-induced acute damage in part by reduction of systemic corticosteroid and pro-inflammatory cytokine responses, and intrathymically through a mechanism orchestrated by medullary thymic epithelial cells and their soluble mediators (e.g. IL-7). Taken together, these studies suggest a physiological role for leptin signaling in the thymus for maintaining healthy thymic epithelium and promoting thymopoiesis, which is revealed when thymus homeostasis is perturbed by stress.
Item Unknown Mucosal Associated Invariant T (MAIT) Cell Responses Differ by Sex in COVID-19.(Med (New York, N.Y.), 2021-04-13) Yu, Chen; Littleton, Sejiro; Giroux, Nicholas S; Mathew, Rose; Ding, Shengli; Kalnitsky, Joan; Yang, Yuchen; Petzold, Elizabeth; Chung, Hong A; Rivera, Grecia O; Rotstein, Tomer; Xi, Rui; Ko, Emily R; Tsalik, Ephraim L; Sempowski, Gregory D; Denny, Thomas N; Burke, Thomas W; McClain, Micah T; Woods, Christopher W; Shen, Xiling; Saban, Daniel RSexual dimorphisms in immune responses contribute to coronavirus disease 2019 (COVID-19) outcomes, yet the mechanisms governing this disparity remain incompletely understood. We carried out sex-balanced sampling of peripheral blood mononuclear cells from confirmed COVID-19 inpatients and outpatients, uninfected close contacts, and healthy controls for 36-color flow cytometry and single cell RNA-sequencing. Our results revealed a pronounced reduction of circulating mucosal associated invariant T (MAIT) cells in infected females. Integration of published COVID-19 airway tissue datasets implicate that this reduction represented a major wave of MAIT cell extravasation during early infection in females. Moreover, female MAIT cells possessed an immunologically active gene signature, whereas male counterparts were pro-apoptotic. Collectively, our findings uncover a female-specific protective MAIT profile, potentially shedding light on reduced COVID-19 susceptibility in females.Item Unknown Murine Model of Thymic Damage and Recovery Following Sublethal Ionizing Radiation(2012) Kepuska, ZanaThe thymus is the primary lymphoid organ responsible for generation of functional T lymphocytes. The loss of thymic function, either as a consequence of physiological senescence or the result of disease- and/or treatment-related pathology, affects individual¡¯s capacity to maintain a broad T cell antigen receptor repertoire. In consequence, the ability to mount an efficient adaptive immune response may become restricted. Currently, there are no available treatments to protect against acute thymic involution, and little is known about the mechanisms that drive thymic involution and recovery. The induction of thymic involution and the delay in thymus recovery emphasize the need to identify the mechanisms that drive stress-induced acute thymic involution, and the need to develop therapeutics to block involution and/or enhance thymus recovery during acute stress events. While many studies have characterized poor immune recovery due to high/lethal doses of radiation, the overall response of the immune system after exposure to a sublethal dose of radiation is unclear. The goal of this research was to develop a murine model of acute thymic involution induced by sublethal irradiation where damage and recovery effects induced by radiation could be examined.
We present here our two-phase irradiation-induced (¡Ü 125 cGy, 250 cGy and 550 cGy) thymic involution model in young BALB/c mice. We observed a dramatic dose-dependent impact of irradiation on thymopoiesis on day 7. By day 35 there was spontaneous recovery of thymus, and restoration of the peripheral lymphoid compartments. Thymus function was monitored by thymus weight, cellularity, and TCR gene re-arrangement (mTREC). During the damage phase our studies demonstrated decreased expression of thymostimulatory cytokine, KGF, and loss of active TCR gene rearrangement following radiation exposure in young mice. An increase of KGF levels correlated with the overall spontaneous recovery observed. Thus, suggesting a critical role of thymic-stromal derived KGF in promoting stroma/thymocyte crosstalk to mediate thymus recovery.
Overall, our characterization of our model provided a useful estimate of thymic response to stress induced by irradiation and our findings may provide a model to a better future understanding of mechanisms involved in thymus recovery from damage and inform development of strategies to restore thymic function in the stressed-induced acute thymic involution.
Item Unknown Neutralizing antibody vaccine for pandemic and pre-emergent coronaviruses.(Nature, 2021-06) Saunders, Kevin O; Lee, Esther; Parks, Robert; Martinez, David R; Li, Dapeng; Chen, Haiyan; Edwards, Robert J; Gobeil, Sophie; Barr, Maggie; Mansouri, Katayoun; Alam, S Munir; Sutherland, Laura L; Cai, Fangping; Sanzone, Aja M; Berry, Madison; Manne, Kartik; Bock, Kevin W; Minai, Mahnaz; Nagata, Bianca M; Kapingidza, Anyway B; Azoitei, Mihai; Tse, Longping V; Scobey, Trevor D; Spreng, Rachel L; Rountree, R Wes; DeMarco, C Todd; Denny, Thomas N; Woods, Christopher W; Petzold, Elizabeth W; Tang, Juanjie; Oguin, Thomas H; Sempowski, Gregory D; Gagne, Matthew; Douek, Daniel C; Tomai, Mark A; Fox, Christopher B; Seder, Robert; Wiehe, Kevin; Weissman, Drew; Pardi, Norbert; Golding, Hana; Khurana, Surender; Acharya, Priyamvada; Andersen, Hanne; Lewis, Mark G; Moore, Ian N; Montefiori, David C; Baric, Ralph S; Haynes, Barton FBetacoronaviruses caused the outbreaks of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome, as well as the current pandemic of SARS coronavirus 2 (SARS-CoV-2)1-4. Vaccines that elicit protective immunity against SARS-CoV-2 and betacoronaviruses that circulate in animals have the potential to prevent future pandemics. Here we show that the immunization of macaques with nanoparticles conjugated with the receptor-binding domain of SARS-CoV-2, and adjuvanted with 3M-052 and alum, elicits cross-neutralizing antibody responses against bat coronaviruses, SARS-CoV and SARS-CoV-2 (including the B.1.1.7, P.1 and B.1.351 variants). Vaccination of macaques with these nanoparticles resulted in a 50% inhibitory reciprocal serum dilution (ID50) neutralization titre of 47,216 (geometric mean) for SARS-CoV-2, as well as in protection against SARS-CoV-2 in the upper and lower respiratory tracts. Nucleoside-modified mRNAs that encode a stabilized transmembrane spike or monomeric receptor-binding domain also induced cross-neutralizing antibody responses against SARS-CoV and bat coronaviruses, albeit at lower titres than achieved with the nanoparticles. These results demonstrate that current mRNA-based vaccines may provide some protection from future outbreaks of zoonotic betacoronaviruses, and provide a multimeric protein platform for the further development of vaccines against multiple (or all) betacoronaviruses.