Document text
Principal Investigator: Renren Wen
Organization: VERSITI BLOOD HEALTH, INC.
Fiscal Year: 2022
Award: $659,871
Funding agency: National Heart Lung and Blood Institute
Abstract
COVID-19 severity/lethality is associated with a dysfunctional inflammatory immune response and a hyper-
engagement of pathways driving hemostasis and thrombosis, but the link between the two manifestations is not
understood. Compared to patients with mild symptoms, severe COVID-19 patients have stronger IgG reactivity
to SARS-CoV-2 virus and its spike protein receptor binding domain (RBD) and a robust B-cell response with a
marked increase of the CD11c+CD21- B cells and plasmablast compartments. The incidence of thrombosis and
inflammatory disease in severe COVID-19 is unprecedented, manifested by increased plasma inflammatory
markers, such as IL-6, tumor necrosis factor alpha, C-reactive protein, and activation of compliment pathway
etc., and dysregulated activation of cellular components participating in inflammatory and coagulation responses
that include platelets, endothelial, monocytes, and neutrophils. The thrombotic manifestation ranges from
arterial, venous, and tissue micro thrombosis to thromboembolism and is predominated by venous
thromboembolism. Similar manifestations are observed in catastrophic thrombosis associated with heparin-
induced thrombocytopenia and thrombosis (HIT). Patients with catastrophic HIT have the sudden onset of
multiple arterial and venous thrombi with, but sometime without, heparin exposure, due to prothrombotic platelet-
activating IgGs that recognize platelet factor 4 complexed with heparin polysaccharide (PF4/H). Using methods
employed in previous studies of HIT, we studied patients with severe COVID-19 patients and identified PF4/H-
reactive, pro-thrombotic IgG antibodies that closely resemble pathogenic antibodies found in patients with HIT
in their ability to activate platelets. Surprisingly, levels of PF4/H antibodies in the patient plasma correlated with
levels of antibodies specific for the receptor binding domain (RBD) of the SARS-CoV-2 spike protein. We cloned
RBD-specific antibodies that are able to activate platelets. Compared to those that recognize RBD alone,
significantly more B cells recognizing both RBD and PF4/H were CD11c+, CD21- and CXCR3+, which mark a
subset of extrafollicular B cells robustly expanded in severe COVID-19. Based on these findings, we hypothesize
that SARS-CoV-2 infection drives a subset of RBD-specific B cells to respond via an extrafollicular
pathway and generate platelet-activating antibodies that contribute to thrombotic complications but not
virus neutralization in severe COVID-19. To test our hypothesis, we will 1) investigate the prothrombotic
activity of RBD-specific antibodies in the plasma of hospitalized COVID-19 patients; 2) investigate the expansion
of B cells that make RBD-specific platelet-activating antibodies in severe COVID-19; 3) investigate the
developmental pathway that governs affinity maturation of RBD and PF4/H cross-reactive B cells. Our proposal
studies a novel B-cell/platelet axis in thrombotic complications in COVID-19 and should unravel a large portion
of the complex pathogenesis of morbidity/mortality in this disease and suggest new treatment.
Terms: <(TNF)-α><2019 novel corona virus><2019 novel coronavirus><2019-nCoV><2019-nCoV S protein><2019-nCoV spike glycoprotein><2019-nCoV spike protein><7S Gamma Globulin><Ab response><Affinity><Antibodies><Antibody Formation><Antibody Production><Antiheparin Factor><Autoantibodies><Automobile Driving><B blood cells><B cell><B cell differentiation factor><B cell stimulating factor 2><B cells><B-Cell Differentiation Factor><B-Cell Differentiation Factor-2><B-Cell Stimulatory Factor-2><B-Cells><B-Lymphocytes><B-cell><BCDF><BSF-2><BSF2><Binding><Blood Neutrophil><Blood Plasma><Blood Platelet Factor IV><Blood Platelets><Blood Polymorphonuclear Neutrophil><Blood monocyte><Blood platelet factor 4><Body Tissues><C-reactive protein><C3d Receptors><CD 21 Antigens><CD11c><CD183><CD21><CD21 Antigens><CKR-L2><CMKAR3><COVID disease severity><COVID infected patient><COVID patient><COVID positive patient><COVID severity><COVID-19><COVID-19 S protein><COVID-19 disease severity><COVID-19 infected patient><COVID-19 infection><COVID-19 patient><COVID-19 positive patient><COVID-19 severity><COVID-19 spike glycoprotein><COVID-19 spike protein><COVID-19 virus><COVID19><COVID19 S protein><COVID19 disease severity><COVID19 infection><COVID19 patient><COVID19 positive patient><COVID19 severity><COVID19 spike glycoprotein><COVID19 spike protein><COVID19 virus><CR2><CR2 Receptors><CV-19><CV19><CXCR3><CXCR3 gene><Cachectin><Cell Body><Cells><Chemokine (C-X-C Motif) Receptor 3><Chemokine (C-X-C motif) Ligand 4><Cloning><Clotting><CoV-2><CoV2><Coagulation><Coagulation Process><Complement 3d Receptors><Complement Receptors 2><Complex><D-dimer><D-dimer fibrin><D-dimer fragments><Development><Disease><Disorder><Endothelium><Epstein-Barr Virus Receptors><Factor 4><Fibrin fragment D><G Protein-Coupled Receptor 9><GPR9><Germinal Center><Glycans><HPGF><Hemostasis><Hemostatic function><Heparin><Heparin Neutralizing Protein><Heparinic Acid><Hepatocyte-Stimulating Factor><Hybridoma Growth Factor><IFN-beta 2><IFNB2><IL-6><IL6 Protein><IP10><IP10 Receptor><IP10-Mig receptor><IP10-R><ITGAX><ITGAX gene><IgG><IgG1><Immune Globulins><Immune response><Immunoglobulin G><Immunoglobulins><Immunological response><Impairment><Incidence><Inflammatory><Interleukin-6><Link><Literature><MGI-2><Macrophage-Derived TNF><Marrow Neutrophil><Marrow monocyte><Marrow platelet><Memory><Methods><Mig Receptor><Mig-R><MigR><Molecular><Molecular Interaction><Monocyte-Derived TNF><Morbidity><Morbidity - disease rate><Myeloid Differentiation-Inducing Protein><Neutrophilic Granulocyte><Neutrophilic Leukocyte><PF4 Gene><Pathogenesis><Pathogenicity><Pathway interactions><Patients><Plasma><Plasma Serum><Plasmablast><Plasmacytoma Growth Factor><Platelet Activation><Platelet Factor 4><Platelets><Polymorphonuclear Cell><Polymorphonuclear Leukocytes><Polymorphonuclear Neutrophils><Polysaccharides><Proteins, specific or class, C-reactive><Receptor Protein><Recombinant Platelet Factor 4><Reticuloendothelial System, Serum, Plasma><SARS corona virus 2><SARS-CO-V2><SARS-COVID-2><SARS-CoV-2><SARS-CoV-2 S protein><SARS-CoV-2 disease severity><SARS-CoV-2 infected patient><SARS-CoV-2 infection><SARS-CoV-2 patient><SARS-CoV-2 positive patient><SARS-CoV-2 severity><SARS-CoV-2 spike glycoprotein><SARS-CoV-2 spike protein><SARS-CoV2><SARS-CoV2 S protein><SARS-CoV2 infection><SARS-CoV2 spike glycoprotein><SARS-CoV2 spike protein><SARS-associated corona virus 2><SARS-associated coronavirus 2><SARS-coronavirus-2><SARS-related corona virus 2><SARS-related coronavirus 2><SARSCoV2><SCYB4><Severe Acute Respiratory Coronavirus 2><Severe Acute Respiratory Distress Syndrome CoV 2><Severe Acute Respiratory Distress Syndrome Corona Virus 2><Severe Acute Respiratory Distress Syndrome Coronavirus 2><Severe Acute Respiratory Syndrome CoV 2><Severe Acute Respiratory Syndrome-associated coronavirus 2><Severe Acute Respiratory Syndrome-related coronavirus 2><Severe acute respiratory syndrome associated corona virus 2><Severe acute respiratory syndrome corona virus 2><Severe acute respiratory syndrome coronavirus 2><Severe acute respiratory syndrome coronavirus 2 S protein><Severe acute respiratory syndrome coronavirus 2 infection><Severe acute respiratory syndrome coronavirus 2 spike glycoprotein><Severe acute respiratory syndrome coronavirus 2 spike protein><Severe acute respiratory syndrome related corona virus 2><Severities><Small Inducible Cytokine B4><Small Inducible Cytokine Subfamily B, Member 4><Structure of germinal center of lymph node><Surface><Symptoms><TNF><TNF A><TNF Alpha><TNF gene><TNF-α><TNFA><TNFα><Testing><Thrombocytes><Thromboembolism><Thrombosis><Thrombus><Tissues><Tumor Necrosis Factor><Tumor Necrosis Factor-alpha><Venous><Virus><Wuhan coronavirus><antibody biosynthesis><autoimmune antibody><autoreactive antibody><autoreactivity><base><corona virus disease 2019><coronavirus disease 2019><coronavirus disease 2019 S protein><coronavirus disease 2019 disease severity><coronavirus disease 2019 infected patient><coronavirus disease 2019 infection><coronavirus disease 2019 patient><coronavirus disease 2019 positive patient><coronavirus disease 2019 severity><coronavirus disease 2019 spike glycoprotein><coronavirus disease 2019 spike protein><coronavirus disease 2019 virus><coronavirus disease infected patient><coronavirus disease patient><coronavirus disease positive patient><coronavirus disease severity><coronavirus disease-19><coronavirus disease-19 patient><coronavirus disease-19 virus><coronavirus infectious disease-19><coronavirus patient><cross reactivity><developmental><driving><enhancing factor><experience><fibrin fragment D-dimer><fibrin fragment D1 dimer><fibrin fragment DD><gamma-Thromboglobulin><global gene expression><global transcription profile><hCoV19><heparin-induced thrombocytopenia><host response><immune system response><immunoglobulin biosynthesis><immunoresponse><infected with COVID-19><infected with COVID19><infected with SARS-CoV-2><infected with SARS-CoV2><infected with coronavirus disease 2019><infected with severe acute respiratory syndrome coronavirus 2><inflammation marker><inflammatory marker><inhibiting antibody><interferon beta 2><life-threatening COVID><life-threatening COVID-19><life-threatening SARS-CoV-2><life-threatening coronavirus disease><life-threatening coronavirus disease 2019><life-threatening severe acute respiratory syndrome coronavirus 2><monocyte><mortality><nCoV2><neutrophil><new approaches><novel><novel approaches><novel strategies><novel strategy><pathway><patient infected with COVID><patient infected with COVID-19><patient infected with SARS-CoV-2><patient infected with coronavirus disease><patient infected with coronavirus disease 2019><patient infected with severe acute respiratory syndrome coronavirus 2><patient with COVID><patient with COVID-19><patient with COVID19><patient with SARS-CoV-2><patient with coronavirus disease><patient with coronavirus disease 2019><patient with severe acute respiratory distress syndrome coronavirus 2><platelet factor IV><protein activation><protein expression><receptor><receptor binding><receptor bound><response><scRNA-seq><self reactive antibody><serious COVID><serious COVID-19><serious SARS-CoV-2><serious coronavirus disease><serious coronavirus disease 2019><serious severe acute respiratory syndrome coronavirus 2><severe COVID><severe COVID-19><severe COVID19><severe SARS-CoV-2><severe acute respiratory syndrome coronavirus 2 disease severity><severe acute respiratory syndrome coronavirus 2 infected patient><severe acute respiratory syndrome coronavirus 2 patient><severe acute respiratory syndrome coronavirus 2 positive patient><severe acute respiratory syndrome coronavirus 2 severity><severe coronavirus disease><severe coronavirus disease 19><severe coronavirus disease 2019><severe severe acute respiratory syndrome coronavirus 2><single cell RNA-seq><single cell RNAseq><single cell expression profiling><single cell transcriptomic profiling><single-cell RNA sequencing><thromboembolic complications><thrombosis complications><thrombotic><thrombotic complications><thrombotic disease><thrombotic disorder><transcriptome><venous thromboembolism>