ABSTRACT
SARS-CoV-2 vaccines have unquestionably blunted the overall impact of the COVID-19 pandemic, but host factors such as age, sex, obesity, and other co-morbidities can affect vaccine efficacy. We identified individuals in a relatively healthy population of healthcare workers (CORALE study cohort) who had unexpectedly low peak anti-spike receptor binding domain (S-RBD) antibody levels after receiving the BNT162b2 vaccine. Compared to matched controls, "low responders" had fewer spike-specific antibody-producing B cells after the second and third/booster doses. Moreover, their spike-specific T cell receptor (TCR) repertoire had less depth and their CD4+ and CD8+T cell responses to spike peptide stimulation were less robust. Single cell transcriptomic evaluation of peripheral blood mononuclear cells revealed activation of aging pathways in low responder B and CD4+T cells that could underlie their attenuated anti-S-RBD antibody production. Premature lymphocyte aging may therefore contribute to a less effective humoral response and could reduce vaccination efficacy.
ABSTRACT
Single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) allows in-depth assessment of transcriptional changes in immune cells of patients with COVID-19. However, collecting, processing, and analyzing samples from patients with COVID-19 pose many challenges because blood samples may contain infectious virus, identification of immune cell subtypes can be difficult, and biological interpretation of analytical results is complex. To address these issues, we describe a protocol for sample processing, sorting, methanol fixation, and scRNA-seq analysis of PBMCs from frozen buffy coat samples from patients with COVID-19. For complete details on the use and execution of this protocol, please refer to (Yao et al., 2021).
Subject(s)
COVID-19/immunology , Leukocytes, Mononuclear/immunology , RNA, Viral/genetics , SARS-CoV-2/immunology , Sequence Analysis, RNA/methods , Single-Cell Analysis/methods , COVID-19/blood , COVID-19/genetics , COVID-19/virology , Humans , RNA, Viral/blood , SARS-CoV-2/genetics , Specimen HandlingABSTRACT
Coronavirus disease 2019 (COVID-19) is the latest respiratory pandemic caused by severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). Although infection initiates in the proximal airways, severe and sometimes fatal symptoms of the disease are caused by infection of the alveolar type 2 (AT2) cells of the distal lung and associated inflammation. In this study, we develop primary human lung epithelial infection models to understand initial responses of proximal and distal lung epithelium to SARS-CoV-2 infection. Differentiated air-liquid interface (ALI) cultures of proximal airway epithelium and alveosphere cultures of distal lung AT2 cells are readily infected by SARS-CoV-2, leading to an epithelial cell-autonomous proinflammatory response with increased expression of interferon signaling genes. Studies to validate the efficacy of selected candidate COVID-19 drugs confirm that remdesivir strongly suppresses viral infection/replication. We provide a relevant platform for study of COVID-19 pathobiology and for rapid drug screening against SARS-CoV-2 and emergent respiratory pathogens.
Subject(s)
Alveolar Epithelial Cells/virology , COVID-19 Drug Treatment , COVID-19/pathology , Lung/virology , SARS-CoV-2/drug effects , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Adult , Aged , Alanine/analogs & derivatives , Alanine/pharmacology , Alveolar Epithelial Cells/metabolism , COVID-19/metabolism , COVID-19/virology , Child, Preschool , Drug Discovery/methods , Epithelial Cells/virology , Epithelium/metabolism , Epithelium/virology , Female , Fibroblasts/cytology , Fibroblasts/metabolism , Humans , Lung/pathology , Male , Middle Aged , Models, Biological , Primary Cell Culture , Respiratory Mucosa/virology , SARS-CoV-2/physiology , Virus Replication/drug effectsABSTRACT
Recent studies have demonstrated immunologic dysfunction in severely ill coronavirus disease 2019 (COVID-19) patients. We use single-cell RNA sequencing (scRNA-seq) to analyze the transcriptome of peripheral blood mononuclear cells (PBMCs) from healthy (n = 3) and COVID-19 patients with moderate disease (n = 5), acute respiratory distress syndrome (ARDS, n = 6), or recovering from ARDS (n = 6). Our data reveal transcriptomic profiles indicative of defective antigen presentation and interferon (IFN) responsiveness in monocytes from ARDS patients, which contrasts with higher responsiveness to IFN signaling in lymphocytes. Furthermore, genes involved in cytotoxic activity are suppressed in both natural killer (NK) and CD8 T lymphocytes, and B cell activation is deficient, which is consistent with delayed viral clearance in severely ill COVID-19 patients. Our study demonstrates that COVID-19 patients with ARDS have a state of immune imbalance in which dysregulation of both innate and adaptive immune responses may be contributing to a more severe disease course.