Project description:To gain a deeper understanding of Omicron waves in the context of vaccination, we performed scRNA-seq together with single-cell V(D)J sequencing using PBMCs from nine Omicron breakthrough infection patients and six vaccinees to identify the possible cellular and molecular response mechanisms after breakthrough infection.
Project description:Background Omicron subvariants have led to millions of coronavirus disease 2019 (COVID-19) cases worldwide. Although Omicron breakthrough infections (BTIs) exhibit lower hospitalization rates than previous variants, post-COVID conditions persist. However, the immune response dynamics, lymphocyte subsets, and immune repertoire features following BA.5 sublineage BTI remain poorly understood. Methods In a longitudinal cohort, we monitored the recovery dynamics in patients with BTI at various time points. We employed single-cell transcriptomics, T cell receptor (TCR)/BCR sequencing, and antibody mass spectrometry to sequentially assess the immune response following BA.5.2 or BF.7 BTI. Findings Serological analysis revealed active cellular and humoral immunity 2 weeks post-BTI, with significant increases in cytokines (CKs) like IFN-γ, TNFβ, IL-2, and neutralizing antibodies. CK levels reverted to pre-infection levels, while broadly neutralizing antibodies remained high 1 month post-infection. Single-cell sequencing demonstrated robust immune activation and antiviral responses in NK, T, and B lymphocytes within 1 month post-BTI. Interestingly, the immune system maintained its strength to combat viral infection at 2 weeks post-BTI, transitioning toward repair and tissue damage elimination at 1 month. TCR/BCR library analysis revealed a higher clonal type in the BTI_2w group, mainly in NKT, memory T or B, and plasma cells, crucial for immune memory and antigen clearance. The BTI_1m group exhibited more IgG and IgA BCR subtypes, with somatic hypermutation indicating mature antibodies. Biological function verification of IgG and IgA-type monoclonal antibodies corresponding to expanded BCRs revealed antigen-specific and broad-spectrum antibodies. Interpretation Our study elucidated the dynamic immune profiling of individuals 2 weeks and 1 month after Omicron BA.5 sublineage BTI. This provided essential insights into pathogenicity, sequential immune status, recovery mechanisms of Omicron subvariant BTI, and novel concepts for broad-spectrum antibody development.
Project description:There have been reports of long coronavirus disease (long COVID) and breakthrough infections (BTIs); however, the mechanisms and pathological features of long COVID after Omicron BTIs remain unclear. Assessing long COVID and immune recovery after Omicron BTIs is crucial for understanding the disease and developing and managing new-generation vaccines. Here, we followed up mild BA.2 BTI convalescents for six-month with routine blood tests and neutralization assay. Then, we applied proteomic analysis and single-cell RNA sequencing (scRNA-seq) to study the convalescents’ recovery status. Lastly, we retrospectively analyzed the clinical parameters related to immunity and metabolism of the convalescents. We found that major organs exhibited ephemeral dysfunction in double-Convidecia vaccinated persons who experienced BA.2 BTI and recovered to normal in approximately six-month. We observed durable and potent levels of neutralizing antibodies against major circulating severe acute respiratory syndrome coronavirus 2 sub-variants, including BQ.1, BQ.1.1 and BF.7, indicating that hybrid humoral immunity stays active. However, PLTs may take longer to recover. This was supported by proteomic and scRNA-seq analyses, which also showed coagulation disorder and an imbalance between anti-pathogen immunity and metabolism six-month after BA.2 BTI. The immunity-metabolism imbalance was then proved with retrospective analysis of abnormal levels of hormones, low blood glucose level and coagulation profile. The long-term malfunctional coagulation and imbalance in the material metabolism and immunity may contribute to the development of long COVID and act as useful indicators for assessing recovery and the long-term impacts after Omicron sub-variant BTIs.
Project description:Antibody response following Omicron infection is reported to be less robust than that to other variants. Here we investigated how prior vaccination and/or prior infection modulates that response. Disease severity, antibody responses and immune transcriptomes were characterized in four groups of Omicron-infected outpatients (n=83): unvaccinated/no prior infection, vaccinated/no prior infection, unvaccinated/prior infection and vaccinated/prior infection. The percentage of patients with asymptomatic or mild disease was highest in the vaccinated/no prior infection group (87%) and lowest in the unvaccinated/no prior infection group (47%). Significant anti-Omicron spike antibody levels and neutralizing activity were detected in the vaccinated group immediately after infection but were not present in the unvaccinated/no prior infection group. Within two weeks, antibody levels against Omicron, increased. Omicron neutralizing activity in the vaccinated group exceeded that of the prior infection group. No increase in neutralizing activity in the unvaccinated/no prior infection group was seen. The unvaccinated/prior infection group showed an intermediate response. We then investigated the early transcriptomic response following Omicron infection in these outpatient populations and compared it to that found in unvaccinated hospitalized patients with Alpha infection. Omicron infected patients showed a gradient of transcriptional response dependent upon whether or not they were previously vaccinated or infected. Vaccinated patients showed a significantly blunted interferon response as compared to both unvaccinated Omicron infected outpatients and unvaccinated Alpha infected hospitalized patients typified by the response of specific gene classes such as OAS and IFIT that control anti-viral responses and IFI27, a predictor of disease outcome.
Project description:The Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first identified in November 2021 in South Africa, has initiated the 5th wave of global pandemics. Here, we systemically examined immunological and metabolic characteristics of Omicron variants infection. We found Omicron resisted to neutralizing antibody targeting receptor binding domain (RBD) of wild-type SARS-CoV-2. Omicron could not be neutralized by sera of Corona Virus Disease 2019 (COVID-19) convalescent individuals who were infected with the Delta variant. Through mass spectrometry on MHC-bound peptidomes, we found that the spike protein of the Omicron variants could generate additional CD8+ T cell epitopes, compared with Delta. These epitopes could induce robust CD8+ T cell responses. Moreover, we found booster vaccination increased the cross-memory CD8+ T cell responses against Omicron. Metabolic regulome analysis of Omicron-specific T cell showed a metabolic profile that promoted memory T cell responses. Consistently, a higher fraction of memory CD8+ T cells were found in Omicron stimulated peripheral blood mononuclear cells (PBMCs). In addition, CD147 was also a receptor for the Omicron variants, and CD147 antibody inhibited infection of Omicron. CD147-mediated Omicron infection in a human CD147 transgenic mouse model induced exudative alveolar pneumonia. Taken together, our data suggested that vaccination booster and receptor blocking antibody are two effective strategies against Omicron.
Project description:At this stage in the COVID-19 pandemic, most infections are 'breakthrough' infections that occur in individuals with prior immunity to SARS-CoV-2 through infection or vaccination. Understanding both innate and adaptive immune induction in the setting of breakthrough infection is critical to refining vaccine strategies to ensure long-term efficacy against emerging variants, yet existing studies have primarily focused on adaptive immune responses. Here, we performed single-cell transcriptomic, proteomic, and functional profiling of innate and adaptive immunity during primary and breakthrough COVID-19 infections by comparing immune responses between unvaccinated and vaccinated individuals during the SARS-CoV-2 Delta wave. Breakthrough infections were characterized by a significantly less activated transcriptomic profile in CD56dim NK cells and monocytes, with induction of pathways limiting NK cell proliferation and monocyte migratory potential. Furthermore, we observed a female-specific trend of increased transcriptomic activation of CD16+ monocytes and type-2 conventional dendritic cells (cDC2s) during breakthrough infections. Despite these differences, antibody-dependent cellular cytotoxicity responses were similar between breakthrough and primary infection groups. These insights suggest that prior vaccination prevents overactivation of innate immune responses during breakthrough infections with discernible sex-specific patterns and underscore the potential of harnessing vaccines in mitigating pathologic immune responses resulting from overactivation.
Project description:RNA-Seq was used to study changes in gene expression in saliva samples from 266 human subjects after SARS-COV-2 infection, vaccination, or combined infection and vaccination (breakthrough). Approximately equal numbers of males and females, matched for age, were profiled after subjects tested positive for COVID-19 by PCR and sequencing of the variant. In addition to samples from uninfected controls with and without vaccination, samples from infected subjects with and without vaccination that represent eight major SARS-COV-2 lineages are included: epsilon, iota, alpha, delta, omicron BA.1, omicron BA.2, omicron BA.4, and omicron BA.5. Stranded single-end sequencing was performed using standard Illumina protocols. Reads were quantified to hg38 human transcriptome using Salmon after adapter trimming. Quantified reads were filtered to remove features with fewer than one count in 80% of the samples, and normalized using TPM, followed by quantile and log2 transformation.
Project description:We applied a 4D dia-PASEF proteomic approach to investigate the salivary protein profile of individuals with early-to-acute SARS-CoV-2 Omicron infection. We combined proteomics and functional analyses with feature selection and ROC multivariate analysis to identify and assess salivary proteins for COVID-19 screening.
Project description:There have been reports of long coronavirus disease (long COVID) and breakthrough infections (BTIs); however, the mechanisms and pathological features of long COVID after Omicron BTIs remain unclear. Assessing long COVID and immune recovery after Omicron BTIs is crucial for understanding the disease and developing and managing new-generation vaccines. Here, we followed up mild BA.2 BTI convalescents for six-month with routine blood tests and neutralization assay. Then, we applied proteomic analysis and single-cell RNA sequencing (scRNA-seq) to study the convalescents’ recovery status. Lastly, we retrospectively analyzed the clinical parameters related to immunity and metabolism of the convalescents. We found that major organs exhibited ephemeral dysfunction in double-Convidecia vaccinated persons who experienced BA.2 BTI and recovered to normal in approximately six-month. We observed durable and potent levels of neutralizing antibodies against major circulating severe acute respiratory syndrome coronavirus 2 sub-variants, including BQ.1, BQ.1.1 and BF.7, indicating that hybrid humoral immunity stays active. However, PLTs may take longer to recover. This was supported by proteomic and scRNA-seq analyses, which also showed coagulation disorder and an imbalance between anti-pathogen immunity and metabolism six-month after BA.2 BTI. The immunity-metabolism imbalance was then proved with retrospective analysis of abnormal levels of hormones, low blood glucose level and coagulation profile. The long-term malfunctional coagulation and imbalance in the material metabolism and immunity may contribute to the development of long COVID and act as useful indicators for assessing recovery and the long-term impacts after Omicron sub-variant BTIs.