ABSTRACT
Human adenovirus serotype 26 (Ad26) is used as a gene-based vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HIV-1. However, its primary receptor portfolio remains controversial, potentially including sialic acid, coxsackie and adenovirus receptor (CAR), integrins, and CD46. We and others have shown that Ad26 can use CD46, but these observations were questioned on the basis of the inability to cocrystallize Ad26 fiber with CD46. Recent work demonstrated that Ad26 binds CD46 with its hexon protein rather than its fiber. We examined the functional consequences of Ad26 for infection in vitro and in vivo. Ectopic expression of human CD46 on Chinese hamster ovary cells increased Ad26 infection significantly. Deletion of the complement control protein domain CCP1 or CCP2 or the serine-threonine-proline (STP) region of CD46 reduced infection. Comparing wild-type and sialic acid-deficient CHO cells, we show that the usage of CD46 is independent of its sialylation status. Ad26 transduction was increased in CD46 transgenic mice after intramuscular (i.m.) injection but not after intranasal (i.n.) administration. Ad26 transduction was 10-fold lower than Ad5 transduction after intratumoral (i.t.) injection of CD46expressing tumors. Ad26 transduction of liver was 1,000-fold lower than that ofAd5 after intravenous (i.v.) injection. These data demonstrate the use of CD46 by Ad26 in certain situations but also show that the receptor has little consequence by other routes of administration. Finally, i.v. injection of high doses of Ad26 into CD46 mice induced release of liver enzymes into the bloodstream and reduced white blood cell counts but did not induce thrombocytopenia. This suggests that Ad26 virions do not induce direct clotting side effects seen during coronavirus disease 2019 (COVID-19) vaccination with this serotype of adenovirus. IMPORTANCE The human species D Ad26 is being investigated as a low-seroprevalence vector for oncolytic virotherapy and gene-based vaccination against HIV-1 and SARS-CoV-2. However, there is debate in the literature about its tropism and receptor utilization, which directly influence its efficiency for certain applications. This work was aimed at determining which receptor(s) this virus uses for infection and its role in virus biology, vaccine efficacy, and, importantly, vaccine safety.
ABSTRACT
Background. Almost 4 million children have tested positive for Coronavirus Disease 2019 (COVID-19) as of June 3 2021, representing 14% of all cases in USA. Children present with diverse clinical findings including the multisystem inflammatory syndrome in children (MIS-C). In this study, we measured serum cytokine concentrations in children with COVID-19 to identify differences in immune profiles according to clinical presentations. Methods. A total of 133 children 0-21 years of age with COVID-19 were enrolled at Nationwide Children's Hospital, in Columbus, Ohio. Nasopharyngeal swab RT-PCR testing was used for SARS-CoV-2 detection and quantification. Clinical and laboratory information were obtained, and blood samples were collected for measurement of cytokines with a 92-plex inflammation assay (Olink). Normalized cytokine expression levels in patients were compared with serum samples from 66 pre-pandemic agematched healthy controls. Results. COVID-19 children included: 1) those identified by universal screening (n=47);2) moderate disease (ward;n=48);3) severe disease (PICU;n=20);4) MIS-C (n=18). Children identified by universal screening were hospitalized for trauma, appendicitis or new onset diabetes among others. Children with symptomatic COVID-19 had significantly higher SARS-CoV-2 viral loads than children with MIS-C or those identified via universal screening. Concentrations of interferon (IFN) related cytokines (IFNg, CXCL9, CXCL10, CXCL11), interleukins (IL6, IL8, IL10, IL17A, IL18, IL24) and other inflammatory cytokines (TGF, TNF, VEGF, MCP, CD40) were significantly increased in children with acute COVID-19 and MIS-C compared with children identified by universal screening and healthy controls. These cytokines were positively correlated with C-reactive protein, D-dimer and disease severity in COVID-19, but negatively correlated with viral loads (Fig 1). MIS-C showed stronger inflammatory response than acute COVID-19 (Fig 2). Correlation of Age-adjusted cytokine expression values with viral load, disease severity, CRP and D-dimer. Pearson correlation coefficient is shown for each pair. Red: positive correlation;blue: negative correlation Cytokines that differentiate MIS-C from acute COVID-19 Heatmap shows the differential expressed cytokines between MIS-C and acute severe COVID-19 (padj<0.05, FC>2). The age-adjusted expression values are normalized the median of healthy controls. Red: up-regulation, blue: down-regulation. Conclusion. We identified three cytokine clusters in children with COVID-19 according to clinical presentations. Correlations of serum cytokines with clinical/laboratory parameters could be used to identify potential biomarkers associated with disease severity in COVID-19.
ABSTRACT
Background: Complement dysregulation has been documented in the molecular pathophysiology of COVID-19 and recently implicated in the relevant pediatric patient inflammatory responses. Aims: Based on our previous data in adults, we hypothesized that signatures of complement genetic variants would also be detectable in pediatric patients exhibiting COVID-19 signs and symptoms. Methods: We prospectively studied consecutive pediatric patients from our COVID-19 Units (November 2020-March 2021). COVID-19 was confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR). Patient data were recorded by treating physicians that followed patients up to discharge. DNA was obtained from peripheral blood samples. Probes were designed using the Design studio (Illumina). Amplicons cover exons of complement-associated genes (C3, C5, CFB, CFD, CFH, CFHR1, CFI, CD46, CD55, MBL2, MASP1, MASP2, COLEC11, FCN1, FCN3 as well as ADAMTS13 and ΤHBD) spanning 15 bases into introns. We used 10ng of initial DNA material. Libraries were quantified using Qubit and sequenced on a MiniSeq System in a 2x150 bp run. Analysis was performed using the TruSeq Amplicon application (BaseSpace). Alignment was based on the banded Smith-Waterman algorithm in the targeted regions (specified in a manifest file). We performed variant calling with the Illumina-developed Somatic Variant Caller in germline mode and variant allele frequency higher than 20%. Both Ensembl and Refseq were used for annotation of the output files. A preliminary analysis (A) for the identification of variants of clinical significance was based on annotated ClinVar data, while a further and more selective analysis (B) was performed to identify missense complement coding variants that may biochemically contribute to the deregulation of innate responses during infection. This analysis was mainly based on the dbSNP and UniProt databases and available literature. Results: We studied 80 children and adolescents, 8 of whom developed inflammatory syndromes (MIS-C group). Among them, 41 were hospitalized and eventually all survived. 1. In our preliminary analysis, patients exhibited heterogeneous variant profiles including pathogenic, benign, likely benign, and variants of unknown significance (median number of variants: 97, range: 61-103). We found a variant of ADAMTS13 (rs2301612, missense) in 39 patients. We also detected two missense risk factor variants, previously detected in complement-related diseases: rs2230199 in C3 (33 patients);and rs800292 in CFH (36 patients). Among them, 40 patients had a combination of these characterized variants. This combination was significantly associated with the presence of dyspnea (p=0.031) and cough (p=0.042). Furthermore, 27 patients had a pathogenic variant in MBL2 (rs1800450), and 7 a pathogenic deletion in FCN3 that have been previously associated with inflammatory syndromes. 2. The results of our further analysis are summarized in Figure. We identified common variants, some well represented by relatively high frequencies (>70%) (rs11098044 in CFI, rs1061170 in CFH and rs12711521 in MASP2) and others less abundant, but varying considerably between the hospitalized group, the non-admitted group and the MIS-C individuals (rs2230199 in C3, rs1065489 in CFH, rs12614 and rs641153 in CFB, rs1800450 in MBL2, rs2273346 and rs72550870 in MASP2, rs72549154 in MASP3 and rs7567833 in COLEC11, all highlighted in Figure in red).). Structurally, the majority of these common variants of interest encode charge reversal mutations. These may influence protein-protein interactions in complex formations that are important for complement activation and/or regulation. Conclusion: In pediatric COVID-19 we have detected a novel set of complement missense coding variants some of which have been implicated earlier in inflammatory syndromes and endothelial stress responses. Certain combinations of mutations of alternative and/or lectin pathway components may increase the threshold dynamics of complement consumption and therefore alter COVID-19 phenotypes. [Formula prese ted] Disclosures: Gavriilaki: Alexion, Omeros, Sanofi Corporation: Consultancy;Gilead Corporation: Honoraria;Pfizer Corporation: Research Funding. Anagnostopoulos: Abbvie: Other: clinical trials;Sanofi: Other: clinical trials;Ocopeptides: Other: clinical trials;GSK: Other: clinical trials;Incyte: Other: clinical trials;Takeda: Other: clinical trials;Amgen: Other: clinical trials;Janssen: Other: clinical trials;novartis: Other: clinical trials;Celgene: Other: clinical trials;Roche: Other: clinical trials;Astellas: Other: clinical trials.
ABSTRACT
Background: Atypical Hemolytic Uremic Syndrome (aHUS) is a complement-mediated thrombotic microangiopathy. Pathophysiological mechanism involves uncontrolled complement activation due to a genetic or acquired anomaly coupled with a triggering event. We report a case of aHUS recurrence following COVID-19 vaccination. Material and methods: Whole blood (EDTA) was collected and processed with CD46-PE, CD45-PerCP, isotype control-PE markers. Staining was measured through median fluorescence intensity and expressed as CD46/isotype ratio. Sanger sequencing was used for identification of variants in CD46 gene. All the participants provided informed written consent. Results: Proband (P) is a 39-year-old woman admitted for nausea, vomiting, epigastric pain and haematuria, three days after first dose of ChAdOx1 nCov-19 vaccine. Laboratory testing showed MAHA (Hb:8.8g/dL, Ht:26%), thrombocytopenia (80x109/mm3) and acute kidney injury (Cr:2.15mg/dL, Ur:92mg/dL). P and three of her siblings have experienced recurrent TMA episodes since childhood. In 2019, genetic study from P's sister (S) identified two heterozygous variants in CD46, one pathogenic (Glu179Gln) and one of uncertain significance (Cys94Tyr). We demonstrated that P carries the same variants and observed a 50% decrease of CD46 expression in both P and S (fig.1). Platelet transfusion, corticosteroids and 9 sessions of plasmapheresis contributed to rapid recovery of P. Discussion: Glu179Gln was reported to increase CD46 expression on granulocytes in aHUS patient and to reduce C4b cofactor activity1. We observed that combination of Glu179Gln and Cys94Tyr was associated with low levels of CD46 on cell surface. Conclusion: This case report supports the evidence of COVID-19 vaccine as a precipitating event for aHUS recurrence.