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1.
Clinical Immunology ; Conference: 2023 Clinical Immunology Society Annual Meeting: Immune Deficiency and Dysregulation North American Conference. St. Louis United States. 250(Supplement) (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-20244368

ABSTRACT

Bivalent COVID-19 vaccines that contain two mRNAs encoding Wuhan-1 and Omicron BA.4/5 spike proteins are successful in preventing infection from the original strain and Omicron variants, but the quality of adaptive immune responses is still not well documented. This study aims at characterizing adaptive immune responses to the bivalent booster vaccination in 46 healthy participants. Plasma and PBMC were collected prior and three weeks after bivalent booster. We measured anti-N, anti-S, and RBD IgM, IgA, IgG plasma titers against original, Omicron BA.1, and BA.5 variants (pending) as well as total anti-S IgG titers and surrogate Virus Neutralization capacity against the Alpha, Delta, and BA.1 variant. With spectral flow-cytometry we identified peripheral blood B-cells specific for the RBD of the S-protein of the original and BA.1 variants. T-cell-specific responses were assessed by cytokine release assay after stimulation with SARS-CoV-2 peptides from the original, BA.1, BA.4, and BA.5 variants (pending). Finally, we performed TRB and IGH repertoire studies on sorted CD4+, CD8+, CD19+ lymphocytes, to study breadth of SARS-CoV-2 specific clonotypes (pending). 27/46 participants were analyzed;9 had SARS-CoV-2 infection (COVID+), while 18 are infection naive (COVID-). In both groups, median time since last dose of SARS-CoV-2 vaccine (3rd or 4th) was 11 months. All subjects were positive for anti-S IgG prior to bivalent booster. The COVID + group displayed anti-S IgG pre-booster levels and neutralization against BA.1 higher than the COVID- group. Significant increase post-boost of total anti-S IgG and BA.1 neutralizing activity was detected in the COVID- but not in the COVID+ group;however, no difference in neutralization activity post-boost was detected between the two groups. Furthermore, the COVIDgroup showed significant increase in the frequency of CD19+ and CD27+ switched memory B-cells specific for BA.1 RBD in post-boost compared to pre-boost samples. However, post-boost frequencies of the same B-cells were higher in the COVID+ compared to the COVID- group. These preliminary findings confirm that among individual immunized with the original COVID-19 mRNAvaccine, prior COVID infection provides increased protection against SARS-CoV-2 variants. They also demonstrate that booster immunization with the bivalent vaccine induces robust adaptive immune responses against Omicron variant.[Formula presented][Formula presented]Copyright © 2023 Elsevier Inc.

2.
Acta Medica Bulgarica ; 50(2):10-19, 2023.
Article in English | EMBASE | ID: covidwho-20244214

ABSTRACT

Compared to other respiratory viruses, the proportion of hospitalizations due to SARS-CoV-2 among children is relatively low. While severe illness is not common among children and young individuals, a particular type of severe condition called multisystem inflammatory syndrome in children (MIS-C) has been reported. The aim of this prospective cohort study, which followed a group of individuals under the age of 19, was to examine the characteristics of patients who had contracted SARS-CoV-2, including their coexisting medical conditions, clinical symptoms, laboratory findings, and outcomes. The study also aimed to investigate the features of children who met the WHO case definition of MIS-C, as well as those who required intensive care. A total of 270 patients were included between March 2020 and December 2021. The eligible criteria were individuals between 0-18 with a confirmed SARS-CoV-2 infection at the Infectious Disease Hospital "Prof. Ivan Kirov"in Sofia, Bulgaria. Nearly 76% of the patients were <= 12 years old. In our study, at least one comorbidity was reported in 28.1% of the cases, with obesity being the most common one (8.9%). Less than 5% of children were transferred to an intensive care unit. We observed a statistically significant difference in the age groups, with children between 5 and 12 years old having a higher likelihood of requiring intensive care compared to other age groups. The median values of PaO2 and SatO2 were higher among patients admitted to the standard ward, while the values of granulocytes and C-reactive protein were higher among those transferred to the intensive care unit. Additionally, we identified 26 children who met the WHO case definition for MIS-C. Our study data supports the evidence of milder COVID-19 in children and young individuals as compared to adults. Older age groups were associated with higher incidence of both MIS-C and ICU admissions.Copyright © 2023 P. Velikov et al., published by Sciendo.

3.
Journal of Biological Chemistry ; 299(3 Supplement):S396-S397, 2023.
Article in English | EMBASE | ID: covidwho-20243840

ABSTRACT

Objective: Immunohistochemistry of post-mortem lung tissue from Covid-19 patients with diffuse alveolar damage demonstrated marked increases in chondroitin sulfate and CHST15 and decline in N-acetylgalactosamine-4-sulfatase. Studies were undertaken to identify the mechanisms involved in these effects. Method(s): Human primary small airway epithelial cells (PCS 301-010;ATCC) were cultured and exposed to the SARSCoV- 2 spike protein receptor binding domain (SPRBD;AA: Lys310-Leu560;Amsbio). Expression of the spike protein receptor, angiotensin converting enzyme 2 (ACE2), was enhanced by treatment with Interferon-beta. Promoter activation, DNA-binding, RNA silencing, QPCR, Western blots, ELISAs, and specific enzyme inhibitors were used to elucidate the underlying molecular mechanisms. Result(s): Treatment of the cultured cells by the SPRBD led to increased CHST15 and CHST11 expression and decline in ARSB expression. Sulfotransferase activity, total chondroitin sulfate, and sulfated glycosaminoglycan (GAG) content were increased. Phospho-T180/T182-p38-MAPK and phospho- S423/S425-Smad3 were required for the activation of the CHST15 and CHST11 promoters. Inhibition by SB203580, a phospho-p38 MAPK inhibitor, and by SIS3, a Smad3 inhibitor, blocked the CHST15 and CHST11 promoter activation. SB203580 reversed the SPRBD-induced decline in ARSB expression, but SIS3 had no effect on ARSB expression or promoter activation. Phospho-p38 MAPK was shown to reduce retinoblastoma protein (RB) S807/S811 phosphorylation and increase RB S249/T252 phosphorylation. E2F-DNA binding declined following exposure to SPRBD, and SB203580 reversed this effect. This indicates a mechanism by which SPRBD, phospho-p38 MAPK, E2F, and RB can regulate ARSB expression and thereby impact on chondroitin 4-sulfate and dermatan sulfate and molecules that bind to these sulfated GAGs, including Interleukin-8, bone morphogenetic protein-4, galectin-3 and SHP-2 (Src homology region 2-containing protein tyrosine phosphatase 2). Conclusion(s): The enzyme ARSB is required for the degradation of chondroitin 4-sulfate and dermatan sulfate, and accumulation of these sulfated GAGs can contribute to lung pathophysiology, as evident in Covid-19. Some effects of the SPRBD may be attributable to unopposed Angiotensin II, when Ang1-7 counter effects are diminished due to binding of ACE2 with the SARS-CoV-2 spike protein and reduced production of Ang1-7. Aberrant cell signaling and activation of the phospho-p38 MAPK and Smad3 pathways increase CHST15 and CHST11 production, which can contribute to increased chondroitin sulfate in infected cells. Decline in ARSB may occur as a consequence of effects of phospho-p38 MAPK on RB phosphorylation and E2F1 availability. Decline in ARSB and the resulting impaired degradation of sulfated GAGs have profound consequences on cellular metabolic, signaling, and transcriptional events. Funding is VA Merit Award.Copyright © 2023 The American Society for Biochemistry and Molecular Biology, Inc.

4.
Clinical Immunology ; Conference: 2023 Clinical Immunology Society Annual Meeting: Immune Deficiency and Dysregulation North American Conference. St. Louis United States. 250(Supplement) (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-20243635

ABSTRACT

Coronavirus disease 2019 (COVID-19) is a fatal pandemic viral disease caused by the severe acute respiratory syndrome corona virus type-2 (SARS-CoV-2). The aim of this study is to observe the associations of IL-6, SARS-COV-2 viral load (RNAemia), IL- 6 gene polymorphism and lymphocytes and monocytes in peripheral blood with disease severity in COVID-19 patients. This study was carried out from March 2021 to January 2022. RT-PCR positive 84 COVID-19 patients and 28 healthy subjects were enrolled. Blood was collected to detect SARS-COV-2 viral RNA (RNAemia) by rRT-PCR, serum IL-6 level by chemiluminescence method, SNPs of IL-6 by SSP-PCR, immunophenotyping of lymphocytes and monocyte by flow cytometry. Serum IL-6 level (pg/ml) was considerably high among critical patients (102.02 +/- 149.7) compared to severe (67.20 +/- 129.5) and moderate patients (47.04 +/- 106.5) and healthy controls (3.5 +/- 1.8). Serum SARS-CoV-2 nucleic acid positive cases detected mostly in critical patients (39.28%) and was correlated with extremely high IL-6 level and high mortality (R =.912, P < 0.001). Correlation between IL-6 and monocyte was statistically significant with disease severity (severe group, p < 0.001, and 0.867*** and critical group p < 0.001 and 0.887***). In healthy controls, moderate, severe and critically ill COVID-19 patients, IL-6 174G/C (rs 1800795) GG genotype was 82.14%, 89.20%, 67.85% and 53.57% respectively. CC and GC genotype had strong association with severity of COVID-19 when compared with GG genotype. Significant statistical difference found in genotypes between critical and moderate groups (p < 0.001, OR-10.316, CI-3.22-23.86), where CC genotype was associated with COVID-19 severity and mortality. The absolute count of T cell, B cell, NK cell, CD4+ T cells and CD8+ T cells were significantly decreased in critical group compared to healthy, moderate and severe group (P < 0.001). Exhaustion marker CD94/NKG2A was increased on NK cells and CD8+ cytotoxic T cell among critical and severe group. Absolute count of monocyte was significantly increased in critical group (P < 0.001). Serum IL-6, IL-6 174 G/C gene and SARS-CoV-2 RNAaemia can be used in clinical practice for risk assessment;T cell subsets and monocyte as biomarkers for monitoring COVID-19 severity. Monoclonal antibody targeting IL-6 receptor and NKG2A for therapeutics may prevent disease progression and decrease morbidity and mortality.Copyright © 2023 Elsevier Inc.

5.
Annals of the Rheumatic Diseases ; 82(Suppl 1):1897-1898, 2023.
Article in English | ProQuest Central | ID: covidwho-20242556

ABSTRACT

BackgroundAcetaminophen (APAP = paracetamol) may potentially impact vaccine-associated immune responses as the intake of APAP has been associated with a worse outcome in tumor patients receiving checkpoint inhibitors.[1]Different DMARD regimen have been shown to impair the humoral immune response to mRNA SARS-CoV-2 vaccines in patients with rheumatoid arthritis but the effect of paracetamol has not been explored thus far.ObjectivesTo analyse whether the intake of APAP may interfere with antiviral humoral immune responses following two doses of an anti-SARS-CoV-2 mRNA based vaccine in patients with rheumatoid arthritis (RA) on DMARD therapy.MethodsThe RECOVER trial (Rheumatoid Covid-19 Vaccine Immune Response) was a non-randomised, prospective observational control group trial and enrolled 77 RA patients on DMARD therapy and 21 healthy controls (HC). We performed a posthoc analysis of blood samples taken before the first vaccine dose (T0), two (T1) and three (T2) weeks after the first and second vaccine dose, and at 12 (T3) weeks. APAP intake was measured using ELISA. The antibody response (anti-S) to the receptor binding domain (RBD) within the SARS-CoV-2 S1 protein was measured with the Elecsys Anti-SARS-CoV-2-S (Roche Diagnostics GmbH) test. The neutralizing activity NT50 at week 12 was assessed using an HIV-based pseudovirus neutralization assay against Wuhan-Hu-1.ResultsBaseline characteristics of participants are detailed in Table 1. The immunogenicity analyses were based on 73 RA patients after exclusion of 4 patients with previously unnoticed SARS-CoV-2 infection (positive for anti-nucleoprotein at baseline). APAP was detected in serum samples from 34/73 (25%) RA patients and in 7/21 (33%) HC (least at one timepoint T0, T1 and/or T2). APAP intake in HC did not affect levels of anti-S at any timepoint and all HC developed potent neutralizing activity (NT50 ≥ 250) at week 12. RA patients, who tested positive for APAP at T1, showed comparable anti-S levels at T1, T2 and T3 compared to RA patients not exposed to APAP. The detection of APAP at T2 corresponded to lower anti-S levels at T2 (Figure 1 A, B). The detection of APAP at T2 was associated with a significantly lower SARS-CoV-2 neutralizing activity at week 12 compared to patients without perivaccination APAP exposure (p =0.04) (Figure 1 C).ConclusionA decrease of antiviral humoral immune responses was observed in RA patients (but not in HC) who were exposed to APAP at the time of the second mRNA vaccine dose compared to patients in whom APAP was not detected. Our data suggest that the use of paracetamol within the time period around vaccination may impair vaccine-induced immune responses in patients with an already higher risk for blunted immune responses.Reference[1]Bessede A et al. Ann Oncol 2022;33: 909-915Table 1.Baseline characteristics: RA patients and HC with/without APAP exposureRA APAP – n = 37RA APAP + n = 36p-valueHC APAP – n = 8HC APAP + n = 13p-valueAge (yrs), mean (± SD)62 (13)67 (10)0.07 (NS)45 (12)44 (14)0.90 (NS)Female sex, n (%)24 (65)19 (53)0.29 (NS)2 (25)5 (38)0.53 (NS)Vaccination type/schedulemRNA-1273, n (%)4 (11)8 (22.2)0.19 (NS)0 (0)0 (0)BNT162b2, n (%)33 (89)28 (77.8)0.19 (NS)8 (100)13 (100)RA disease characteristicsACPA ± RF, n (%)17/37 (46)19/36 (53)0.56 (NS)NANANARA disease duration (yrs ± SD)9.2 (9.8)10.2 (8.1)0.67 (NS)NANANADMARD therapycsDMARD-mono, n (%)13/37 (35)9/36 (25)0.35 (NS)NANANAbDMARD-mono/combo, n (%)16/37 (43)16/36 (44)0.92 (NS)NANANAtsDMARDs-mono/combo, n (%)8/37 (22)11/36 (31)0.38 (NS)NANANAPrednisone, n (%)15/37 (41)12/36 (33.3)0.52 (NS)NANANAMean daily dose prednisone (mg ± SD)4.6 ± 1.13.9 ± 2.30.39 (NS)NANANA* APAP = acetaminophenFigure 1.Acknowledgements:NIL.Disclosure of InterestsNone Declared.

6.
Cancer Research Conference: American Association for Cancer Research Annual Meeting, ACCR ; 83(8 Supplement), 2023.
Article in English | EMBASE | ID: covidwho-20242368

ABSTRACT

The TG6002.03 trial is a dose-escalation phase 1 clinical trial of TG6002 infusion via the hepatic artery in patients with liver-dominant colorectal cancer metastases. TG6002 is an engineered Copenhagen strain oncolytic Vaccinia virus, deleted of thymidine kinase and ribonucleotide reductase to enhance tumor selective viral replication and expressing FCU1, an enzyme converting the non-cytotoxic prodrug 5-fluorocytosine (5-FC) into the chemotherapeutic compound 5-fluorouracil (5-FU). In this trial, patients with advanced unresectable liver-dominant metastatic colorectal cancer who had failed previous oxaliplatin and irinotecan-based chemotherapy were treated with up to 2 cycles of TG6002 infusion 6 weeks apart via the hepatic artery on day 1 combined with oral 5-FC on days 5 to 14 (where day 1 = TG6002 infusion). TG6002 infusion was performed over 30 minutes via selective catheterization of the hepatic artery proper. 5-FC oral dosing was 50mg/kg x4 daily. Blood was sampled for TG6002 pharmacokinetics and 5-FC and 5-FU measurements. Sampling of liver metastases was performed at screening and on day 4 or day 8 for virus detection and 5-FC and 5-FU quantification. In total, 15 patients (median age 61 years, range 37-78) were treated in 1 UK centre and 2 centres in France and received a dose of TG6002 of 1 x 106 (n=3), 1 x 107 (n=3), 1 x 108 (n=3), or 1 x 109 pfu (n=6). Fourteen of the 15 patients received a single cycle of treatment, including one patient who did not received 5-FC, and one patient received two cycles. TG6002 was transiently detected in plasma following administration, suggesting a strong tissue selectivity for viral replication. In the highest dose cohort, a virus rebound was observed on day 8, concordant with replication time of the virus. In serum samples, 5-FU was present on day 8 in all patients with a high variability ranging from 0.8 to 1072 ng/mL and was measurable over several days after initiation of therapy. Seven of the 9 patients evaluable showed the biodistribution of the virus in liver lesions by PCR testing on day 4 or day 8. Translational blood samples showed evidence for T-cell activation and immune checkpoint receptor-ligand expression. At 1 x 109 pfu, there was evidence for T-cell proliferation and activation against tumour-associated antigens by ELISpot and for immunogenic cell death. In terms of safety, a total of 34 TG6002-related adverse events were reported, of which 32 were grade 1-2 and 2 were grade 3. The maximum tolerated dose was not reached, and a single dose-limiting toxicity was observed consisting of a myocardial infarction in a context of recent Covid-19 infection in a 78-year-old patient. These results indicate that TG6002 infused via the hepatic artery in combination with oral 5-FC was well tolerated, effectively localized and replicated in the tumor tissues, expressed its therapeutic payload and showed anti-tumoral immunological activity.

7.
Clinical Immunology ; Conference: 2023 Clinical Immunology Society Annual Meeting: Immune Deficiency and Dysregulation North American Conference. St. Louis United States. 250(Supplement) (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-20242119

ABSTRACT

Background: Patients with primary and secondary immunodeficiencies have shown an impaired humoral immune response to COVID-19 vaccination. It is therefore of paramount importance to investigate anti-SARS-CoV-2 antibody levels in plasma pools and in immunoglobulin (IgG) products used to treat these patients. AIM: To assess the evolution of anti-SARS-CoV-2 antibodies (S protein) in plasma pools and IgG products and its neutralizing activity to original-type virus (Wuhan) and the variants of concern (VOC), including Omicron. Method(s): Healthy donors plasma pools collected in the US and Europe, and the subsequent intravenous (Flebogamma DIFand Gamunex-C, Grifols) and subcutaneous (Xembify, Grifols) IgG manufactured batches were followed from March 2020. Anti-SARS-CoV-2 S protein IgG titers were determined in plasma pools and in IgG batches by ELISA. Neutralization assays analyzed the capacity of IgG products to neutralize original-type virus and VOC (Alpha, Beta, Delta, Omicron BA.1 and BA.5), using pseudo viruses expressing S protein. Results were expressed as the dilution producing 50% neutralization (ID50). Result(s): In plasma pools, anti-SARS-CoV-2 S antibodies continuously increased throughout the study period regardless of the geographic origin. In the US, the first positive plasma pools were collected at the end of 2020. Since July 2021, an exponential increase over 30-fold of anti-SARS-CoV-2 S antibodies was reported. This trend continued increasing until the end of study period. Similarly, IgG products showed a similar evolution of anti-SARS-CoV-2 S antibodies. As expected, IgG batches released at the end of 2020 presented low SARS-CoV-2 neutralization activity. However, IgG products manufactured since August 2021 showed high neutralization activity against original-type virus and the rest of VOC. Regarding Omicron BA.5, a 5 to 10-fold increase was observed over time. Conclusion(s): This study reported the onset of elevated anti-SARS-CoV-2 antibody titers in plasma pools and IgG products since mid-2021, reflecting the evolution of the pandemic and vaccine campaigns. Intravenous and subcutaneous IgG products efficiently neutralized the current circulating VOC, Omicron BA.5. Further research is warranted to assess whether a clinical protective titer against SARS-CoV-2 and passive immunization is achieved in patients with immunodeficiencies treated with IgG products.Copyright © 2023 Elsevier Inc.

8.
Annals of the Rheumatic Diseases ; 82(Suppl 1):1622-1623, 2023.
Article in English | ProQuest Central | ID: covidwho-20241909

ABSTRACT

BackgroundAnti-synthetase syndrome (ASS) is a rare auto-immune condition that combines autoantibodies and specifics clinical manifestations, including myositis, interstitial lung disease (ILD), polyarthritis, mechanic's hands, Raynaud's phenomenon, and unexplained fever. The hallmark of this syndrome is the presence of anti-aminoacyl-tRNA-synthetase (ARS) antibodies. Several anti-ARS antibodies have been described, anti-Jo1 being the most common, followed by anti-PL7, anti-PL12, anti-OJ, anti-EJ, anti-KS, anti-YRS, and anti-Zo. According to a recent epidemiological survey, the rising number of patients with autoimmune diseases, including idiopathic inflammatory myopathies (IIM) coincides with the COVID-19 pandemic.ObjectivesTo evaluate the clinical characteristics of ASS patients with different anti-ARS antibodies from a tertiary rheumatology center.MethodsWe conducted a retrospective, single-centered study on consecutive patients diagnosed with ASS from 1 January 2015 to 31 December 2022. Clinical and serologic data were obtained by medical records review from hospital database. Myositis-specific antibodies (MSA) and myositis-associated antibodies (MAA) were tested using commercial ELISA kits. We included all patients fulfilling Connor's criteria for ASS.ResultsSixty-one patients (44 females) with mean age 54.4 (13.8) years were included. The most frequently reported clinical manifestation was arthralgia (68.8%), followed by Raynaud's phenomenon (67.2%), ILD (65.6%), myositis (46%), mechanic's hands (44.3%), arthritis (39.3%), and fever (18.0%). The typical triad for ASS, including myositis, arthritis and ILD was present in 17 patients. Twenty-eight (45.9%) patients were PL7+, 21 (34.4%) were Jo1+, 3 (4.9%) were PL12+, and 2 (3.2%) were OJ+. Seven patients were positive for more than two anti-ARS antibodies. The most frequently found MAA was anti-Ro52 (n=23, 37.7%). Of the 61 patients included, 41 (67.2%) patients were diagnosed in the last 3 years (COVID-19 pandemic). The most frequently detected MSA in ASS patients diagnosed during COVID-19 pandemic was anti-PL7 (25/28), while anti-Jo1 was the most common MSA in ASS patients diagnosed before 2020 (p<0.05) (Fig 1).The anti-Jo1+ patients were younger, have significantly more frequent muscle involvement and significantly higher levels of CK than anti-PL7+ patients (p<0.05). The co-occurance of anti-Ro52 antibodies was more frequently observed in anti-Jo1+ patients (n=11, 52.4%) than in anti-PL7+ patients (n=6, 21.4%) (p<0.05). We did not find statistically significant differences between ASS groups regarding sex, disease duration, clinical manifestations including dermatologic lesions, Raynaud's phenomenon, arthralgia/arthritis, ILD, fever, and cancers (all p>0.05).ConclusionASS patients have heterogenous manifestations, and different types of anti-ARS antibodies are associated to distinct clinical and immunological features. The COVID-19 pandemic led to increase prevalence of ASS cases and to a remarkable shift in the anti-ARS antibodies profile, with increased frequency of anti-PL7 antibodies. Further studies are needed to investigate the link between SARS-CoV-2 infections and myositis.References[1]Witt LJ, et al. The Diagnosis and Treatment of Antisynthetase Syndrome. Clin Pulm Med. 2016 Sep;23(5):218-226.[2]Gracia-Ramos AE, et al. New Onset of Autoimmune Diseases Following COVID-19 Diagnosis. Cells. 2021 Dec 20;10(12):3592.[3]Connors GR, et al. Interstitial lung disease associated with the idiopathic inflammatory myopathies: what progress has been made in the past 35 years? Chest. 2010 Dec;138(6):1464-74.[4]García-Bravo Let al. Association of anti-SARS-COV-2 vaccine with increased incidence of myositis-related anti-RNA-synthetases auto-antibodies. J Transl Autoimmun. 2022 Jun 30;5:100160.Figure 1.ASS patients with positive anti-ARS antibodies per year (from 2015 to 2022). The green line shows the PL7+ patients;and the orange line shows the Jo1+ cases.[Figure omitted. See PDF]AcknowledgementsI have no acknowledgements to declare.Disclosure of Inter stsNone Declared.

9.
Nieren- und Hochdruckkrankheiten ; 52(4):134-135, 2023.
Article in English | EMBASE | ID: covidwho-20241899

ABSTRACT

Objective: COVID-19 has emerged as a significant global health crisis causing devastating effects on world population accounting for over 6 million deaths worldwide. Although acute RTI is the prevalent cause of morbidity, kidney outcomes centered on a spectrum of AKI have evolved over the course of the pandemic. Especially the emerging variants have posed a daunting challenge to the scientific communities, prompting an urging requirement for global contributions in understanding the viral dynamics. In addition to canonical genes, several subgroup- specific accessory genes are located between the S and E genes of coronaviruses regarding which little is known. Previous studies have shown that accessory proteins (aps) in viruses function as viroporins that regulate viral infection, propagation and egress [1]. In this study we attempted to characterize the function of aps of coronavirus variants as ion channels. Furthermore, we also probed the interaction of ap4 with the host system. Method(s): Serial passaging (selection pressure), growth kinetics, confocal imaging, genome sequence analysis and proteomics were performed in Huh-7, MRC5 cells and/or human monocyte derived macrophages. Potassium uptake assay was performed in a Saccharo myces cerevisiae strain, which lacks the potassium transporters trk1 and trk2. Ion conductivity experiments were performed in Xenopus laevis oocytes using Two Electrode Voltage Clamp (TEVC) method. Result(s): Serial passaging demonstrated the acquisition of several frameshift mutations in ORF4 resulting in C-terminally truncated protein versions (ap4 and ap4a) and indicate a strong selection pressure against retaining a complete ORF4 in vitro. Growth kinetics in primary cells illustrated a reduction of viral titers when the full-length ap4 was expressed compared to the C-terminally truncated protein ap4a. Confocal imaging showed that ap4 and ap4a are not exclusively located in a single cellular compartment. Potassium uptake assay in yeast and TEVC analyses in Xenopus oocytes showed that ap4 and ap4a act as a weak K+ selective ion channel. In addition, accessory proteins of other virus variants also elicited microampere range of currents. Conclusion(s): Our study provides the first evidence that ap4 and other accessory proteins of coronavirus variants act as viroporins. Future studies are aimed at demonstrating the role of ap4 during the viral life cycle by modulating ion homeostasis of host cell in vivo (interacting proteins obtained from proteomic studies) and thereby serve as a tool for potential drug target.

10.
Infektsionnye Bolezni ; 21(1):5-9, 2023.
Article in Russian | EMBASE | ID: covidwho-20241373

ABSTRACT

Objective. To assess the T-cell immune status against SARS-CoV-2 in HIV patients with or without antiretroviral therapy. Patients and methods. The study included 21 HIV patients who had laboratory-confirmed COVID-19 between September and December 2021 without previous immunization against SARS-CoV-2. The characteristics of HIV infection (CD4-lymphocytes count, HIV viral load in blood plasma, the presence of antiretroviral therapy) and COVID-19 (the severity degree and duration of the disease) were analyzed, the T-cell immune response to SARS-CoV-2 was assessed using the ELISPOT method 1 month after COVID-19. Statistical analysis was carried out by non-parametric methods (Mann-Whitney U test, Spearman's rank correlation coefficient) using the IBM SPSS Statistics 22 software package. Results. The study showed a more favorable course of COVID-19 in HIV-infected persons who achieved HIV suppression in the blood: a mild form of the disease was significantly more common, and the virus was eliminated faster. T-cell immune response to SARS-CoV-2 was recorded more frequently in these patients. Significant correlation of T-cell immune status with the CD4-lymphocytes count and HIV suppression in the blood was revealed. Conclusion. Thus, T-cell immune response to SARS-CoV-2 as assessed using the ELISPOT method was registered significantl.Copyright © 2023, Dynasty Publishing House. All rights reserved.

11.
Annals of the Rheumatic Diseases ; 82(Suppl 1):547, 2023.
Article in English | ProQuest Central | ID: covidwho-20240086

ABSTRACT

BackgroundA 3rd COVID-19 vaccination is currently recommended for patients under immunosuppression. However, a fast decline of antibodies against the SARS-CoV-2 receptor-binding domain (RBD) of the spike protein has been observed.ObjectivesIt remains unclear whether immunosuppressive therapy affects kinetics of humoral and cellular immune responses.Methods50 patients under immunosuppression and 42 healthy controls (HCs) received a 3rd dose of an mRNA-based vaccine and were monitored over a 12-weeks period. Humoral immune response was assessed 4 and 12 weeks after 3rd dose. Antibodies were quantified using the Elecsys Anti-SARS-CoV-2 Spike immunoassay against the receptor-binding domain (RBD) of the spike protein. SARS-CoV-2-specific T cell responses were quantified by IFN-γ ELISpot assays. Adverse events, including SARS-CoV-2 infections, were monitored over a 12-week period.ResultsAt week 12, reduced anti-RBD antibody levels were observed in IMID patients as compared to HCs (median antibody level 5345 BAU/ml [1781 – 10208] versus 9650 BAU/ml [6633 - 16050], p < 0.001). Reduction in relative antibody levels was significantly higher in IMID patients as compared to HCs at week 12 (p < 0.001). Lowest anti-RBD antibody levels were detected in IMID patients who received biological diseases modifying anti-rheumatic drugs (DMARDs) or a combination therapy with conventional synthetic and biological DMARDs. Number of SARS-CoV-2-specific T cells against wildtype and Omicron variants remained stable over 12 weeks in IMID patients. No serious adverse events were reported.ConclusionDue to a fast decline in anti-RBD antibodies in IMID patients an early 4th vaccination should be considered in this vulnerable group of patients.REFERENCES:NIL.Acknowledgements:NIL.Disclosure of InterestsDaniel Mrak Consultant of: AstraZeneca, Felix Kartnig: None declared, Daniela Sieghart: None declared, Elisabeth Simader Speakers bureau: Lilly, Helga Radner Speakers bureau: Gilead, Merck Sharp and Pfizer, Peter Mandl: None declared, Lisa Göschl: None declared, Philipp Hofer: None declared, Thomas Deimel: None declared, Irina Gessl: None declared, Renate Kain Speakers bureau: Otsuka, Consultant of: AstraZeneca, Takeda Pharma, MEDahead and Janssen Cilag, Stefan Winkler: None declared, Josef S. Smolen Consultant of: AbbVie, Amgen, AstraZeneca, Astro, Bristol-Myers Squibb, Celltrion, Gilead-Galapagos, Janssen, Lilly, Pfizer, R-Pharma, Samsung, Sanofi, Chugai, Merck Sharp & Dohme, Novartis-Sandoz Roche, Samsung and UCB, Grant/research support from: Abbvie, AstraZeneca, Lilly, Novartis, and Roche, Thomas Perkmann: None declared, Helmuth Haslacher Grant/research support from: Glock Health, BlueSky Immunotherapies and Neutrolis, Daniel Aletaha Speakers bureau: Abbvie, Amgen, Galapagos, Lilly, Janssen, Merck, Novartis, Pfizer, Sandoz, and Sanofi, Consultant of: Abbvie, Amgen, Galapagos, Lilly, Janssen, Merck, Novartis, Pfizer, Sandoz, and Sanofi, Grant/research support from: Abbvie, Amgen, Galapagos, Lilly, Janssen, Merck, Novartis, Pfizer, Sandoz, and Sanofi, Leonhard Heinz: None declared, Michael Bonelli Consultant of: EliLilly.

12.
Archives of Clinical Infectious Diseases ; 18(1) (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-20239807

ABSTRACT

Background: Many aspects of the severe acute respiratory syndrome coronavirus 2 (SARSCoV2) pandemic in 2019 have been unclear, especially in newborns, and reports of neonatal diseases are usually associated with perinatal infection. Objective(s): The purpose of this study was to evaluate clinical and para-clinical manifestations in newborns that contracted the infection after birth. Method(s): This observational research was conducted from October 2020 to March 2022 to examine postnatal SARSCoV2 infection in infants admitted to the NICU or neonatal ward at the Children's Medical Center in Tehran, Iran. Inclusion in the study was open to neonates who had positive RT-PCR results postnatally. Result(s): In total, 55 newborns were confirmed to have postnatal SARSCOV2. Fever was the most frequently observed symptom, with 35 (61%). Necrotizing enterocolitis was seen in 18% of neonates, and 30% of them were preterm. Neutropenia was seen in 34% of cases, with five cases having severe neutropenia. All neonates had a normal platelet count. Twenty percent of patients showed C-reactive protein higher than 6 mg/L. Two newborns had co-existing bacterial urinary tract infections. Our neonates didn't require antiviral, anticoagulant, or corticosteroid medications, and they recovered while receiving only supportive care. Everyone in the group of newborns was discharged without complications, and there were no deaths. Conclusion(s): The high rate of fever, high C-reactive protein, and neutropenia in SARSCoV2 neonates suggests that more observational research is needed to compare these symptoms to bacterial sepsis to avoid the overuse of antibiotics in these patients.Copyright © 2023, Author(s).

13.
Cytotherapy ; 25(6 Supplement):S72, 2023.
Article in English | EMBASE | ID: covidwho-20239522

ABSTRACT

Background & Aim: The pro-angiogenic, immunoregulatory and anti- inflammatory properties of MSCs are being exploited for the development of cellular therapies, including the treatment of graft versus host disease (GvHD), inflammatory bowel disease and COVID-19. SNBTS have developed a GMP process to bank umbilical cord MSCs (UC-MSCs) whereby we can reliably bank 100 vials of 10 million P2 UC-MSCs per cord. Each of these vials can be extensively expanded and stored for specific applications. The ultimate aim of the bank is for off-the-shelf clinical use, e.g., in GvHD or as an adjuvant therapy in Islet transplantations. Methods, Results & Conclusion(s): During process development, different basal media and supplements were screened for proliferation and MSC marker expression. Cells grown in promising media combinations were then tested for tri-lineage differentiation (identity), their chemokine/cytokine expression and T-cell inhibition (function) assessed. Medium selected for further GMP development and scale up was ultimately determined by all round performance and regulatory compliance. GMP-like UC-MSCs were shown to have immune-modulatory activity in T-cell proliferation assays at 4:1 or 16:1 ratios. Co-culture of UC-MSCs and freshly isolated leukocytes, +/- the immune activating agent LPS, show a dose dependent survival effect on leukocytes. In particular, neutrophils, which are normally very short lived in vitro demonstrated increased viability when co-cultured with UCMSCs. The survival effect was partially reproduced when UC-MSC were replaced with conditioned medium or cell lysate indicating the involvement of soluble factors. This improved neutrophil survival also correlates with results from leukocyte migration studies that demonstrate neutrophils to be the main cell type attracted to MSCs in in vitro and in vivo. Genetic modification of UC-MSC may improve their therapeutic potential. We have tested gene editing by CRISPR/Cas9 technology in primary UC-MSCS. The CXCL8 gene, highly expressed in UC-MSC, was targeted in isolates from several different donors with editing efficiencies of 78-96% observed. This translated to significant knockdown of CXCL8 protein levels in resting cells, however after stimulation levels of CXCL8 were found to be very similar in edited and non-edited UC-MSCs. This observation requires further study, but overall the results show the potential to generate future banks of primary UC-MSCS with genetically enhanced pro-angiogenic, immunoregulatory and/or anti-inflammatory activities.Copyright © 2023 International Society for Cell & Gene Therapy

14.
Cancer Research Conference: American Association for Cancer Research Annual Meeting, ACCR ; 83(7 Supplement), 2023.
Article in English | EMBASE | ID: covidwho-20238091

ABSTRACT

Introduction Patients with hematological malignancies, including multiple myeloma (MM), experience suboptimal responses to SARS-CoV-2 vaccination. Monoclonal Gammopathy of Undetermined Significance (MGUS) and Smoldering Multiple Myeloma (SMM) are precursors to MM and exhibit altered immune cell composition and function. The SARS-CoV-2 pandemic and the subsequent population-wide vaccination represent an opportunity to study the real-life immune response to a common antigen. Here, we present updated results from the IMPACT study, a study we launched in November 2020 to characterize the effect of plasma cell premalignancy on response to SARS-CoV2 vaccination (vx). Methods We performed: (i) ELISA for SARS-CoV-2-specific antibodies on 1,887 peripheral blood (PB) samples (237 healthy donors (HD), and 550 MGUS, 947 SMM, and 153 MM patients) drawn preand post-vx;(ii) single-cell RNA, T cell receptor (TCR), and B cell receptor (BCR) sequencing (10x Genomics) on 224 PB samples (26 HD, and 20 MGUS, 48 SMM, and 24 MM patients) drawn preand post-vx;(iii) plasma cytokine profiling (Olink) on 106 PB samples (32 HD, and 38 MGUS and 36 SMM patients) drawn pre- and post-vx;and (iv) bulk TCR sequencing (Adaptive Biotechnologies) on 8 PB samples from 4 patients (2 MGUS, 2 SMM) drawn pre- and post-vx. Results Patients with MGUS and SMM achieved comparable antibody titers to HD two months post-vx. However, patient titers waned significantly faster, and 4 months post-vx we observed significantly lower titers in both MGUS (Wilcoxon rank-sum, p=0.030) and SMM (p=0.010). These results indicate impaired humoral immune response in patients with MGUS and SMM.At baseline, the TCR repertoire was significantly less diverse in patients with SMM compared to HD (Wilcoxon rank-sum, p=0.039), while no significant difference was observed in the BCR repertoire (p=0.095). Interestingly, a significant increase in TCR repertoire diversity was observed post-vx in patients with SMM (paired t-test, p=0.014), indicating rare T cell clone recruitment in response to vaccination. In both HD and patients, recruited clones showed upregulation of genes associated with CD4+ naive and memory T cells, suggesting preservation of the T cell response in SMM, which was confirmed by bulk TCR-sequencing in 4 patients.Lastly, by cytokine profiling, we observed a defect in IL-1beta and IL-18 induction post-vx in patients with SMM compared to HD (Wilcoxon rank-sum, p=0.047 and p=0.015, respectively), two key monocyte-derived mediators of acute inflammation, suggesting an altered innate immune response as well. Conclusion Taken together, our findings highlight that despite the absence of clinical manifestations, plasma cell premalignancy is associated with defects in both innate and adaptive immune responses. Therefore, patients with plasma cell premalignancy may require adjusted vaccination strategies for optimal immunization.

15.
Cytotherapy ; 25(6 Supplement):S232-S233, 2023.
Article in English | EMBASE | ID: covidwho-20237943

ABSTRACT

Background & Aim: Immunological characteristics of COVID-19 show pathological hyperinflammation associated with lymphopenia and dysfunctional T cell responses. These features provide a rationale for restoring functional T cell immunity in COVID-19 patients by adoptive transfer of SARS-CoV-2 specific T cells. Methods, Results & Conclusion(s): To generate SARS-CoV-2 specific T cells, we isolated peripheral blood mononuclear cells from 7 COVID-19 recovered and 13 unexposed donors. Consequently, we stimulated cells with SARS-CoV-2 peptide mixtures covering spike, membrane and nucleocapsid proteins. Then, we culture expanded cells with IL-2 for 21 days. We assessed immunophenotypes, cytokine profiles, antigen specificity of the final cell products. Our results show that SARSCoV- 2 specific T cells could be expanded in both COVID-19 recovered and unexposed groups. Immunophenotypes were similar in both groups showing CD4+ T cell dominance, but CD8+ and CD3+CD56+ T cells were also present. Antigen specificity was determined by ELISPOT, intracellular cytokine assay, and cytotoxicity assays. One out of 14 individuals who were previously unexposed to SARS-CoV-2 failed to show antigen specificity. Moreover, ex-vivo expanded SARS-CoV-2 specific T cells mainly consisted of central and effector memory subsets with reduced alloreactivity against HLA-unmatched cells suggesting the possibility for the development of third-party partial HLA-matching products. In conclusion, our findings show that SARSCoV- 2 specific T cell can be readily expanded from both COVID-19 and unexposed individuals and can therefore be manufactured as a biopharmaceutical product to treat severe COVID-19 patients.Copyright © 2023 International Society for Cell & Gene Therapy

16.
Clinical Immunology ; Conference: 2023 Clinical Immunology Society Annual Meeting: Immune Deficiency and Dysregulation North American Conference. St. Louis United States. 250(Supplement) (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-20236174

ABSTRACT

Introduction: With the onset of the COVID-19 pandemic, there was increased attention on anti- IFN-alpha autoantibodies and its correlation with severe clinical outcomes in a large group of patients. However, this correlation has not been extensively investigated in patients with partial Recombinase Activating Gene Deficiency (pRD) who are known to have increased prevalence of anti- IFN-alpha autoantibodies. Therefore, there is a need to assess the presence of anti- IFN-alpha antibodies in pRD patients before and after the COVID-19 pandemic and explore the relationship between anti- IFN-alpha antibody presence and clinical outcomes. Method(s): Sera was collected from the whole blood after informed consent and Enzyme-Linked Immunosorbent Assay was conducted to confirm the presence of IgG-specific anti- IFN-alpha autoantibodies. Positive samples were determined as OD values above 3 standard deviations of the healthy donor OD mean. Result(s): Our cohort included both adult (n = 13) and pediatric (n = 9) patients with variants in RAG1 and RAG2. Eleven patients (50%) out of the 22 showed elevated anti- IFN-alpha autoantibodies levels. Five patients (23%) were defined as low positive for anti- IFN-alpha autoantibodies, and 6 patients had no autoantibody titers. Of the 22 patients, 16 were symptomatic with infectious and non-infectious complications including recurrent viral and/or bacterial infections, autoimmune cytopenias, and lymphoproliferation. Ten (63%) of the symptomatic patients demonstrated high anti-IFN-alpha autoantibodies titers. Of the 11 patients with no or low neutralizing anti- IFN-alpha autoantibodies levels, 5 were asymptomatic. In temporal comparison, 16 samples were collected pre-COVID-19 pandemic;8 samples were collected during the pandemic, 2 of which belonged to patients with samples collected before and during the pandemic. In the pre-pandemic cohort, 66% had anti- IFN-alpha autoantibodies. Conversely, during the COVID-19 pandemic, 89% had anti- IFN-alpha autoantibodies. Of note, one patient who had neutralizing anti- IFN-alpha autoantibodies remained positive both before and during the pandemic despite HSCT. Patient also had a SARS-CoV-2 infection in summer of 2022 with a mild clinical course. Conclusions & Next Steps: We observed persistence of anti-IFN-alpha autoantibodies in our cohort post-pandemic and even post-HSCT. It is unclear whether the presence of anti-cytokine antibodies are risk factor for severe COVID-19.Copyright © 2023 Elsevier Inc.

17.
Cancer Research Conference: American Association for Cancer Research Annual Meeting, ACCR ; 83(7 Supplement), 2023.
Article in English | EMBASE | ID: covidwho-20235541

ABSTRACT

Background: Neutrophil extracellular traps (NETs) are composed of processed chromatin bound to granular and selected cytoplasmic proteins and released by neutrophils. NETs consist of smooth filaments composed of stacked nucleosomes. Fully hydrated NETs have a cloud-like appearance and occupy a space 10-15-fold larger than the volume of the cells they originate from. DNases are the enzymes that cleave extracellular DNA including NETs. Together with their protective role in microbial infections, NETs are involved in multiple pathological processes and represent key events in a variety of pathologies including cancer, autoimmunity, and cardiovascular disease. Sites of NETs concentration are dangerous for the host if the process of NETs formation becomes chronic or the mechanism of NETs removal does not work. NETosis has been linked to the development of periodontitis, cystic fibrosis, type 2 diabetes, COVID-19 or rheumatoid arthritis as well as cancer progression. Purpose(s): Thus, the destruction of NETs is of primary significance in many pathologies. In our approach, we are focusing on mimicking one of the natural mechanisms of destroying excessive NETs by delivering deoxyribonuclease I to the specific site of pathological NETs accumulation by modifying the nanoparticles using an anti-nucleosome monoclonal antibody (2C5). The antibody is specific to nucleosomes and can recognize histones in NETs. DNase I is U.S. Food and Drug Administration (FDA)-approved active component and is commonly used in therapeutic methods of modern medicine for cystic fibrosis to clear extracellular DNA fibers in the lungs and systemic lupus erythematosus. Recent findings have also shown the effectiveness of DNase I in the digestion of NETs. However, the low serum stability and fast deactivation by environmental stimuli have been considered as the limiting factors for clinical applications of DNase I, which can be overcome by its targeted specific delivery in pharmaceutical nanocarriers. Method(s): In this study, we generate NETs in vitro using human neutrophils and HL-60 cells differentiated into granulocyte-like cells. We used interleukin-8, lipopolysaccharide from E.Coli (LPS), phorbol myristate acetate (PMA), and calcium ionophore A23187 (CI) to generate the NETs. We confirmed the specificity of 2C5 toward NETs by ELISA, which showed that it binds to NETs with the specificity like that for purified nucleohistone substrate. We further utilized that feature to create two delivery systems (liposomes and micelles) for DNAse I enzyme to destroy NETs, which was confirmed by staining NETs with SYTOX Green dye and followed by flow cytometric measurements and microscopic images. Conclusion(s): Our results suggest that 2C5 could be used to identify and visualize NETs and serve as a ligand for NET-targeted diagnostics and therapies. Also, we proved that our carrier can successfully deliver DNase to NETs to provide their degradation.

18.
Iranian Journal of Pharmaceutical Sciences ; 18(2):116-127, 2022.
Article in English | EMBASE | ID: covidwho-20235375

ABSTRACT

The prevalence of psychiatric disorders namely depression, anxiety, and sleep disturbances has been increased worldwide, particularly during the COVID-19 pandemic. In this regard, the interest of recent investigations is moved toward phytomedicines and bioactive substances derived from natural sources. Although Tilia platyphyllos Scop. contains high amounts of phenolic compounds such as quercetin, kaempferol, and catechin, there is no study on the possible effects of its extract on psychological disorders. The present study was carried out to determine the antidepressant-like, anxiolytic, and sedative-hypnotic effects of the hydroethanolic extract of T. platyphyllos leaves using forced swimming test (FST), tail suspension test (TST), elevated plus maze test (EPMT), pentobarbital-induced loss of righting reflex test and open field test (OFT). Following the ethanolic extraction of T. platyphyllos leaves, the extraction yield was 14% and the total phenolic and total flavonoid contents were found to be 135.23 +/- 0.14 mg gallic acid equivalent/g dry extract and 19.02 +/- 0.03 mg rutin equivalent/g dry extract, respectively. Both FTS and TST revealed a significant antidepressant-like activity for the tested extract at 400 mg/kg compared to the control group. In addition, the anxiolytic activity of the extract was proven through OFT and EPMT in the same dose. Finally, T. platyphyllos extract at 200 mg/kg and 400 mg/kg significantly increased the sleeping time when compared to the control group reflecting its potential hypnotic activity. Co-administration of T. platyphyllos extract at 400 mg/kg and flumazenil as the GABA-A receptor antagonist decreased the sleeping time but the observed effect was not statistically significant. Therefore, we cannot completely rule out the GABA-A receptor's involvement in the hypnotic activity of the extract. The biological results presented here led us to conclude that T. platyphyllos extract can be a prominent source of antidepressant, anxiolytic and hypnotic agents. Probably, the main phenolic compounds of T. platyphyllos such as quercetin, kaempferol, and catechin are involved in the observed effects. However, there is still a great need for additional investigations on the exact mechanisms.Copyright © 2022, Iranian Association of Pharmaceutical Scientists. All rights reserved.

19.
BIOpreparations ; Prevention, Diagnosis, Treatment. 23(1):76-89, 2023.
Article in Russian | EMBASE | ID: covidwho-20234832

ABSTRACT

Monitoring of the proportion of immune individuals and the effectiveness of vaccination in a population involves evaluation of several important parameters, including the level of virus-neutralising antibodies. In order to combat the COVID-19 pandemic, it is essential to develop approaches to detecting SARS-CoV-2 neutralising antibodies by safe, simple and rapid methods that do not require live viruses. To develop a test system for enzyme-linked immunosorbent assay (ELISA) that detects potential neutralising antibodies, it is necessary to obtain a highly purified recombinant receptor-binding domain (RBD) of the spike (S) protein with high avidity for specific antibodies. The aim of the study was to obtain and characterise a SARSCoV-2 S-protein RBD homodimer and a recombinant RBD-expressing cell line, as well as to create an ELISA system for detecting potential neutralising antibodies. Material(s) and Method(s): the genetic construct was designed in silico. To generate a stable producer cell line, the authors transfected CHO-S cells, subjected them to antibiotic pressure, and selected the optimal clone. To isolate monomeric and homodimeric RBD forms, the authors purified the recombinant RBD by chromatographic methods. Further, they analysed the activity of the RBD forms by Western blotting, bio-layer interferometry, and indirect ELISA. The analysis involved monoclonal antibodies GamXRH19, GamP2C5, and h6g3, as well as serum samples from volunteers vaccinated with Gam-COVID-Vac (Sputnik V) and unvaccinated ones. Result(s): the authors produced the CHO-S cell line for stable expression of the recombinant SARS-CoV-2 S-protein RBD. The study demonstrated the recombinant RBD's ability to homodimerise after fed-batch cultivation of the cell line for more than 7 days due to the presence of unpaired cysteines. The purified recombinant RBD yield from culture broth was 30-50 mg/L. Monomeric and homodimeric RBD forms were separated using gel-filtration chromatography and characterised by their ability to interact with specific monoclonal antibodies, as well as with serum samples from vaccinated volunteers. The homodimeric recombinant RBD showed increased avidity for both monoclonal and immune sera antibodies. Conclusion(s): the homodimeric recombinant RBD may be more preferable for the analysis of levels of antibodies to the receptor-binding domain of the SARS-CoV-2 S protein.Copyright © 2023 Authors. All rights reserved.

20.
Clinical Immunology ; Conference: 2023 Clinical Immunology Society Annual Meeting: Immune Deficiency and Dysregulation North American Conference. St. Louis United States. 250(Supplement) (no pagination), 2023.
Article in English | EMBASE | ID: covidwho-20234616

ABSTRACT

Introduction: Type 1 interferon (IFN) autoantibodies, such as anti-IFNalpha, have pathogenic significance in life-threatening COVID-19 pneumonia. Ten to twenty percent of severe COVID cases are associated with type I IFN autoantibodies. These autoantibodies likely pre-exist while others arise de novo relative to SARS-CoV-2 infection. It is unclear to what extent type I anti-IFN autoantibodies are induced by SARS-CoV-2 infection and contribute to COVID-19 severity. We investigated these phenomena in those with inborn errors of immunity (IEI) and rheumatic disease (RHE). Aim(s): We aim to compare the prevalence and neutralization ability of anti-IFNalpha autoantibodies in IEI and RHE patients using archived blood samples before and after the COVID-19 pandemic began. Method(s): We determined the presence of autoantibodies against IFNalpha in plasma samples by enzyme linked immunosorbent assay in 453 patients with IEI or RHE who were testing either before or after the COVID-19 pandemic began in March 2020. Using flow cytometry, we determined the function of IFNalpha autoantibodies in plasma to block CD4T cell activation by inhibiting STAT-1 phosphorylation. Result(s): We found that 25 patients with IEI or RHE were positive for anti-IFNalpha autoantibodies. 10 out of 229 patient samples collected before the pandemic (4.2%) tested positive whereas 15 out of 224 patient samples collected after the pandemic began (7.0%) were positive. Seven of the 25 patients (28%) who tested positive had neutralizing antibodies in plasma, which prevented STAT-1 phosphorylation in CD4T cells;all of these patients had partial recombination activating gene deficiency (pRD) except for one patient with autoimmunity, leukemia and selective IgA deficiency. One pRD patient had anti-IFNalpha autoantibodies with neutralization capacity before the pandemic, which persisted after hematopoietic stem cell transplantation (HSCT) with full immune reconstitution. The patient was immunized for SARS-CoV-2 before and after HSCT and acquired COVID-19 infection a year after HSCT. The patient was symptomatic but never hospitalized and fully recovered despite having anti-IFNalpha autoantibodies. Conclusion(s): Anti-IFNalpha autoantibody levels were comparable before and after the start of the COVID-19 pandemic in IEI and RHE patients but only 28% of cases were neutralizing. The clinical implications of these autoantibodies are yet to be determined.Copyright © 2023 Elsevier Inc.

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