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1.
Birth Defects Research ; 115(8):867, 2023.
Article in English | EMBASE | ID: covidwho-20241292

ABSTRACT

Remdesivir (RDV) is an antiviral medication used most recently for the treatment of COVID-19. Although no adverse effects were observed on perinatal parameters in reproductive and development toxicology studies at doses up to four-fold clinical area under the curve (AUC) exposures, some researchers have reported that therapeutic levels of RDV may impair early embryogenesis, as observed by in vitro studies. In addition, the influence of prenatal RDV exposure on maternal IgG transfer in the placenta is still unknown. Administration of RDV in pregnant humanized mouse model (Tg32), which expresses the human Fc gamma receptor and transporter (FCGRT) gene, was used to further evaluate potential effects on IgG transfer and concurrent perinatal endpoints. Animals were dosed daily from gestational days (GDs) 10- 14 with 25 mg/kg RDV (GS-5734) via intravenous injection (n=3-5 per group). Concurrent vehicle control animals were dosed intravenously with 12% sulfobutyl ether- beta-cyclodextrin in water (pH3.5;NaOH/HCl). All animals were administered 2 mg/kg human IgG via intravenous injection on GD 14. Placentae and fetuses were collected from dams on GD 14, 15, 16, and 18 and evaluated using histopathology and qPCR for inflammation markers. No abnormal morphologies (necrosis/apoptosis) of placentae were observed between the concurrent control and RDVdosed groups. Additionally, no differences in maternal body weights were observed. There were no statistically significant differences in placenta weights. There were no statistically significant changes in pregnancy parameters (implantation sites and dead fetuses/litter) and fetal weights between the RDV-dosed group and concurrent controls at GD 14, 15, 16, and 18. No changes were observed in transcript levels of inflammation markers in the RDV-dosed group when compared to the concurrent control group. There was a slightly lower ratio of fetal IgG level to maternal IgG levels in the RDV-dosed group;however, no statistically significant differences were observed between the RDV-dosed group and concurrent controls on GD 14, 15, 16, and 18. Our results suggest that a daily dose of 25 mg/kg RDV on GDs 10-14 in humanized mice did not cause adverse effects on placenta and fetal development. (Funded by the Perinatal Health Center of Excellence: E0300201.).

2.
Topics in Antiviral Medicine ; 31(2):138, 2023.
Article in English | EMBASE | ID: covidwho-2319031

ABSTRACT

Background: People with HIV (PWH) on antiretroviral therapy (ART) appear to be at higher risk for worse COVID-19 outcomes, but the underlying mechanisms-including effects of COVID-19 and host factors on the broader humoral immune repertoire-are poorly understood. Method(s): REPRIEVE enrolled a global cohort of ART-treated PWH ages 40-75. COVID+ was defined by positive receptor binding domain IgG or IgA from annual visits 5/2020-2/2021. Antibody isotype, subclass, and Fc receptor Luminex arrays to SARS-CoV-2, CMV, EBV, HSV, HIV, influenza, pneumococcus, and RSV were assessed. Report of COVID diagnosis (collected every 4 months) was defined as mild, moderate, or severe (asymptomatic if no clinical diagnosis but IgG/ IgA+). FDR-corrected regression was used to assess effects of 1) COVID+ on non- SARS-CoV-2 repertoire in full cohort and 2) host factors on non-SARS-CoV-2 and SARS-CoV-2 repertoire in COVID- and COVID+ cohorts, respectively, adjusted for age, sex, region, nadir CD4, and HIV VL at entry. Result(s): Of 2,464 unvaccinated participants, 283 (11%) were COVID+;260 (92%) were asymptomatic. Median age was 53, 35% were women, 50% had nadir CD4 < 200, median current CD4 was 649, and 97% had HIV VL < 400. In the full cohort, COVID+ was associated with higher CMV PP65 IgG3 and FcgammaRIIA (P< 0.05);COVID severity was not associated with the non-SARS-CoV-2 repertoire. Among COVID-, older age, female sex, and lower nadir CD4 were associated with higher EBV and CMV responses;IgG1 levels were higher in women for all non-SARS-CoV-2 antigens assessed (P< 0.05). Among COVID+, higher BMI was associated with amplified SARS-CoV-2 IgG, IgA, IgM, and FcgammaRIIA responses (P< 0.05). Lower nadir CD4 was associated with a SARSCoV- 2 repertoire shift toward IgM and FcgammaRIIB (P< 0.05). Age and sex were not associated with SARS-CoV-2-related repertoire changes in COVID+. Conclusion(s): Our analysis presents a comprehensive view of host factors associated with the humoral immune repertoire among a global cohort of ART-treated PWH. COVID's association with higher CMV responses may suggest increased susceptibility to or a consequence of persistent inflammation after infection. The striking amplification of SARS-CoV-2 responses with higher BMI suggests an excessive inflammatory response. Lower nadir CD4 was related to uncontrolled extra-follicular and inhibitory SARS-CoV-2 responses, which are unlikely to be protective. These findings may suggest mechanisms underlying factors associated with worse COVID-19 outcomes among PWH. (Figure Presented).

3.
Topics in Antiviral Medicine ; 31(2):94-95, 2023.
Article in English | EMBASE | ID: covidwho-2318189

ABSTRACT

Background: The role of myeloid cells in the pathogenesis of SARS-CoV-2 is well established, in particular as drivers of cytokine production and systemic inflammation characteristic of severe COVID-19. However, the potential for myeloid cells to act as bona fide targets of productive SARS-CoV-2 infection remains unclear. Method(s): Using anti-SARS-CoV-2 mAbs with a range of neutralisation potencies and binding specificities, we performed a detailed assessment of mAb-mediated infection of monocytes/macrophages. THP-1 cells were used as a model system, with results confirmed in primary macrophages. Result(s): Infection of THP-1 cells was seen via mAbs targeting the spike RBD, but not with those targeting the NTD or S2 subunit. mAbs with the most consistent potential to mediate infection targeted a conserved region of the RBD (group 1/class IV). No infection was seen with the same quantity of virus but in the absence of antibody, and pre-treating the cells with FcgammaRI and -II blocking antibodies inhibited infection. Thus, antibody-FcR interactions are able to expand the tropism of SARS-CoV-2. Time-course studies demonstrated high-level and productive infection. Studies performed in human iPSC-derived macrophages and primary monocyte-derived macrophages paralleled results seen in THP-1 cells but with lower infection levels. Up to 2% of macrophages were infected, with infected cells appearing multinucleated and syncytial. Addition of ruxolitinib, an inhibitor of JAK1/2 signalling, increased infection up to 10-fold, indicating limitation of infection through innate immune mechanisms. Sera from primary infections (n=80) mediated rare infection events, with a minority of samples (n=3) promoting significant infection. Competition assays confirmed results seen in sera, with the addition of neutralising mAbs diminishing the infection seen with infection-mediating mAbs. Thus, the presence of antibodies with potential to mediate infection is not sufficient to predict myeloid cell infection, rather, the context in which the antibodies are produced is key. Conclusion(s): We hypothesise that a nascent antibody response during peak viral replication in primary infection presents a window of opportunity for myeloid cells to become infected, while establishment of a robust polyclonal response via vaccination or prior infection reduces the likelihood of this occurring. Infection via antibody-FcR interactions could contribute to pathogenesis in primary infection, systemic virus spread or persistent infection.

4.
Brain ; 2023 May 10.
Article in English | MEDLINE | ID: covidwho-2319491

ABSTRACT

Coronavirus disease 2019 (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains a global public health emergency. Although SARS-CoV-2 is primarily a respiratory pathogen, extra-respiratory organs, including the central nervous system (CNS), can also be affected. Neurologic symptoms have been observed not only during acute SARS-CoV-2 infection, but also at distance from respiratory disease, also known as long-COVID or neurological post-acute sequelae of COVID-19 (neuroPASC). The pathogenesis of neuroPASC is not well understood, but hypotheses include SARS-CoV-2-induced immune dysfunctions, hormonal dysregulations, and persistence of SARS-CoV-2 reservoirs. In this prospective cohort study, we used a high throughput systems serology approach to dissect the humoral response to SARS-CoV-2 (and other common Coronaviruses - 229E, HKU1, NL63, OC43) in the serum and cerebrospinal fluid (CSF) from 112 infected individuals who developed (n = 18) or did not develop (n = 94) neuroPASC. Unique SARS-CoV-2 humoral profiles were observed in the CSF of neuroPASC, compared to serum responses. All antibody isotypes (IgG, IgM, IgA) and subclasses (IgA1-2; IgG1-4) were detected in serum, whereas CSF was characterized by focused IgG1 (and absence of IgM). These data argue in favor of compartmentalized brain-specific responses against SARS-CoV-2 through selective transfer of antibodies from the serum to the CSF across the blood-brain-barrier, rather than intrathecal synthesis, where more diversity in antibody classes/subclasses would be expected. Compared to individuals who did not develop post-acute complications following infection, individuals with neuroPASC had similar demographic features (median age 65 vs 66.5 years, respectively, p = 0.55; females 33% vs 44%, p = 0.52), but exhibited attenuated systemic antibody responses against SARS-CoV-2, characterized by decreased capacity to activate antibody-dependent complement deposition (ADCD), NK cell activation (ADNKA) and to bind Fcγ receptors. However, surprisingly, neuroPASC individuals showed significantly expanded antibody responses to other common Coronaviruses, including 229E, HKU1, NL63, and OC43. This biased humoral activation across coronaviruses was particularly enriched in neuroPASC individuals with poor outcome, suggesting an original antigenic sin (or immunologic imprinting), where pre-existing immune responses against related viruses shape the response to current infection, as a key prognostic marker of neuroPASC disease. Overall, these findings point to a pathogenic role for compromised anti-SARS-CoV-2 responses in the CSF, likely resulting in incomplete virus clearance from the brain and persistent neuroinflammation, in the development of post-acute neurologic complications of SARS-CoV-2 infection.

5.
Int J Mol Sci ; 24(4)2023 Feb 20.
Article in English | MEDLINE | ID: covidwho-2254740

ABSTRACT

Classified as a class B infectious disease by the World Organization for Animal Health (OIE), bovine viral diarrhea/mucosal disease is an acute, highly contagious disease caused by the bovine viral diarrhea virus (BVDV). Sporadic endemics of BVDV often lead to huge economic losses to the dairy and beef industries. To shed light on the prevention and control of BVDV, we developed two novel subunit vaccines by expressing bovine viral diarrhea virus E2 fusion recombinant proteins (E2Fc and E2Ft) through suspended HEK293 cells. We also evaluated the immune effects of the vaccines. The results showed that both subunit vaccines induced an intense mucosal immune response in calves. Mechanistically, E2Fc bonded to the Fc γ receptor (FcγRI) on antigen-presenting cells (APCs) and promoted IgA secretion, leading to a stronger T-cell immune response (Th1 type). The neutralizing antibody titer stimulated by the mucosal-immunized E2Fc subunit vaccine reached 1:64, which was higher than that of the E2Ft subunit vaccine and that of the intramuscular inactivated vaccine. The two novel subunit vaccines for mucosal immunity developed in this study, E2Fc and E2Ft, can be further used as new strategies to control BVDV by enhancing cellular and humoral immunity.


Subject(s)
Diarrhea Virus 2, Bovine Viral , Immunity, Mucosal , Viral Vaccines , Animals , Cattle , Humans , Antibodies, Viral , Diarrhea , HEK293 Cells , Vaccines, Subunit/immunology , Viral Vaccines/immunology , Hemorrhagic Syndrome, Bovine/prevention & control
6.
Cell Rep ; 41(4): 111544, 2022 10 25.
Article in English | MEDLINE | ID: covidwho-2104501

ABSTRACT

Each severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant renews concerns about decreased vaccine neutralization weakening efficacy. However, while prevention of infection varies, protection from disease remains and implicates immunity beyond neutralization in vaccine efficacy. Polyclonal antibodies function through Fab domains that neutralize virus and Fc domains that induce non-neutralizing responses via engagement of Fc receptors on immune cells. To understand how vaccines promote protection, we leverage sera from 51 SARS-CoV-2 uninfected individuals after two doses of the BNT162b2 mRNA vaccine. We show that neutralizing activities against clinical isolates of wild-type and five SARS-CoV-2 variants, including Omicron BA.2, link to FcγRIIIa/CD16 non-neutralizing effector functions. This is associated with post-translational afucosylation and sialylation of vaccine-specific antibodies. Further, polyfunctional neutralizing and non-neutralizing breadth, magnitude, and coordination diminish with age. Thus, studying Fc functions in addition to Fab-mediated neutralization provides greater insight into vaccine efficacy for vulnerable populations, such as the elderly, against SARS-CoV-2 and novel variants.


Subject(s)
COVID-19 , Viral Vaccines , Humans , Aged , SARS-CoV-2 , Antibodies, Viral , BNT162 Vaccine , Receptors, Fc , Antibodies, Neutralizing
7.
Drug Development and Delivery ; 22(4):18-23, 2022.
Article in English | Scopus | ID: covidwho-2012508
8.
Scandinavian Journal of Immunology ; 2022.
Article in English | EMBASE | ID: covidwho-1956794

ABSTRACT

There are two approaches to scientific investigation, the common approach (proving one’s theory) and Popper’s approach (falsification of one’s theories). Popper’s approach has advantages as well as dangers (being perceived as not sure of one’s theories, or even be hostile to them—an ‘auto-traitor’). Nevertheless, the Popper approach can bridge the gap between inhibition (directly observable) and inhibitory regulation (not directly observable). Suppression of immune responses by antigen-specific antibody has led to theories regarding immunoregulation by immune products. There are many immune products capable of regulating immune responses. The inhibitory outcomes of this regulation have been called coinhibition and immune checkpoint inhibition. Coinhibition should be used when regulation begins at the cell surface or in the cell cytoplasm, which opens up the possibility of antigen-specific regulation. Immune checkpoint inhibition should be used when the initiating inhibitory event occurs in the nucleus, such as by directly affecting the cell cycle, where the concept of antigen-specific regulation is more difficult to invoke. These forms of immunoregulation could be corrupted by viral infections, such as in COVID-19 infections.

9.
Journal of the Peripheral Nervous System ; 27, 2022.
Article in English | EMBASE | ID: covidwho-1935098

ABSTRACT

The proceedings contain 69 papers. The topics discussed include: chemotherapy induced peripheral neurotoxicy: why should we care?;studying the caudal nerve anatomy and physiology to refine detection of peripheral nerve damage in rodent models;anxiety and depression in Charcot-Marie-tooth disease: data from the Italian CMT National Registry;fatigue in CMT: a web based survey from the Italian CMT National Registry;early molecular diagnosis of mutations on the transthyretin gene as a strategy to improve the prognosis of hereditary transthyretin-mediated amyloidosis - an update of the GENILAM project;THR124MET myelin protein zero mutation mimicking motor neuron disease;torsional neuropathy in parsonage turner syndrome following anti-COVID19 vaccination. how to detect and manage with it?;isolated musculocutaneous involvement in parsonage-turner syndrome associated with SARS-COV2 vaccination;neonatal FC receptor expression in patients with chronic dysimmune neuropathy. a feasibility study;and peripheral neuropathies after common organ transplantations. literature review and the use of electrophysiological tests and ultrasound.

10.
Chinese Journal of Microbiology and Immunology (China) ; 42(3):161-170, 2022.
Article in Chinese | EMBASE | ID: covidwho-1928715

ABSTRACT

Objective To investigate the immune characteristics of SARS-CoV-2 membrane (M) protein, especially the possibility of inducing antibody-dependent enhancement effect (ADE) .Methods Full-length SARS-CoV-2 M protein was prepared by prokaryotic expression system and purified.BALB/ c mice were immunized subcutaneously three times (on day 1, day 14 and day 21) by purified M protein.Serum samples were collected before immunization and after each immunization.The specificity of immune sera against M protein was identified by Western blot, and the antibody titers were detected by ELISA and neutralization test.In the presence of anti-M protein serum, the proliferation of SARS-CoV-2 in dendritic cells, nature killer cells, T and B cells was detected in vitro.Results The immune sera from BALB/ c mice immunized with purified full-length M protein of SARS-CoV-2 specifically recognized viral M protein.The titer of anti-whole virus antibody in immune sera was about 1 ∶ 400, but the antibody could not neutralize live virus.Moreover, the antibody could not help the virus to infect and proliferate in the various types of immune cells with Fc receptor (FcR).Conclusions Non-neutralizing antibody induced by M protein could not cause ADE through FcR pathway.

11.
European Stroke Journal ; 7(1 SUPPL):349, 2022.
Article in English | EMBASE | ID: covidwho-1928082

ABSTRACT

Background and aims: Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare syndrome of unclear aetiology occurring after vaccinations against COVID-19. The aim of this study was to investigate the DNA vaccine-encoded Sars-cov-2 soluble spike protein (SP) as a potential trigger of platelet activation in VITT. Methods: We studied three VITT patients and seven healthy controls (HCs) within 3 weeks from the first dose of ChAdOx1 nCoV-19. Serum levels of SP, soluble angiotensin-converting enzyme 2 (sACE2), and platelet response to VITT serum stimulation were studied. A thrombus retrieved from middle cerebral artery during mechanical thrombectomy of one VITT patient, was analysed by immunohistochemistry for SP and ACE2. Neutrophil extracellular traps (NETs) markers and coagulation parameters were also measured. Results: We detected SP and sACE2 in all VITT patients, and in two and three out of 7 HCs, respectively. VITT sera markedly activated platelets and this activation was inhibited by both anti-SP and anti-FcγRIIA blocking antibodies. The retrieved thrombus showed positive immunohistochemical labelling of platelets using an anti-SP antibody with reduced ACE2 expression, compared to a thrombus from a pre-pandemic stroke patient. Markers of endothelial dysfunction, NETs and hypercoagulability state were present in VITT sera. Conclusions: The present data provide first evidence that DNA vaccineencoded Sars-cov-2 SP is detectable in VITT sera (up to several weeks post-vaccination) and in a platelet-rich thrombus, and suggest that SP may contribute to the initial platelet stimulation in VITT patients. Anti-PF4/ polyanion antibodies development could represent an epiphenomenon, which amplifies platelet aggregation, NETosis, and coagulation cascade.

12.
American Journal of Respiratory and Critical Care Medicine ; 205(1), 2022.
Article in English | EMBASE | ID: covidwho-1927910

ABSTRACT

RATIONALE: The proteomic responses of hospitalized patients with SARS Co-V-2 infection may provide insight into risk, time course, and mechanisms associated with this infection. We used a high throughput proteomic platform to examine proteins that were differentially expressed relative to the length of hospital stay (LOS). METHOD:26 patients, hospitalized with SARS CoV-2 infection (mean age 48 yrs, 44% women) had blood samples obtained within 72 hours of admission. Initial plasma samples were analyzed from patients who were hospitalized for < 3 days (n=6), < 7days (n=12) and > 7 days (n=8) of LOS and compared to healthy controls (HC, n=8). Samples were analyzed with the modified aptamer-based array (SomaScan) that measures more than 7,000 human proteins representing different molecular pathways and gene families. Differentially regulated proteins with > 1.5 fold change and a false discovery rate of 5% were analyzed using the Ingenuity Pathway Analysis (IPA). Unique protein categories associated with LOS were assessed. RESULT: Compared to HC, differentially expressed proteins were detected among the 3 groups: 461 at < 3 days, 1,635 proteins at < 7 days and 1,738 proteins in >7 days. 407 proteins were common among all hospitalized COVID 19 individuals independent of LOS and 12, 250 and 361 proteins were uniquely present at < 3 days, < 7 days and > 7 days respectively compared to HC. The table below demonstrates the top highly enriched canonical pathway, molecular function and upstream regulator of differentially expressed proteins. The temporal sequence of these protein networks varied with LOS. Representative examples include early responses;platelet membrane glycoprotein GP6 signaling pathway that involves the FcR gamma-chain and the Src kinases linked to platelet aggregation, signaling involved in T cell receptor-mediated IL-2 production (TEC kinase). Less than 7 days include diacylglycerol associated with T cell activation, carnitine palmitoyltransferase associated with mitochondrial beta-oxidation of long chain fatty acids. CXCR4 a receptor for stromal -cell derived factor 1 and associated with COVID-19 prognosis. Late responses after 7 days include pathways involved in remodeling of epithelial adherens junctions. CONCLUSIONS : A high throughput proteomic approach provides insight into the dynamic regulation of protein pathways associated with the progression of SARS-Co-V2 infection. This may provide additional insight into risk and mechanisms associated with outcomes in COVID. (Table Presented).

13.
American Journal of Reproductive Immunology ; 87(SUPPL 1):69, 2022.
Article in English | EMBASE | ID: covidwho-1927546

ABSTRACT

Problem: There is a persistent bias toward increased severity of coronavirus disease 2019 (COVID-19) in males. Etiologies of this sex difference remain incompletely understood. Interferon responses have been implicated as a modulator of COVID-19 disease in adults, and play a key role in the placental antiviral response. The interferon response has also been shown to alter Fc receptor expression, and thereforemay impact placental antibody transfer to the fetus. Method of Study: We examined viral-induced placental interferon responses, maternal-fetal antibody transfer, and sex differences in this regard in pregnant individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Placental Fc receptor abundance, interferon stimulated gene (ISG) expression, and SARS-CoV-2 antibody transfer were interrogated in 68 human pregnancies. Results: Sexually dimorphic expression of placental Fc receptors, and interferon-stimulated genes and proteins was observed following maternal SARS-CoV-2 infection, with upregulation of these features in placental tissue of pregnant individuals with male fetuses. Reduced maternal SARS-CoV-2-specific antibody titers and impaired placental antibody transfer were also observed in pregnancies with a male fetus. Conclusions: These results demonstrate fetal sex-specific placental innate immune responses to SARS-CoV-2.

14.
Vox Sanguinis ; 117(SUPPL 1):64, 2022.
Article in English | EMBASE | ID: covidwho-1916337

ABSTRACT

Background: Vaccines have been an important strategy to control the SARS-CoV-2 pandemic. In The Netherlands two mRNA vaccines (BTN162b2, Pfizer-BioNTech;mRNA-1273, Moderna), and two adenovirus vector-based vaccines (ChAdOx1 nCoV-19, AstraZeneca;Ad26. COV2.S, Johnson & Johnson/Janssen) have been administered. In 2021, vaccination with the ChAdOx1 nCoV-19 was ceased in The Netherlands and other European countries due to the occurrence of thrombocytopenia and thromboembolic events. This new phenomenon was termed vaccine-induced thrombotic thrombocytopenia (VITT) and was clinically associated with thrombocytopenia and thrombosis at unusual sites, in particular cerebral venous sinus thrombosis (CVST). In addition, VITT was characterized by the presence of IgG-antibodies directed against platelet factor 4 (PF4). As PF4 appears to play a central role in the pathophysiology of VITT, it is recommended that the role of PF4 should be taken into account for VITT diagnostic testing. Aims: To characterize and define the patient population of clinically suspected VITT cases in The Netherlands from a diagnostics perspective. Methods: We describe a cohort of 283 clinically suspected VITT patients. We assessed these patients based on their clinical presentation and using an anti-PF4 IgG ELISA and a functional PF4-dependent platelet activation assay. Results: We found that when the 283 clinically suspected VITT patients were analysed in the anti-PF4 IgG ELISA: 24 (8.5%) tested positive, 248 (87.6%) tested negative, and 11 (3.9%) tested weak positive. Out of the 24 patients that tested positive in the anti-PF4 IgG ELISA, 19 (79.2%) patients also demonstrated increased PF4-dependent platelet activation. Furthermore, we observed that platelet activation was inhibited by excess levels of heparin and by a FcγRIIa-blocking antibody, indicating a role for platelet-FcγRIIa in the pathophysiology of VITT. Remarkably, we found that patients vaccinated with mRNA vaccines BTN162b2 (N = 84) and mRNA-1273 (N = 36), did not test positive in the anti-PF4 IgG ELISA. Based on these test results 19 patients (11 women) were eventually diagnosed with probable VITT, of which 13 presented with both thrombocytopenia and thrombosis and three suffered from CVST. Strikingly, discrepancies in test results were also present, including nine patients with low levels of anti-PF4 IgG but with increased PF4-dependent platelet activation, and two patients with high levels of anti-PF4 IgG but without any PF4-dependent platelet activation. Summary/Conclusions: VITT is a rare but serious complication of SARS-CoV-2 virus vaccination, particularly due to adenovirus vectorbased vaccines. Our results underline the importance of using the clinical presentation, in combination with the anti-PF4 IgG ELISA and the PF4-dependent platelet activation assay for VITT diagnostics. Discrepancies in test results, however, proved it difficult to unequivocally diagnose VITT. Therefore, it will be essential to obtain more insights into the pathophysiology of VITT in order to improve the diagnostic accuracy and identify preventive and therapeutic approaches.

15.
Chinese Journal of Pharmaceutical Biotechnology ; 29(1):87-94, 2022.
Article in Chinese | EMBASE | ID: covidwho-1791589

ABSTRACT

Since the establishment of hybridoma in the 1980s, the antibody technology has achieved great development.Antibody is an immunoglobulin secreted by B lymphocytes, which produces many biological activity, such as blocking, neutralization, activation, kill target cells and regulate immune system via Fc receptor.The development of antibody technology has undergone a long history of mouse monoclonal antibodies, chimeric antibodies, humanized antibodies, and full human monoclonal antibodies.In the transition from mouse antibody to human antibody, a variety of biotechnology breakthroughs have been achieved, such as antibody library technology, humanized mouse technology and B cell cloning technology.Today, antibody drugs have a pivotal position throughout the drug market.Ten years come (2 011.01~2 021.11), 78 monoclonal antibody drugs have been approved for marketing by FDA, are widely distributed in the field of tumor disrases, immune diseases, anti-pathogen infections, nerves, etc.This article reviews monoclonal antibody technologies and antibody drug listing, and provides ideas for the preparation of new antibodies and the choice of drug target.

16.
Open Access Macedonian Journal of Medical Sciences ; 10:220-227, 2022.
Article in English | EMBASE | ID: covidwho-1771282

ABSTRACT

BACKGROUND: Cytokine storm in COVID-19 patients has contributed to many morbidities and mortalities in patients. Studies have found that toll-like receptors (TLRs) and some Fc receptors play essential roles in the hyperactivation of the immune system. Up to date, researchers are still in progress to discover effective and safe drugs to alleviate the hyperinflammatory state in COVID-19. The previous studies had shown that Carthamus tinctorius and its bioactive compounds might have anti-inflammatory activities in animal models. AIM: We aimed to investigate the possible interactions of several flavonoids from C. tinctorius with several immune system components using a biocomputational approach. METHODS: Molecular docking was done using the AutoDock program based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) COVID-19 pathway. The most suitable receptors found were studied to study the interactions with several flavonoids from C. tinctorius. RESULTS: TLR4, TLR8, and FcγRIIa were found to bind with SARS CoV2 inflammatory pathway and further selected as macromolecules for potential interactions study with 22 flavonoids from C. tinctorius. Of the 22 flavonoids studied, daphnoretin showed the best binding affinity with TLR4 and Rutin was shown to attach best with FcγRIIa. Unlike its excellent binding to TLR4, daphnoretin showed weak binding to TLR8. CONCLUSION: Daphnoretin showed an excellent affinity with TLR4 and might be a good candidate as an inhibitor in hyperinflammatory reactions in COVID-19 DTLR8.

17.
Blood ; 138(SUPPL 1):3801, 2021.
Article in English | EMBASE | ID: covidwho-1770457

ABSTRACT

BACKGROUND: Multiple myeloma (MM) and Waldenström macroglobulinemia (WM) are associated with significant immunoparesis. Based on the ongoing COVID-19 pandemic, there is an urgent need to understand whether patients are able to mount a sufficient response to COVID-19 vaccines. METHODS: MM and WM patients are vaccinated with mRNA-1273 (Moderna), BNT162b2 mRNA (Pfizer/BioNTech), or JNJ-78436735 (Johnson & Johnson) in a prospective clinical trial. Primary endpoint is SARS-CoV-2 spike protein (S) antibody (Ab) detection 28 days after final vaccination. Secondary endpoints include functional serologic assessments and T-cell responses at 28 days, 6 months, 9 months, and 12 months following vaccination. S Abs were detected by Elecsys assay (Roche Diagnostics), with 3 0.80 U/mL defined as positive and titers > 250 U/mL considered stronger correlates of neutralization. SARS-CoV-2 wildtype and variant S-specific Ab isotypes and FcγR binding profiles were quantified by custom Luminex assay. Antibody-dependent neutrophil and cellular phagocytosis (ADNP and ADCP) were assessed using flow cytometry. RESULTS: To date 141 patients have been enrolled, 137 (91 MM and 46 WM) of whom had an S Ab assessment. Median Ab titer was 178.0 (IQR, 16.10-1166.0) for MM and 3.92 (IQR, 0-278.9) for WM. S Ab response rate was 91% (83/91) in MM and 56% (27/46) in WM. However, responses achieving S Ab >250 U/mL were 47.3% (43/91) in MM and 26.1% (12/46) in WM. In patients 375 years, responses >250 u/mL were 13.3% (2/15;p<0.05). Vaccine-specific S Ab responses >250 u/mL following mRNA-1273, BNT162b2, and JNJ-78436735 were 67.6% (23/34;p<0.05), 38.3% (18/47;p=NS), and 20% (2/10;p=NS) in MM and 50.0% (8/16;p<0.05), 14.8% (4/27;p<0.05), and 0% (0/3;p=NS) in WM. Among MM patients with progressive disease, S Ab response >250 u/mL occurred in 30% (6/20) as opposed to 55.6% (30/54) for VGPR+ (p<0.05). MM patients having autologous stem cell transplant within 12 months demonstrated 100% (5/5;p<0.05) S Ab responses. For MM patients actively receiving an anti-CD38 monoclonal Ab or an immunomodulatory drug, S Ab response occurred in 38.9% (14/36;p=NS) and 50.9% (28/55;p<0.05). Among WM patients, S Ab responses >250 U/mL occurred in 63.6% (7/11;p<0.05) previously untreated;0% (0/9;p<0.05) who received rituximab within 12 months;10% (2/20);p<0.05) on an active Bruton Tyrosine Kinase (BTK) inhibitor;and 20% (3/15;p=NS) who received other therapies. Functional Ab studies were performed on 14 MM patients, 14 WM, patients, and 14 healthy donors (HD) (Figure 1). All patients were assessed 28 days following their final vaccination and myeloma patients had an additional assessment 28 days following initial vaccination. MM and WM patients demonstrated less IGG1 and IGG3 S Ab production than HD. MM patients showed increased IgA and IgM S Ab production as well as increased FcgR2A binding following a second vaccine in contrast to HD. Both ADNP and ADCP were reduced in MM and WM patients. MM patients demonstrated improved ADCP in SARS-CoV-2 variants B.1.351, B.1.117, and P.1 versus wildtype (p<0.05). CONCLUSIONS: We report the first known evidence of impaired functional humoral responses following COVID-19 vaccines in patients with MM and WM. Overall, WM patients showed more severe impairment of COVID-19 S Ab responses. Most previously untreated WM patients achieved S Ab responses, however the most significant reduction in S Ab responses were seen in WM patients who received rituximab within 12 months or active BTK inhibitors. For MM patients, being in disease remission associated with improved S Ab response. Among MM and WM patients, age 375 years associated with significantly lower rates and vaccination with MRNA-1273 (Moderna) elicited significantly higher S Ab response rates than other vaccines. A defect in ADNP and more profound defect in ADCP suggests overall compromised opsinophagocytic activity among MM and WM patients. Data comparing first and second vaccine responses in MM patients, suggest less efficient class switching to IGG as well as incomple e maturation of their FcgR2A binding profiles but normal maturation of FcgR3A. Interestingly, ADCP was improved in several emerging SARS-CoV-2 variants. T-cell studies are pending and will be updated. Further understanding of the immunological response to COVID19 vaccination is needed to clarify patients risks, and necessity for booster or alternative protective measures against COVID-19. (Figure Presented).

18.
Microbiol Spectr ; 10(2): e0155321, 2022 04 27.
Article in English | MEDLINE | ID: covidwho-1759307

ABSTRACT

Antibody-dependent enhancement (ADE) of infection is generally known for many viruses. A potential risk of ADE in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has also been discussed since the beginning of the coronavirus disease 2019 (COVID-19) pandemic; however, clinical evidence of the presence of antibodies with ADE potential is limited. Here, we show that ADE antibodies are produced by SARS-CoV-2 infection and the ADE process can be mediated by at least two different host factors, Fcγ receptor (FcγR) and complement component C1q. Of 89 serum samples collected from acute or convalescent COVID-19 patients, 62.9% were found to be positive for SARS-CoV-2-specific IgG. FcγR- and/or C1q-mediated ADE were detected in 50% of the IgG-positive sera, whereas most of them showed neutralizing activity in the absence of FcγR and C1q. Importantly, ADE antibodies were found in 41.4% of the acute COVID-19 patients. Neutralizing activity was also detected in most of the IgG-positive sera, but it was counteracted by ADE in subneutralizing conditions in the presence of FcγR or C1q. Although the clinical importance of ADE needs to be further investigated with larger numbers of COVID-19 patient samples, our data suggest that SARS-CoV-2 utilizes multiple mechanisms of ADE. C1q-mediated ADE may particularly have a clinical impact since C1q is present at high concentrations in plasma and its receptors are ubiquitously expressed on the surfaces of many types of cells, including respiratory epithelial cells, which SARS-CoV-2 primarily infects. IMPORTANCE Potential risks of antibody-dependent enhancement (ADE) in the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been discussed and the proposed mechanism mostly depends on the Fc gamma receptor (FcγR). However, since FcγRs are exclusively expressed on immune cells, which are not primary targets of SARS-CoV-2, the clinical importance of ADE of SARS-CoV-2 infection remains controversial. Our study demonstrates that SARS-CoV-2 infection induces antibodies that increase SARS-CoV-2 infection through another ADE mechanism in which complement component C1q mediates the enhancement. Although neutralizing activity was also detected in the serum samples, it was counteracted by ADE in the presence of FcγR or C1q. Considering the ubiquity of C1q and its cellular receptors, C1q-mediated ADE may more likely occur in respiratory epithelial cells, which SARS-CoV-2 primarily infects. Our data highlight the importance of careful monitoring of the antibody properties in COVID-19 convalescent and vaccinated individuals.


Subject(s)
Antibody-Dependent Enhancement , COVID-19 , Antibodies, Neutralizing , Antibodies, Viral , Complement C1q , Humans , Immunoglobulin G , Receptors, IgG , SARS-CoV-2
19.
Open Forum Infectious Diseases ; 8(SUPPL 1):S634-S635, 2021.
Article in English | EMBASE | ID: covidwho-1746329

ABSTRACT

Background. ADG20 is a fully human IgG1 monoclonal antibody engineered to have potent and broad neutralization against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and additional SARS-like CoVs with pandemic potential and an extended half-life. A QSP/PBPK model was constructed using ADG20-specific physiochemical properties and published non-human primate (NHP) and human PK data for other antibodies;it was used to a priori predict and confirm NHP and human PK. Methods. An existing QSP/PBPK model was modified to include 3 distinct lung sub-compartments: upper airway, lower airway, and alveolar tissue (Figure A). Each sub-compartment (Figure B) contained an epithelial lining fluid (ELF) space (Figure B). The model was fit separately to digitized NHP and human serum PK data for 7 extended half-life antibodies to estimate the apparent neonatal Fc receptor (FcRn) binding affinity (KD,FcRn) and bioavailability by drug. Nasopharyngeal swab (upper airway) and lung (lower airway) ELF PK data from 4 additional antibodies were used to optimize a single rate constant for transcytosis in lung. Patches of positive charge was a covariate on the rate of pinocytosis of antibody entry and exit from the endosomal space (Figure B). Observed NHP (ADG20 10 mg/kg IM) and human (ADG20 300 mg IM) PK data collected over the initial 21 days post dose were compared with model forecasts from a 1000-iteration simulation. Results. The distribution of fitted NHP KD,FcRn provided accurate predictions of NHP serum PK data (Figure C). NHP ADG20 KD,FcRn was optimized to be 35.7 nM and human ADG20 KD,FcRn (9.55 nM) was derived using a mean NHP:human KD,FcRn ratio of 3.74 across antibodies. Model-based simulated human serum PK data using inter-subject variability from NHP and actual weight distribution from an ongoing Phase 1 study aligned with initial 21-day data (Figure D). Using an adult CDC weight distribution (45-150 kg), the simulated median exceeded 74 days. Conclusion. The QSP/PBPK model a priori predicted NHP and human ADG20 PK. This innovative QSP-based modeling and simulation approach enabled the evaluation of candidate dose regimens prior to the availability of PK data, supporting the rapid advancement of the ADG20 clinical program during the COVID-19 pandemic.

20.
Blood ; 138:582, 2021.
Article in English | EMBASE | ID: covidwho-1582369

ABSTRACT

[Formula presented] Introduction Vaccine-induced thrombotic thrombocytopenia (VITT) is a severe complication of recombinant adenoviral vector vaccines used to prevent COVID-19, likely due to anti-platelet factor 4 (PF4) IgG antibodies. The specificity and platelet-activating activity of VITT antibodies strikingly resemble that of antibodies detected in “autoimmune” heparin-induced thrombocytopenia (HIT), but their features remain poorly characterized. In particular, a better knowledge of these antibodies should help to understand the mechanisms leading to hypercoagulability and the particular thrombotic events observed in VITT, but rarely in typical HIT. We have recently developed a chimeric IgG1 anti-PF4 antibody, 1E12, which strongly mimics “autoimmune” HIT antibodies in terms of specificity and cellular effects. Therefore, we assessed whether 1E12 could mimic VITT antibodies. We then evaluated the capability of DG-1E12, a deglycosylated form of 1E12 unable to bind FcγR, to inhibit cellular activation induced by VITT antibodies. Methods and Results Using a PF4-sensitized serotonin release assay (PF4-SRA) (Vayne C, New Engl J Med, 2021), we demonstrated that 1E12 (5 and 10 μg/mL) strongly activated platelets, with a pattern similar to that obtained with human VITT samples (n=7), i.e. in a PF4-dependent manner and without heparin. This platelet activation was inhibited by low heparin concentration (0.5 IU/mL), an effect also observed with VITT samples. Serotonin release induced by 1E12 was also fully inhibited by IV-3, a monoclonal antibody blocking FcγRIIa, or by IdeS, a bacterial protease that cleaves IgG and strongly inhibits the binding of IgG antibodies to FcγRIIa. This inhibitory effect of IV-3 and IdeS strongly supports that interactions between pathogenic anti-PF4 IgG and FcγRIIa play a central role in VITT. Incubation of 1E12 or VITT samples with isolated neutrophils (PMN) and platelets with PF4 (10 µg/mL) strongly induced DNA release and NETosis, supporting that PMN are involved in the processes leading to thrombosis in VITT. Furthermore, when whole blood from healthy donors incubated with 1E12 or VITT plasma was perfused in capillaries coated with von Willebrand Factor, numerous large platelet/leukocyte aggregates containing fibrin(ogen) were formed. To investigate whether 1E12 and VITT antibodies recognize overlapping epitopes on PF4, we then performed competitive assays with a deglycosylated form of 1E12 (DG-1E12), still able to bind PF4 but not to interact with Fcγ receptors. In PF4-SRA, pre-incubation of DG-1E12 (50 µg/mL) dramatically reduced platelet activation induced by VITT antibodies, which was fully abrogated for 9 of the 14 VITT samples tested. Additional experiments using a whole blood PF4-enhanced flow cytometry assay recently designed for VITT diagnosis (Handtke et al, Blood 2021), confirmed that DG-1E12 fully prevented platelet activation induced by VITT antibodies. Moreover, when platelets and neutrophils were pre-incubated with DG-1E12 (100 µg/mL), NETosis and thus DNA release, nuclear rounding, and DNA decondensation induced by VITT antibodies were completely inhibited. Finally, DG-1E12 (100 µg/mL) also fully abolished VITT antibody-mediated thrombus formation in whole blood in vitro under vein flow conditions. Comparatively, DG-1E12 did not inhibit ALB6, a murine monoclonal anti-CD9 antibody, which also strongly activates platelets in a FcγRIIa-dependent manner. Conclusions Our results show that 1E12 exhibits features similar to those of human VITT antibodies in terms of specificity, affinity and cellular effects, and could therefore be used as a model antibody to study the pathophysiology of VITT. Our data also demonstrate that DG-1E12 prevents blood cell activation and thrombus formation induced by VITT antibodies, likely due to the competitive effect of its Fab fragment on antibody binding to PF4. DG-1E12 may allow the development of a new drug neutralizing the pathogenic effect of autoimmune anti-PF4 antibodies, such as those associated with VITT. Disclosures: T iele: Bristol Myers Squibb: Honoraria, Other;Pfizer: Honoraria, Other;Bayer: Honoraria;Chugai Pharma: Honoraria, Other;Novo Nordisk: Other;Novartis: Honoraria;Daichii Sankyo: Other. Pouplard: Stago: Research Funding. Greinacher: Macopharma: Honoraria;Biomarin/Prosensa: Other, Research Funding;Sagent: Other, Research Funding;Rovi: Other, Research Funding;Gore inc.: Other, Research Funding;Bayer Healthcare: Other, Research Funding;Paringenix: Other, Research Funding;BMS: Honoraria, Other, Research Funding;MSD: Honoraria, Other, Research Funding;Boehringer Ingelheim: Honoraria, Other, Research Funding;Aspen: Honoraria, Other, Research Funding;Portola: Other;Ergomed: Other;Instrument Laboratory: Honoraria;Chromatec: Honoraria. Gruel: Stago: Other: symposium fees, Research Funding. Rollin: Stago: Research Funding.

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