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Accuracy of the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay

Accuracy of the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay from the Centers for Disease Control and Prevention (CDC Zika MAC-ELISA) for Diagnosis of Zika Virus Infection

 

Serological diagnosis of Zika virus (ZIKV) infection is challenging because of antigenic cross-reactivity with dengue virus (DENV). This study evaluated the accuracy of the Zika IgM antibody capture enzyme-linked immunosorbent assay (CDC Zika IgM MAC-ELISA) in differentiating between ZIKV and DENV infections. To determine sensitivity, we used acute- and convalescent-phase sera from 21 patients with RT-PCR-confirmed ZIKV infection.

To determine specificity, we used acute- and convalescent-phase sera from 60 RT-PCR-confirmed dengue cases and sera from 23 blood donors.

During the acute-phase of the illness, the assay presented a sensitivity of 12.5% (2/16) for samples collected 0-4 days post symptoms onset (DPSO), and of 75.0% (3/4) for samples collected 5-9 DPSO. During the convalescent-phase of the illness, the test sensitivity was 90.9% (10/11), 100% (2/2), and 0% (0/2) for samples obtained 12-102, 258-260, and 722-727 DPSO, respectively.

Specificity for acute- and convalescent-phase samples from RT-PCR-confirmed dengue cases was 100% and 93.2%, respectively. Specificity for blood donor samples was 100%. The assay is an accurate method for Zika serological diagnosis and proved to be reliable for use during surveillance and outbreak investigations in settings where ZIKV and DENV cocirculate.

 

Characterization of an Antibody Recognizing the Conserved Inner Core of Pseudomonas aeruginosa Lipopolysaccharides

 

  • Bacterial infections are a growing public health threat with carbapenem-resistant Pseudomonas aeruginosabeing classified as a Priority 1 critical threat by the World Health Organization. Antibody-based therapeutics can serve as an alternative and in some cases supplement antibiotics for the treatment of bacterial infections.

 

  • The glycans covering the bacterial cell surface have been proposed as intriguing targets for binding by antibodies; however, antibodies that can engage with high affinity and specificity with glycans are much less common compared to antibodies that engage with protein antigens. In this study, we sought to characterize an antibody that targets a conserved glycan epitope on the surface of Pseudomonas.

 

 

  • First, we characterized the breadth of binding of VSX, demonstrating that the VSX is specific to Pseudomonasbut can bind across multiple serotypes of the organism. Next, we provide insight into how VSX engages with its target epitope, using a combination of biolayer interferometry and nuclear magnetic resonance, and verify our results using site-directed mutagenesis experiments.

 

  • We demonstrate that the antibody, with limited somatic hypermutation of the complementarity-determining regions (CDRs) and with a characteristic set of arginines within the CDRs, specifically targets the conserved inner core of Pseudomonas Our results provide important additional context to antibody-glycan contacts and provide insight useful for the construction of vaccines and therapeutics against Pseudomonas aeruginosa, an important human pathogen.

 

 

Role of monoclonal antibody drugs in the treatment of COVID-19

 

Currently clinicians all around the world are experiencing a pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The clinical presentation of this pathology includes fever, dry cough, fatigue and acute respiratory distress syndrome that can lead to death infected patients. Current studies on coronavirus disease 2019 (COVID-19) continue to highlight the urgent need for an effective therapy. Numerous therapeutic strategies have been used until now but, to date, there is no specific effective treatment for SARS-CoV-2 infection.

 

Elevated inflammatory cytokines have been reported in patients with COVID-19. Evidence suggests that elevated cytokine levels, reflecting a hyperinflammatory response secondary to SARS-CoV-2 infection, are responsible for multi-organ damage in patients with COVID-19.

For these reason, numerous randomized clinical trials are currently underway to explore the effectiveness of biopharmaceutical drugs, such as, interleukin-1 blockers, interleukin-6 inhibitors, Janus kinase inhibitors, in COVID-19. The aim of the present paper is to briefly summarize the pathogenetic rationale and the state of the art of therapeutic strategy blocking hyperinflammation.

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Preconditioning of the tumor microenvironment with oncolytic reovirus converts CD3-bispecific antibody treatment into effective immunotherapy

 

Background: T-cell-engaging CD3-bispecific antibodies (CD3-bsAbs) are promising modalities for cancer immunotherapy. Although this therapy has reached clinical practice for hematological malignancies, the absence of sufficient infiltrating T cells is a major barrier for efficacy in solid tumors. In this study, we exploited oncolytic reovirus as a strategy to enhance the efficacy of CD3-bsAbs in immune-silent solid tumors.

 

Methods: The mutant p53 and K-ras induced murine pancreatic cancer model KPC3 resembles human pancreatic ductal adenocarcinomas with a desmoplastic tumor microenvironment, low T-cell density and resistance to immunotherapy.

Immune-competent KPC3 tumor-bearing mice were intratumorally injected with reovirus type 3 Dearing strain and the reovirus-induced changes in the tumor microenvironment and spleen were analyzed over time by NanoString analysis, quantitative RT-PCR and multicolor flow cytometry.

 

The efficacy of reovirus in combination with systemically injected CD3-bsAbs was evaluated in immune-competent mice with established KPC3 or B16.F10 tumors, and in the close-to-patient human epidermal growth factor receptor 2 (HER2)+ breast cancer model BT474 engrafted in immunocompromised mice with human T cells as effector cells.

 

Results: Replication-competent reovirus induced an early interferon signature, followed by a strong influx of natural killer cells and CD8+ T cells, at the cost of FoxP3+ Tregs. Viral replication declined after 7 days and was associated with a systemic activation of lymphocytes and the emergence of intratumoral reovirus-specific CD8+ T cells. Although tumor-infiltrating T cells were mostly reovirus-specific and not tumor-specific, they served as non-exhausted effector cells for the subsequently systemically administered CD3-bsAbs.

 

Combination treatment of reovirus and CD3-bsAbs led to the regression of large, established KPC3, B16.F10 and BT474 tumors. Reovirus as a preconditioning regimen performed significantly better than simultaneous or early administration of CD3-bsAbs.

This combination treatment induced regressions of distant lesions that were not injected with reovirus, and systemic administration of both reovirus and CD3-bsAbs also led to tumor control. This suggests that this therapy might also be effective for metastatic disease.

 

Conclusions: Oncolytic reovirus administration represents an effective strategy to induce a local interferon response and strong T-cell influx, thereby sensitizing the tumor microenvironment for subsequent CD3-bsAb therapy. This combination therapy warrants further investigation in patients with non-inflamed solid tumors.

 

Antibodies targeting epitopes on the cell-surface form of NS1 protect against Zika virus infection during pregnancy

 

There are no licensed therapeutics or vaccines available against Zika virus (ZIKV) to counteract its potential for congenital disease. Antibody-based countermeasures targeting the ZIKV envelope protein have been hampered by concerns for cross-reactive responses that induce antibody-dependent enhancement (ADE) of heterologous flavivirus infection.

 

Nonstructural protein 1 (NS1) is a membrane-associated and secreted glycoprotein that functions in flavivirus replication and immune evasion but is absent from the virion. Although some studies suggest that antibodies against ZIKV NS1 are protective, their activity during congenital infection is unknown.

Here we develop mouse and human anti-NS1 monoclonal antibodies that protect against ZIKV in both non-pregnant and pregnant mice. Avidity of antibody binding to cell-surface NS1 along with Fc effector functions engagement correlate with protection in vivo. Protective mAbs map to exposed epitopes in the wing domain and loop face of the β-platform. Anti-NS1 antibodies provide an alternative strategy for protection against congenital ZIKV infection without causing ADE.

 

 


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Impact of Immune Priming, Vaccination and Infection on Influenza A

Impact of Immune Priming, Vaccination and Infection on Influenza A(H3N2) Antibody Landscapes in Children

Background: Pre-existing antibodies to influenza, formed by early an infection and subsequent exposures, might affect responses to influenza vaccination.

Methods: We enrolled 72 youngsters (7-17 years) in 2015-16, all obtained inactivated influenza vaccines. Forty-one have been additionally vaccinated in 2014-15 with 12 grew to become contaminated with A(H3N2) in 2014-15. Thirty-one youngsters didn’t have documented influenza exposures within the prior 5 seasons. Sera have been collected pre- and post-vaccination in each seasons. We constructed antibody landscapes utilizing hemagglutination inhibition antibody titers towards 16 A(H3N2) viruses consultant of main antigenic clusters that circulated between 1968 and 2015.

Results: The breadth of the antibody landscapes elevated with age. Vaccine-induced antibody responses correlated with boosting of titers to beforehand encountered antigens. Post-vaccination titers have been highest towards vaccine antigens reasonably than the historic A(H3N2) viruses beforehand encountered. Pre-vaccination titers to the vaccine have been the strongest predictors of post-vaccination titers. Responses to vaccine antigens didn’t differ by doubtless priming virus. Influenza A(H3N2) contaminated youngsters in 2014-15 had narrower antibody landscapes than these uninfected, however prior season an infection standing had little impact on antibody landscapes following 2015-16 vaccination.

Conclusions: A(H3N2) antibody landscapes in youngsters have been largely decided by age-related immune priming, reasonably than current vaccination or an infection.

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Adsorption of non-ionic surfactant and monoclonal antibody on siliconized floor studied by neutron reflectometry

  • The adsorption of monoclonal antibodies (mAbs) on hydrophobic surfaces is understood to trigger protein aggregation and degradation. Therefore, surfactants, comparable to Poloxamer 188, are extensively utilized in therapeutic formulations to stabilize mAbs and defend mAbs from interacting with liquid-solid interfaces. Here, the adsorption of Poloxamer 188, one mAb and their aggressive adsorption on a mannequin hydrophobic siliconized floor is investigated with neutron scattering coupled with distinction variation to find out the molecular construction of adsorbed layers for every case.
  • Small angle neutron scattering measurements of the affinity of Poloxamer 188 to this mAb point out that there’s negligible binding at these answer circumstances. Neutron reflectometry measurements of the mAb present irreversible adsorption on the siliconized floor, which can’t be washed off with neat buffer. Poloxamer 188 will be adsorbed on the floor already occupied by mAb, which allows partial elimination of some adsorbed mAb by washing with buffer.
  • The adsorption of the surfactant introduces vital conformational adjustments for mAb molecules that stay on the floor. In distinction, if the siliconized floor is first saturated with the surfactant, no adsorption of mAb is noticed. Competitive adsorption of mAb and Poloxamer 188 from answer results in a floor dominantly occupied with surfactant molecules, whereas solely a minor quantity of mAb absorbs. These findings clearly point out that Poloxamer 188 can defend towards mAb adsorption in addition to modify the adsorbed conformation of beforehand adsorbed mAb.

Antibody kinetics and serologic profiles of SARS-CoV-2 an infection utilizing two serologic assays

Background: Coronavirus illness 2019 (COVID-19) is an rising risk worldwide. This research goals to evaluate the serologic profiles and time kinetics of antibodies towards extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in sufferers with COVID-19 utilizing two immunoassays.

Methods: A complete of 97 samples serially collected from 17 sufferers with COVID-19 and 137 adverse management samples have been analyzed for IgM and IgG towards SARS-CoV-2 utilizing the AFIAS COVID-19 Ab (Boditech Med Inc., Chuncheon, Republic of Korea) and the EDI™ Novel Coronavirus COVID-19 ELISA Kit (Epitope Diagnostics, Inc., San Diego, CA).

Results: With each assays, IgM and IgG quickly elevated after 7 days submit symptom onset (PSO). IgM antibody ranges reached a peak at 15-35 d PSO and regularly decreased. IgG ranges regularly elevated and remained at comparable ranges after 22-35 d. The diagnostic sensitivities of IgM/IgG for ≤14d PSO have been 21.4%/35.7~57.1% and elevated to 41.2~52.9%/88.2~94.1% at >14 d PSO with specificities of 98.5%/94.2% for AFIAS COVID-19 Ab and 100.0%/96.4% for EDI™ Novel Coronavirus COVID-19 ELISA Kit. Among 137 adverse controls, 12 samples (8.8%) confirmed constructive or indeterminate outcomes.

Conclusions: The antibody kinetics towards SARS-CoV-2 are just like widespread findings of acute viral infectious ailments. Antibody testing is helpful for ruling out SARS-CoV-2 an infection after 14 d PSO, detecting previous an infection, and epidemiologic surveys.

A cancer-specific anti-podocalyxin monoclonal antibody (60-mG 2a-f) exerts antitumor results in mouse xenograft fashions of pancreatic carcinoma

  • Overexpression of podocalyxin (PODXL) is related to development, metastasis, and poor outcomes in a number of cancers. PODXL additionally performs an vital position within the growth of regular tissues. For antibody-based remedy to focus on PODXL-expressing cancers utilizing monoclonal antibodies (mAbs), cancer-specificity is important to scale back the danger of hostile results to regular tissues.
  • In this research, we developed an anti-PODXL cancer-specific mAb (CasMab), named as PcMab-60 (IgM, kappa) by immunizing mice with soluble PODXL, which is overexpressed in LN229 glioblastoma cells. The PcMab-60 reacted with the PODXL-overexpressing LN229 (LN229/PODXL) cells and MIA PaCa-2 pancreatic most cancers cells in move cytometry however didn’t react with regular vascular endothelial cells (VECs), whereas considered one of non-CasMabs, PcMab-47 confirmed excessive reactivity for not solely LN229/PODXL and MIA PaCa-2 cells but in addition VECs, indicating that PcMab-60 is a CasMab.
  • Next, we engineered PcMab-60 right into a mouse IgG2a-type mAb, named as 60-mG2a, so as to add antibody-dependent mobile cytotoxicity (ADCC). We additional developed a core fucose-deficient kind of 60-mG2a, named as 60-mG2a-f, to increase its ADCC exercise. In vivoevaluation revealed that 60-mG2a-f exerted antitumor exercise in MIA PaCa-2 xenograft fashions at a dose of 100 μg/mouse/week administered thrice. These outcomes steered that 60-mG2a-f might be helpful for antibody-based remedy towards PODXL-expressing pancreatic cancers.

Factors Involved within the Development of Inhibitory Antibodies in Patients with Hemophilia in Colombia: A Case-Control Study

Background: The look of inhibitory antibodies towards antihemophilic components is likely one of the most severe issues associated to hemophilia.

Objective: The goal of this research was to establish variables and components associated to the event of inhibitory antibodies in a gaggle of sufferers present process antihemophilic remedy in Colombia.

Methods: A case-control research in sufferers with hemophilia handled in Specialized Healthcare Provider Institutions (IPS-E) in 21 cities of Colombia of any age and with a analysis of inhibitory antibodies towards issue VIII or IX throughout 2016. Four controls per case paired by age and kind of hemophilia have been used. Sociodemographic, medical, and pharmacological variables have been recognized and analyzed.

Results: Seventeen sufferers with inhibitory antibodies and 68 controls with hemophilia have been recognized. The imply age was 28.3 ± 17.Eight years. A complete of 94.1% had hemophilia A, and 88.2% of the circumstances and 50.0% of the controls had extreme hemophilia; 47.1% of the circumstances and 54.4% of the controls have been receiving prophylaxis with coagulation components. Multivariate evaluation confirmed that having extreme hemophilia (OR:17.0, 95%CI:1.32-219.60) and lack of understanding of the coagulation issue with which the affected person was handled earlier than coming into the care program within the IPS-E (OR:8.9, 95%CI:1.82-43.75) have been considerably related to the next likelihood of growing inhibitory antibodies.

Conclusion and relevance: Coagulation components related to the event of inhibitory antibodies have been extreme hemophilia and lack of understanding of the kind of issue used previous to coming into the follow-up cohort.