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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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Systemic phenotype associated to major Sjögren’s syndrome in 279 sufferers

Systemic phenotype associated to major Sjögren’s syndrome in 279 sufferers carrying remoted anti-La/SSB antibodies

 

Objectives: To consider the systemic phenotype related to the presence of remoted anti-La/SSB antibodies in a big worldwide registry of sufferers with major Sjögren’s syndrome (pSS) fulfilling the 2002 classification standards.

 

Methods: The Big Data Sjögren Project Consortium is a world, multicentre registry created in 2014. Baseline scientific info from main centres on scientific analysis in SS of the 5 continents was collected. Combination patterns of anti-Ro/SSA-La/SSB antibodies on the time of analysis outlined the next 4 immunological phenotypes: double optimistic (mixed Ro/SSA and La/SSB,) remoted anti-Ro/SSA, remoted anti-La/SSB, and immunonegative.

 

Results: The cohort included 12,084 sufferers (11,293 females, imply 52.Four years) with recorded ESSDAI scores out there. Among them, 279 (2.3%) had remoted anti-La/SSB antibodies. The imply whole ESSDAI rating at analysis of sufferers with pSS carrying remoted anti-La/SSB was 6.0, and 80.4% of sufferers had systemic exercise (international ESSDAI rating ≥1) at analysis. The domains with the very best frequency of lively sufferers had been the organic (42.8%), glandular (36.8%) and articular (31.2%) domains.

 

Patients with remoted anti-La/SSB confirmed the next frequency of lively sufferers in all ESSDAI domains however two (articular and peripheral nerve) as compared with immune-negative sufferers, and even the next absolute frequency in six scientific ESSDAI domains as compared with sufferers with remoted anti-Ro/SSA.

In addition, sufferers with remoted anti-La/SSB confirmed the next frequency of lively sufferers in two ESSDAI domains (pulmonary and glandular) with respect to essentially the most lively immunological subset (double-positive antibodies). Meanwhile, systemic exercise detected in sufferers with remoted anti-La/SSB was overwhelmingly low. Even in ESSDAI domains the place sufferers with remoted anti-La/SSB had the very best frequencies of systemic exercise (lymphadenopathy and muscular), the share of sufferers with average or excessive exercise was decrease as compared with the mixed Ro/SSA and La/SSB group.

 

Conclusions: Patients carrying remoted La/SSB antibodies symbolize a really small subset of sufferers with a systemic SS phenotype characterised by a big frequency of lively sufferers in most scientific ESSDAI domains however with a relative low frequency of the very best extreme organ-specific involvements. Primary SS nonetheless stays the most effective scientific analysis for this subset of sufferers.

 

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Seroprevalence of Specific Antibodies in opposition to SARS-CoV-2 from Hotspot Communities within the Dominican Republic

 

  • Seroprevalence surveys are of utmost significance to evaluate the proportion of a inhabitants that has developed antibodies in opposition to a newly launched virus and will subsequently probably exhibit immunologic safety in opposition to subsequent an infection. This research goals to know the distribution of IgM and IgG antibodies within the Dominican Republic.
  • We surveyed a complete of 12,897 contributors between April and June 2020 in 10 provinces of the Dominican Republic. Survey efforts in rising hotspots yielded a positivity for all contributors of anti-SARS-CoV-2 IgM of three.8% and IgG of 5.4%, indicating that the pathogen was in circulation earlier than the identification of these specific communities as hotspots.
  • We discovered vital age variations between contributors who participated within the serological research the place the next imply age is related IgM positivity and a decrease age with IgG positivity. Our outcomes spotlight the necessity for methods that contain community-based seroprevalence monitoring. These ought to preclude syndromic case identification.
  • Also, the upper imply age of IgM-positive contributors means that methods primarily based on syndromic surveillance may establish hotspots at later phases, primarily based on the variety of instances detected on the healthcare heart, as such community-based seroprevalence monitoring could also be an efficient intervention for future outbreaks.

SARS-CoV-2 antibody prevalence, titres and neutralising exercise in an antenatal cohort, United Kingdom, 14 April to 15 June 2020

 

SARS-CoV-2 IgG screening of 1,000 antenatal serum samples within the Oxford space, United Kingdom, between 14 April and 15 June 2020, yielded a 5.3% seroprevalence, mirroring contemporaneous regional knowledge. Among the 53 optimistic samples, 39 confirmed in vitro neutralisation exercise, correlating with IgG titre (Pearson’s correlation p<0.0001). While SARS-CoV-2 seroprevalence in being pregnant cohorts may probably inform inhabitants surveillance, scientific correlates of an infection and immunity in being pregnant, and antenatal epidemiology evolution over time want additional research.

Coronavirus Disease 2019 in a Premature Infant: Vertical Transmission and Antibody Response or Lack Thereof

With the worldwide unfold of extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) an infection, a number of studies spotlight its results on pregnant ladies. Based on scant out there knowledge, vertical transmission is taken into account unlikely. We current right here a preterm neonate born to a critically sick mom with SARV-CoV-2 with early proof of an infection with a optimistic reverse transcription polymerase chain response on day 1.

Lack of parental contact previous to testing and strict adherence to really helpful airborne precautions perinatally recommend vertical transmission of an infection. Critical maternal sickness and medicines might have contributed to the necessity for intensive resuscitation at beginning and spotlight the significance of shut fetal monitoring. Infant lacked immunoglobulin G antibody response by Three weeks, presumably secondary to delicate scientific course and prematurity. Effects of SARS-CoV-2 in preterm infants, their antibody response and potential for asymptomatic carriage stay unsure.

 

Towards middle-up evaluation of polyclonal antibodies: subclass-specific N-glycosylation profiling of murine immunoglobulin G (IgG) by the use of HPLC-MS

 

  • In current years, superior HPLC-MS methods primarily based on intact protein (“top-down”) or protein subunit (“middle-up/middle-down”) evaluation have been carried out for the characterization of therapeutic monoclonal antibodies. Here, we assess feasibility of middle-up/middle-down evaluation for polyclonal IgGs exhibiting intensive sequence variability. Specifically, we addressed IgGs from mouse, representing an vital mannequin system in immunological investigations.
  • To receive Fc/2 parts as conserved subunits of IgGs, we made use of the bacterial protease SpeB. For this goal, we initially decided SpeB cleavage websites in murine IgGs. The ensuing Fc/2 parts attribute of various subclasses had been subsequently analysed by ion-pair reversed-phase HPLC hyphenated to high-resolution mass spectrometry.
  • This enabled simultaneous relative quantification of IgG subclasses and their N-glycosylation variants, each of which affect IgG effector capabilities. To assess methodology capabilities in an immunological context, we utilized the analytical workflow to polyclonal antibodies obtained from BALB/c mice immunized with the grass pollen allergen Phl p 6.
  • The research revealed a shift in IgG subclasses and Fc-glycosylation patterns in whole and antigen-specific IgGs from totally different mouse cohorts, respectively. Eventually, Fc/2 characterization might reveal different protein modifications together with oxidation, amino acid exchanges, and C-terminal lysine, and should thus be carried out for high quality management of useful antibodies.