Biology subjects

Doering, J.

Publications and source records attributed to Doering, J..

9 recordsLinked to original sources

bioRxiv2025

Maternal transfer of mRNA LNP-derived, pathogen-specific, monoclonal IgG to suckling mice

Breast milk provides a rich source of naturally derived maternal antibodies that confer passive immunity to infants, protecting them from a variety of respiratory and enteric infections. For at-risk newborns in low- and middle-income countries, supplementing breast milk with pathogen-specific neutralizing and bactericidal antibodies could offer significant short- and long-term health benefits. In this study, we explored the use of mRNA and lipid nanoparticle (LNP) technology to deliver a Vibrio cholerae-specific monoclonal IgG antibody ("ZAC-3") into the milk of lactating mice. Swiss Webster mice were intravenously administered ZAC-3 IgG mRNA-LNPs, and we monitored serum and breast milk for the presence of V. cholerae-specific human IgG1. A single injection of mRNA-LNPs led to rapid and sustained expression of ZAC-3 IgG in both the blood and breast milk of lactating dams. ZAC-3 IgG1 in these samples recognized whole V. cholerae cells by ELISA and exhibited potent vibriocidal activity in the presence of human complement. Furthermore, ZAC-3 IgG was detected in the sera of suckling pups at levels proportional to those in the mothers, demonstrating successful transfer of functional antibodies to the newborns. In conclusion, our findings highlight the potential of mRNA-based monoclonal antibody platforms in the maternal-newborn context and address key challenges associated with the direct delivery of recombinant antibodies.

immunology↗

bioRxiv2024

Antibody Profiles Elicited by Potent and Subpotent Whole Cell Pertussis Vaccines in Mice

Inactivated, whole cell pertussis (wP) vaccines remain at the frontline in the global fight against the resurgence of whooping cough, especially in low- and middle-income countries. However, the reliance on the intracerebral mouse potency test (ic-MPT or Kendrick assay) as the standard batch release assay is challenging for the production of commercial wP vaccines. The ic-MPT is technically challenging, labor intensive and, arguably, incongruous with modern animal welfare guidelines. Replacing the ic-MPT with a whole cell Bordetella pertussis ELISA, the so-called pertussis serology potency test (PSPT), has shown promise, but has been difficult to implement in practice. In this report, we tested the hypothesis that potent and subpotent wP vaccines have distinct serologic profiles in mice that could be developed as a substitute for the ic-MPT. We first established an accelerated decay (thermal stress) protocol in which wP, in the context of DTwP, was rendered >10-fold less effective than unstressed vaccine when evaluated in a mouse model of B. pertussis lung clearance following intranasal challenge. We then screened immune sera on a limited B. pertussis Tahoma I proteome array and identified >30 antigens whose antibody reactivity profiles increased, decreased or were unchanged as a function of wP potency. Interestingly, virtually all the "indicator" antigens identified are known virulence factors or reactive with human convalescent sera, thereby establishing a potential link between wP potency and pertussis infection and immunity. These results bode well for the development of a limited B. pertussis antigen array as a stability-indicating surrogate potency assay for the ic-MPT.

immunology↗

bioRxiv2023

Maternofetal transfer of human NMDAR antibodies leads to cortical network defect in the adult

Anti-N-methyl-D-aspartate-receptor IgG-antibodies (NMDAR-Ab) can be detected in up to 1% of the healthy population. Because maternal IgG can cross the placental barrier during pregnancy, these antibodies may influence fetal neurodevelopment. Using a mouse model of maternofetally transferred human NMDAR-Ab, we asked whether in utero exposure impacts functional brain dynamics later in life. We conducted two-photon calcium imaging and fMRI in adolescent mice, to evaluate both local and global neuronal network integrity. At the microcircuit scale, NMDAR-Ab exposed offspring exhibited lower spontaneous activity, reduced firing variability, and reduced orientation selectivity upon visual stimulation. Globally, fMRI revealed a selective bilateral functional hypoconnectivity of the entorhinal-hippocampal pathway while overall functional connectivity is unaffected. Together, our data indicates that maternal-fetal transfer of NMDAR-Ab leads to a lasting impairment in sensory processing and memory-routing circuits, revealing a vulnerability of the developing fetal brain to maternal autoantibodies.

neuroscience↗

bioRxiv2023

Effects of aluminum-salt, CpG and emulsion adjuvants on the stability and immunogenicity of a virus-like particle displaying the SARS-CoV-2 receptor binding domain (RBD)

Second-generation COVID-19 vaccines with improved immunogenicity (e.g., breadth, duration) and availability (e.g., lower costs, refrigerator stable) are needed to enhance global coverage. In this work, we formulated a clinical-stage SARS-CoV-2 receptor binding domain (RBD) virus-like particle (VLP) vaccine candidate (IVX-411) with widely available adjuvants. Specifically, we assessed the in vitro storage stability and in vivo mouse immunogenicity of IVX-411 formulated with aluminum-salt adjuvants (Alhydrogel, AH and Adjuphos, AP), without or with the TLR-9 agonist CpG-1018 (CpG), and compared these profiles to IVX-411 adjuvanted with an oil-in-water nano-emulsion (AddaVax, AV). Although IVX-411 bound both AH and AP, lower binding strength of antigen to AP was observed by Langmuir binding isotherms. Interestingly, AH- and AP-adsorbed IVX-411 had similar storage stability profiles as measured by antigen binding assays (competitive ELISAs), but the latter displayed higher pseudovirus neutralizing titers (pNT) in mice, at levels comparable to titers elicited by AV-adjuvanted IVX-411. CpG addition to alum (AP or AH) resulted in a marginal trend of improved pNTs in stressed samples only, yet did not impact the storage stability profiles of IVX-411. In contrast, previous work with AH-formulations of a monomeric RBD antigen showed greatly improved immunogenicity and decreased stability upon CpG addition to alum. At elevated temperatures (25, 37{degrees}C), IVX-411 formulated with AH or AP displayed decreased in vitro stability compared to AV-formulated IVX-411and this rank-ordering correlated with in vivo performance (mouse pNT values). This case study highlights the importance of optimizing antigen-adjuvant interactions to develop low cost, aluminum-salt adjuvanted recombinant subunit vaccine candidates.

immunology↗

bioRxiv2021

Defective linear and circular RNAs biogenesis in Huntington's disease: CAG repeat expansion hijacks neuronal splicing

Alternative splicing (AS) appears to be altered in Huntingtons disease (HD), but its significance for early, pre-symptomatic disease stages has not been inspected. Here, taking advantage of Htt CAG knock-in mouse in vitro and in vivo models, we demonstrate a strong correlation between Htt CAG repeat length and increased aberrant linear AS, specifically affecting neural progenitors and, in vivo, the striatum prior to overt behavioral phenotypes stages. Remarkably, expanded Htt CAG repeats reflect on a previously neglected, global impairment of back-splicing, leading to decreased circular RNAs production in neural progenitors. Though the mechanisms of this dysregulation remain uncertain, our study unveils network of transcriptionally altered micro-RNAs and RNA-binding proteins (CELF, hnRNPS, PTBP, SRSF) which, in turn, might influence the AS machinery, primarily in neural cells. We suggest that this unbalanced expression of linear and circular RNAs might result in altered neural fitness, contributing to HD striatal vulnerability.

genetics↗

bioRxiv2021

Durable Immunity to Ricin Toxin Elicited by a Thermostable, Lyophilized Subunit Vaccine

The development of vaccines against biothreat toxins like ricin (RT) is considered an integral component of the United States national security efforts. RiVax(R) is a thermostable, lyophilized RT subunit vaccine adsorbed to aluminum salt adjuvant intended for use by military personnel and first responders. Phase 1 studies indicated that RiVax is safe and immunogenic, while a three dose, intramuscular vaccination regimen in non-human primates elicited protection against lethal dose RT challenge by aerosol. Here we investigated, in a mouse model, the durability of RiVax-induced antibody responses and corresponding immunity to lethal dose RT challenge. Groups of mice were subcutaneously administered 3 or 1 g of RiVax on days 0 and 21 and challenged with 10 x LD50 RT by injection at six different intervals over the course of twelve months. Serum antibody titers and epitope-specific competition assays were determined prior to each challenge. We report that the two-dose, 3 g regimen conferred near complete protection against RT challenge on day 35 and complete protection thereafter (challenge days 65, 95, 125, 245, and 365). The two-dose, 3 g regimen was superior to the 1 g regimen as revealed by slight differences in survival and morbidity scores (e.g., hypoglycemia, weight loss) on challenge days 35 and 365. In separate experiments, a single 3 g RiVax vaccination proved only marginally effective at eliciting protective immunity to RT, underscoring the necessity of a prime-boost regimen to achieve full and long-lasting protection against RT. IMPORTANCERicin toxin (RT) is a notorious biothreat, as exposure to even trace amounts via injection or inhalation can induce organ failure and death within a matter of hours. In this study, we advance the preclinical testing of a candidate RT vaccine known as RiVax(R). RiVax is a recombinant non-toxic derivative of RTs enzymatic subunit that has been evaluated for safety in Phase I clinical trials and efficacy in a variety of animal models. We demonstrate that two doses of RiVax is sufficient to protect mice from lethal dose RT challenge for up to one year. We describe kinetics and other immune parameters of the antibody response to RiVax and discuss how these immune factors may translate to humans.

immunology↗

bioRxiv2020

Endpoint and Epitope-specific Antibody Responses as Correlates of Vaccine-mediated Protection of Mice against Ricin Toxin

The successful licensure of vaccines for biodefense is contingent upon the availability of well-established correlates of protection (CoP) in at least two animal species that can then be applied to humans, without the need to assess efficacy in the clinic. In this report we describe a multivariate model that combines pre-challenge serum antibody endpoint titers (EPT) and values derived from an epitope profiling immune-competition capture (EPICC) assay as a predictor in mice of vaccine-mediated immunity against ricin toxin (RT), a Category B biothreat. EPICC is a modified competition ELISA in which serum samples from vaccinated mice were assessed for their ability to inhibit the capture of soluble, biotinylated (b)-RT by a panel of immobilized monoclonal antibodies (mAbs) directed against four immunodominant toxin-neutralizing regions on the enzymatic A chain (RTA) of RT. In a test cohort of mice (n=40) vaccinated with suboptimal doses of the RTA subunit vaccine, RiVax(R), we identified two mAbs, PB10 and SyH7, which had EPICC inhibition values in pre-challenge serum samples that correlated with survival following a challenge with 10 x LD50 of RT administered by intraperitoneal (IP) injection. Analysis of a larger cohort of mice (n=645) revealed that a multivariate model combining endpoint titers and an epitope-profiling immune-competition capture (EPICC) assay values for PB10 and SyH7 as predictive variables had significantly higher statistical power than any one of the independent variables alone. Establishing the correlates of vaccine-mediated protection in mice represents an important steppingstone in the development of RiVax(R) as a medical countermeasure under the United States Food and Drug Administrations "Two Animal Rule."

immunology↗

bioRxiv2020

Navigating the translational roadblock: Towards highly specific and effective all-optical interrogations of neural circuits

Two-photon (2-P) all-optical approaches combine in vivo 2-P calcium imaging and 2-P optogenetic modulations and have the potential to build a framework for network-based therapies, e.g. for rebalancing maladaptive activity patterns in preclinical models of neurological disorders. Here, our goal was to tailor these approaches for this purpose: Firstly, we combined in vivo juxtacellular recordings and GCaMP6f-based 2-P calcium imaging in layer II/III of mouse visual cortex to tune our detection algorithm towards a 100 % specific identification of AP-related calcium transients. False-positive-free detection was achieved at a sensitivity of approximately 73 %. To further increase specificity, secondly, we minimized photostimulation artifacts as a potential source for false-positives by using extended-wavelength-spectrum laser sources for optogenetic stimulation of the excitatory opsin C1V1. We achieved artifact-free all-optical experiments performing photostimulations at 1100 nm or higher and simultaneous calcium imaging at 920 nm in mouse visual cortex in vivo. Thirdly, we determined the spectral range for maximizing efficacy of optogenetic control by performing 2-P photostimulations of individual neurons with wavelengths up to 1300 nm. The rate of evoked transients in GCaMP6f/C1V1-co-expressing cortical neurons peaked already at 1100 nm. By refining spike detection and defining 1100 nm as the optimal wavelength for artifact-free and effective stimulations of C1V1 in GCaMP-based all-optical interrogations, we increased the translational value of these approaches, e.g. for the use in preclinical applications of network-based therapies. One Sentence SummaryWe maximize translational relevance of 2-P all-optical physiology by increasing specificity, minimizing artifacts and optimizing stimulation efficacy.

neuroscience↗

bioRxiv2019

Inhibition of Invasive Salmonella by Orally Administered IgA and IgG Monoclonal Antibodies

BackgroundNon-typhoidal Salmonella enterica strains, including serovar Typhimurium (STm), are an emerging cause of invasive disease among children and the immunocompromised, especially in regions of sub-Saharan Africa. STm invades the intestinal mucosa through Peyers patch tissues before disseminating systemically. While vaccine development efforts are ongoing, the emergence of multidrug resistant strains of STm affirms the need to seek alternative strategies to protect high-risk individuals from infection.\n\nMethodology/Principal FindingsIn this report we investigated the potential of an orally administered O5 serotype-specific IgA monoclonal antibody (mAb), called Sal4, to protect mice against invasive Salmonella enterica serovar Typhimurium (STm) infection. Sal4 IgA was delivered to mice prior to or concurrently with STm challenge. Infectivity was measured as bacterial burden in Peyers patch tissues one day after challenge. Using this model, we defined the minimal amount of Sal4 IgA required to significantly reduce STm uptake into Peyers patches. The relative efficacy of Sal4 in dimeric and secretory IgA (SIgA) forms was compared, as was a second lower avidity O5-specific IgA mAb that we produced from STm immunized mice. To assess the role of isotype in oral passive immunization, we engineered a recombinant IgG1 mAb carrying the Sal4 variable regions and evaluated its ability to block invasion of STm into epithelial cells in vitro and Peyers patch tissues.\n\nConclusions/SignificanceOur results demonstrate the potential of orally administered monoclonal IgA and SIgA, but not IgG, to passively immunize against invasive Salmonella. Nonethless, the prophylactic window of IgA/SIgA in the mouse was on the order of minutes, underscoring the need to develop formulations to protect mAbs in the gastric environment and to permit sustained release in the small intestine.\n\nAuthor SummaryThe bacterium Salmonella enterica is responsible for significant morbidity and mortality in the developed and developing worlds. While the pathogen is most renowed as the causative agent of typhoid fever, the emergence of invasive non-typhoid strains like S. enterica serovar Typhimurium (STm) are of great concern because of their propensity to cause severe disease in children under the age of five. In this report, we demonstrate in a mouse model that oral administration of a monoclonal antibody targeting the surface of STm is able to prevent the bacterium from infecting gastrointestinal tissues, the first step in the dissemination process. We show that IgA antibodies (which are normally found in the gut) were far superior than an equivalent IgG antibody (normally found in blood) at protecting the intestine from STm infection. These results lay the foundation for future studies aimed at the development of an orally administered antibody cocktail capable of providing temporary immunity to pathogens like S. enterica.

immunology↗