Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-18 (of 18 Records) |
Query Trace: Bagarozzi D[original query] |
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Rapid Development of Neutralizing and Diagnostic SARS-COV-2 Mouse Monoclonal Antibodies (preprint)
Chapman AP , Tang X , Lee JR , Chida A , Mercer K , Wharton RE , Kainulainen M , Harcourt JL , Martines RB , Schroeder M , Zhao L , Bryksin A , Zhou B , Bergeron E , Bollweg BC , Tamin A , Thornburg N , Wentworth DE , Petway D , Bagarozzi DA Jr , Finn MG , Goldstein JM . bioRxiv 2020 2020.10.13.338095 The need for high-affinity, SARS-CoV-2-specific monoclonal antibodies (mAbs) is critical in the face of the global COVID-19 pandemic, as such reagents can have important diagnostic, research, and therapeutic applications. Of greatest interest is the ~300 amino acid receptor binding domain (RBD) within the S1 subunit of the spike protein because of its key interaction with the human angiotensin converting enzyme 2 (hACE2) receptor present on many cell types, especially lung epithelial cells. We report here the development and functional characterization of 29 nanomolar-affinity mouse SARS-CoV-2 mAbs created by an accelerated immunization and hybridoma screening process. Differing functions, including binding of diverse protein epitopes, viral neutralization, impact on RBD-hACE2 binding, and immunohistochemical staining of infected lung tissue, were correlated with variable gene usage and sequence.Competing Interest StatementThe authors have declared no competing interest. |
Design and optimization of a monkeypox virus specific serological assay
Taha TY , Townsend MB , Pohl J , Karem KL , Damon IK , Mbala Kingebeni P , Muyembe Tamfum JJ , Martin JW , Pittman PR , Huggins JW , Satheshkumar PS , Bagarozzi DA Jr , Reynolds MG , Hughes LJ . Pathogens 2023 12 (3) Monkeypox virus (MPXV), a member of the Orthopoxvirus (OPXV) genus, is a zoonotic virus, endemic to central and western Africa that can cause smallpox-like symptoms in humans with fatal outcomes in up to 15% of patients. The incidence of MPXV infections in the Democratic Republic of the Congo, where the majority of cases have occurred historically, has been estimated to have increased as much as 20-fold since the end of smallpox vaccination in 1980. Considering the risk global travel carries for future disease outbreaks, accurate epidemiological surveillance of MPXV is warranted as demonstrated by the recent Mpox outbreak, where the majority of cases were occurring in non-endemic areas. Serological differentiation between childhood vaccination and recent infection with MPXV or other OPXVs is difficult due to the high level of conservation within OPXV proteins. Here, a peptide-based serological assay was developed to specifically detect exposure to MPXV. A comparative analysis of immunogenic proteins across human OPXVs identified a large subset of proteins that could potentially be specifically recognized in response to a MPXV infection. Peptides were chosen based upon MPXV sequence specificity and predicted immunogenicity. Peptides individually and combined were screened in an ELISA against serum from well-characterized Mpox outbreaks, vaccinee sera, and smallpox sera collected prior to eradication. One peptide combination was successful with ~86% sensitivity and ~90% specificity. The performance of the assay was assessed against the OPXV IgG ELISA in the context of a serosurvey by retrospectively screening a set of serum specimens from the region in Ghana believed to have harbored the MPXV-infected rodents involved in the 2003 United States outbreak. |
Analysis of the initial lot of the CDC 2019-Novel Coronavirus (2019-nCoV) real-time RT-PCR diagnostic panel.
Lee JS , Goldstein JM , Moon JL , Herzegh O , Bagarozzi DAJr , Oberste MS , Hughes H , Bedi K , Gerard D , Cameron B , Benton C , Chida A , Ahmad A , Petway DJJr , Tang X , Sulaiman N , Teklu D , Batra D , Howard D , Sheth M , Kuhnert W , Bialek SR , Hutson CL , Pohl J , Carroll DS . PLoS One 2021 16 (12) e0260487 At the start of the COVID-19 pandemic, the Centers for Disease Control and Prevention (CDC) designed, manufactured, and distributed the CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel for SARS-CoV-2 detection. The diagnostic panel targeted three viral nucleocapsid gene loci (N1, N2, and N3 primers and probes) to maximize sensitivity and to provide redundancy for virus detection if mutations occurred. After the first distribution of the diagnostic panel, state public health laboratories reported fluorescent signal in the absence of viral template (false-positive reactivity) for the N3 component and to a lesser extent for N1. This report describes the findings of an internal investigation conducted by the CDC to identify the cause(s) of the N1 and N3 false-positive reactivity. For N1, results demonstrate that contamination with a synthetic template, that occurred while the "bulk" manufactured materials were located in a research lab for quality assessment, was the cause of false reactivity in the first lot. Base pairing between the 3' end of the N3 probe and the 3' end of the N3 reverse primer led to amplification of duplex and larger molecules resulting in false reactivity in the N3 assay component. We conclude that flaws in both assay design and handling of the "bulk" material, caused the problems with the first lot of the 2019-nCoV Real-Time RT-PCR Diagnostic Panel. In addition, within this study, we found that the age of the examined diagnostic panel reagents increases the frequency of false positive results for N3. We discuss these findings in the context of improvements to quality control, quality assurance, and assay validation practices that have since been improved at the CDC. |
Development and Evaluation of a TaqMan Real-Time PCR Assay for the Rapid Detection of Cross-Contamination of RD (Human) and L20B (Mouse) Cell Lines Used in Poliovirus Surveillance.
Ahmad A , Lee JR , Metz JM , Tang X , Lin SC , Bagarozzi DAJr , Petway D , Herzegh O . J Virol Methods 2021 300 114354 BACKGROUND: The cross-contamination of cell lines in culture is a persistent problem. Genetically modified L20B (Mouse) and RD (Human Rhabdomyosarcoma) cell lines are commonly used in poliovirus research, surveillance, and diagnostics. Cross-contamination between these cell lines leads to unreproducible results and unreliable surveillance data, negatively affecting public health. The gold standard method for cell authentication is Short Tandem Repeats analysis, which is time-consuming and expensive. The disadvantage of STR is limited detection of interspecies contamination. METHODS: This assay targets the mitochondrial cytochrome c oxidase subunit I (MTCO1) gene, a highly conserved and emergent DNA barcode region for detection of cross-contamination in RD and L20B cell lines. The MagNA Pure Compact instrument and ABI 7500 Fast Dx Real-time PCR systems were used for DNA extraction and to perform real-time PCR respectively. RESULTS: The newly developed assay is very sensitive with a limit of detection of 100 RD cells/1 million L20B/mL. The amplification efficiency and R(2)-value were 102.26% and 0.9969 respectively. We evaluated specificity of the assay with five human and four mouse cell lines, as well as monkey and rat cell lines. The assay showed no cross-reactivity with genomic DNA from human, mouse, rat, or monkey cell lines. The analytical sensitivity was also evaluated by spiking varying amounts of RD cells (0.001% - 10%) into L20B cells. There was no difference in C(T) values when running single-plex or duplex PCR reactions with similar experimental conditions. CONCLUSIONS: We have developed and validated a TaqMan real-time PCR assay, a sensitive method for the detection of cross-contamination of RD and L20B cell lines. |
Point-of-Care Antigen Test for SARS-CoV-2 in Asymptomatic College Students.
Tinker SC , Szablewski CM , Litvintseva AP , Folster J , Shewmaker PL , Medrzycki M , Bowen MD , Bohannon C , Bagarozzi D Jr , Petway M , Rota PA , Kuhnert-Tallman W , Thornburg N , Prince-Guerra JL , Barrios LC , Tamin A , Harcourt JL , Honein MA . Emerg Infect Dis 2021 27 (10) 2662-2665 We used the BinaxNOW COVID-19 Ag Card to screen 1,540 asymptomatic college students for severe acute respiratory syndrome coronavirus 2 in a low-prevalence setting. Compared with reverse transcription PCR, BinaxNOW showed 20% overall sensitivity; among participants with culturable virus, sensitivity was 60%. BinaxNOW provides point-of-care screening but misses many infections. |
Rapid development of neutralizing and diagnostic SARS-COV-2 mouse monoclonal antibodies.
Chapman AP , Tang X , Lee JR , Chida A , Mercer K , Wharton RE , Kainulainen M , Harcourt JL , Martines RB , Schroeder M , Zhao L , Bryksin A , Zhou B , Bergeron E , Bollweg BC , Tamin A , Thornburg N , Wentworth DE , Petway D , Bagarozzi DA Jr , Finn MG , Goldstein JM . Sci Rep 2021 11 (1) 9682 The need for high-affinity, SARS-CoV-2-specific monoclonal antibodies (mAbs) is critical in the face of the global COVID-19 pandemic, as such reagents can have important diagnostic, research, and therapeutic applications. Of greatest interest is the ~ 300 amino acid receptor binding domain (RBD) within the S1 subunit of the spike protein because of its key interaction with the human angiotensin converting enzyme 2 (hACE2) receptor present on many cell types, especially lung epithelial cells. We report here the development and functional characterization of 29 nM-affinity mouse SARS-CoV-2 mAbs created by an accelerated immunization and hybridoma screening process. Differing functions, including binding of diverse protein epitopes, viral neutralization, impact on RBD-hACE2 binding, and immunohistochemical staining of infected lung tissue, were correlated with variable gene usage and sequence. |
"Making the right decisions: Adapting to emerging needs": The 7th Annual Meeting of the Southeastern Association of Shared Resources, Atlanta, GA, USA, June 12-14, 2019
Dahlman KB , Bagarozzi D , Bagchi P , Blum D , Boukli NM , Colton-Lee F , Constable S , Seagroves TN , Somasundaram T . J Biomol Tech 2020 31 (4) 165-167 One hundred and nine shared resource directors, managers, administrators, and staff from 26 academic, government, or nonprofit institutions and 24 corporate partners descended upon Atlanta, Georgia, to attend the seventh Annual Meeting of the Southeastern Association of Shared Resources (SEASR) at the Emory Conference Center Hotel from June 12 to 14, 2019. Due to the overwhelming interest and response from SEASR sponsors, meeting registration was complimentary for all noncorporate attendees. This one-and-a-half-day meeting presented a combination of scientific, administrative, and networking sessions that are summarized herein. |
Comparison of Zika virus inactivation methods for reagent production and disinfection methods
Chida AS , Goldstein JM , Lee J , Tang X , Bedi K , Herzegh O , Moon JL , Petway D , Bagarozzi DAJr , Hughes LJ . J Virol Methods 2020 287 114004 Zika virus (ZIKV) infection remains a public health concern necessitating demand for long-term virus production for diagnostic assays and R&D activities. Inactivated virus constitutes an important component of the Trioplex rRT-PCR assay and serological IgM assay (MAC-ELISA). The aim of our study is to establish standard methods of ZIKV inactivation while maintaining antigenicity and RNA integrity. We tested viral supernatants by four different inactivation methods: 1. Heat inactivation at 56 °C and 60 °C; 2. Gamma-Irradiation; 3. Chemical inactivation by Beta-propiolactone (BPL) and 4. Fast-acting commercial disinfecting agents. Effectivity was measured by cytopathic effect (CPE) and plaque assay. RNA stability and antigenicity were measured by RT-PCR and MAC-ELISA, respectively. Results: Heat inactivation: Low titer samples, incubated at 56 °C for 2 hrs, showed neither CPE or plaques compared to high titer supernatants that required 2.5 hrs. Inactivation occurred at 60 °C for 60 min with all virus titers. Gamma irradiation: Samples irradiated at ≥3 Mrad for low virus concentrations and ≥5Mrad for high virus titer completely inactivated virus. Chemical Inactivation: Neither CPE nor plaques were observed with ≥0.045% BPL inactivation of ZIKV. Disinfectant: Treatment of viral supernatants with Micro-Chem Plus(TM), inactivated virus in 2 min, whereas, Ethanol (70%) and STERIS Coverage® Spray TB inactivated the virus in 5 min. |
The effects of gamma irradiation on chemical biomarker recovery from mixed chemical/biological threat exposure specimens
Isenberg SL , Carter MD , Moon JL , Laughlin S , Petway M , Mojica MA , Rood JE , Gursky AK , Sheppard CI , Bagarozzi DA , Pirkle JL , Johnson RC . J Appl Lab Med 2020 5 (2) 273-280 BACKGROUND: Irradiative sterilization of clinical specimens prior to chemical laboratory testing provides a way to not only sterilize pathogens and ensure laboratorian safety but also preserve sample volume and maintain compatibility with quantitative chemical diagnostic protocols. Since the compatibility of clinical biomarkers with gamma irradiation is not well characterized, a subset of diagnostic biomarkers ranging in molecular size, concentration, and clinical matrix was analyzed to determine recovery following gamma irradiation. METHODS: Sample irradiation of previously characterized quality control materials (QCs) at 5 Mrad was carried out at the Gamma Cell Irradiation Facility at the Centers for Disease Control and Prevention (CDC) in Atlanta, GA. Following irradiation, the QCs were analyzed alongside non-irradiated QCs to determine analyte recovery between dosed and control samples. RESULTS: Biomarkers for exposure to abrin, ricin, and organophosphorus nerve agents (OPNAs) were analyzed for their stability following gamma irradiation. The diagnostic biomarkers included adducts to butyrylcholinesterase, abrine, and ricinine, respectively, and were recovered at over 90% of their initial concentration. CONCLUSIONS: The results from this pilot study support the implementation of an irradiative sterilization protocol for possible mixed-exposure samples containing both chemical and biological threat agents (mixed CBTs). Furthermore, irradiative sterilization significantly reduces a laboratorian's risk of infection from exposure to an infectious agent without compromising chemical diagnostic testing integrity, particularly for diagnostic assays in which the chemical analyte has been shown to be fully conserved following a 5 Mrad irradiative dose. |
Zeptomole per milliliter detection and quantification of edema factor in plasma by LC-MS/MS yields insights into toxemia and the progression of inhalation anthrax
Lins RC , Boyer AE , Kuklenyik Z , Woolfitt AR , Goldstein J , Hoffmaster AR , Gallegos-Candela M , Leysath CE , Chen Z , Brumlow JO , Quinn CP , Bagarozzi DA Jr , Leppla SH , Barr JR . Anal Bioanal Chem 2019 411 (12) 2493-2509 Inhalation of Bacillus anthracis spores can cause a rapidly progressing fatal infection. B. anthracis secretes three protein toxins: lethal factor (LF), edema factor (EF), and protective antigen (PA). EF and LF may circulate as free or PA-bound forms. Both free EF (EF) and PA-bound-EF (ETx) have adenylyl cyclase activity converting ATP to cAMP. We developed an adenylyl cyclase activity-based method for detecting and quantifying total EF (EF+ETx) in plasma. The three-step method includes magnetic immunocapture with monoclonal antibodies, reaction with ATP generating cAMP, and quantification of cAMP by isotope-dilution HPLC-MS/MS. Total EF was quantified from 5PL regression of cAMP vs ETx concentration. The detection limit was 20 fg/mL (225 zeptomoles/mL for the 89 kDa protein). Relative standard deviations for controls with 0.3, 6.0, and 90 pg/mL were 11.7-16.6% with 91.2-99.5% accuracy. The method demonstrated 100% specificity in 238 human serum/plasma samples collected from unexposed healthy individuals, and 100% sensitivity in samples from 3 human and 5 rhesus macaques with inhalation anthrax. Analysis of EF in the rhesus macaques showed that it was detected earlier post-exposure than B. anthracis by culture and PCR. Similar to LF, the kinetics of EF over the course of infection were triphasic, with an initial rise (phase-1), decline (phase-2), and final rapid rise (phase-3). EF levels were ~ 2-4 orders of magnitude lower than LF during phase-1 and phase-2 and only ~ 6-fold lower at death/euthanasia. Analysis of EF improves early diagnosis and adds to our understanding of anthrax toxemia throughout infection. The LF/EF ratio may also indicate the stage of infection and need for advanced treatments. |
A high-throughput and rapid method for accurate identification of emerging multidrug-resistant Candida auris.
Ahmad A , Spencer JE , Lockhart SR , Singleton S , Petway DJ , Bagarozzi DAJr , Herzegh OT . Mycoses 2019 62 (6) 513-518 Candida auris is an emerging multidrug-resistant yeast associated with invasive infection in healthcare settings. Recently, C. auris cases in the US have been detected in 11 states with the majority of cases in New York, New Jersey, and Illinois. Rapid and accurate identification of C. auris is critical for patient care and the implementation of public health measures to control the spread of infection. Our aim was to develop and validate a rapid DNA extraction method using the Roche MagNA Pure 96 instrument and a TaqMan real-time PCR assay for reliable, high throughput identification of C. auris. We evaluated 247 patient dermal swab samples previously analyzed by culture/MALDI-TOF. The diagnostic sensitivity and specificity were 93.6% and 97.2%, respectively. The assay was highly reproducible with a detection limit of 1 C. auris CFU/10muL. A ROC curve analysis of the real-time PCR data showed an area of 0.982 under the curve, with a CT cutoff value of </=37.0. The turnaround time from DNA extraction to real-time PCR results was approximately 200 samples/day. In conclusion, we successfully validated a rapid and high throughput method for accurate and reproducible identification of C. auris with a significantly reduced turnaround time compared to culture/MALDI-TOF based methods. This article is protected by copyright. All rights reserved. |
Novel graphene-based biosensor for early detection of Zika virus infection
Afsahi S , Lerner MB , Goldstein JM , Lee J , Tang X , Bagarozzi DA Jr , Pan D , Locascio L , Walker A , Barron F , Goldsmith BR . Biosens Bioelectron 2017 100 85-88 We have developed a cost-effective and portable graphene-enabled biosensor to detect Zika virus with a highly specific immobilized monoclonal antibody. Field Effect Biosensing (FEB) with monoclonal antibodies covalently linked to graphene enables real-time, quantitative detection of native Zika viral (ZIKV) antigens. The percent change in capacitance in response to doses of antigen (ZIKV NS1) coincides with levels of clinical significance with detection of antigen in buffer at concentrations as low as 450pM. Potential diagnostic applications were demonstrated by measuring Zika antigen in a simulated human serum. Selectivity was validated using Japanese Encephalitis NS1, a homologous and potentially cross-reactive viral antigen. Further, the graphene platform can simultaneously provide the advanced quantitative data of nonclinical biophysical kinetics tools, making it adaptable to both clinical research and possible diagnostic applications. The speed, sensitivity, and selectivity of this first-of-its-kind graphene-enabled Zika biosensor make it an ideal candidate for development as a medical diagnostic test. |
Phage display analysis of monoclonal antibody binding to anthrax toxin lethal factor
Goldstein JM , Lee J , Tang X , Boyer AE , Barr JR , Bagarozzi DA Jr , Quinn CP . Toxins (Basel) 2017 9 (7) AVR1674 and AVR1675 are monoclonal antibodies (mAbs) that bind with high specificity to anthrax toxin lethal factor (LF) and lethal toxin (LTx). These mAbs have been used as pivotal reagents to develop anthrax toxin detection tests using mass spectrometry. The mAbs were demonstrated to bind LF with good affinity (KD 10−7–10−9 M) and to enhance LF-mediated cleavage of synthetic peptide substrates in vitro. Sequence analysis indicated that the mAbs shared 100% amino acid identity in their complementarity determining regions (CDR). A phage display library based on a combinatorial library of random heptapeptides fused to the pIII coat protein of M13 phage was enriched and screened to identify peptide sequences with mAb binding properties. Selection and sequence analysis of 18 anti-LF-reactive phage clones identified a 7-residue (P1–P7) AVR1674/1675 consensus target binding sequence of TP1-XP2-K/RP3-DP4-D/EP5-ZP6-X/ZP7 (X = aromatic, Z = non-polar). The phage peptide sequence with highest affinity binding to AVR1674/1675 was identified as T-F-K-D-E-I-V. Synthetic oligopeptides were designed based on the phage sequences and interacted with mAbs with high affinity (KD~ 10−9 M). Single amino acid substitutions of A, H, or Q in the peptides identified positions P1–P5 as critical residues for mAb-peptide interactions. CLUSTALW alignment of phage sequences with native LF implicated residues 644–650 (sequence T-H-Q-D-E-I-Y) as a putative linear epitope component located within a structural loop (L2) of LF Domain IV. The activation effects of these mAbs contribute to the analytic sensitivity of function-based LF detection assays. © 2017 by the authors. Licensee MDPI, Basel, Switzerland. |
The salt-sensitive structure and zinc inhibition of Borrelia burgdorferi protease BbHtrA
Russell TM , Tang X , Goldstein JM , Bagarozzi D , Johnson BJ . Mol Microbiol 2015 99 (3) 586-96 HtrA serine proteases are highly conserved and essential ATP-independent proteases with chaperone activity. Bacteria express a variable number of HtrA homologs which contribute to the virulence and pathogenicity of bacterial pathogens. Lyme disease spirochetes possess a single HtrA protease homolog, Borrelia burgdorferi HtrA (BbHtrA). Previous studies established that, like the human orthologue HtrA1, BbHtrA is proteolytically active against numerous extracellular proteins in vitro. In this study, we utilized size exclusion chromatography and blue native polyacrylamide gel electrophoresis (BN-PAGE) to demonstrate BbHtrA oligomeric structures which were substrate-independent and salt sensitive. Examination of the influence of transition metals on the activity of BbHtrA revealed that this protease is inhibited by Zn2+ >Cu2+ >Mn2+ . Extending this analysis to two other HtrA proteases, E. coli DegP and HtrA1, revealed that all three HtrA proteases were reversibly inhibited by ZnCl2 at all micro molar concentrations examined. Commercial inhibitors for HtrA proteases are not available and physiologic HtrA inhibitors are unknown. Our observation of conserved zinc inhibition of HtrA proteases will facilitate structural and functional studies of additional members of this important class of proteases. |
Production of a Sindbis/Eastern Equine Encephalitis chimeric virus inactivated cell culture antigen
Goodman CH , Russell BJ , Velez JO , Laven JJ , Bagarozzi DA Jr , Moon JL , Bedi K , Johnson BW . J Virol Methods 2015 223 19-24 Eastern Equine Encephalitis virus (EEEV) is a medically important pathogen that can cause severe encephalitis in humans, with mortality rates ranging from 30 to 80%. Unfortunately there are no antivirals or licensed vaccines available for human use, and laboratory diagnosis is essential to differentiate EEEV infection from other pathogens with similar clinical manifestations. The Arboviral Diseases Branch (ADB) reference laboratory at the CDC Division of Vector-Borne Diseases (DVBD) produces reference antigens used in serological assays such as the EEEV immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). However, EEEV is classified as a HHS select agent and requires biosafety level (BSL) three containment, limiting EEEV antigen production in non-select agent and BSL-2 laboratories. A recombinant Sindbis virus (SINV)/EEEV has been constructed for use under BSL-2 conditions and is not regulated as a select agent. Cell culture production of inactivated EEEV antigen from SINV/EEEV for use in the EEEV MAC-ELISA is reported here. Cell culture conditions and inactivation procedures were analyzed for SINV/EEEV using a recently developed antigen production algorithm, with the MAC-ELISA as the performance indicator. |
A highly specific monoclonal antibody against monkeypox virus detects the heparin binding domain of A27
Hughes LJ , Goldstein J , Pohl J , Hooper JW , Lee Pitts R , Townsend MB , Bagarozzi D , Damon IK , Karem KL . Virology 2014 464-465c 264-273 The eradication of smallpox and the cessation of global vaccination led to the increased prevalence of human infections in Central Africa. Serologic and protein-based diagnostic assay for MPXV detection is difficult due to cross-reactive antibodies that do not differentiate between diverse orthopoxvirus (OPXV) species. A previously characterized monoclonal antibody (mAb 69-126-3-7) against MPXV [1] was retested for cross-reactivity with various OPXVs. The 14.5kDa band protein that reacted with mAb 69-126-3 was identified to be MPXV A29 protein (homolog of vaccinia virus Copenhagen A27). Amino acid sequence analysis of the MPXV A29 with other OPXV homologs identified four amino acid changes. Peptides corresponding to these regions were designed and evaluated for binding to mAb 69-126-3 by ELISA and BioLayer Interferometry (BLI). Further refinement and truncations mapped the specificity of this antibody to a single amino acid difference in a 30-mer peptide compared to other OPXV homologs. This particular residue is proposed to be essential for heparin binding by VACV A27 protein. Despite this substitution, MPXV A29 bound to heparin with similar affinity to that of VACV A27 protein, suggesting flexibility of this motif for heparin binding. Although binding of mAb 69-126-3-7 to MPXV A29 prevented interaction with heparin, it did not have any effect on the infectivity of MPXV. Characterization of 69-126-3-7 mAb antibody allows for the possibility of the generation of a serological based species-specific detection of OPXVs despite high proteomic homology. |
Development of an algorithm for production of inactivated arbovirus antigens in cell culture
Goodman CH , Russell BJ , Velez JO , Laven JJ , Nicholson WL , Bagarozzi DA Jr , Moon JL , Bedi K , Johnson BW . J Virol Methods 2014 208 66-78 Arboviruses are medically important pathogens that cause human disease ranging from a mild fever to encephalitis. Laboratory diagnosis is essential to differentiate arbovirus infections from other pathogens with similar clinical manifestations. The Arboviral Diseases Branch (ADB) reference laboratory at the CDC Division of Vector-Borne Diseases (DVBD) produces reference antigens used in serological assays such as the virus-specific immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Antigen production in cell culture has largely replaced the use of suckling mice; however, the methods are not directly transferable. The development of a cell culture antigen production algorithm for nine arboviruses from the three main arbovirus families, Flaviviridae, Togaviridae, and Bunyaviridae, is described here. Virus cell culture growth and harvest conditions were optimized, inactivation methods were evaluated, and concentration procedures were compared for each virus. Antigen performance was evaluated by the MAC-ELISA at each step of the procedure. The antigen production algorithm is a framework for standardization of methodology and quality control; however, a single antigen production protocol was not applicable to all arboviruses and needed to be optimized for each virus. |
Detection of anthrax protective antigen (PA) using europium labeled anti-PA monoclonal antibody and time-resolved fluorescence
Stoddard RA , Quinn CP , Schiffer JM , Boyer AE , Goldstein J , Bagarozzi DA , Soroka SD , Dauphin LA , Hoffmaster AR . J Immunol Methods 2014 408 78-88 Inhalation anthrax is a rare but acute infectious disease following adsorption of Bacillus anthracis spores through the lungs. The disease has a high fatality rate if untreated, but early and correct diagnosis has a significant impact on case patient recovery. The early symptoms of inhalation anthrax are, however, non-specific and current anthrax diagnostics are primarily dependent upon culture and confirmatory real-time PCR. Consequently, there may be a significant delay in diagnosis and targeted treatment. Rapid, culture-independent diagnostic tests are therefore needed, particularly in the context of a large scale emergency response. The aim of this study was to evaluate the ability of monoclonal antibodies to detect anthrax toxin proteins that are secreted early in the course of B. anthracis infection using a time-resolved fluorescence (TRF) immunoassay. We selected monoclonal antibodies that could detect protective antigen (PA), as PA83 and also PA63 and LF in the lethal toxin complex. The assay reliable detection limit (RDL) was 6.63 x 10-6muM (0.551ng/ml) for PA83 and 2.51 x 10-5muM (1.58ng/ml) for PA63. Despite variable precision and accuracy of the assay, PA was detected in 9 out of 10 sera samples from anthrax confirmed case patients with cutaneous (n=7), inhalation (n=2), and gastrointestinal (n=1) disease. Anthrax Immune Globulin (AIG), which has been used in treatment of clinical anthrax, interfered with detection of PA. This study demonstrates a culture-independent method of diagnosing anthrax through use of monoclonal antibodies to detect PA and LF in the lethal toxin complex. |
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