Last data update: Apr 29, 2024. (Total: 46658 publications since 2009)
Records 1-10 (of 10 Records) |
Query Trace: Davis BS[original query] |
---|
Comprehensive evaluation of differential serodiagnosis between Zika and dengue viral infection (preprint)
Chao DY , Whitney MT , Davis BS , Medina FA , Munoz JL , Chang GJ . bioRxiv 2018 421628 Diagnostic testing for Zika virus (ZIKV) or dengue virus (DENV) infection can be accomplished by a nucleic acid detection method; however, a negative result does not exclude infection due to the low virus titer during infection depending on the timing of sample collection. Therefore, a ZIKV- or DENV-specific serological assay is essential for the accurate diagnosis of patients and to prevent potential severe health outcomes. A retrospective study design with dual approaches of collecting human serum samples for testing was developed. All serum samples were extensively evaluated by using both non-infectious virus-like particles (VLPs) and soluble non-structural protein 1 (NS1) in the standard immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Both VLP- and NS1-MAC-ELISAs were found to have similar sensitivity for detecting anti-premembrane/envelope and NS1 antibodies from ZIKV-infected patient sera. Group cross reactive (GR)-antibody-ablated homologous fusion peptide-mutated (FP)-VLPs consistently showed higher P/N values than homologous wild-type VLPs. Therefore, FP-VLPs were used to develop the algorithm for differentiating ZIKV from DENV infection. Overall, the sensitivity and specificity of the FP-VLP-MAC-ELISA and the NS1-MAC-ELISA were each higher than 80% with no statistical significance. A novel approach to differentiate ZIKV from DENV infection serologically has been developed. The accuracy can reach up to 95% when combining both VLP and NS1 assays. In comparison to current guidelines using neutralization tests to measure ZIKV antibody, this approach can facilitate laboratory screening for ZIKV infection, especially in regions where DENV infection is endemic and capacity for neutralization testing does not exist. |
Development of HEK-293 cell lines constitutively expressing flaviviral antigens for use in diagnostics
Powers JA , Skinner B , Davis BS , Biggerstaff BJ , Robb L , Gordon E , Calvert AE , Chang GJ . Microbiol Spectr 2022 10 (3) e0059222 Flaviviruses are important human pathogens worldwide. Diagnostic testing for these viruses is difficult because many of the pathogens require specialized biocontainment. To address this issue, we generated 39 virus-like particle (VLP)- and nonstructural protein 1 (NS1)-secreting stable cell lines in HEK-293 cells of 13 different flaviviruses, including dengue, yellow fever, Japanese encephalitis, West Nile, St. Louis encephalitis, Zika, Rocio, Ilheus, Usutu, and Powassan viruses. Antigen secretion was stable for at least 10 cell passages, as measured by enzyme-linked immunosorbent assays and immunofluorescence assays. Thirty-five cell lines (90%) had stable antigen expression over 10 passages, with three of these cell lines (7%) increasing in antigen expression and one cell line (3%) decreasing in antigen expression. Antigen secretion in the HEK-293 cell lines was higher than in previously developed COS-1 cell line counterparts. These antigens can replace current antigens derived from live or inactivated virus for safer use in diagnostic testing. IMPORTANCE Serological diagnostic testing for flaviviral infections is hindered by the need for specialized biocontainment for preparation of reagents and assay implementation. The use of previously developed COS-1 cell lines secreting noninfectious recombinant viral antigen is limited due to diminished antigen secretion over time. Here, we describe the generation of 39 flaviviral virus-like particle (VLP)- and nonstructural protein 1 (NS1)-secreting stable cell lines in HEK-293 cells representing 13 medically important flaviviruses. Antigen production was more stable and statistically higher in these newly developed cell lines than in their COS-1 cell line counterparts. The use of these cell lines for production of flaviviral antigens will expand serological diagnostic testing of flaviviruses worldwide. |
Monoclonal antibodies to Cache Valley virus for serological diagnosis.
Skinner B , Mikula S , Davis BS , Powers JA , Hughes HR , Calvert AE . PLoS Negl Trop Dis 2022 16 (1) e0010156 Cache Valley virus (CVV) is a mosquito-borne virus in the genus Orthobunyavirus, family Peribunyaviridae. It was first isolated from a Culiseta inorata mosquito in Cache Valley, Utah in 1956 and is known to circulate widely in the Americas. While only a handful of human cases have been reported since its discovery, it is the causative agent of fetal death and severe malformations in livestock. CVV has recently emerged as a potential viral pathogen causing severe disease in humans. Currently, the only serological assay available for diagnostic testing is plaque reduction neutralization test which takes several days to perform and requires biocontainment. To expand diagnostic capacity to detect CVV infections by immunoassays, 12 hybridoma clones secreting anti-CVV murine monoclonal antibodies (MAbs) were developed. All MAbs developed were found to be non-neutralizing and specific to the nucleoprotein of CVV. Cross-reactivity experiments with related orthobunyaviruses revealed several of the MAbs reacted with Tensaw, Fort Sherman, Tlacotalpan, Maguari, Playas, and Potosi viruses. Our data shows that MAbs CVV14, CVV15, CVV17, and CVV18 have high specific reactivity as a detector in an IgM antibody capture test with human sera. |
Comprehensive evaluation of differential serodiagnosis between Zika and dengue viral infections
Chao DY , Whitney MT , Davis BS , Medina FA , Munoz JL , Chang GJ . J Clin Microbiol 2019 57 (3) Diagnostic testing for Zika virus (ZIKV) or dengue virus (DENV) infection can be accomplished by a nucleic acid detection method; however, a negative result does not exclude infection due to the low virus titer during infection depending on the timing of sample collection. Therefore, a ZIKV- or DENV-specific serological assay is essential for the accurate diagnosis of patients and to mitigate potential severe health outcomes. A retrospective study design with dual approaches of collecting human serum samples for testing was developed. All serum samples were extensively evaluated by using both noninfectious wild-type (wt) virus-like particles (VLPs) and soluble nonstructural protein 1 (NS1) in the standard immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Both ZIKV-derived wt-VLP- and NS1-MAC-ELISAs were found to have similar sensitivities for detecting anti-premembrane/envelope and NS1 antibodies from ZIKV-infected patient sera, although lower cross-reactivity to DENV2/3-NS1 was observed. Furthermore, group cross-reactive (GR)-antibody-ablated homologous fusion peptide-mutated (FP)-VLPs consistently showed higher positive-to-negative values than homologous wt-VLPs. Therefore, we used DENV-2/3 and ZIKV FP-VLPs to develop a novel, serological algorithm for differentiating ZIKV from DENV infection. Overall, the sensitivity and specificity of the FP-VLP-MAC-ELISA and the NS1-MAC-ELISA were each higher than 80%, with no statistical significance. The accuracy can reach up to 95% with the combination of FP-VLP and NS1 assays. In comparison to current guidelines using neutralization tests to measure ZIKV antibody, this approach can facilitate laboratory screening for ZIKV infection, especially in regions where DENV infection is endemic and capacity for neutralization testing does not exist. |
Differential neurovirulence of African and Asian genotype Zika virus isolates in outbred immunocompetent mice
Duggal NK , Ritter JM , McDonald EM , Romo H , Guirakhoo F , Davis BS , Chang GJ , Brault AC . Am J Trop Med Hyg 2017 97 (5) 1410-1417 Although first isolated almost 70 years ago, Zika virus (ZIKV; Flavivirus, Flaviviridae) has only recently been associated with significant outbreaks of disease in humans. Several severe ZIKV disease manifestations have also been recently documented, including fetal malformations, such as microcephaly, and Guillain-Barre syndrome in adults. Although principally transmitted by mosquitoes, sexual transmission of ZIKV has been documented. Recent publications of several interferon receptor knockout mouse models have demonstrated ZIKV-induced disease. Herein, outbred immunocompetent CD-1/ICR adult mice were assessed for susceptibility to disease by intracranial (i.c.) and intraperitoneal (i.p.) inoculation with the Ugandan prototype strain (MR766; African genotype), a low-passage Senegalese strain (DakAr41524; African genotype) and a recent ZIKV strain isolated from a traveler infected in Puerto Rico (PRVABC59; Asian genotype). Morbidity was not observed in mice inoculated by the i.p. route with either MR766 or PRVABC59 for doses up to 6 log10 PFU. In contrast, CD-1/ICR mice inoculated i.c. with the MR766 ZIKV strain exhibited an 80-100% mortality rate that was age independent. The DakAr41524 strain delivered by the i.c route caused 30% mortality, and the Puerto Rican ZIKV strain failed to elicit mortality but did induce a serum neutralizing immune response in 60% of mice. These data provide a potential animal model for assessing neurovirulence determinants of different ZIKV strains as well as a potential immunocompetent challenge model for assessing protective efficacy of vaccine candidates. |
Frequent Zika virus sexual transmission and prolonged viral RNA shedding in an immunodeficient mouse model
Duggal NK , Ritter JM , Pestorius SE , Zaki SR , Davis BS , Chang GJ , Bowen RA , Brault AC . Cell Rep 2017 18 (7) 1751-1760 Circulation of Zika virus (ZIKV) was first identified in the Western hemisphere in late 2014. Primarily transmitted through mosquito bite, ZIKV can also be transmitted through sex and from mother to fetus, and maternal ZIKV infection has been associated with fetal malformations. We assessed immunodeficient AG129 mice for their capacity to shed ZIKV in semen and to infect female mice via sexual transmission. Infectious virus was detected in semen between 7 and 21 days post-inoculation, and ZIKV RNA was detected in semen through 58 days post-inoculation. During mating, 73% of infected males transmitted ZIKV to uninfected females, and 50% of females became infected, with evidence of fetal infection in resulting pregnancies. Semen from vasectomized mice contained significantly lower levels of infectious virus, though sexual transmission still occurred. This model provides a platform for studying the kinetics of ZIKV sexual transmission and prolonged RNA shedding also observed in human semen. |
Can reductions in the cross-reactivity of flavivirus structural proteins lead to improved safety and immunogenicity of tetravalent dengue vaccine?
Chao DY , Crill WD , Davis BS , Chang GJJ . Future Virol 2015 10 (5) 477-480 The most advanced dengue vaccine in clinical development is the tetravalent chimeric yellow fever-17D dengue (TCYD) vaccine. Optimistically, this vaccine could be available globally in the very near future, which may potentially reduce the burden of dengue disease [1]. The TCYD vaccine was estimated to achieve 56% efficacy based on primary end point calculations from two Phase III efficacy trials in Asia and Latin America and the efficacies were higher among trial participants with prior dengue virus (DENV) exposure [2]. Several concerns have been raised due to unexpected lower overall efficacy for all DENV serotypes, particularly for DENV-2 [3,4]; thus, there is a need to develop second-generation dengue vaccines to improve efficacy of the current TCYD vaccine. There are other dengue vaccine candidates in clinical trial and research development, but none of them are attempting to modulate the immune responses to improve the vaccine safety and efficacy. In this editorial, we will discuss the principle of immune modulation based on cross-reactivity reduction (CRR) immunogens and the rationale of this approach in the development of second-generation tetravalent dengue vaccine. |
Non-structural protein 1-specific immunoglobulin M and G antibody-capture enzyme-linked immunosorbent assays in diagnosis of flaviviral infections in humans
Chao DY , Galula JU , Shen WF , Davis BS , Chang GJ . J Clin Microbiol 2014 53 (2) 557-66 IgM antibody- and IgG antibody-capture ELISAs (MAC/GAC-ELISA) targeted at envelope protein (E) of dengue viruses (DENV), West Nile virus and Japanese encephalitis virus (JEV) are widely used as sero-diagnostic tests for presumptive confirmation of viral infection. Antibodies directed against the flavivirus nonstructural protein-1 (NS1) have been proposed as serological markers of natural infections among vaccinated populations. The aim of the current study is to optimize an IgM and IgG antibody-capture ELISAs (MAC/GAC-ELISA) to detect anti-NS1 antibodies and compare it with anti-E MAC/GAC-ELISA. Plasmids to express premembrane/envelope (prM/E) or NS1 proteins of six medically important flaviviruses, including dengue (DENV-1 to DENV-4), West Nile (WNV) and Japanese encephalitis (JEV) viruses, were constructed. These plasmids were used for the productions of prM/E containing virus-like particles (VLPs) and secreted NS1 (sNS1) from COS-1 cells. Archived clinical specimens from patients with confirmed DENV, JEV, WNV infections, along with naive sera, were subjected to NS1-MAC/GAC-ELISAs before or after depletion of anti-prM/E antibodies by pre-absorption with or without VLPs. Human serum specimens from previously confirmed DENV infections showed significantly enhanced P/N ratios for NS1-MAC/GAC-ELISAs after the depletion of anti-prM/E antibodies. No statistical differences in sensitivities and specificities were found between the newly developed NS1- and VLP-MAC/GAC-ELISAs. Further application of the assays to WNV and JEV infected serum panels showed similar results. A novel approach to perform MAC/GAC-ELISAs for NS1 antibody detection was successfully developed with great potential to differentiate antibodies elicited by the tetravalent chimeric yellow fever-17D/dengue vaccine or DENV infection. |
Sculpting humoral immunity through dengue vaccination to enhance protective immunity
Crill WD , Hughes HR , Trainor NB , Davis BS , Whitney MT , Chang GJ . Front Immunol 2012 3 334 Dengue viruses (DENV) are the most important mosquito transmitted viral pathogens infecting humans. DENV infection produces a spectrum of disease, most commonly causing a self-limiting flu-like illness known as dengue fever; yet with increased frequency, manifesting as life-threatening dengue hemorrhagic fever (DHF). Waning cross-protective immunity from any of the four dengue serotypes may enhance subsequent infection with another heterologous serotype to increase the probability of DHF. Decades of effort to develop dengue vaccines are reaching the finishing line with multiple candidates in clinical trials. Nevertheless, concerns remain that imbalanced immunity, due to the prolonged prime-boost schedules currently used in clinical trials, could leave some vaccinees temporarily unprotected or with increased susceptibility to enhanced disease. Here we develop a DENV serotype 1 (DENV-1) DNA vaccine with the immunodominant cross-reactive B cell epitopes associated with immune enhancement removed. We compare wild-type (WT) with this cross-reactivity reduced (CRR) vaccine and demonstrate that both vaccines are equally protective against lethal homologous DENV-1 challenge. Under conditions mimicking natural exposure prior to acquiring protective immunity, WT vaccinated mice enhanced a normally sub-lethal heterologous DENV-2 infection resulting in DHF-like disease and 95% mortality in AG129 mice. However, CRR vaccinated mice exhibited redirected serotype-specific and protective immunity, and significantly reduced morbidity and mortality not differing from nasmall yi, Ukrainianve mice. Thus, we demonstrate in an in vivo DENV disease model, that non-protective vaccine-induced immunity can prime vaccinees for enhanced DHF-like disease and that CRR DNA immunization significantly reduces this potential vaccine safety concern. The sculpting of immune memory by the modified vaccine and resulting redirection of humoral immunity provide insight into DENV vaccine-induced immune responses. |
A West Nile virus CD4 T cell epitope improves the immunogenicity of dengue virus serotype 2 vaccines
Hughes HR , Crill WD , Davis BS , Chang GJ . Virology 2012 424 (2) 129-37 Flaviviruses, such as dengue virus (DENV) and West Nile virus (WNV), are among the most prevalent human disease-causing arboviruses world-wide. As they continue to expand their geographic range, multivalent flavivirus vaccines may become an important public health tool. Here we describe the immune kinetics of WNV DNA vaccination and the identification of a CD4 epitope that increases heterologous flavivirus vaccine immunogenicity. Lethal WNV challenge two days post-vaccination resulted in 90% protection with complete protection by four days, and was temporally associated with a rapid influx of activated CD4 T cells. CD4 T cells from WNV vaccinated mice could be stimulated from epitopic regions in the envelope protein transmembrane domain. Incorporation of this WNV epitope into DENV-2 DNA and virus-like particle vaccines significantly increased neutralizing antibody titers. Incorporating such potent epitopes into multivalent flavivirus vaccines could improve their immunogenicity and may help alleviate concerns of imbalanced immunity in multivalent vaccine approaches. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Apr 29, 2024
- Content source:
- Powered by CDC PHGKB Infrastructure