Biology subjects

Velasco, J.

Publications and source records attributed to Velasco, J..

3 recordsLinked to original sources

bioRxiv2018

Human antibody cocktail deploys multiple functions to confer pan-ebolavirus protection

During the unprecedented 2013-2016 Ebola virus disease (EVD) epidemic in Western Africa and in its aftermath, the passive administration of monoclonal antibodies (mAbs) emerged as a promising treatment approach1-7. However, all antibody-based therapeutics currently in advanced development are specific for a single member of the Ebolavirus genus, Ebola virus (EBOV), and ineffective against divergent outbreak-causing ebolaviruses, including Bundibugyo virus (BDBV) and Sudan virus (SUDV)2,3,5,7. Here we advance MBP134, a cocktail of two broadly neutralizing human mAbs targeting the filovirus surface glycoprotein, GP, as a candidate pan-ebolavirus therapeutic. One component of this cocktail is a pan-ebolavirus neutralizing mAb, ADI-15878, isolated from a human EVD survivor8,9. The second, ADI-23774, was derived by affinity maturation of a human mAb8,9 via yeast display to enhance its potency against SUDV. MBP134 afforded exceptionally potent pan-ebolavirus neutralization in vitro and demonstrated greater protective efficacy than ADI-15878 alone in the guinea pig model of lethal EBOV challenge. A second-generation cocktail, MBP134AF, engineered to effectively harness natural killer (NK) cells afforded additional, unprecedented improvements in protective efficacy against EBOV and SUDV in guinea pigs relative to both its precursor and to any mAbs or mAb cocktails tested previously. MBP134AF is a best-in-class mAb cocktail suitable for evaluation as a pan-ebolavirus therapeutic in nonhuman primates.

microbiology↗

bioRxiv2018

Two-antibody pan-ebolavirus cocktail confers broad therapeutic protection in ferrets and nonhuman primates

All available experimental vaccines and immunotherapeutics1,2 against Ebola virus (EBOV), including rVSV-ZEBOV3 and ZMappTM4, lack activity against other ebolaviruses associated with human disease outbreaks. This year, two separate outbreaks of EBOV in the Democratic Republic of Congo underscored the unpredictable nature of ebolavirus reemergence in a region that has historically experienced outbreaks of the divergent ebolaviruses Sudan virus (SUDV) and Bundibugyo virus (BDBV)5. Here we show that MBP134AF, a pan-ebolavirus therapeutic comprising two broadly neutralizing human antibodies (bNAbs)6,7(see companion manuscript, Wec et al.) could protect against lethal EBOV, SUDV, and BDBV infection in ferrets and nonhuman primates (NHPs). MBP134AF not only not only establishes a viable therapeutic countermeasure to outbreaks caused by antigenically diverse ebolaviruses but also affords unprecedented effectiveness and potency--a single 25-mg/kg dose was fully protective in NHPs. This best-in-class antibody cocktail is the culmination of an intensive collaboration spanning academia, industry and government in response to the 2013-2016 EBOV epidemic6,7 and provides a translational research model for the rapid development of immunotherapeutics targeting emerging infectious diseases.

microbiology↗

bioRxiv2017

Nuclear transcriptomes at high resolution using retooled INTACT

Isolated nuclei provide access to early steps in gene regulation involving chromatin as well as transcript production and processing. Here we describe transfer of the Isolation of Nuclei from TAgged specific Cell Types (INTACT) to the monocot rice (Oryza sativa L.). The purification of biotinylated nuclei was redesigned by replacing the outer nuclear envelope-targeting domain of the Nuclear Tagging Fusion (NTF) protein with an outer nuclear envelope-anchored domain. This modified NTF was combined with codon optimized E. coli BirA in a single T-DNA construct. We also developed inexpensive methods for INTACT, T-DNA insertion mapping and profiling of the complete nuclear transcriptome, including a rRNA degradation procedure that minimizes pre-rRNA transcripts. A high-resolution comparison of nuclear and steady-state poly (A)+ transcript populations of seedling root tips confirmed the capture of pre-mRNA and exposed distinctions in diversity and abundance of the nuclear and total transcriptomes. This retooled INTACT can enable high-resolution monitoring of the nuclear transcriptome and chromatin in specific cell-types of rice and other species.\n\nSummaryImproved technology and methodology for affinity purification of nuclei and analysis of nuclear transcriptomes, chromatin and other nuclear components.

plant biology↗