The major accomplishments for this year are summarized below. 1) Previously, we reported the isolation of henipavirus-neutralizing recombinant hmAbs including one, m102.4, which exhibited exceptionally potent and cross-reactive inhibitory activity against both HeV and NiV. HeV is a recently emerged zoonotic paramyxovirus that can cause a severe and often fatal disease in horses and humans. HeV is categorized as a biosafety level 4 agent, which has made the development of animal models and testing of potential therapeutics and vaccines challenging. Infection of African green monkeys (AGMs) with HeV was recently demonstrated, and disease mirrored fatal HeV infection in humans, manifesting as a multisystemic vasculitis with widespread virus replication in vascular tissues and severe pathologic manifestations in the lung, spleen, and brain. We demonstrated that m102.4 can protect AGMs from disease after infection with HeV. Fourteen AGMs were challenged intratracheally with a lethal dose of HeV, and 12 subjects were infused twice with a 100-mg dose of m102.4 beginning at either 10, 24, or 72 hours after infection and again about 48 hours later. The presence of viral RNA, infectious virus, and HeV-specific immune responses demonstrated that all subjects were infected after challenge. All 12 AGMs that received m102.4 survived infection, whereas the untreated control subjects succumbed to disease on day 8 after infection. Animals in the 72-hour treatment group exhibited neurological signs of disease, but all animals started to recover by day 16 after infection. These results represent successful post-exposure in vivo efficacy by an investigational drug against HeV and highlight the potential impact a hmAb can have on human disease. In summary, these results and previous results from animal studies and three humans administered with this mAb confirm our proposition that m102.4 has potential as a therapeutic for treatment of diseases caused by henipaviruses, and could save human lives now. It could be also used for prophylaxis, diagnosis and as a research reagent. Animal studies with this antibody continue and more are planned with GMP produced m102.4.2) We have also performed experiments to identify neutralizing hmAbs against dengue virus. Several mAbs against dengue virus were identified and are being characterized. Some of them exhibit potent neutralizing activity against representative isolates from the four dengue serotypes. The mAbs against dengue could be used as candidate therapeutics and diagnostics and as tools for development of vaccine immunogens. 3) The Crimean-Congo hemorrhagic fever virus (CCHFV) has two Envs, Gn and Gc, with poorly understood role in binding to susceptible cells. We expressed codon optimized Gn and Gc, and identified independently folded soluble Env fragments, one of which (Gc residues 180-300) bound CCHFV susceptible cells supposedly by interacting with a putative receptor. This receptor binding domain (RBD) was used to identify its interacting partner by coimmunoprecipitation and mass spectrometry. Thus we identified the human cell surface nucleolin as a putative CCHFV entry factor. Nucleolin was expressed on all susceptible cells tested but not on the surface of cells resistant to CCHFV infection. Further studies are needed to explore the nucleolin function as a plausible CCHFV receptor and the molecular mechanisms of the Gc-nucleolin interactions. The identification of the CCHFV RBD and its binding partner could provide novel targets for therapy and tools for prevention as well as more complete understanding of the mechanisms of CCHFV entry and pathogenesis.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIABC011156-04
Application #
8553008
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
4
Fiscal Year
2012
Total Cost
$276,826
Indirect Cost
Name
National Cancer Institute Division of Basic Sciences
Department
Type
DUNS #
City
State
Country
Zip Code
Houser, Katherine V; Gretebeck, Lisa; Ying, Tianlei et al. (2016) Prophylaxis With a Middle East Respiratory Syndrome Coronavirus (MERS-CoV)-Specific Human Monoclonal Antibody Protects Rabbits From MERS-CoV Infection. J Infect Dis 213:1557-61
Ying, Tianlei; Li, Wei; Dimitrov, Dimiter S (2016) Discovery of T-Cell Infection and Apoptosis by Middle East Respiratory Syndrome Coronavirus. J Infect Dis 213:877-9
Ying, Tianlei; Prabakaran, Ponraj; Du, Lanying et al. (2015) Junctional and allele-specific residues are critical for MERS-CoV neutralization by an exceptionally potent germline-like antibody. Nat Commun 6:8223
Dimitrov, Dimiter S; Jiang, Shibo; Ying, Tianlei et al. (2015) No evidence for a superior platform to develop therapeutic antibodies rapidly in response to MERS-CoV and other emerging viruses. Proc Natl Acad Sci U S A 112:E5115
Ying, Tianlei; Li, Haoyang; Lu, Lu et al. (2015) Development of human neutralizing monoclonal antibodies for prevention and therapy of MERS-CoV infections. Microbes Infect 17:142-8
Geisbert, Thomas W; Mire, Chad E; Geisbert, Joan B et al. (2014) Therapeutic treatment of Nipah virus infection in nonhuman primates with a neutralizing human monoclonal antibody. Sci Transl Med 6:242ra82
Ying, Tianlei; Du, Lanying; Ju, Tina W et al. (2014) Exceptionally potent neutralization of Middle East respiratory syndrome coronavirus by human monoclonal antibodies. J Virol 88:7796-805
Zhu, Zhongyu; Prabakaran, Ponraj; Chen, Weizao et al. (2013) Human monoclonal antibodies as candidate therapeutics against emerging viruses and HIV-1. Virol Sin 28:71-80
Chen, Weizao; Streaker, Emily D; Russ, Daniel E et al. (2012) Characterization of germline antibody libraries from human umbilical cord blood and selection of monoclonal antibodies to viral envelope glycoproteins: Implications for mechanisms of immune evasion and design of vaccine immunogens. Biochem Biophys Res Commun 417:1164-9
Zhao, Qi; Zhu, Zhongyu; Dimitrov, Dimiter S (2012) Yeast display of engineered antibody domains. Methods Mol Biol 899:73-84

Showing the most recent 10 out of 16 publications