Filoviruses, which include Marburg viruses and Ebola viruses, can cause severe viral hemorrhagic fever in primates including humans. The family Filoviridae includes one species of Marburg virus and five species of Ebola virus (Sudan, Zaire, Reston, Bundibugyo, and Taï Forest). Filoviral hemorrhagic fever is characterized by rapid disease onset and mortality rates of up to 90 percent. The 2014-2016 West Africa outbreak of Ebola killed over 10,000 people as it made the leap from isolated villages to crowded cities.
Following an incubation period of 2-21 days, infected patients commonly develop nonspecific flulike symptoms of fever, vomiting, loss of appetite, headache, abdominal pain, fatigue, and diarrhea, which can be difficult to differentiate from symptoms of other infections. Internal and external bleeding occurs in a smaller number of cases. Fatalities are associated with reduced adaptive immune responses, as well as the release of high levels of immune response mediators that contribute to vascular dysfunction, coagulation disorders, shock, and eventual multi-organ failure.
There is a persistent need for sensitive and reliable serological approaches to diagnose filoviral infections. Because viral genetic material is often missing from lab samples, antibody detection methods are indispensable, especially for examining nonviremic patients and for disease surveillance. ELISA assays for detecting specific IgG and IgM antibodies have been developed, but their utilization of live virus preparations, the requirement for BSL-4 labs, and associated safety issues using live pathogens are major limitations.
To address this diagnostic gap, Army researchers developed a protein microarray assay using recombinant antigens from the six species of Ebola and Marburg viruses, then tested the antibody responses of rhesus macaques to infection and vaccination. The nucleoprotein (NP) and glycoprotein (GP) antigens were most useful for distinguishing Zaire Ebola virus infection from Marburg virus infection, while results with the Marburg virus sera indicated that the VP40 strain of Marburg induced a cross-reactive VP40 antibody response against all Ebola viruses. The florescence-based readout for the microarray proved highly sensitive, and the assay only requires 1 to 2 μl of biological sample for full evaluation.
- A highly sensitive protein microarray displays nucleoprotein, virion protein 40, and glycoprotein antigens from isolates of six filovirus species
- Bound antibodies are detected fluorescently on an inexpensive microarray scanner
- US application number 20170089920 available for license
- Potential for collaboration with Army researchers