A major new class of highly potent and broadly reactive antibodies, which are capable of neutralizing Dengue Virus (DENV), is reported online this week in Nature Immunology. This is the first reported incidence of an antibody that is capable of neutralising all four forms of the virus, including the form present in mosquitoes, and may lead to the development of effective vaccines and treatments for the disease.
Dengue is a rapidly emerging mosquito borne viral infection with an estimated 400 million infections annually. Geographical spread of DENV continues to widen, threatening the Southern United States and Australia, and there is also concern of possible spread to Southern Europe. Infection with one form of the virus leads to life-long protection against that specific form but not against others. In addition, antibody recognition of virus particles is complicated by dramatic changes in the shell of the virus during its lifecycle. There is therefore an urgent need to understand the human immune response to naturally acquired DENV infection and the response following vaccination.
Gavin Screaton and colleagues analysed a large panel of anti-dengue monoclonal antibodies from human patients who were infected with the virus at the time. They found a new class of antibodies that are highly effective at neutralising the virus, which bind to a newly discovered epitope (a unique structure that antibodies can recognise and bind to) that is present in the envelope of all forms of DENV. In lab tests they find that antibodies capable of recognising this structure can efficiently neutralize viruses produced in both insect and human cells. This discovery makes the development of potent and broadly neutralizing antibodies a realistic goal for future vaccines and may also pave the way for a universal DENV vaccine.