Characterization of monoclonal antibodies produced from memory B lymphocytes isolated from patients with primary and secondary dengue virus infection.

• Grant number: 11/13352-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2011
• End date: October 31, 2013
• Field of knowledge: Biological Sciences - Immunology
• Principal Investigator: Silvia Beatriz Boscardin
• Grantee: Catarina Joelma Magalhães Braga
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In recent decades, the number of severe dengue cases has increased dramatically in endemic areas where there is co-circulation of the four dengue virus serotypes. It is believed that the presence of antibodies that react with a virus serotype different from that of the primary infection are responsible for the worsening of the disease. However, the mechanisms responsible for both severity and protection against dengue fever are not completely understood, since no correlates of protection in humans have been found. Almost all knowledge on the pathogenicity of the virus and the humoral immune response comes from studies with antibodies generated in animal models, and the results often do not support what happens in the serum of naturally infected individuals. This project aims to characterize the binding properties of antibodies produced by virus-specific memory B cells isolated from patients with dengue fever and dengue hemorrhagic fever and the functional outcomes of these interactions. Specifically the project will focus on three main experimental steps: (i) obtainment of the recombinant viral envelope (E) protein; (II) obtainment of monoclonal antibodies cloned from memory B lymphocytes specific for the E protein and isolated from peripheral blood of infected individuals, (III) characterization of these antibodies in what refers to specificity, affinity, and neutralization of the viral particle in tests in vitro and in vivo. The development of this approach is unique in the country and represents an important contribution to clinical and applied research for the development of therapies against dengue.