Human Heavy Chain Antibody Genes Elicited in Thai Dengue Patients during DENV2 Secondary Infection

Dengue is one of the most serious mosquito-borne viral diseases occurring in humans. To combat the complexity of 4 antigenically distinct serotypes, the ideal vaccine for dengue should be able to stimulate cross-neutralizing antibodies. Recently, genetics-based immune responses have been studied to guide vaccine design against several viral pathogens. Despite a recent approval of dengue vaccine, information on genetics-based immune responses against dengue virus (DENV) is still limited. Consequently, we aimed to determine the profiles of immunoglobulin heavy chain genes from DENV2 infected patients. The immunoglobulin heavy chain variable region genes (IGHV) were amplified from peripheral blood mononuclear cells of DENV2 secondary infected patients in the acute, convalescence, and recovery phases. Antibody heavy chain genes were sequenced using next-generation sequencing, and analyzed to identify correlations with neutralizing and enhancing activities of the serum samples. IGHV1-69, 3-23, and 3-30 were frequently discovered in our Thai DENV2 infected patients. Our findings provide new data on the human B cell response during secondary DENV2 infections in Thai dengue patients that offer supportive information for dengue vaccine design and therapeutics development.