Long-term memory cellular immune response to dengue virus after a natural primary infection

Abstract Objectives: This study was conducted to examine the memory T -cell response to dengue virus 20 years after a primary infection. We took advantage of the exceptional epidemiologic situation in Cuba, where the population initially suffered two large successive epidemics due to dengue virus 1 and 2 respectively over a 4-year period. Thereafter, no dengue virus circulation was subsequently observed, except for the Santiago de Cuba municipality. Design: T-cell response was evaluated in peripheral blood mononuclear cells (PBMCs) from 20 individuals with history of a primary infection by dengue virus 1 or 2. Methods previously shown to induce lymphoproliferation of CD4 + memory T-cell subpopulations were used. We evaluated the proliferative responses generated in those PBMCs after stimulation with dengue virus 1, 2, 3 and 4 antigens in a serotype-specific and serotype-crossreactive way. Results: Serotype-specific and serotype-crossreactive lymphoproliferative responses in all PBMCs donated by dengue immune donors were observed. The serotype-crossreactive response for dengue 2 was stronger than for the rest of the serotypes. Conclusions: This is the first report of cellular memory lymphocyte response specific for dengue virus detected 20 years after a primary infection by dengue.