CD8+ T Lymphocyte Expansion,Proliferation and Activation in Dengue Fever

Dengue fever induces a robust immune response,including massive t cell activation. the level of t cell activation may,however,be associated with more severe disease. in this study,we explored the level of cd8+ t lymphocyte activation in the first six days after onset of symptoms during a denv2 outbreak in early 2010 on the coast of são paulo state,brazil. using flow cytometry we detected a progressive increase in the percentage of cd8+ t cells in 74 dengue fever cases. peripheral blood mononuclear cells from 30 cases were thawed and evaluated using expanded phenotyping. the expansion of the cd8+ t cells was coupled with increased ki67 expression. cell activation was observed later in the course of disease,as determined by the expression of the activation markers cd38 and hla-dr. this increased cd8+ t lymphocyte activation was observed in all memory subsets,but was more pronounced in the effector memory subset,as defined by higher cd38 expression. our results show that most cd8+ t cell subsets are expanded during denv2 infection and that the effector memory subset is the predominantly affected sub population. © 2015 de matos et al.