Innate immunity phenotypic features point toward simultaneous raise of activation and modulation events following 17DD live attenuated yellow fever first-time vaccination

Detailed multiparametric phenotypic investigation aiming to characterize the kinetics of the innate immune response in the peripheral blood following 17DD yellow fever (17DD-YF) first-time vaccination was performed. Results showed increased frequency of monocytes and NK cell subpopulations besides unexpected up-regulation of granulocytes activation status (CD28(+)/CD23(+) and CD28(+)/HLA-DR+, respectively). Up-regulation of Fc gamma-R and IL-10-R expression emerge as putative events underlying the mixed pattern of phenotypic features triggered by the 17DD yellow fever (17DD-YF) vaccination. Mixed pattern of chemokine receptors expression further support our hypothesis that a parallel establishment of activation/ modulation microenvironment plays a pivotal role in the protective immunity triggered by the 17DD-YF vaccine. (C) 2008 Elsevier Ltd. All rights reserved.