Phenotypical and functional characterization of non-human primate Aotus spp. dendritic cells and their use as a tool for characterizing immune response to protein antigens

A population of cells exhibiting bona fide dendritic cell (DC) morphological and functional characteristics was obtained by treating Aotus spp. monocytes with human IL-4 and GM-CSF. Although the purity of mature DCs was relatively low IL-4/GM-CSF-treated monocytes (hereafter called Aotus spp. DCs) down-regulated CD14 and up-regulated discrete levels of CD80, MHC-Class II and CD1b molecules in response to different maturation stimuli. Aotus spp. DCs generated a potent allogeneic in vitro response evidenced in mixed lymphocyte reaction (MLR) where DCs were 2- to 10-fold more efficient than peripheral blood mononuclear cells (PBMCs). Aotus spp. DC ability to boost T-cells or priming naive T-cells in vivo was proved by vaccinating Aotus spp. with autologous DCs pulsed with tetanus toxoid (TT). A single dose of TT-pulsed DCs was sufficient to increase cellular response to TT in these experiments as assessed by lymphoproliferation and cytokine production. Since Aotus spp. represents a suitable animal model for evaluating anti-Plasmodium falciparum malaria vaccine, the results shown here suggest that using antigen-pulsed Aotus spp. DCs as vaccines might lead to identifying new prospects for malarial vaccines unidentified to date because they are being formulated in less efficient adjuvants.