In vivo, dendritic cells can cross-present virus-like particles using an endosome-to-cytosol pathway

VÍCTOR GABRIEL MORÓN; PALOMA RUEDA; CHRISTINE SEDLIK; CLAUDE LECLERC

JOURNAL OF IMMUNOLOGY

AMER ASSOC IMMUNOLOGISTS

Año: 2003 vol. 171 p. 2242 - 2250

0022-1767

Recombinant parvovirus-like particles (PPV-VLPs) are particulate exogenous Ags that induce strong CTL response in the absenceof adjuvant. In the present report to decipher the mechanisms responsible for CTL activation by such exogenous Ag, we analyzedex vivo and in vitro the mechanisms of capture and processing of PPV-VLPs by dendritic cells (DCs). In vivo, PPV-VLPs are veryefficiently captured by CD8+ and CD8- DCs and then localize in late endosomes of DCs. Macropinocytosis and lipid raftsparticipate in PPV-VLPs capture. Processing of PPV-VLPs does not depend upon recycling of MHC class I molecules, but requiresvacuolar acidification as well as proteasome activity, TAP translocation, and neosynthesis of MHC class I molecules. This studytherefore shows that in vivo DCs can cross-present PPV-VLPs using an endosome-to-cytosol processing pathway.