TY - JOUR
T1 - Host ER-parasitophorous vacuole interaction provides a route of entry for antigen cross-presentation in Toxoplasma gondii- I nfected dendritic cells
AU - Goldszmid, Romina S.
AU - Coppens, Isabelle
AU - Lev, Avital
AU - Caspar, Pat
AU - Mellman, Ira
AU - Sher, Alan
PY - 2009/2/16
Y1 - 2009/2/16
N2 - Toxoplasma gondii tachyzoites infect host cells by an active invasion process leading to the formation of a specialized compartment, the parasitophorous vacuole (PV). PVs resist fusion with host cell endosomes and lysosomes and are thus distinct from phagosomes. Because the parasite remains sequestered within the PV, it is unclear how T. gondii-derived antigens (Ag 's) access the major histocompatibility complex (MHC) class I pathway for presentation to CD8 + T cells. We demonstrate that recruitment of host endoplasmic reticulum (hER) to the PV in T. gondii-infected dendritic cells (DCs) directly correlates with cross-priming of CD8 + T cells. Furthermore, we document by immunoelectron microscopy the transfer of hER components into the PV, a process indicative of direct fusion between the two compartments. In strong contrast, no association between hER and phagosomes or Ag presentation activity was observed in DCs containing phagocytosed live or dead parasites. Importantly, cross-presentation of parasite-derived Ag in actively infected cells was blocked when hER retrotranslocation was inhibited, indicating that the hER serves as a conduit for the transport of Ag between the PV and host cytosol. Collectively, these findings demonstrate that pathogen-driven hER-PV interaction can serve as an important mechanism for Ag entry into the MHC class I pathway and CD8 + T cell cross-priming.
AB - Toxoplasma gondii tachyzoites infect host cells by an active invasion process leading to the formation of a specialized compartment, the parasitophorous vacuole (PV). PVs resist fusion with host cell endosomes and lysosomes and are thus distinct from phagosomes. Because the parasite remains sequestered within the PV, it is unclear how T. gondii-derived antigens (Ag 's) access the major histocompatibility complex (MHC) class I pathway for presentation to CD8 + T cells. We demonstrate that recruitment of host endoplasmic reticulum (hER) to the PV in T. gondii-infected dendritic cells (DCs) directly correlates with cross-priming of CD8 + T cells. Furthermore, we document by immunoelectron microscopy the transfer of hER components into the PV, a process indicative of direct fusion between the two compartments. In strong contrast, no association between hER and phagosomes or Ag presentation activity was observed in DCs containing phagocytosed live or dead parasites. Importantly, cross-presentation of parasite-derived Ag in actively infected cells was blocked when hER retrotranslocation was inhibited, indicating that the hER serves as a conduit for the transport of Ag between the PV and host cytosol. Collectively, these findings demonstrate that pathogen-driven hER-PV interaction can serve as an important mechanism for Ag entry into the MHC class I pathway and CD8 + T cell cross-priming.
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U2 - 10.1084/jem.20082108
DO - 10.1084/jem.20082108
M3 - Article
C2 - 19153244
AN - SCOPUS:63049095770
SN - 0022-1007
VL - 206
SP - 399
EP - 410
JO - Journal of Experimental Medicine
JF - Journal of Experimental Medicine
IS - 2
ER -