Rhoptry and Dense Granule Secreted Effectors Regulate CD8 T Cell Recognition of Infected Host Cells.

secretes rhoptry (ROP) and dense granule (GRA) effector proteins to evade host immune clearance mediated by interferon gamma (IFN-γ), immunity-related GTPase (IRG) effectors, and CD8 T cells. Here, we investigated the role of parasite-secreted effectors in regulating host access to parasitophorous vacuole (PV) localized parasite antigens and their presentation to CD8 T cells by the major histocompatibility class I (MHC-I) pathway. Antigen presentation of PV localized parasite antigens by MHC-I was significantly increased in macrophages and/or dendritic cells infected with mutant parasites that lacked expression of secreted GRA (GRA2, GRA3, GRA4, GRA5, GRA7, GRA12) or ROP (ROP5, ROP18) effectors.

CXCR3 monocytes/macrophages are required for establishment of pulmonary metastases.

We present a new foundational role for CXCR3 monocytes/macrophages in the process of tumor engraftment in the lung. CXCR3 is associated with monocytic and lymphocytic infiltration of inflamed or tumor-bearing lung. Although the requirement for tumor-expressed CXCR3 in metastatic engraftment has been demonstrated, the role of monocyte-expressed CXCR3 had not been appreciated.