The cell surface translocation of calreticulin (ecto-CRT) serves as an "eat me" signal for phagocytosis of dying cells, which plays a pivotal role in activating anti-tumor immunity.
Calreticulin (CRT), a multifunctional Ca<sup>2+</sup>-binding glycoprotein mainly located in the endoplasmic reticulum, is a tumor-associated antigen that has been shown to play protective roles in angiogenesis suppression and anti-tumor immunity.
Taken together, these results suggest that local CIRT combined with IV DCs augments an immunogenicity of the tumor cells by ecto-calreticulin expression and the maturation of DCs to stimulate anti-tumor immunity to decrease lung metastases.
To enhance the immunogenecity of CEA, we developed a fusion gene (CRT-TAT-DeltaCEA) of the TAT protein transduction domain (PTD) and calreticulin (CRT) with human CEA devoid of its signal sequences (DeltaCEA) and evaluated anti-tumor immunity using RNA-pulsed dendritic cell (DC) vaccination.