Enhancement of sindbis virus self-replicating RNA vaccine potency by targeting antigen to endosomal/lysosomal compartments
Journal
Human Gene Therapy
Journal Volume
12
Journal Issue
3
Pages
235-252
Date Issued
2001
Author(s)
Abstract
Self-replicating RNA vaccines (RNA replicons) have emerged as an attractive approach for tumor immunotherapy. RNA replicons do not integrate into host chromosomes, eliminating the concern for oncogenicity associated with a DNA vaccine. In this study, we used human papillomavirus type 16 (HPV-16) E7 as a model antigen and evaluated E7-specific immunity generated by a Sindbis virus self-replicating RNA vector, SIN-rep5. Three different constructs were created to target E7 antigen to different cellular localizations: (1) E7, a cytosolic/nuclear protein; (2) Sig/E7, a secretory protein; (3) Sig/E7/LAMP-1, in which we linked the transmembrane and cytoplasmic regions of the lysosome-associated membrane protein 1 (LAMP-1) to E7 protein to target E7 to the endosomal/lysosomal compartment. We found that the RNA replicon vaccine containing the Sig/E7/LAMP-1 fusion gene generated the highest E7-specific T cell-mediated immune responses and antitumor effects relative to RNA vaccines containing either wild-type E7 or Sig/E7. Our in vitro studies demonstrated that E7 antigen from Sig/E7/LAMP-1 RNA replicon-transfected apoptotic cells can be taken up by bone marrow-derived dendritic cells (DCs) and presented more efficiently through the MHC class I pathway than wild-type E7 RNA replicon-transfected apoptotic cells. Furthermore, our data revealed that CD8+ T cells, CD4+ T cells, and NK cells were important for the antitumor effects generated by Sig/E7/LAMP-1 RNA vaccination. These results indicate that targeting antigen to the endosomal/lysosomal compartment via fusion to LAMP-1 may greatly enhance the potency of self-replicating RNA vaccines.
SDGs
Other Subjects
DNA vaccine; major histocompatibility antigen class 1; membrane protein; virus antigen; virus vaccine; animal cell; animal experiment; antineoplastic activity; article; cancer immunotherapy; controlled study; dendritic cell; drug potency; endosome; female; fusion gene; gene targeting; immune response; lysosome; mouse; natural killer cell; nonhuman; replicon; Sindbis virus; T lymphocyte; virus replication; Wart virus; Animals; Antigens, CD; Apoptosis; Bone Marrow Cells; Cancer Vaccines; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Line; Cell Membrane; Cricetinae; Dendritic Cells; DNA; Endosomes; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Genes, MHC Class I; Humans; In Situ Nick-End Labeling; Killer Cells, Natural; Lysosome-Associated Membrane Glycoproteins; Lysosomes; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Neoplasms; Oncogene Proteins, Viral; Phagocytosis; Plasmids; Sindbis Virus; Spleen; T-Lymphocytes, Cytotoxic; Time Factors; Transfection; Vaccines, DNA; Animalia; Human papillomavirus; Human papillomavirus type 16; Human papillomavirus types; Sindbis virus
Type
journal article