Shiga Toxin/Peptide Vaccine Elicits Cytotoxic T-Lymphocyte Responses.(Brief Article)

2001 FEB 21 - (NewsRx.com & NewsRx.net) --

by Michelle Marble, staff medical writer -- Researchers in France have developed a cancer vaccine that works without an adjuvant.

"Immunization with peptide or recombinant proteins generally fails to elicit cytotoxic T lymphocytes (CTL), which are thought to play a key role in the control of virus-infected cells and tumor growth," said N. Haicheur and colleagues, University of Paris. "In this study we show that the non-toxic B subunit of Shiga toxin fused to a tumor peptide derived from the mouse mastocytoma P815 can induce specific CTL in mice without the use of adjuvant."

Haicheur et al. published their study in the Journal of Immunology ("The B subunit of Shiga toxin fused to a tumor antigen elicits CTL and targets dendritic cells to allow MHC class I-restricted presentation of peptides derived from exogenous antigens," J Immunol, 2000;165(6):3301-3308).

"The Shiga B subunit acts as a vector rather than as an adjuvant because co-injection of the tumor peptide and the B subunit as separate entities does not lead to CTL induction," the researchers said.

They demonstrated through in vitro experiments that the B subunit mediated the delivery of various exogenous CD8 T-cell epitopes into the conventional major histocompatibility complex (MHC) class I-restricted pathway. They reported ...