Nanoparticle Boost for Anti-tumour Vaccines

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Researchers have known for some time that certain sequences of synthetic DNA induce potent immune responses when injected into animals and humans. A new study, conducted by Ying Tam, Ph.D., and colleagues at Inex Pharmaceuticals, demonstrates that encapsulating these synthetic DNAs in lipid-based nanoparticles greatly enhances the immunogenicity of these DNAs and that the nanoparticle-encased DNA sequences trigger antitumour activity when administered together with tumour-associated antigens.

Previous work by this group of investigators showed that lipid-based nanoparticles enhance the immune system stimulation activity of so-called CpG oligodeoxynucleotides by improving their uptake by immune cells. This boost occurs regardless of whether the nanoparticles are injected into the bloodstream, beneath the skin (subcutaneously), or directly into a tumour.

In the current study, the results of which were published in the journal Cancer Immunology and Immunotherapy, the investigators wanted to determine if the nanoparticle-encapsulated CpG construct could be used to create antitumour vaccines from tumour-associated antigens. To test this hypothesis, the researchers co-injected the nanoparticles and an antigen known as TRP-2, which is found on melanoma cells, into a mouse model of melanoma. Animals injected with TRP-2 or empty nanoparticles showed no antitumour response. In contrast, mice injected with CpG-containing nanoparticles and TRP-2 showed a large, statistically signficant decrease in the number of lung metastases.

This work is detailed in a paper titled, “Encapsulation in liposomal nanoparticles enhances the immunostimulatory, adjuvant and anti-tumour activity of subcutaneously administered CpG ODN.” Investigators from the University of British Columbia also participated in this study. An abstract of this paper is available through PubMed.





Source: NanoTechWire

http://nanotechwire.com/news.asp?nid=4349&ntid=&pg=1



Story first posted: 20th February 2007.