chapter  20
32 Pages

Alphaviruses: Multiplicity of Vectors and Their Promising Application as Vaccines and Cancer Therapy Agents

The latest virus-based technologies contribute significantly to the progress of modern medicine, which, today, is directed to the gene therapy, targeted cancer therapy, vaccine, and drug design. Among other heterologous gene expression systems based on recombinant viral replicons the alphavirus-driven vectors are gaining wide use because of their high efficiency in delivering and

expressing the cloned gene of interest. During the last decade the alphaviral vectors were significantly modified to increase their potential for application in vitro and in vivo. The most remarkable application of alphavirus-based vectors is for vaccine development and gene therapy including promising results in cancer treatment. The immunogenicity and protective efficacy of recombinant hybrid alphavirus particles against different infectious disease agents, such as viruses, bacteria, and parasites have been demonstrated in vivo. A high-level antigen expression, lack of DNA stage precluding genome integration, cytoplasmic amplification through double-stranded RNA intermediates that stimulate innate immune responses, direct targeting of dendritic cells or affecting by crosspriming mechanism, and the absence of anti-vector immunity are some important advantages of the alphavirus-based vaccines.