Colorectal cancer (CRC) is the fourth most common type of cancer in the U.S. , but screening and early diagnosis have helped to reduce the death rate from CRC in the U.S. However, developing and transitional countries experience increases in the incidence of CRC. The primary treatment approaches used (surgery, chemotherapy, radiotherapy) are associated with adverse events and poor survival rates.
Lentivirus vectors (LVs) very efficiently deliver disease antigens when used in vaccines to provoke immune responses. Interestingly, long-term immunity is observed although immunization is accomplished with viral particles that are short-lived and do not replicate. Dendritic cells, antigen-presenting cells, appear to be an important aspect of the long-term immunity seen with the use of these viral particles. After vaccination, there are transduced cells (cells infected with or containing viral particles) at the injection site and lymph nodes well after the lifespan of the dendritic cells of those locations. Therefore, there may be other cells that continue to present LV-encoded antigen to T cells past the dendritic cell life spans.