"

From 2013.igem.org

GM-CSF recruits Immune Cells to Site of Infection

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a protein secreted by macrophages, T cells, mast cells, NK cells, endothelial cells and fibroblasts. It is a cytokine that acts as a white blood cell growth factor and stimulates growth of granulocytes. It also induces monocytes to activate into macrophages, making it a potent activator of the immune response. GM-CSF causes rapid multiplication of macrophage numbers near infection sites and has been used to stimulate white blood cell development post-chemotherapy. The ASU iGEM team is engineering GM-CSF to be expressed and secreted from the bacterial vaccine chassis to:

1. Recruit Immune Cells, including Dendritic Cells, to engulf the vaccine and present the antigens via the MHC Class I pathway. This creates an antigen-presenting cell-targeted vaccine system.
2. Stimulate production of more immune cells to mount a stronger anti-tumor response.
3. Act as a potential factor for translational applications of the vaccine system in conjunction with chemotherapy to replenish white blood cell levels.

CpG Motifs

Synthetic CpG Oligodeoxynucleotides are short single-stranded synthetic DNA molecules that contain a cytosine triphosphate deoxynucleotide ("C)" followed by a guanine triphosphate deoxynucleotide ("G"). Because they are unmethylated, they act as immunostimulants. Because bacterial chassis contain a large number of unmethylated CG motifs in their genome, they provide a strong natural immunostimulant in parallel with antigen delivery.