Immune system has several components like cytokines, lymphocytes, macrophages etc. CD-8 cell is one major component produced by the host immune system to fight pathogens like bacteria, virus etc. Upon exposure to any invading pathogen like virus, CD8 cells multiply rapidly. At the initial stage they are effector cells, acting like foot soldiers and killing the pathogen. Once the pathogen is destroyed, most of these effector cells suicide to not continue attacking the body’s own cells. Few effector CD8 cells that survive become memory cells guarding the host from the respective pathogen and enacting faster combat reaction upon exposure to same pathogen.
CAR T cell therapy gathered lot of attention from the public for its effective use in immunotherapy against cancer and chronic infections like HIV. Application of CD-8 cells in immunotherapy has been discussed recently. The usual problem encountered is that CD8 cells get exhausted or stop functioning properly in cancer and HIV infections. However recent research by Shomyseh Sanjabi and her team have discovered a great finding which could offer a greater option against cancer and chronic infections.
The team identified 2 molecules namely Sprouty 1 and Sprouty 2. These molecules are known to modify the survival and development of effector and memory CD8 cells respectively. Upon animal model research, the team found that in absence of these molecules in CD8 cells, the CD8 effector cells survived in larger numbers and became memory cells. The memory cells without these molecules had better protective capacity against bacterial pathogens than normal CD8 memory cells with Sprouty molecules.
In tumors, as tumor cells consume lot of glucose the effector CD8cells get killed due to glucose deprive however the CD8 cells without Sprouty 1& 2 molecules can survive and function in a tumor environment upon consuming less glucose. Also the memory CD8 cells without Sprouty molecules can tackle cancer cells and also cells activated with latent virus in viral infections. Hence the memory plays a good role in immunotherapy and the future engineering of CAR Tcells in combination with genome editing technique like CRISPR can help in future to eliminate the Sprouty molecules and employ CD8 cells against cancer and infected cells.