The study found two target molecules associated with effector T cell survival and memory CD8 T cell development

Copyright © iCell Bioscience Inc, Shanghai 2018-2019

T cells are the "knife guards" in our body and are one of the important components of the body's immune system. But in cancer or chronic infections (such as HIV infection), T cells tend to die in large numbers or stop normal work, making it difficult for us to fight disease. However, scientists at the University of California, San Francisco (UCSF) have recently discovered two protein targets that inhibit their activity to prevent this from happening.

When the human body is invaded by pathogens, CD8 T cells will rapidly multiply and become "effect cells." They are the guards who protect us and will take the initiative to kill infected cells. But once the pathogen disappears, these aggressive effector cells die to ensure they don't attack normal cells.

However, there are still a small number of effector cells that will survive and become memory cells. They are more like full-time guards and remain in your body. When encountering the same pathogen invaders, these memory cells react more quickly and quickly destroy the pathogen.

However, this protection of T cells is not indestructible. In the face of tumors or chronic infections like HIV, these loyal guards are often powerless.

On August 20th, Dr. Shomyseh Sanjabi of the University of California, San Francisco and her team discovered two target molecules: Sprouty 1 and Sprouty 2, which are involved in the survival of effector T cells and the development of memory CD8 T cells, which is in cancer. There is great potential for immunotherapy with chronic infections.

The team found that when Sprouty 1 and Sprouty 2 were removed from CD8 T cells, more effector cells survived and turned into memory cells. It also demonstrates that memory cells lacking Sprouty have better resistance to pathogens than normal memory cells.

These memory cells consume less glucose than normal CD8 T cells, and although effector cells rely on glucose to survive, memory cells typically consume more fatty acids.

Tumor cells consume a lot of glucose, so it is difficult for effector cells to survive in the tumor environment because it does not have enough energy sources. Although memory cells are usually not dependent on glucose, studies have shown that effector cells without Sprouty 1 and Sprouty 2 consume less glucose, so they can survive well in the tumor environment.

This study provides a completely new way to increase the number of memory CD8 T cells, which can help improve anti-tumor and anti-infective immunotherapy.

The potential of T cells was discovered by revealing the effects of Sprouty 1 and Sprouty 2. Cells lacking Sprouty1 and Sprouty 2 not only have enormous anti-tumor potential, but also have the potential to fight chronic viral infections.

The activated cells that lurk the HIV virus are the main obstacles to the treatment of AIDS, but after removing the two Sprouty molecules, the memory cells may survive better, which will help the immune system to recognize and kill these cells carrying latent viruses.

Studies have shown that patients treated with effector cells tend to relapse, while treatment with memory cells can help reduce tumor size or even completely eliminate tumors.

The scientific community is very interested in this method of increasing the number of memory CD8 T cells, but also improving their developmental status and function, because in immunotherapy, the use of memory cells is better than the use of effector T cells. Research can be combined with studies of CAR T cells against tumors, or with genome editing techniques like CRISPR to make them more effective.