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Title: PD-L1/PD-1 passway: A security checkpointurl
Introduction：
Cancer uses a sort of “cellular camouflage”, tricking the immune system into seeing it as a normal cell. Dan Chen, M.D., Ph.D., global head of development for cancer immunotherapies at Genentech, explains how immunotherapy may affect the PD-L1/PD-1 pathway, enabling the body to better detect and fight cancer.
Content：
As a scientist, I specialize in the cancer immunotherapy. My work, and that with my colleagues, is to figure out the stimulate immune systems to kill cancer. To understand this concept, Let’s talk a little more about our immune system, and how it works.
Taking a looking inside our body, All of us were born with immune system, that acts as security checkpoint at the airport. Our immune system is like high-tech full body scanner system, that protect us from things that’s harmful. In the immune system, T cell has receptors that scan cells to distinguish between normal cells and abnormal cells, like virus infected cells. Once detected, abnormal cells are attacked and removed by T cells. T cells also identify the cells for future recognition. The same T cells also play important role in protecting us from cancer. Cancer cells are normal cells that have mutated. The more mutation cancer cells have, the more easily they are detected. Until recently, We didn’t understand why T cells were detecting these cancer cells, but not destroying them. But on a closer look, we’ve made some reviewing discoveries, we’ve learned that one of the ways cancer cells get pass through the security system, is with the help of the molecular called PD-L1, that is found on the surface of cancer cells. PD-L1 is almost like disguise that allow cancer cells to remain undetected. PD-L1 basically hacks the T cell scanning system by jamming the signal to parts of the T cell system, called PD-1, and B7.1. Think of PD-1 as the sensor, that is part of T cell scanning system, and B7.1 is like alarm that issues alert when sth is wrong. When PD-L1 hacks the system, it prevent them from doing what is supposed to do, in other words, it may prevent T cells from destroying cancel cells. Scientists have been working on fixing this problem, and have designed moleculars to target PD-L1/PD-1 passway, you can think of cancer immunotherapy, as kind of like software update for immune system, early stages started by targeting PD-L1/PD-1 passway, T cells may be able to detect and destroy cancer cells.
Let me show you more details, T cells have receptors that allow them to recognize cancer, cancer cells can prevent elimination by turning on PD-L1, PD-L1 deactivates T cells by binding to PD-1, and B7.1. Blocking PD-L1 from binding to PD-1 and B7.1, could prevent PD-L1 from communicating with them. When this happens, T cells may finally be able to responding,- kill cancer cells.
Clinical trials are currently underway to understand the facts of trying to block the PD-L1/PD-1 passway in the body.
We are committed to studying cancer immunotherapy. So that we can continue to find new ways to harmonize immune system to flight multiple types of cancer.
Brought to you by Genetech, a member of Roche group.
