... people lived without T-Lymphozyte?

Our Immune system is very complex. Every protein, every cell has its task to do. I was asking myself what would happen if one small detail of this complex system would simply not exist or would disappear in one second. To find an answer I thought about the T-Lymphocyte cells in our immune system which is a subtype of our white blood cells and it gets constructed in our bone marrow.

While they get around in our body, transferred by the blood, they have their task to observe every cell and check if there is a mistake inside. The T-Lymphocyte checks the entire cell by docking on the cell. In case that the cell is either a foreign, a damaged or mutating cell, the T-Lymphozyt cell gives its alarm.

After that, a chain of processes in order to destroy the cell starts. T-killer cells try to destroy the cell. The T-helper cells make a chemical reaction in order to destroy or to make the cell harmless. Furthermore, some small harmless parts of the cells got saved in your body in order that your immune system remembers this infection.

Okay, now let’s say if we had no T-Lymphocyte cells, the immune system would not react to an effect, no killer cells would kill the virus and it would live in our body and spread. If you just sneezed a bit, usually in a few days you would get well again, but without this cells, you would sneeze so much and your small 3-day-illness would get so worse, that you would die after a few days.

Luckily there is no kind of illness which can destroy your T-Lymphocytes, but there are some diseases that attack the T-Lymphocytes or which can trick them. If you had cancer for example, the damaged or bad cells would look for the T-Lymphocytes like a normal cell, but inside they would proliferate. Another serious disease is AIDS. The HI-virus can not survive alone and need the T-helper-cell in order to reproduce themselves. Through this they destroy the T-helper-cell and your body is very infectious for usually quite harmless illnesses.