B2 [ U ] a situation in which people are peaceful and agree with each other, or when things seem right or suitable together: racial harmony (= good feelings between different races) domestic harmony (= good feelings in the family or home) Imagine a society in which everyone lived together in (perfect) harmony. We must ensure that tourism develops in harmony with the environment.
Once activated, helper T cells start to divide and to produce proteins that activate B and T cells as well as other immune cells. The killer T cell is specialized in attacking cells of the body infected by viruses and sometimes also by bacteria. It can also attack cancer cells. The killer T cell has receptors that are used to search each cell that it meets.
There are many different types of T cells that all perform different functions, but among the most important are Helper T cells and Killer T cells. Both of these types of cells bind cells in the body and can identify whether the cell is healthy and belongs to the body or whether it's not healthy or doesn't belong.In the latter two cases, the T cell will start an immune reaction to destroy the unhealthy cell or germ.here are many different types of T cells that all perform different functions, but among the most important are Helper T cells and Killer T cells. Both of these types of cells bind cells in the body and can identify whether the cell is healthy and belongs to the body or whether it's not healthy or doesn't belong.