For example, the complement system helps to dissolve and remove immune complexes and to kill foreign cells. The co-stimulatory molecules help to stimulate or decrease the immune response produced by the two cells. For example, some cytokines can cause growth and activation of immune system cells. A gene carries the directions that a cell uses to perform a specific function. T cells and B cells are lymphocytes that look similar under the microscope but have different functions.
Molecules are the building blocks of a cell.
Neutrophils contain granules filled with potent chemicals that can destroy bacteria or other nearby cells when the chemicals are released. These molecules can sometimes destroy healthy body tissues nearby. The T-cell receptor can recognize and interact with a corresponding MHC molecule that is displaying an antigen.