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Specific cellular defences against pathogensT lymphocytes

Lymphocytes are the white blood cells involved in the specific immune response. They produce antibodies that respond to specific antigens on the surface of pathogens. Memory cells remain in the blood stream and lead to a quicker and stronger defence against a secondary infection by the same pathogen.

Part of Human BiologyNeurobiology and immunology

T lymphocytes

The role of the T lymphocytes is to destroy body cells that have been infected by the pathogen. T lymphocytes recognise the antigens of the pathogen on the surface of the cell and induce apoptosis (programmed cell death).

T lymphocytes attach onto infected cells and release proteins. These proteins diffuse into the infected cells. This causes production of self-destructive enzymes, which cause cell death. The remains of the cell are then removed by .

T lymphocytes can identify the difference between antigens found on the body's own cells (self-antigens) and antigens belonging to the pathogen (non-self-antigens).

However if the immune system fails to recognise the difference between self and non-self-antigens it can result in T lymphocytes attacking the body's own cells. This can lead to autoimmune diseases.

Examples of autoimmune diseases include rheumatoid arthritis and type 1 diabetes.