A major component of the . In the thymus lymphoid cells undergo a process of maturation and education prior
to release into
circulation. This process allows to develop
self tolerance (distinguishing self from nonself).
While developing in the thymus gland, any that reacts to the
thymus' (MHC) is eliminated. T-cells that tolerate the MHC
learn to cooperate with cells expressing MHC molecules and are allowed mature and leave the thymus.
The result is that surviving T-lymphocytes tolerate the body's cells and cooperates with them when
However, some T-lymphocytes lose this ability to differentiate self from nonself, which results
in the diseases
such as or multiple sclerosis.