AIRE Is a Transcriptional Regulator That Promotes the Expression of Some

Multiple Choice

AIRE is a transcriptional regulator that promotes the expression of some 'tissue-specific' proteins in thymic stromal cells. This provides a means to induce central tolerance of developing T cells to these antigens. Patients with inactivating mutations in AIRE (a disease known as APECED) develop a range of symptoms, several of which involve autoimmune attack of exocrine glands. However, analysis of many patients with APECED reveals that some organs in the body are never attacked by autoimmune T cells in individuals with this syndrome, whereas other organs are commonly found to be destroyed in these patients. This targeted autoimmune response against a subset of tissues in APECED patients indicates:

A) Some tissues in the body cannot be targeted by autoimmune mechanisms.
B) AIRE likely regulates genes expressed in this subset of tissues, but not genes in other tissues.
C) Central tolerance is more efficient in deleting T cells reactive to some tissues in the body than others.
D) Central tolerance is only important for deleting auto-reactive T cells recognizing self-antigens expressed in exocrine glands.
E) Exocrine glands express much higher levels of self-antigens than other tissues do.