Outline the function, cellular distribution and clinical significance associated with defects in gene expression of the following proteins: a) IL-2RG (common gamma chain). b) STAT-3. c) FOXP3.

Question

Outline the function, cellular distribution and clinical significance associated with defects in gene expression of the following proteins:

a) IL-2RG (common gamma chain).

b) STAT-3.

c) FOXP3.

(15 marks)

Answer 1

IL2r is a receptor for IL2, which is an important molecule in the development of Th cells in the thymus. IL2 binds to IL2r. deficiency of IL2r will lead to a global loss of Th cells, causing severe combined immunodeficiency.

Stat-3 is a signaling molecule, when deficient will lead to Hyper IgE syndrome (Job syndrome). Job syndrome presents with recurrent accesses, recurrent infections, hypereosinophilia, and eczema.

Fox-P3 is important in the development of Treg cells. Loss of FOX-P3 results in an immune regulatory disorder called IPEX syndrome, which causes multiple autoimmune disorders such as atopic dermatitis, diabetes etc.