Purpose of review: To summarize studies on the development and function of T-regulatory (TR) cells in primary immune deficiencies (PIDs).
Recent findings: PIDs are associated with high rates of autoimmunity. TR cells, which are critical to the control of autoimmunity, appear involved in the pathogenesis of PID-related autoimmunity. A number of PIDs, including Omenn's syndrome and Wiskott-Aldrich syndrome, have been associated with impaired production and/or function of thymus-derived (natural) TR cells. Recently defined primary immunodeficiencies, including Stim1 deficiency, IL-10 receptor deficiency, and xIAP deficiency, have been associated with defects in TR cells. De-novo generated TR cells from peripheral CD4+ conventional T cells is impaired in the hyper IgE syndrome.
Summary: Gene defects underlying PIDs may also compromise the TR cell, leading to breakdown of peripheral tolerance.