[CXCR4, a therapeutic target in rare immunodeficiencies?].

Currently, more than 200 primary immunodeficiency diseases have been discovered. In most cases, genetic defects affect the expression or the function of proteins involved in immune development and homeostasis. Some orphan immuno-hematological disorders are characterized by an abnormal leukocyte trafficking, a notion predictive of an anomaly of the chemokine/chemokine receptor system. In this review, we focus on recent advances in the characterization of dysfunctions of the CXCL12 (SDF-1)/CXCR4 signaling axis in two rare human immunodeficiencies, one associated with a loss of CXCR4 function, the Idiopathic CD4(+) T-cell Lymphocytopenia, and the other with a gain of CXCR4 function, the WHIM syndrome.