One of the manifestations of X-linked lymphoproliferative disease (XLP) is progressive agammaglobulinemia, caused by the absence of a functional signaling lymphocyte activation molecule (SLAM)-associated protein (SAP) in T, invariant natural killer T (NKT) cells and NK cells.
To delineate the role of SAP in the pathophysiology of X-linked lymphoproliferative disease, a strain of sap-deficient mice has been generated by deleting exon 2 of the gene.
The aberrant immune responses in SAP-deficient mice show that SAP controls several distinct key T cell signal transduction pathways, which explains in part the complexity of the XLP phenotypes.