Molecular and cellular pathogenesis of X-linked lymphoproliferative disease.
X-linked lymphoproliferative disease (XLP) is an inherited immune defect caused by mutations in the Src homology 2 domain-containing gene 1A, which encodes the adapter protein, signaling lymphocytic activation molecule (SLAM)-associated protein (SAP). SAP is expressed in T cells, natural killer (NK) cells, and NKT cells, where it binds to the cytoplasmic domain of the surface receptor SLAM (CD150) and the related receptors, 2B4 (CD244), CD84, Ly9 (CD229), NK-T-B-antigen, and CD2-like receptor-activating cytotoxic T cells. SAP also binds to the Src family tyrosine kinase Fyn and recruits it to SLAM, which leads to the generation of downstream phosphotyrosine signals. While the roles of the SLAM family receptors are only beginning to be understood, experiments suggest that these molecules regulate important aspects of lymphocyte function, such as proliferation, cytokine secretion, cytotoxicity, and antibody production. Thus, in XLP patients who lack functional SAP, the SLAM family receptors may not signal properly. This property likely contributes to the phenotypes of XLP, including fulminant infectious mononucleosis, lymphoma, and hypogammaglobulinemia. Further studies of SAP and the SLAM family receptors will provide insights into XLP and elucidate the signaling events regulating lymphocyte ontogeny and function.
Nichols
Kim E
KE
Pediatric Oncology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA. nicholsk@email.chop.edu
Ma
Cindy S
CS
Cannons
Jennifer L
JL
Schwartzberg
Pamela L
PL
Tangye
Stuart G
SG
D000818:Animals; D015703:Antigens, CD; D004406:Dysgammaglobulinemia / Q000209:etiology; D006023:Glycoproteins / Q000502:physiology; D006801:Humans; D007136:Immunoglobulins / Q000502:physiology; D007244:Infectious Mononucleosis / Q000209:etiology; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000502:physiology*; D008232:Lymphoproliferative Disorders / Q000150:complications / Q000235:genetics* / Q000276:immunology*; D051379:Mice; D009154:Mutation / Q000235:genetics; D011956:Receptors, Cell Surface / Q000502:physiology; D000071179:Signaling Lymphocytic Activation Molecule Associated Protein; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1
D015703:Antigens, CD; D006023:Glycoproteins; D007136:Immunoglobulins; D047908:Intracellular Signaling Peptides and Proteins; D011956:Receptors, Cell Surface; C114953:SH2D1A protein, human; C000604059:SLAMF1 protein, human; C499569:Sh2d1a protein, mouse; D000071179:Signaling Lymphocytic Activation Molecule Associated Protein; D000071177:Signaling Lymphocytic Activation Molecule Family Member 1