Signaling lymphocytic activation molecule-associated protein controls NKT cell functions.
X-linked lymphoproliferative disease (XLP) is a fatal immunological disorder that typically manifests following EBV infection. XLP patients exhibit a number of immune defects including abnormal T, B, and NK lymphocyte function. These defects have been attributed to mutations of Src homology 2 domain-containing gene 1A (SH2D1A), the gene encoding signaling lymphocytic activation molecule-associated protein (SAP), an intracellular adaptor molecule expressed in lymphocytes. We have observed that SAP knockout (SAPKO) mice and humans with XLP have a complete lack of CD1d-restricted NKT cells. As expected, SAPKO mice injected with the NKT cell agonist, alpha-galactosylceramide failed to generate NKT cell IFN-gamma or IL-4. Furthermore, in contrast to wild-type littermates, SAPKO mice coinjected with OVA and alpha-galactosylceramide failed to mount OVA-specific CTL responses. These data suggest that an absence of NKT cells may underlie part of the immune dysregulation seen in SAPKO mice and in XLP patients.
Chung
Brian
B
Department of Pathology and Laboratory Medicine, British Columbia Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
Aoukaty
Ala
A
Dutz
Jan
J
Terhorst
Cox
C
Tan
Rusung
R
D000818:Animals; D018949:Antigens, CD1 / Q000378:metabolism; D055610:Antigens, CD1d; D016207:Cytokines / Q000096:biosynthesis; D005699:Galactosylceramides / Q000276:immunology / Q000494:pharmacology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000172:deficiency / Q000235:genetics / Q000276:immunology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D008213:Lymphocyte Activation; D008232:Lymphoproliferative Disorders / Q000235:genetics / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009154:Mutation; D000071179:Signaling Lymphocytic Activation Molecule Associated Protein; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D018949:Antigens, CD1; D055610:Antigens, CD1d; C526877:CD1D protein, human; D016207:Cytokines; D005699:Galactosylceramides; D047908:Intracellular Signaling Peptides and Proteins; C114953:SH2D1A protein, human; C499569:Sh2d1a protein, mouse; D000071179:Signaling Lymphocytic Activation Molecule Associated Protein