CD40-CD40 ligand (CD40L) interactions and X-linked hyperIgM syndrome (HIGMX-1).
Interactions between the B cell surface antigen CD40 and its ligand (CD40L) expressed on activated T cells play a critical role in isotype switching. This is illustrated by failure of isotype switching in patients with X-linked hyperIgM syndrome in whom the CD40L gene is mutated and by failure of isotype switching of CD40-deficient mice in response to T-cell-dependent antigens. We review these findings and discuss the signaling mechanisms of CD40 and the developmental control and transcriptional regulation of CD40L expression.
Ramesh
N
N
Division of Immunology, Children's Hospital, Boston, Massachusetts 02115, USA.
Morio
T
T
Fuleihan
R
R
Worm
M
M
Horner
A
A
Tsitsikov
E
E
Castigli
E
E
Geha
R S
RS
D000818:Animals; D019013:CD40 Antigens / Q000378:metabolism*; D023201:CD40 Ligand; D006801:Humans; D006942:Hypergammaglobulinemia / Q000235:genetics* / Q000276:immunology*; D007075:Immunoglobulin M / Q000097:blood*; D007231:Infant, Newborn; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D014960:X Chromosome / Q000235:genetics
D019013:CD40 Antigens; D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D023201:CD40 Ligand