Fetal proteins protect against rejection

Findings provide new clues to why mothers don?t attack fetal tissue

Charles Choi
Mar 16, 2006
Proteins hitherto linked with tumors may help fetuses evade immune rejection from their mothers, scientists reported this week in the Journal of Immunology. These findings provide a new explanation for a curious scenario -- why mothers don't attack fetal tissue -- and may even present additional clues for other unanswered questions in biology, according to the authors.Not only could further research into these proteins shed light on both pregnancy, cancer, and immunity, the fact that fetuses are genetically distinct from their mothers makes them interesting models on transplantation, coauthor Lucia Mincheva-Nilsson at Umeå University in Sweden told The Scientist.The proteins in question include the MHC class I chain related proteins A and B (MICA and MICB), which are up-regulated in cancer, infections, and autoimmune disorders. Membrane-bound MICA and MICB trigger immune responses by binding to the NK cell receptor known as NKG2D on white blood cells,...