TIM gene family and their role in atopic diseases.

The TIM gene family was discovered seven years ago by positional cloning in a mouse model of asthma and allergy. Three of the family members (TIM-1, TIM-3, and TIM-4) are conserved between mouse and man, and have been shown to critically regulate adaptive immunity. In addition, TIM-1 has been shown to play a major role as a human susceptibility gene for asthma, allergy and autoimmunity. Recently, TIM-4 has been identified as a ligand of phosphatidylserine and to control the uptake of apoptotic cells. These studies together suggest that the TIM gene family evolved to regulate immune responses by managing survival and cell death of hematopoetic cells.