Ca^2+ signals and T lymphocytes; New mechanisms and functions in Ca^2+ signalling".

Interaction between a T cell and an antigen-presenting cell leads to the rapid formation of an immunological synapse allowing antigen detection by the T cell and the development of an immune response. Antigen detection triggers various cellular responses including a modest but sustained T cell Ca^2+ increase. In this review are discussed a series of related questions. What are the various molecular events by which a T cell Ca^2+ response can be triggered in the immunological synapse by a very small amount of antigen? How is Ca^2+ released from intracellular stores and how can these stores remain empty for hours? Through which channels does Ca^2+ influx takes place, and how is Ca2+ influx coupled to Ca2+ release from intracellular stores? What are the main immediate and indirect cellular targets of the Ca^2+ increase?