Building up the family of ITIM-bearing negative coreceptors.

The acronym (ITAM) for immunoreceptor tyrosine-based activation motif was first proposed in September 1994, during the 8th Meeting on Signals and Signal Processing in the Immune System held in Kecskemet, Hungary, to designate the di-tyrosine-based YxxL activation motifs that had been previously understood by Michael Reth to account for the cell-triggering properties of BCR, TCR and FcR. It was then agreed, by those who signed the collective letter John Cambier had been commissioned to submit to Immunology Today (Cambier, J.C. (1994) Immunol. Today 16, 110-110) that it was premature to propose ITIM (for immunoreceptor tyrosine-based inhibition motif) to designate the one inhibitory sequence containing a single Ys1L motif that had been identified in the intracytoplasmic domain of a low-affinity Fc receptor for IgG. Right away, ITAM became unanimously accepted and widely used in the literature. Remarkably, ITIM was soon adopted too and, in September 1996, a whole session of the 9th Signal Meeting, held in Tihany, Hungary, was devoted to ITIM. During the last 2 years, evidence accumulated that indeed accredited the ITIM concept.