Cloning and characterization of a novel ITIM containing lectin-like immunoreceptor LLIR and its two transmembrane region deletion variants

A novel full-length cDNA was cloned from human dendritic cells (DC) by subt ractive cloning and RACE. The deduced protein is a type II lectin-like memb rane protein that contains an ITIM proximal to N terminal and is designated as lectin-like immunoreceptor (LLIR). The gene of LLIR is located in a reg ion of chromosomal 12p13 and shows highest homologous with ASGPR. Two alter natively spliced transmembraneless variants of LLIR were identified by RT-P CR and named as LLIRv1 and LLIRv2. RT-PCR and immunoblotting analysis revea led that LLIR was expressed with much higher level in immature DC than in m ature DC, The ITIM in LLIR was demonstrated to bind SHP-1 in HL-60 cell aft er the tyrosine had been phosphorylated. In addition, the mRNA expression l evel of LLIRv2 was raised when leukemia cells were induced to differentiate by PMA. (C) 2001 Academic Press.