Description
Interferon-inducible T cell a chemoattractant (ITAC), which is also known as SCYB9B, -R1 or H174, is a non-ELR CXC chemokine. ITAC"s cDNA encodes a 94 amino acid precursor with a 21 amino acid putative signal sequence which is cleaved to form the mature 73 amino acid protein. ITAC shares 36% and 37% sequence homology with IP-10 and MIG, respectively. ITAC is expressed at low levels in normal tissues including the thymus, spleen and pancreas. The expression of ITAC mRNA is radically up regulated in interferon- and IL-1 stimulated astrocytes. Moderate increases in expression are also observed in stimulated monocytes. ITAC possesses potent chemoattractant activity for IL-2 activated T-cells and transfected cell lines expressing CXCR3 receptors, but not freshly isolated T-cells, neutrophils or monocytes. The gene which encodes ITAC has been mapped to chromosome 4