Recombinant Rat CCL27/CTACK Protein

CCL27, also known as CTACK (cutaneous T cell-attracting chemokine), ALP, ILC, and ESkine, is a member of the CC family of chemokines (1). Sequence comparison of the rat CCL27 with the mature human and mouse CCL27 suggests that the mature rat CCL27 is a 95 amino acid (aa) protein. It shares 57% and 87% aa sequence identity with human and mouse CCL27, respectively (2). It shares 16% - 33% aa sequence identity with other rat CC chemokines. An alternately spliced form of mouse CCL27, known as PESKY, is localized to the nucleus and promotes cellular migration (3). CCL27 is constitutively expressed by keratinocytes and is upregulated by inflammatory stimuli and wounds in skin (4 - 7). CCL27 binds CCR10, glycosaminoglycans in the extracellular matrix, sulfated tyrosine residues on PSGL-1, and determinants on the surface of fibroblasts and endothelial cells (5, 7 - 9). CCL27 cooperates with CCL17/TARC in inducing the migration of cutaneous lymphocyte antigen (CLA) positive memory T cells to the skin during inflammation (4, 6, 10 - 12). Endothelial cell-bound CCL27 can mediate the adhesion of endothelium to CLA⁺ T cells (6). CCL27 also induces the migration of keratinocyte precursors from bone marrow to the skin, thereby promoting wound healing (7). In humans, serum CCL27 levels are elevated and correlate with disease severity in atopic dermatitis, psoriasis vulgaris, and mycosis fungoides (13 - 15).