CCL16 Human

Human CCL16, also known as HCC-4, LEC (liver-expressed chemokine), and LMC (lymphocyte and monocyte chemoattractant), is a CC chemokine initially identified through bioinformatics analysis. The cDNA of CCL16 encodes a 120-amino acid precursor protein, including a 23-amino acid signal peptide. Upon cleavage of the signal peptide, the mature CCL16 protein consists of 97 amino acids. CCL16 exhibits limited sequence similarity to other CC chemokines, with less than 30% identity. Among CC chemokines, it shares the highest similarity with HCC-1. The human CCL16 gene contains two potential polyadenylation signals, resulting in two transcripts of approximately 1,500 base pairs and 500 base pairs in length. CCL16 expression is generally low and observed in certain lymphocyte subsets, including NK cells, T cells, and some T cell clones. Monocytes, upon stimulation with IL-10, show significantly enhanced CCL16 expression. Notably, CCL16 exhibits chemotactic activity primarily towards lymphocytes and monocytes, with minimal attraction of neutrophils. Additionally, CCL16 possesses myelosuppressive properties, inhibiting the proliferation of myeloid progenitor cells. In functional assays, CCL16 demonstrates chemotactic activity for monocytes, including the THP-1 monocytic cell line, but not for resting lymphocytes or neutrophils. Furthermore, CCL16 induces calcium flux in THP-1 cells, leading to desensitization to subsequent stimulation with RANTES.

Recombinant human CCL16, produced in E. coli, is a non-glycosylated polypeptide chain comprising 97 amino acids. With a molecular weight of 11.2 kDa, this protein is purified using proprietary chromatographic techniques.

White, sterile-filtered lyophilized powder.

The CCL16 protein was lyophilized from a sterile solution at a concentration of 1 mg/mL in 20 mM PBS (pH 7.4) containing 0.15 M sodium chloride.

To reconstitute the lyophilized CCL16, it is recommended to dissolve it in sterile 18 MΩ-cm H2O to a concentration of at least 100 µg/mL. This solution can then be further diluted in other aqueous solutions.

Lyophilized CCL16, though stable at room temperature for up to 3 weeks, should be stored desiccated at -18 °C or lower. After reconstitution, CCL16 should be stored at 4 °C for 2-7 days. For long-term storage, it is advisable to freeze CCL16 at -18 °C or lower, ideally with the addition of a carrier protein like HSA or BSA (0.1%). Avoid repeated freeze-thaw cycles.

The purity of CCL16 is determined to be greater than 97.0% based on the following analyses: (a) Reverse-phase high-performance liquid chromatography (RP-HPLC) and (b) Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE).

The biological activity of CCL16 is evaluated based on its chemoattractant properties towards human monocytes. Using a concentration range of 10-100 ng/mL, the specific activity is determined to be in the range of 10,000-100,000 IU/mg.

C-C motif chemokine 16, Small-inducible cytokine A16, IL-10-inducible chemokine, Chemokine LEC, Monotactin-1, Chemokine CC-4, Lymphocyte and monocyte chemoattractant, CCL-16, HCC-4, HCC4, NCC4, NCC-4, Liver Expressed Chemokine, LMC, LCC-1, LCC1, MTN-1, MTN1, SCYL4, ckB12, SCYA16, LEC, ILINCK, MGC117051.

Escherichia Coli.

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