Regulated Production and Molecular Diversity of Human Liver and Activation-Regulated Chemokine/Macrophage Inflammatory Protein-3α from Normal and Transformed Cells

Abstract

Liver and activation-regulated chemokine (LARC), also designated macrophage inflammatory protein-3alpha (MIP-3alpha), Exodus, or CCL20, is a C-C chemokine that attracts immature dendritic cells and memory T lymphocytes, both expressing CCR6. Depending on the cell type, this chemokine was found to be inducible by cytokines (IL-1beta) and by bacterial, viral, or plant products (including LPS, dsRNA, and PMA) as measured by a specific ELISA. Although coinduced with monocyte chemotactic protein-1 (MCP-1) and IL-8 by dsRNA, measles virus, and IL-1beta in diploid fibroblasts, leukocytes produced LARC/MIP-3alpha only in response to LPS. However, in myelomonocytic THP-1 cells LARC/MIP-3alpha was better induced by phorbol ester, whereas in HEp-2 epidermal carcinoma cells IL-1beta was the superior inducer. The production levels of LARC/MIP-3alpha (1-10 ng/ml) were, on the average, 10- to 100-fold lower than those of IL-8 and MCP-1, but were comparable to those of other less abundantly secreted chemokines. Natural LARC/MIP-3alpha protein isolated from stimulated leukocytes or tumor cell lines showed molecular diversity, in that NH(2)- and COOH-terminally truncated forms were purified and identified by amino acid sequence analysis and mass spectrometry. In contrast to other chemokines, including MCP-1 and IL-8, the natural processing did not affect the calcium-mobilizing capacity of LARC/MIP-3alpha through its receptor CCR6. Furthermore, truncated natural LARC/MIP-3alpha isoforms were equally chemotactic for lymphocytes as intact rLARC/MIP-3alpha. It is concluded that in addition to its role in homeostatic trafficking of leukocytes, LARC/MIP-3alpha can function as an inflammatory chemokine during host defense.

Identification of Biologically Active Chemokine Isoforms from Ascitic Fluid and Elevated Levels of CCL18/Pulmonary and Activation-regulated Chemokine in Ovarian Carcinoma

“…CCL20/LARC mRNA was previously detected in pancreatic adenocarcinoma cells and in epithelial cells of the appendix and of inflamed tonsils (37)(38)(39). In addition, CCL20/LARC protein was inducible in epidermal carcinoma cells (23). However, we found that the CCL7/MCP-3 and CCL20/LARC concentrations in ascitic fluid accompanying epithelial ovarian cancer remained below 0.5 and 0.4 ng/ml, respectively.…”

“…Chemokines and Chemokine Immunoassays-The chemokines CXCL8/IL-8, CCL2/MCP-1, and CCL20/LARC were quantified with specific ELISAs as described previously (23). The detection limits were 0.02, 0.1, and 0.04 ng/ml, respectively.…”

“…Purification of Natural Chemokines from Ascitic Fluids-Chemokines were isolated from the ascitic fluid from two different patients with ovarian carcinoma (FIGO stage IIIc and stage Ic, respectively) following a standard four-step purification procedure (23). Briefly, the ascitic fluid was concentrated by adsorption to silicic acid (Matrex, Amicon, Beverly, MA) and partially purified by heparin affinity chromatography (Amersham Biosciences).…”

IL-1β and IFN-γ induce the expression of diverse chemokines and IL-15 in human and rat pancreatic islet cells, and in islets from pre-diabetic NOD mice

“…It is noteworthy that IFN-γ inhibits MIP-3α production by both TNF-α and IL-1β. IL-1β and/or TNF-α induce MIP-3α in different cell types including keratinocytes, melanocytes, fibroblasts and monocytes [22,23,56], but the inhibitory effect of IFN-γ has not, to our knowledge, been previously described. On the contrary, IFN-γ induces MIP-3α protein expression in human keratinocytes [23], emphasizing the different regulation of chemokine expression in diverse cell types.…”

Control of Salmonella dissemination in vivo by macrophage inflammatory protein (MIP)-3α/CCL20

“…9,27,28 This combined constitutive/inducible profile is relatively unique among the chemokines, which, in turn, suggests a unique role for CCL20 in immune surveillance 15 and inflammation, as indicated by its upregulation in response to LPS. 29,30 and during infection (the present study).…”