Leukotactin‐1/CCL15‐induced chemotaxis signaling through CCR1 in HOS cells

Abstract

Leukotactin-1 (Lkn-1)/CCL15 is a recently cloned CC-chemokine that binds to the CCR1 and CCR3. Although Lkn-1 has been known to function as a chemoattractant for neutrophils, monocytes and lymphocytes, its cellular mechanism remains unclear. To understand the mechanism of Lkn-1-induced chemotaxis signaling, we examined the chemotactic activities of human osteogenic sarcoma cells expressing CCR1 in response to Lkn-1 using inhibitors of signaling molecules. Inhibitors of G i /G o protein, phospholipase C (PLC) and protein kinase CN N (PKCN N) inhibited the chemotactic activity of Lkn-1 indicating that Lkn-1-induced chemotaxis signal is transduced through G i /G o protein, PLC and PKCN N. The activities of PLC and PKCN N were also enhanced by Lkn-1 stimulation. Chemotactic activity of Lkn-1 was inhibited by the treatment of cycloheximide and actinomycin D suggesting that newly synthesized proteins are needed for chemotaxis. Nuclear factor-U UB (NF-U UB) inhibitor reduced chemotactic activity of Lkn-1. DNA binding activity of NF-U UB was also enhanced by Lkn-1 stimulation. These results suggest that Lkn-1 transduces the signal through G i /G o protein, PLC, PKCN N, NF-U UB and newly synthesized proteins for chemotaxis. ß 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.

Macrophage Inflammatory Protein 1α Inhibits Postentry Steps of Human Immunodeficiency Virus Type 1 Infection via Suppression of Intracellular Cyclic AMP

“…MIP-1␣ can bind and signal through both CCR5 and CCR1. Previous studies demonstrated that chemokine binding induces coupling of both CCR5 and CCR1 to inhibitory G (G i ) proteins (25,42). To determine whether MIP-1␣-mediated postentry inhibition of HIV-1 involves activation of G i proteins, we incubated parallel cultures of lymphocytes in the presence or absence of 5 nM pertussis toxin (PTX) prior to HIV-1 infection and MIP-1␣ treatment.…”

Differential chemokine activation of CC chemokine receptor 1‐regulated pathways: ligand selective activation of Gα 14‐coupled pathways

“…Furthermore, treatment of astrocytes with the PKA inhibitor H89 mimics the powerful effect of RANTES on the production of proinflammatory mediators [30]. In addition to PLC and MAPK pathways, G § 16 subunits are known to activate NF-‹ B [31], whose DNA binding activity is responsive to CCR1 activation by Lkn-1 [32], but the contribution of these pathways to chemoattraction activity has not been established yet.…”

Human LZIP induces monocyte CC chemokine receptor 2 expression leading to enhancement of monocyte chemoattractant protein 1/CCL2-induced cell migration

“…Migration of cells was monitored using a 48-well microchamber (Neuroprobe, Cabin John, MD) as previously described (Ko et al, 2002). Briefly, the lower wells were filled with 28 μl buffer alone or with buffer containing MCP-1 or Lkn-1 and the upper wells were filled with 50 μl of THP-1 cells at 1 × 10 6 cells/ml in RPMI 1640 containing 1% BSA and 30 mM HEPES.…”