Molecular cloning and characterization of a novel CXC chemokine macrophage inflammatory protein-2 gamma chemoattractant for human neutrophils and dendritic cells.
Chemokines play important roles in leukocyte trafficking as well as function regulation. In this study, we described the identification and characterization of a novel CXC chemokine from a human dendritic cell (DC) cDNA library, the full-length cDNA of which contains an open reading frame encoding 111 aa with a putative signal peptide of 34 aa. This CXC chemokine shares greatest homology with macrophage inflammatory protein (MIP)-2alphabeta, hence is designated as MIP-2gamma. Mouse MIP-2gamma was identified by electrocloning and is highly homologous to human MIP-2gamma. Northern blotting revealed that MIP-2gamma was constitutively and widely expressed in most normal tissues with the greatest expression in kidney, but undetectable in most tumor cell lines except THP-1 cells. In situ hybridization analysis demonstrated that MIP-2gamma was mainly expressed by the epithelium of tubules in the kidney and hepatocytes in the liver. Although no detectable expression was observed in freshly isolated or PMA-treated monocytes, RT-PCR analysis revealed MIP-2gamma expression by monocyte-derived DC. Recombinant MIP-2gamma from 293 cells is about 9.5 kDa in size and specifically detectable by its polyclonal Ab developed by the immunization with its 6His-tagged fusion protein. The eukaryotically expressed MIP-2gamma is a potent chemoattractant for neutrophils, and weaker for DC, but inactive to monocytes, NK cells, and T and B lymphocytes. Receptor binding assays showed that MIP-2gamma does not bind to CXCR2. This implies that DC might contribute to the innate immunity through the production of neutrophil-attracting chemokines and extends the knowledge about the regulation of DC migration.
Cao
X
X
Department of Immunology and Shanghai Brilliance Biotechnology Institute, Second Military Medical University, Shanghai, People's Republic of China. caoxt@public3.sta.net.cn
Zhang
W
W
Wan
T
T
He
L
L
Chen
T
T
Yuan
Z
Z
Ma
S
S
Yu
Y
Y
Chen
G
G
D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D054426:Chemokine CXCL2; D019743:Chemokines, CXC / Q000737:chemistry* / Q000235:genetics*; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000302:isolation & purification; D003713:Dendritic Cells / Q000737:chemistry / Q000276:immunology*; D005822:Genetic Vectors / Q000096:biosynthesis; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D015846:Monokines / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics*; D009504:Neutrophils / Q000276:immunology* / Q000378:metabolism; D009928:Organ Specificity / Q000235:genetics / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D019707:Receptors, Chemokine / Q000502:physiology; D018123:Receptors, Interleukin / Q000502:physiology; D023063:Receptors, Interleukin-8B; D011994:Recombinant Proteins / Q000096:biosynthesis; D014162:Transfection; D014407:Tumor Cells, Cultured
D054426:Chemokine CXCL2; D019743:Chemokines, CXC; D018076:DNA, Complementary; D015846:Monokines; D019707:Receptors, Chemokine; D018123:Receptors, Interleukin; D023063:Receptors, Interleukin-8B; D011994:Recombinant Proteins