Mouse langerhans cells differentially express an activated T cell-attracting CC chemokine.
Epidermal Langerhans cells represent an immature population of dendritic cells, not yet able to prime naïve T cells. Following in vitro culture Langerhans cells mature into potent immunostimulatory cells. We constructed a representative cDNA library of in vitro matured murine Langerhans cells. Applying a differential screening procedure 112 differentially expressed cDNA clones were isolated. Thirty-six clones represented cDNA fragments of the same gene, identifying it to be the most actively expressed gene induced in maturing Langerhans cells. A full-length cDNA was sequenced completely. The open reading frame codes for a protein of 92 amino acids containing a leader peptide of 24 amino acids, yielding a mature protein of 7.8 kDa molecular weight. Database searches revealed 99.4% sequence identity on the nucleotide level to the recently described mouse CC chemokine ABCD-1, as well as 74% sequence identity to the human CC chemokine, the macrophage-derived chemokine/stimulated T cell chemotactic protein. Expression was analyzed by reverse transcriptase-polymerase chain reaction on a large panel of cell types. Unlike the macrophage-derived chemokine, expression was not detected in macrophages stimulated by various cytokines. Expression is restricted to cultured Langerhans cells, in vitro cultured dendritic cells, and lipopolysaccharide-activated B cells. Recombinant protein was expressed in the yeast Pichia pastoris and purified to homogeneity. Whereas no chemotactic activity was observed in chemotaxis assays for naïve T cells, B cells, cultured dendritic cells, and Langerhans cells, a strong chemoattractant activity was exerted on activated T cells. Thus, production of this chemokine by dendritic cells may be essential for the establishment and amplification of T cell responses.
Ross
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R
Clinical Research Unit, Department of Dermatology, Johannes Gutenberg University, Mainz, Germany.
Ross
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XL
Ghadially
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H
Lahr
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T
Schwing
J
J
Knop
J
J
Reske-Kunz
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AB
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology; D054422:Chemokine CCL22; D019742:Chemokines, CC / Q000096:biosynthesis*; D002630:Chemotactic Factors / Q000096:biosynthesis*; D018076:DNA, Complementary / Q000302:isolation & purification; D007801:Langerhans Cells / Q000378:metabolism*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D011994:Recombinant Proteins / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology*
C515482:CCL22 protein, human; C515483:Ccl22 protein, mouse; D054422:Chemokine CCL22; D019742:Chemokines, CC; D002630:Chemotactic Factors; D018076:DNA, Complementary; D012333:RNA, Messenger; D011994:Recombinant Proteins