Characterization of the protein tyrosine phosphatase CD45 on human epidermal Langerhans cells.
Human Langerhans cells (LC) express CD45, but clear data about the isoform(s) and their function(s) are lacking. In the present study, double labeling experiments reveal that freshly isolated LC from normal skin are CD45RO+/RA-/RB-. However, after isolation and short-time culture where LC undergo an in vitro maturation resembling that to lymphoid dendritic cells, CD45RB emerges whereas CD45RO expression decreases. This evolution results from dynamic alternative RNA splicing. Addition of granulocyte-macrophage colony-stimulating factor or tumor necrosis factor-alpha to short-time cultures has no significant effect on CD45RB, but both cytokines accelerate the loss of CD45RO. LC isolated from lesional skin of atopic eczema highly express CD45RO and CD45RB. Cross-linking of CD45 on LC isolated from atopic individuals inhibits the calcium mobilization in response to activation via Fc epsilon receptor type I (Fc epsilon RI). Hence, the protein tyrosine phosphatase CD45 from human LC is subjected to a splicing phenomenon related to the differentiation and activation stage of these cells and regulates their Fc epsilon RI-mediated activation.
Bieber
T
T
Department of Dermatology, Ludwig-Maximilians University of Munich, Germany.
Jürgens
M
M
Wollenberg
A
A
Sander
E
E
Hanau
D
D
de la Salle
H
H
D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003876:Dermatitis, Atopic / Q000378:metabolism; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D007801:Langerhans Cells / Q000737:chemistry*; D017493:Leukocyte Common Antigens / Q000032:analysis* / Q000502:physiology; D017027:Protein Tyrosine Phosphatases / Q000032:analysis*; D012867:Skin / Q000737:chemistry; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D014409:Tumor Necrosis Factor-alpha; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D017493:Leukocyte Common Antigens; D017027:Protein Tyrosine Phosphatases; D002118:Calcium