Effects of UVB on fascin expression in dendritic cells and Langerhans cells.
BACKGROUND
Fascin is an actin-binding protein that regulates the rearrangement of cytoskeletal elements and their interactions with the cell membrane. Previous studies have indicated that fascin expression is enhanced in DC upon maturation and plays a critical role in T cell activation. Ultraviolet irradiation exerts immunosuppressive effects.


OBJECTIVE
We examined the effects of UVB irradiation on the interaction of DC/LC with T cells through fascin.


METHODS
Murine bone marrow-derived DC (BM-DC) were induced by recombinant murine GM-CSF and LPS, and UVB irradiation was applied prior to supplementation with LPS. I-A(+) cells (Langerhans cells (LC)) in the epidermal cell suspensions were exposed to UVB irradiation at the beginning of the 24-h culture. BM-DC and LC were analysed by immunohistochemical staining and flow cytometric analyses. To evaluate the effects of UVB irradiation on DC-T cell binding, we examined the clustering of BM-DC with allogeneic CD4(+) T cells under a confocal microscope.


RESULTS
Fascin expression in BM-DC and LC was decreased by UVB irradiation. Furthermore, UVB irradiation reduced the ability of BM-DC to cluster with allogeneic CD4(+) T cells. Polarization of fascin and filamentous actin (F-actin) at the point of contact of BM-DC with T cells was also disturbed by UVB irradiation.


CONCLUSIONS
These results suggest that the suppression of fascin expression by UVB irradiation down-regulates the rearrangement of the cytoskeleton and, thereby, antigen presentation in DC/LC.
Sugihara
Akira
A
Department of Dermatology, Kansai Medical University, Fumizono 10-15, Moriguchi, Osaka 570-8507, Japan. sugihaak@takii.kmu.ac.jp
Okamoto
Hiroyuki
H
Horio
Takeshi
T
D000818:Animals; D017951:Antigen Presentation / Q000528:radiation effects; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D002352:Carrier Proteins / Q000378:metabolism*; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000378:metabolism; D003713:Dendritic Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects; D005260:Female; D005434:Flow Cytometry; D007801:Langerhans Cells / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008840:Microfilament Proteins / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology; D014466:Ultraviolet Rays
D002352:Carrier Proteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; C020324:fascin