Internalization of Ia molecules into Birbeck granule-like structures in murine dendritic cells.
Dendritic cells isolated from the draining lymph nodes of mice sensitized epicutaneously with hapten are potent antigen-presenting cells and contain Birbeck granules and cored tubules characteristic of antigen-activated epidermal Langerhans cells. We used immunogold labeling and transmission electron microscopy to follow the internalization of Ia molecules in these antigen-presenting cells. We found that Ia molecules were internalized into Birbeck granule-like structures in the antigen-activated dendritic cells. Computer reconstruction of serial sections of the dendritic cells demonstrated that these structures span the cytoplasm from the cell membrane to the nuclear membrane and are associated with lysosomes. The internalization of Ia molecules into these structures supports the hypothesis that the Birbeck granule-like structures are derived from the cell membrane and are involved in the antigen-processing/presenting function of the dendritic cells.
Bucana
C D
CD
UT M.D. Anderson Cancer Center, Houston 77030.
Munn
C G
CG
Song
M J
MJ
Dunner
K
K
Kripke
M L
ML
D000818:Animals; D003198:Computer Simulation; D003594:Cytoplasmic Granules / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology* / Q000648:ultrastructure*; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D007150:Immunohistochemistry; D051379:Mice; D008809:Mice, Inbred C3H; D008854:Microscopy, Electron
D000949:Histocompatibility Antigens Class II