title: Lateral diffusion and patch formation of H-2Kk antigens on mouse spleen lymphocytes.
abstract: We have studied the diffusion and aggregation of H-2Kk antigens labeled with a fluorescent anti-H-2Kk monoclonal antibody (IgG) on mouse splenic lymphocytes, employing fluorescence photobleaching recovery and fluorescence microscopy. The H-2Kk antigens were initially distributed homogeneously on all lymphocytes. Upon antibody binding, sub-micron patches were formed on 50-60% of the cells. A lateral diffusion coefficient, D, of 7.1 X 10(-10) cm2/s and a mobile fraction of 0.73 were found for H-2Kk antigens on diffusely-labeled cells, while these antigens were immobile (D less than or equal to 5 X 10(-12) cm2/s) on patched cells. The patched and nonpatched sub-populations did not correspond to B- and T-lymphocytes. Subjection to low temperature or treatment with NaN3 or cytoskeleton-disrupting drugs did not affect the diffusion or patching of H-2Kk, indicating no involvement of metabolic energy or drug-sensitive cytoskeletal components. These findings could be related to the interactions of H-2 antigens on the cell surface, and to the different susceptibilities of various cells to lysis by cytotoxic T-cells.
mesh_terms: D000818:Animals; D001386:Azides / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology; D003571:Cytochalasin B / Q000378:metabolism; D004058:Diffusion; D006183:H-2 Antigens / Q000378:metabolism*; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008856:Microscopy, Fluorescence; D019810:Sodium Azide; D013154:Spleen / Q000166:cytology*; D013601:T-Lymphocytes / Q000276:immunology; D014018:Tissue Distribution
chemical_list: D001386:Azides; D006183:H-2 Antigens; C024755:H-2K(K) antigen; D003571:Cytochalasin B; D019810:Sodium Azide