CD4-Positive T-Lymphocytes/immunology; Dermatitis, Contact/immunology; Down-Regulation/immunology; Membrane Glycoproteins/physiology; T-Lymphocytes, Regulatory/cytology; T-Lymphocytes, Regulatory/immunology; fas Receptor/metabolism; Administration, Cutaneous; Animals; Antigen Presentation; Apoptosis/genetics; Apoptosis/immunology; CD4-Positive T-Lymphocytes/metabolism; CD8-Positive T-Lymphocytes/cytology; CD8-Positive T-Lymphocytes/immunology; Cell Differentiation/genetics; Cell Differentiation/immunology; Dendritic Cells/cytology; Dendritic Cells/immunology; Dermatitis, Contact/genetics; Dinitrofluorobenzene/administration & dosage; Dinitrofluorobenzene/immunology; Dinitrofluorobenzene/metabolism; Down-Regulation/genetics; Epitopes, T-Lymphocyte/immunology; Fas Ligand Protein; Female; Haptens/administration & dosage; Haptens/immunology; Haptens/metabolism; Ligands; Lymph Nodes/immunology; Lymph Nodes/metabolism; Lymphocyte Count; Lymphocyte Depletion; Membrane Glycoproteins/biosynthesis; Membrane Glycoproteins/deficiency; Membrane Glycoproteins/genetics; Mice; Mice, Inbred C57BL; Mice, Mutant Strains