Antigen Presentation; Antigen-Presenting Cells/immunology; CD4-Positive T-Lymphocytes/immunology; CD4-Positive T-Lymphocytes/transplantation; Cell Communication/immunology; Immune Tolerance; Administration, Oral; Amino Acid Sequence; Animals; Antigen Presentation/genetics; Antigen-Presenting Cells/enzymology; Antigen-Presenting Cells/metabolism; CD4-Positive T-Lymphocytes/enzymology; Cell Communication/genetics; Cell Cycle Proteins/metabolism; Female; Immune Tolerance/genetics; Isoenzymes/deficiency; Isoenzymes/metabolism; Membrane Microdomains/metabolism; Mice; Mice, Inbred BALB C; Mice, Transgenic; Molecular Sequence Data; Ovalbumin/administration & dosage; Ovalbumin/immunology; Protein Kinase C/deficiency; Protein Kinase C/metabolism; Protein Kinase C-theta; Protein Transport/genetics; Protein Transport/immunology; Proto-Oncogene Proteins/deficiency; Proto-Oncogene Proteins/metabolism; Proto-Oncogene Proteins c-vav; Receptors, Antigen, T-Cell/deficiency; Receptors, Antigen, T-Cell/genetics; Receptors, Antigen, T-Cell/metabolism; cdc42 GTP-Binding Protein/deficiency; cdc42 GTP-Binding Protein/metabolism; rac1 GTP-Binding Protein/deficiency; rac1 GTP-Binding Protein/metabolism