Dendritic Cells/cytology; Dendritic Cells/immunology; Drosophila Proteins; Lipid A/genetics; Lipid A/immunology; Antigens, CD/metabolism; Antigens, Surface/metabolism; B7-2 Antigen; Base Sequence; Cell Differentiation; DNA, Bacterial/genetics; Dendritic Cells/drug effects; Dendritic Cells/metabolism; Escherichia coli/genetics; Escherichia coli/immunology; Genes, Bacterial; Humans; In Vitro Techniques; Interleukin-8/biosynthesis; Lipid A/pharmacology; Lymphocyte Antigen 96; Membrane Glycoproteins/metabolism; Mutagenesis, Insertional; Mutation; NF-kappa B/metabolism; Receptors, Cell Surface/metabolism; Recombinant Proteins/genetics; Recombinant Proteins/immunology; Toll-Like Receptor 4; Toll-Like Receptors; Tumor Necrosis Factor-alpha/biosynthesis