Immunogenicity defined

M H C major histocompatibihty complex MIDGE minimahstic, immunogenically defined gene expression ODN oligodeoxynucleotides... 

Recently, a new vector system, MIDGE (Minimalistic Immunogenically Defined Gene Expression), was developed in order to overcome the hurdles of plasmid-based technologies and to solve the above-mentioned problems. These small and linear expression vectors are superior in several aspects to all other known vectors. In particular, they are characterized by their excellent safety and their intrinsic and unique structure that allows the chemical attachment of targeting signals. 

Tam IP, Lu YA. Vaccine engineering enhancement of immunogenicity of synthetic peptide vaccine related to hepatitis in chemically defined models consisting of T- and B-cell epitopes. Proc Natl Acad Sci USA 1989 86 9084. 

Peptides have many desirable properties as components of synthetic vectors. Peptide synthetic chemistry is well established, with the convenience of automated synthesis resulting in a well-defined, high-purity product of low toxicity and immunogenicity for in vivo use. Furthermore, even short peptides of 7 to 30 amino acids can accommodate enormous structural diversity, functionality, and combinations of properties. 

Some of the best understood polyvalent interactions are found in immune and host defense systems as well as ligand-receptor activation. An example is the use of a polyvalent immunogen based on a synthetic peptide to elicit immune responses. The subsequent production of site-specific antibodies can then be employed to confirm the identity of proteins derived from recombinant DNA, to explore biosynthetic pathways, to define precursor-product relationships (e.g., proenzyme and preproenzyme), and to determine protein structural domains.19 ... 

The toroidal structure of PCNA has distinct front and back faces that might provide a variety of sites for interaction with other proteins. The loop region between the twin domains of each monomer is a highly immunogenic exposed site that is important for interaction with other proteins. Such functional protein partners are thought to be crucial in regulating the role of PCNA in replication and repair. The aforementioned symmetry could define the directionality of PCNA movement as it slides along DNA. 

PCBs are small molecules and they do not have antigenic effects. They are defined as haptens, i.e. they are molecules that need to be linked with a transport protein in order to generate an immunogenic response. 

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