Protein antigens types

In this chapter we demonstrate that urease can be used as a label for protein antigen type of molecules by employing a urease-bovine serum albumin (BSA) conjugate to carry out competitive binding EIA for BSA. 

Yen N, Ioannides CG, Xu K, et al. Cellular and humoral immune responses to adenovirus and p53 protein antigens in patients following intratumor injection of an adenovirus vector expressing wild-type p53 (Ad-p53). Cancer Gene Ther 2000 7 530-536. 

It should be noted that the above strategy, although first employed In the delineation of protein antigenic sites. Is applicable, with appropriate adaptations, to the precise delineation and chemical synthesis of other types of protein binding sites. The Introduction of the concept of surface-simulation synthesis ( 4, ) has provided a methodology by which In principle any type of protein binding site can be mimicked synthetically after careful chemical characterization. 

However, the molecular weight, for example, may vary from 15,000 (hen egg white lysozyme) to 2,000,000 (keyhole limpet hemocyanin) daltons. Protein antigens function as the most potent immunogens, and polysaccharide antigens rank second. For cell-mediated immunity, only proteins serve as immunogens. Certain nucleic acid types such as Z-DNA and other molecules can also stimulate antibody production. 

There are several types of vaccine antigens. The most common antigens used for vaccine development are protein antigens. Immune epitopes may also be manufactured and used for vaccine development. Other molecules can also be used as vaccine antigens (e.g., lipopolysaccharide) (6). The commonly used databases for protein and epitope antigens are introduced here. 

Infection of a cell by a virus has two outcomes, depending on the nature of the virus and the particular cell type. Some viruses go into a lytic cycle, which results in the replication of the virus and the lysis of the cell. This is the case with viruses such as poliovirus and vaccinia virus, both of which are used in vaccination. The use of live viruses expressing protein antigens in vaccination has been discussed in Chapter 3. In vaccination, the goal is the transient replication of viruses for a period sufficient to raise antibody response. Thus, the use of lytic viruses leading to transient, self-limiting lytic infection is acceptable or even desirable. 

Plum pox virus capsid protein Baculovirus gp41 tegument protein HCMV UL32 (BPP) tegument protein NS26 rotavirus protein SV-40 large T antigen Virion basic phosphoprotein Adenovirus type 2 fiber protein Adenovirus type 5 fiber protein... 

This results in expression of the antigen and the subsequent induction of an immune response to the expressed proteinAs the protein antigen is produced naturally in vivo, both cellular and humoral responses are developed. Skin has been proposed as an attractive site of immunization, and several skin cell types can become involved in DNA uptake, antigen expression and presentation. Quite recently, for example, in a mouse model, immunization has been reported following topical application of an aqueous solution of naked Given what one knows... 

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