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Team:Stockholm/Planning
From 2010.igem.org
Planning
Here follows the ongoing discussion amongst the group members about the project we are putting together. In addition we include theoretical support from scientific articles for what we want to accomplish.
Cell penetrating peptide (CPP)
Protein A would be secreted from the bacteria, penetrating the skin and bind IgG antibodies - that in vitiligo patients bind melanocytes - so that the igG antibodies can not induce an immune response.
"It binds proteins from many of mammalian species, most notably IgGs" - http://en.wikipedia.org/wiki/Protein_A (Find better source)
Johan: Good as IgGs are the main antibody in excess for vitiligo
“It binds with the Fc region of immunoglobulins through interaction with the heavy chain. The result of this type of interaction is that, in serum, the bacteria will bind IgG molecules in the wrong orientation (in relation to normal antibody function) on their surface which disrupts opsonization and phagocytosis.” - http://en.wikipedia.org/wiki/Protein_A
Johan: The disruption is what we want (are there more disruptions to think of, other than opsonization and phagocytosis?)
“It binds with high affinity to human IgG1 and IgG2 as well as mouse IgG2a and IgG2b. Protein A binds with moderate affinity to human IgM, IgA and IgE as well as to mouse IgG3 and IgG1.[1] It does not react with human IgG3 or IgD, nor will it react to mouse IgM, IgA or IgE.” - http://en.wikipedia.org/wiki/Protein_A
Johan: See if the antibody in excess in vitiligo hopefully is IgG1/IgG2
“... possesses several properties which makes it suitable as a partner in fusion proteins: (a) SpA enables purification of the fusion protein by affinity chromatography due to its specific binding to the Fc part of immunoglobulins, (b) it is competent for secretion in E. coli, (c) it is monomeric and relatively small, (d) it has been reported to be extremely soluble in water solutions (Samuels- son et al., 1991), (e) it is proteolytically very stable intracellularly (Nilsson et al., 1985a) and in the periplasm of E. coli (Nilsson and Abrahms6n, 1990). Fusions to the IgG-binding domains of SpA have successfully been applied for high-level production of peptide hormones (Abrahms6n et al., 1986; Moks et al., 1987a, b; Nilsson et al., 1991, 1985b) and as a tool for the production of specific antibodies against gene products (L6wenadler et al., 1987, 1986).” - Fusions to the 5' end of a gene encoding a two-domain analogue of staphylococcal protein A, pp 270-271
Johan: There are shortened versions of protein A. These might have some advantages (to secrete, to penetrate the skin etc. Elisabeth also said that it doesnt bind back to the bacteria such as the normal protein A.
