Plasmid DNA contamination, the SV40 promoter, and cross linking
What happens when 200 billion pieces of DNA PLASMID CONTAMINATION pieces per dose (approx.), come in contact 40 Billion LNPs, full of positively charged cationic lipids, and form adducts? As if their presence wasn't catastrophic enough.
Mostly layman's terms below:
2/ When positively charged cationic lipids come into contact with DNA, such as the SV40 promoter on a DNA plasmid, several things could potentially happen:
Positively charged cationic lipids may bind to the negatively charged phosphate groups in the DNA backbone, and the SV40.
3/This binding can disrupt the native structure of the DNA, potentially leading to conformational changes or even DNA denaturation.
The interaction between cationic lipids and DNA may result in chemical modifications of the DNA, such as covalent adduct formation or cross-linking.
4/ Cross-linking in the context of DNA refers to the formation of covalent bonds between different DNA strands or between DNA and other molecules. These covalent bonds link two or more DNA molecules together or DNA with another molecule, which can have various biological and
5/chemical consequences. Cross-linking can physically distort the DNA structure and cause breaks in the DNA strands. Cross-linked DNA can be more challenging for cells to repair because it involves covalent bonds that need to be broken. This can lead to a buildup of DNA damage.
6/ Cross-linking can interfere with the normal functioning of DNA. In the case of a promoter region like the SV40 promoter, cross-linking can have implications which are unknown on the SV40 promoter, or pieces of it. It's activity can be impacted in unknown ways (could be worse).
7/ If the positively charged lipids come into contact with the unmethylated CpG motifs in the DNA plasmids, they can form covalent bonds between the lipids and the DNA, producing mutations in that, and complex formation, including hybrid complex formation. Complexes could involve
8/DNA, proteins, and other biomolecules.
"DNA-protein crosslink formation"
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7192481/
9/ "Crosslinking of DNA
These can be manifested as either intrastrand DNA cross-links, that is, occurring within one strand of DNA, or interstrand DNA cross-links, which occur between two strands of DNA."
https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/crossli