poly I: C is not a conventional adjuvant, as it has opposite features. First of all it does not bind to the molecules to which it is associated, and does not alter either the confromation thereof, nor their processing by the body. In fact the poly I: C induces a very strong apoptosis of the cells which express an entire TLR3, and causes the depletion of these cells, on the other hand it can activate certain sub-populations of DC cells, either by stimulating them or by inhibiting, depending on the status of the TLR3 they express. This is the case for pDCs whose controversial functions are now well established, and have a prominent role in the vaccine response.

Thanks. Do you have/know of publications which reported poly(I:C)'s opposite effects?

How is CpG as an adjuvant? How does it compare with poly(I:C)? You can supply references as well?

Both CpG and Poly I:C are good adjuvants. The problem for you is that they are both negatively charged and they won't complex with your DNA vaccine. Furthermore, they are not great alone because they can be easily degraded when injected in animals. They have to be complexed as nanoparticles or a similar structure.

They both act at the endosome level activating TLRs.

In this paper they use both : https://www.ncbi.nlm.nih.gov/pubmed/?term=cpg+poly+I%3Ac+DNA+vaccine

'' Do positively charged chemical adjuvants interact with DNA vaccines thus affecting protein expression? ''

Yes of course, usually they are a good combination because positive cations are able to disrupt endosome membranes releasing the DNA vaccine in the cytoplasm (which is good since it tends to degrade faster in lysosomes)

You can use stable CpG that has tioesther bonds. I use them, they are very stable and very good as adjuvants for Th1 responde induction in leishmaniasis. It depends on your model, because we tried poly I:C and they didn't work.

@ Fransesco, Thanks for the article. I found it very helpful. It looks like there very few of such studies in literature. Do you know of any company supplying these adjuvants as plasmids?

@ David, Are you using CpG in DNA vaccines or protein based vaccines. I am asking because most of the studies (save for the one above cited by Francesco) use these adjuvants in protein based vaccines. Can you share any publications you have from your work? I also understand Invivogen has HMW Vaccigrade poly (I:C) as an adjuvant. Do you have any experiences with the adjuvant? Thanks

Thomas Tipih, we have been using CpG as adjuvant in protein based vaccines. We have tried DNA vaccines, but without any adjuvant of this kind (just the mere DNA). I don't have experience at all with Poly(I:C), but I do have it with CpG (and we use the one with thioester bonds so it's more stable). We don't have a paper yet but I recently uploaded a presentation about or protein vaccine with CpG adjuvant.

Presentation Preclinical development of a molecularly-defined liposomal v...

Thanks David