Nucleic Acids as Adjuvants

Nucleic acids presenting polymer nanomaterials as vaccine adjuvants

“…22 Aluminum salts and oil-in-water emulsions such as MF59 (squalene, polysorbate 80, sorbitan trioleate) and AS03 (a-tocopherol, squalene, polysorbate 80), the most common adjuvants present in vaccines approved for human use, induce antibodies production and T H 2 response but they do not induce antigen-specific CTLs and T H 1 response. 23 On the other hand, immunostimulatory agents as adjuvants induce T H 1 response, which is required in vaccines against intracellular pathogens and cancer, to specifically activate DCs and fine-tune T cell activation. These molecular adjuvants not only induce maturation and antigen presentation on DCs but can also modulate the quality of the immune response, promoting a specific type of immunity essential for a specific antigen.…”

“…These molecular adjuvants not only induce maturation and antigen presentation on DCs but can also modulate the quality of the immune response, promoting a specific type of immunity essential for a specific antigen. 23 The limited amount of adjuvants available for clinical use but especially the ineffectiveness of alum in inducing cellular responses boosted the research of new immunostimulatory agents. Additionally, it has been shown that aluminum salts compromise long-term antigen stability, possibly due to the different pH on the microenvironment of the aluminum surface.…”

“…41 Moreover, nucleic acids are able to induce T H 1 and CTL responses, useful for anticancer and antiviral vaccination. 23 In this review, we will focus on three main categories of nucleic acids with adjuvant potential: TLR3-binding analogs of dsRNA, synthetic small molecules agonists of TLR7/8 and CpG-motif-containing DNA sequences binding TLR9 (Fig. 2).…”

“…2A). 23 Poly(I:C) was the first synthetic dsRNA analog developed and tested. 23 Chemically, it is composed of one strand of riboinosinic acid polymer and of another strand of ribocytidylic acid polymer.…”

“…23 Poly(I:C) was the first synthetic dsRNA analog developed and tested. 23 Chemically, it is composed of one strand of riboinosinic acid polymer and of another strand of ribocytidylic acid polymer. Two forms are available, low molecular weight (LMW, length 0.2-1 kb) and high molecular weight (HMW, length 1.5-1 kb) poly(I:C), and both are able to bind TLR3, even if stronger activation was observed for HMW poly(I:C), probably due to the induction of a bigger multivalent complex by the latter.…”