Nano-adjuvants as Effective Next-Generation Antimicrobial Agents

Adaptive immunity is a feature peculiar to vertebrates which is responsible for defence against invading pathogens. It is a system that recognizes pathogenic antigens from a previous encounter and builds a robust immune response that neutralizes the pathogen. Vaccines are a perfect application of exploiting our adaptive immunity where pathogenic antigens are introduced into our body resulting in the generation of long-lived immune cells known as memory cells. These cells recognize pathogenic signatures upon infection and initiate the adaptive immune response. An essential component of a vaccine is an adjuvant which enhances the efficiency of an antigen to produce a robust immune response. The exact mechanisms behind adjuvant enhancement of immune response are not fully understood; thus, they have been referred to as ‘the immunologists’ dirty little secret’ – Janeway. Recent studies have shown that nano-adjuvants are very efficient immune regulators and double Toll-like receptor (TLR) stimulation might be the reason for their efficacy. Adjuvant development is emerging as an important trend in vaccine delivery, since a wide range of antigens that are not immunogenic need to be enhanced. This chapter aims to highlight the potential role of nanoparticles as nano-adjuvants and the recent developments made in this evolving field.