Title:Endogenous and Exogenous Natural Adjuvants for Vaccine Development
Volume: 17
Issue: 15
Author(s): Azam Bolhassani*, Somayeh Talebi and Ali Anvar
Affiliation:
- Department of Hepatitis and AIDs, Pasteur Institute of Iran, Tehran,Iran
Keywords:
Endogenous, exogenous, immune response, liposome, natural adjuvant, vaccine.
Abstract: Objective & Background: Various adjuvants are usually co-injected with an antigen for
stimulation of effective immune responses. Adjuvants are able to elicit innate immune responses at the
injection site. Depending on the activated type of innate responses, adjuvants can modify the quality
and quantity of adaptive immune responses. Their mechanisms of action in vaccine development include:
a) enhancement of the total antibody titers; b) reduction of the antigen dose; c) induction of potent
cell-mediated immunity; d) increase in the speed and duration of the protective response; e) stimulation
of mucosal immunity; and f) cross-protection.
Up to now, different exogenous adjuvants have been identified to boost immune responses including
inorganic compounds, mineral oil, bacterial products, non-bacterial organics, detergents or Quil A,
plant saponins, Freund’s complete or incomplete adjuvants, and delivery systems. However, some immune
responses can be generated in the absence of the exogenous adjuvants. Indeed, endogenous adjuvants
released from the cells were known as the danger signals and immunogenic compounds. Several
main endogenous adjuvants contain cytokines, chemokines, alarmins, dendritic cells (DCs), toll like
receptor (TLR) ligands or agonists, and antibodies.
Results & Conclusion: In this review, the immune activities of the natural adjuvants especially endogenous
adjuvants and their mechanisms of action are discussed.
