Applications of chemokines as adjuvants for vaccine immunotherapy.

Vaccinations are expected to aid in building immunity against pathogens. This objective often requires the addition of an adjuvant with certain vaccine formulations containing weakly immunogenic antigens. Adjuvants can improve antigen processing, presentation, and recognition, thereby improving the immunogenicity of a vaccine by simulating and eliciting an immune response. Chemokines are a group of small chemoattractant proteins that are essential regulators of the immune system. They are involved in almost every aspect of tumorigenesis, antitumor immunity, and antimicrobial activity and also play a critical role in regulating innate and adaptive immune responses. More recently, chemokines have been used as vaccine adjuvants due to their ability to modulate lymphocyte development, priming and effector functions, and enhance protective immunity. Chemokines that are produced naturally by the body's own immune system could serve as potentially safer and more reliable adjuvant options versus synthetic adjuvants. This review will primarily focus on chemokines and their immunomodulatory activities against various infectious diseases and cancers.