Novel vaccine development strategies for inducing mucosal immunity

Abstract

To develop protective immune responses against mucosal pathogens, the delivery route and adjuvants for vaccination are important. The host, however, strives to maintain mucosal homeostasis by responding to mucosal antigens with tolerance, instead of immune activation. Thus, induction of mucosal immunity through vaccination is a rather difficult task, and potent mucosal adjuvants, vectors or other special delivery systems are often used, especially in the elderly. By taking advantage of the common mucosal immune system, the targeting of mucosal dendritic cells and microfold epithelial cells may facilitate the induction of effective mucosal immunity. Thus, novel routes of immunization and antigen delivery systems also show great potential for the development of effective and safe mucosal vaccines against various pathogens. The purpose of this review is to introduce several recent approaches to induce mucosal immunity to vaccines, with an emphasis on mucosal tissue targeting, new immunization routes and delivery systems. Defining the mechanisms of mucosal vaccines is as important as their efficacy and safety, and in this article, examples of recent approaches, which will likely accelerate progress in mucosal vaccine development, are discussed.

Keywords::

• delivery system
• mucosal adjuvant
• secretory IgA

Acknowledgement

The authors thank Ms Sheila D Turner for preparation of the manuscript.

Financial & competing interests disclosure

Parts of research described in this manuscript were supported by US NIH grants AG 025873 and DE 012242 and the Japan Society of the Promotion of Science program entitled “Young Researcher Overseas Visits Program for Vitalizing Brain Circulation”, Global Center of Excellence Program “Center of Education and Research for the Advanced Genome-based Medicine – for personalized medicine, the control of worldwide infectious diseases – MEXT,” Japan, a grant from the Global Center of Excellence and “Academic Frontier” Project for Private Universities Matching Fund Subsidy from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and Research for Promoting Technological Seeds from Japan Science and Technology Agency (13-043), the Japan Foundation for Pediatric Research and Houjinkai fellowship award of the Department of Pediatrics at Osaka City University Graduate School of Medicine, and The Mochida Memorial Foundation for Medical and Pharmaceutical Research. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was used in the production of this manuscript.