Th17 cell based vaccines in mucosal immunity

• Th17 responses show protection against both bacterial and fungal pathogens.
• Mucosal and systemic vaccines can elicit protective Th17 responses.
• Th17 responses can mediate serotype immunity against clades of organisms.

Vaccination is proven to be effective in controlling many infections including small pox, influenza and hepatitis, but strain-specific factors may limit vaccine efficacy. All of these vaccines work through the generation of neutralizing antibodies but for some pathogens there may be roles for serotype-independent immunity. Recently several groups using murine vaccine models have shown that induced T helper cell responses including Th17 responses have shown the potential for CD4+ T-cell dependent vaccine responses. Th17 mediated protective responses involve the recruitment of neutrophils, release of anti-microbial peptides and IL-17-driven Th1 immunity. These effector mechanisms provide immunity against a range of pathogens including the recently described antibiotic-resistant metallo-beta-lactamase 1 Klebsiella pneumoniae. Continued elucidation of the mechanism of Th17 responses and identification of effective adjuvants for inducing robust non pathogenic Th17 responses may lead to successful Th17 based vaccines. Here we summarize the recent advances in understanding the role of Th17 in vaccine induced immunity. We also discuss the current status and future challenges in Th17-based mucosal vaccine development.