The cathelicidin LL-37 exerts its mucosal adjuvant activity via enhancing germinal center formation and dendritic cell maturation (P3234)

• Published in: The Journal of immunology (1950) Vol. 190; no. 1_Supplement; pp. 124 - 124.28
• Main Authors: Jang, Yong-Suk, Kim, Sae-Hae, Lee, Ha-Yan, Lee, Hojun, Kim, Ju, Kim, Dae-Hyuk, Lee, Kyung-Yeol
• Format: Journal Article
• Language: English
• Published: 01-05-2013
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.190.Supp.124.28

Oral mucosal vaccine confers feasibility and efficacy in vaccination. However, it imposes restrictions such as difficulty in antigen delivery and poor immunogenic environment. Consequently, many studies have been concentrated to develop effective mucosal adjuvants. We determined mucosal adjuvant activity of cathelicidin LL-37 based on the previous report of its activity in parenteral vaccination, although it has not been studied in mucosal system. In oral mucosal vaccination using EGFP protein, LL-37-conjugated antigen effectively evoked the antigen-specific systemic and mucosal immunities. Notably, when the LL-37 was applied to pathogenic antigen, an EDIII of dengue virus, antibody responses with high neutralization activity was induced. Further studies on chemokine profiling induced by LL-37 in Peyer’s patch lymphocytes were well accordance with the increase in the number of germinal centers in Peyer’s patch and mesenteric lymph node by chemotactic effect of LL-37. In addition, oral priming with LL-37-conjugated antigen induced Th1- and Th17-skewed immune responses through CD11c+ CD70+ cell activation in Peyer’s patch. More interestingly, we found the expression of formyl peptide receptor-2, one of the receptors for LL-37, in subepithelial dome of Peyer’s patch and M cells. Collectively, we conclude that LL-37 can play a role as mucosal adjuvant through enhanced antigen delivery, dendritic cell maturation, and chemotactic effect by FPR-2 on M cells and subepithelial dome.