9-Phenanthrol enhances the generation of an CD8+ T cell response following transcutaneous immunization with imiquimod in mice. Issue 3 (September 2017)

• Record Type: Journal Article
• Authors: Hartmann, Ann-Kathrin; Aranda Lopez, Pamela; Zajac, Marek; Freichel, Marc; Schild, Hansjörg; Radsak, Markus P.; Stassen, Michael
• Is Part Of: Journal of dermatological science. Volume 87:Issue 3(2017:Sep.)
• Page Start: 260
• Page End: 267
• Publication Date: 2017-09
• Subjects: APC antigen presenting cell -- BMMC bone marrow derived mast cells -- CTL cytotoxic T lymphocyte -- DC dendritic cell -- 9-phe 9-phenanthrol -- TCI transcutaneous immunization -- TLR toll-like receptor; Transcutaneous immunization -- Imiquimod -- 9-Phenanthrol -- Mast cells -- CTL Response; Dermatology -- Periodicals; Skin Diseases -- Periodicals; Dermatologie -- Périodiques; 616.5005
• DOI: 10.1016/j.jdermsci.2017.07.018
• Languages: English
• ISSNs: 0923-1811

Abstract

Highlights: 9-Phenanthrol causes degranulation of mast cells in vitro and in vivo . 9-Phenanthrol transiently increases intracellular calcium-levels in mast cells. 9-Phenanthrol improves generation of CTL responses using Aldara as adjuvant. Abstract: Background: Transcutaneous immunization (TCI) is a non-invasive vaccination strategy targeting the skin-associated lymphoid tissue. Topical application of the TLR7 agonist imiquimod as adjuvant in combination with peptide antigens activates the innate immune system and mounts cytotoxic T lymphocyte (CTL) responses. Objective: Based on the commercial 5% imiquimod-containing drug Aldara we aimed to develop an improved formulation with superior vaccination efficiencies. The primary target was the enhancement of mast cell activation as important key for the function of the innate immune system. Methods: We investigated the effects of 9-phenanthrol (9-phe) on the activation of mast cells in vitro and in vivo . For TCI, we applied 0.2% 9-phe in Aldara or Aldara alone as adjuvants in combination with the MHC class I – restricted peptide SIINFEKL. To monitor vaccination, mast cell degranulation, migration of DC and frequencies of epitope-specific CTL was assessed. In a transgenic tumor model, the efficiencies of prophylactic immunization against a tumor antigen were also monitored. Results: 9-phe induced degranulation of mast cells in vitro and upon topical application in vivo. A mixture of 0.2% 9-phe in Aldara showed superior results regarding the migration of DC and the expansion of antigen-specific CTL. Consequently, prophylactic immunization with 0.2% 9-phe in Aldara caused enhanced protection against tumor inoculation. Conclusion: Our data demonstrate that a simple modification of an adjuvant formulation can yield superior results in experimental vaccination protocols by boosting critical steps leading to the generation of an efficient CTL response.