An intranasally delivered toll-like receptor 7 agonist elicits robust systemic and mucosal responses to Norwalk virus-like particles

Lissette S. Velasquez, Brooke E. Hjelm, Charles J. Arntzen, Melissa M. Herbst-Kralovetz

Research output: Contribution to journalArticle

34 Scopus citations


Norwalk virus (NV) is an enteric pathogen from the genus Norovirus and a major cause of nonbacterial gastroenteritis in humans. NV virus-like particles (VLPs) are known to elicit systemic and mucosal immune responses when delivered nasally; however, the correlates of immune protection are unknown, and codelivery with a safe and immunogenic mucosal adjuvant may enhance protective anti-NV immune responses. Resiquimod (R848), an imidazoquinoline-based Toll-like receptor 7 and/or 8 (TLR7/8) agonist, is being evaluated as an adjuvant in FDA-approved clinical vaccine trials. As such, we evaluated the adjuvant activity of two imidazoquinoline-based TLR7 and TLR7/8 agonists when codelivered intranasally with plant-derived NV VLPs. We also compared the activity of these agonists to the gold standard mucosal adjuvant, cholera toxin (CT). Our results indicate that codelivery with the TLR7 agonist, gardiquimod (GARD), induces NV VLP-specific serum IgG and IgG isotype responses and mucosal IgA responses in the gastrointestinal, respiratory, and reproductive tracts that are superior to those induced by R848 and comparable to those induced by the mucosal adjuvant CT. This study supports the continued investigation of GARD as a mucosal adjuvant for NV VLPs and possible use for other VLP-based vaccines for which immune responses at distal mucosal sites (e.g., respiratory and reproductive tracts) are desired.

Original languageEnglish (US)
Pages (from-to)1850-1858
Number of pages9
JournalClinical and Vaccine Immunology
Issue number12
StatePublished - Dec 1 2010


ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Clinical Biochemistry
  • Microbiology (medical)

Cite this