Profound CD8+ T cell immunity elicited by sequential daily immunization with exogenous antigen plus the TLR3 agonist poly(I:C)

Vaccine. 2011 Jan 29;29(5):984-93. doi: 10.1016/j.vaccine.2010.11.036. Epub 2010 Nov 27.


The development of vaccines that elicit robust CD8(+) T cell immunity has long been a subject of intense investigation. Although whole exogenous protein has not historically been considered as useful for eliciting CD8(+) T cell immunity, we report herein that whole, protein antigen is capable of eliciting profound levels of CD8(+) T cell immunity if it is administered via repeated, daily subcutaneous immunization in combination with the TLR3 agonist poly(I:C). Mice immunized for four consecutive days with 100 μg of either whole exogenous OVA or whole HPV16 E7 protein combined with 10 μg of poly(I:C) mounted remarkable antigen-specific CD8(+) T cell responses as measured by tetramer staining and ELISPOT analysis of splenocytes and peripheral blood, with up to 30% of peripheral CD8(+) T cells being antigen specific within 7-8 days of vaccination. CD8(+) T cell immunity elicited using this vaccination approach was critically dependent upon cross presentation, as either whole protein or long synthetic peptides were highly effective immunogens whereas minimal peptide epitopes were not. Vaccine-induced CD8(+) T cells were also able to regress large, established tumors in vivo. Together these data suggest that 'cluster' vaccination with exogenous antigen combined with TLR3 agonist may constitute a profoundly important advancement in therapeutic vaccine design.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / administration & dosage*
  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • Cytokines / metabolism
  • Enzyme-Linked Immunospot Assay
  • Female
  • Immunization / methods*
  • Injections, Subcutaneous
  • Mice
  • Mice, Inbred C57BL
  • Ovalbumin / administration & dosage
  • Ovalbumin / immunology*
  • Papillomavirus E7 Proteins / administration & dosage
  • Papillomavirus E7 Proteins / immunology*
  • Poly I-C / administration & dosage*
  • Toll-Like Receptor 3 / agonists*


  • Adjuvants, Immunologic
  • Cytokines
  • Papillomavirus E7 Proteins
  • TLR3 protein, mouse
  • Toll-Like Receptor 3
  • oncogene protein E7, Human papillomavirus type 16
  • Ovalbumin
  • Poly I-C