Immunization with viruslike particles induces long-term protection of rabbits against challenge with cottontail rabbit papillomavirus.

  • Christensen N
  • Reed C
  • Cladel N
 et al. 
  • 26


    Mendeley users who have this article in their library.
  • 197


    Citations of this article.


Rabbits were immunized with recombinant baculovirus-produced virus-like particles (VLPs) of cottontail rabbit papillomavirus (CRPV) to determine whether these antigens could induce long-term protection against experimental challenge with CRPV. Infectious CRPV and human papillomavirus type 11 L1 VLPs were used as positive and negative control immunogens, respectively. Three groups of immunized animals were challenged with 10-fold serial dilutions of infectious CRPV at 2 weeks, 6 months, and 12 months after immunizations. Antibody titers in serum reached 1:10,000 immediately after the final booster immunization and then decayed to 1:150 at 6 months and 1:100 at 12 months in unchallenged rabbits. Serum neutralization titers followed similar kinetics. Papillomas grew on control-immunized rabbits at sites challenged with 10(-1) (100% of sites), 10(-2) (96% of sites), 10(-3) (63% of sites), and 10(-4) (13% of sites) dilutions of virus. At 2 weeks after CRPV L1 VLP immunizations, the rabbits were completely protected against virus challenge. At both 6 and 12 months after CRPV L1 VLP immunizations, strong protection was also observed. In the last two groups, three of seven rabbits were completely protected and only 4 of 14 or 29% of sites challenged with 10(-1 dilution of virus grew papillomas. Papillomas growing at these four sites were also reduced in size (3.5 +/- 0.7 mm) at 50 days postchallenge compared with sites challenged with 10(-1) dilution on control-immunized rabbits (13.2 +/- 4.2 mm). The results demonstrate that strong and long-lasting protection against experimental challenge with papillomaviruses can be achieved with VLP immunogens.

Author-supplied keywords

  • Animals
  • Antibodies, Viral
  • Antibodies, Viral: blood
  • Antibodies, Viral: immunology
  • Antigens, Viral
  • Antigens, Viral: immunology
  • Cell Line
  • Cottontail rabbit papillomavirus
  • Cottontail rabbit papillomavirus: immunology
  • Humans
  • Immunization
  • Neutralization Tests
  • Papillomavirus Infections
  • Papillomavirus Infections: immunology
  • Papillomavirus Infections: prevention & control
  • Rabbits
  • Time Factors
  • Tumor Virus Infections
  • Tumor Virus Infections: immunology
  • Tumor Virus Infections: prevention & control
  • Vaccines, Synthetic
  • Vaccines, Synthetic: immunology
  • Viral Structural Proteins
  • Viral Structural Proteins: immunology
  • Viral Vaccines
  • Viral Vaccines: immunology
  • Virion
  • Virion: immunology

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document


  • N D Christensen

  • C a Reed

  • N M Cladel

  • R Han

  • J W Kreider

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free