Novel replication-incompetent adenoviral B-group vectors: high vector stability and yield in PER.C6 cells

J Gen Virol. 2006 Aug;87(Pt 8):2135-2143. doi: 10.1099/vir.0.81956-0.

Abstract

Adenoviral vectors based on adenovirus type 35 (rAd35) have the advantage of low natural vector immunity and induce strong, insert-specific T- and B-cell responses, making them prime-candidate vaccine carriers. However, severe vector-genome instability of E1-deleted rAd35 vectors was observed, hampering universal use. The instability of E1-deleted rAd35 vector proved to be caused by low pIX expression induced by removal of the pIX promoter, which was located in the E1B region of B-group viruses. Reinsertion of a minimal pIX promoter resulted in stable vectors able to harbour large DNA inserts (> 5 kb). In addition, it is shown that replacement of the E4-Orf6 region of Ad35 by the E4-Orf6 region of Ad5 resulted in successful propagation of an E1-deleted rAd35 vector on existing E1-complementing cell lines, such as PER.C6 cells. The ability to produce these carriers on PER.C6 contributes significantly to the scale of manufacturing of rAd35-based vaccines. Next, a stable rAd35 vaccine was generated carrying Mycobacterium tuberculosis antigens Ag85A, Ag85B and TB10.4. The antigens were fused directly, resulting in expression of a single polyprotein. This vaccine induced dose-dependent CD4+ and CD8+ T-cell responses against multiple antigens in mice. It is concluded that the described improvements to the rAd35 vector contribute significantly to the further development of rAd35 carriers for mass-vaccination programmes for diseases such as tuberculosis, AIDS and malaria.

MeSH terms

  • Adenoviridae / genetics*
  • Adenoviridae / isolation & purification*
  • Adenoviridae / physiology
  • Adenovirus E4 Proteins / genetics
  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Capsid Proteins / biosynthesis
  • Capsid Proteins / genetics
  • Cell Line
  • Genetic Complementation Test
  • Genetic Vectors*
  • Humans
  • Immunity, Cellular
  • Interferon-gamma / biosynthesis
  • Mice
  • Models, Animal
  • Mycobacterium tuberculosis / genetics
  • Mycobacterium tuberculosis / immunology
  • Promoter Regions, Genetic
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / immunology
  • Recombination, Genetic
  • Tuberculosis Vaccines / genetics
  • Tuberculosis Vaccines / immunology
  • Vaccines, Synthetic* / genetics
  • Vaccines, Synthetic* / immunology
  • Virus Replication

Substances

  • Adenovirus E4 Proteins
  • Bacterial Proteins
  • Capsid Proteins
  • Recombinant Fusion Proteins
  • Tuberculosis Vaccines
  • Vaccines, Synthetic
  • hexon capsid protein, Adenovirus
  • Interferon-gamma