Adenovirus type 5 with modified hexons induces robust transgene‐specific immune responses in mice with pre‐existing immunity against adenovirus type 5
S Abe, K Okuda, T Ura, A Kondo… - The Journal of Gene …, 2009 - Wiley Online Library
S Abe, K Okuda, T Ura, A Kondo, A Yoshida, S Yoshizaki, H Mizuguchi, D Klinman…
The Journal of Gene Medicine: A cross‐disciplinary journal for …, 2009•Wiley Online LibraryAbstract Background Adenovirus type 5 (Ad5) is widely used as a vehicle for vaccine
delivery in the treatment of infectious disease and cancer. However, the efficacy of Ad5
vectors has been limited in humans because exposure to Ad5 infections results in most
adults having neutralizing antibodies against Ad5. To overcome this limitation, the hexon
epitope present in the fifth hypervariable region of Ad5 was modified. Methods To evaluate
the ability of Ad5 vectors encoding the HIV env protein to induce Ag‐specific immune …
delivery in the treatment of infectious disease and cancer. However, the efficacy of Ad5
vectors has been limited in humans because exposure to Ad5 infections results in most
adults having neutralizing antibodies against Ad5. To overcome this limitation, the hexon
epitope present in the fifth hypervariable region of Ad5 was modified. Methods To evaluate
the ability of Ad5 vectors encoding the HIV env protein to induce Ag‐specific immune …
Background
Adenovirus type 5 (Ad5) is widely used as a vehicle for vaccine delivery in the treatment of infectious disease and cancer. However, the efficacy of Ad5 vectors has been limited in humans because exposure to Ad5 infections results in most adults having neutralizing antibodies against Ad5. To overcome this limitation, the hexon epitope present in the fifth hypervariable region of Ad5 was modified.
Methods
To evaluate the ability of Ad5 vectors encoding the HIV env protein to induce Ag‐specific immune responses in the face of pre‐existing anti‐Ad5 immunity, mice were administrated intramuscularly with the Ad‐Luc vector, and then vaccinated with parental or hexon‐modified Ad5 vectors (Ad‐HisHIV, Ad‐END/AAAHIV or Ad‐HIV) at week 8. HIV‐specific cell‐mediated immune responses were detected through a combination of tetramer assays and intracellular cytokine staining from weeks 8–23.
Results
The hexon‐modified Ad vector was able to escape from anti‐Ad5 neutralizing antibody, and mice with the modified vector generated significantly lower individual neutralizing antibody than those immunized with the parental vector. Furthermore, mice with pre‐existing anti‐Ad immunity immunized with the modified vector generated significantly stronger cell‐mediated anti‐env responses than those immunized with the parental vector.
Conclusions
These data demonstrate that Ad5 vector with hexon modification reduce their sensitivity to pre‐existing anti‐Ad immunity and improve their clinical utility. Copyright © 2009 John Wiley & Sons, Ltd.
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