Optimizing vaccine-induced CD8⁺ T-cell immunity: focus on recombinant adenovirus vectors

Abstract

Recombinant adenoviruses have emerged as promising viral vectors for CD8⁺ T-cell vaccines. Our studies have indicated that unlike most acute infections, the CD8⁺ T-cell memory population elicited by recombinant human adenovirus serotype 5 (rHuAd5) displays a dominant effector memory phenotype. Persistent, low-level transgene expression from the rHuAd5 vector sustains the CD8⁺ T-cell memory population and a nonhematopoietic cell compartment appears to be involved in long-term presentation of adenoviral antigens. Although we are beginning to learn more about the factors that control the maintenance and functionality of memory CD8⁺ T cells, we do not yet fully understand what comprises a protective CD8⁺ T-cell response. Results from upcoming Phase II clinical trials will be important for determining whether rHuAd5 T-cell vaccines are effective in humans and should help identify correlates of CD8⁺ T-cell protection.

Keywords::

• antigen-presenting cell
• immunology
• memory CD8⁺ T cell
• recombinant adenovirus vaccine
• T-cell polyfunctionality
• vaccine optimization

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.