Transferrin-binding domain inserted-adenovirus hexon engineering enables systemic immune evasion and intratumoral T-cell activation

<b>Rationale:</b> Adenovirus-based therapies have encountered significant challenges due to host immunity, particularly from pre-existing antibodies. Many trials have struggled to evade antibody response; however, the efficiency of these efforts was limited by the diversity of antibody Fv-region recognizing multiple amino acid sequences. <b>Methods:</b> In this study, we developed an antibody-evading adenovirus vector by encoding a plasma-rich protein transferrin-binding domain. The coding sequence was employed from <i>Neisseria Meningitides</i> and inserted in the experimentally-optimized site within the adenovirus capsid protein. <b>Result:</b> This engineered antibody-evading oncolytic adenovirus overcame the reduction in productivity and infectivity typically caused by the insertion of a foreign domain. We observed decreased immune recognition and compromised formation of anti-adenovirus antibodies. Furthermore, the anti-tumor efficacy was demonstrated both <i>in vitro</i> and <i>in vivo</i>, with increased recruitment of CD8⁺ T cells. <b>Conclusion:</b> This novel antibody-evading strategy effectively evades neutralizing antibodies and innate immunity while boosting cytotoxic immunity by recruiting CD8⁺ T cells at the tumor site. Additionally, this strategy holds potential for application in other gene therapies and adenovirus vectors.