A conditionally replicative adenovirus with enhanced infectivity shows improved oncolytic potency

Area of Science:

• Oncolytic virotherapy
• Adenovirus engineering
• Cancer treatment

Background:

• The Coxsackievirus and adenovirus receptor (CAR) is crucial for adenovirus entry into cells.
• Limited CAR expression on certain tumors restricts the effectiveness of current oncolytic adenoviruses.
• Conditionally replicative adenoviruses (CRAds) are engineered to selectively target and destroy cancer cells.

Purpose of the Study:

• To enhance the oncolytic potency of CRAds by enabling CAR-independent tumor cell infection.
• To investigate the efficacy of genetically modified adenoviruses with altered fiber knobs for improved cancer treatment.

Main Methods:

• Genetic modification of the adenovirus fiber knob to facilitate CAR-independent infection.
• Utilized an E1A-defective CRAd backbone for tumor-specific replication.
• Evaluated viral replication, tumor cell infection, and lysis in vitro and in vivo.

Main Results:

• The fiber-modified CRAd demonstrated enhanced infectivity and replication in tumor cells.
• Significant lysis of tumor cells was observed in vitro with the modified adenovirus.
• Improved antitumor effects were confirmed in vivo, highlighting the enhanced efficacy of the fiber-modified CRAd.

Conclusions:

• Combining genomic modifications for tumor selectivity with capsid modifications for enhanced infectivity creates more potent oncolytic adenoviruses.
• This dual-modification strategy represents a promising approach for developing effective adenoviral cancer therapies.
• Fiber modification of CRAds offers a viable strategy to overcome CAR-dependent entry limitations in cancer treatment.