Table 2.

Examples for combination of oncolytic adenovirus with immune checkpoint modulators

	Advantages	Disadvantages
OA + antagonist antibodies to block immune inhibitors (CTLA-4, PD-1)	Abrogate T cell anergy	Affect all T cells Induce global effect, autoimmunity
OA + antagonist antibodies to block immune inhibitor ligands (PD-L1)	Target tumor cells	Affect other APCs Induce global effect, autoimmunity
OA expressing single-chain antibodies against immune inhibitors	Limit effect at tumor site Achieve high levels of antibodies within the tumor	Technically possible but complicated; Paucity of publications; require confirmation
OA expressing ligands for immune co-stimulators	Confine effect to tumor cells Technically straight forward	Paucity of publications; require confirmation
OA expressing decoy receptors to block immune inhibitor ligands	Limit effect at tumor site Target tumor cells	Require confirmation

OA, Oncolytic adenovirus