Table 5.

Immunotherapeutic aptamers

Aptamer name	Type	Target	RNA or DNA	Modification	Function	Refs.
RNA Aptamer	Antagonistic	CTLA-4	RNA	–	Inhibition of CTLA-4 functions and enhance tumor immunity in cell and animal models	[124]
aptCTLA-4	Antagonistic	CTLA-4	DNA	–	Promotes lymphocyte proliferation, and inhibits tumor growth in both in vitro and in vivo	[125]
CTLA4apt–STAT3 siRNA	Antagonistic	CTLA-4	RNA	Covalently linked to a STAT-3 siRNA	STAT-3 gene silencing in CD8+ infiltrated lymphocytes and regulatory T cells (Tregs) in tumors and subsequently inhibits tumor growth and metastasis	[126]
MP7	Antagonistic	PD-1	DNA	Conjugated to the polyethylene glycol (PEG)	Inhibits the suppression of IL-2 secretion in primary T-cells and suppresses the tumor growth	[127]
aptPD-L1	Antagonistic	PD-L1	DNA	–	Stimulate lymphocyte proliferation in vitro, suppress tumor growth in vivo, and increase in the levels of infiltrating CD4+ and CD8+ T cells, as well as the cytokines IL-2, TNF-α, IFN-γ and the C-X-C motif chemokines	[128]
BSA-Apt	Antagonistic	PD-L1	DNA	Conjugated to the bovine serum albumin	Stronger antitumor efficacy	[129]
TIM-3 aptamer	Antagonistic	TIM-3	DNA	Trimeric form of the TIM-3 aptamer	Reduced cell death, and enhanced survival, proliferation, and cytokine secretion in vitro	[130]
LAG3 aptamer	Antagonistic	LAG3	RNA	2′-fluoro-pyrimidines	Enhances the threshold of T-cell activation	[131]
4-1BB aptamer	Agonistic	4-1BB	RNA	Bivalent and multivalent	Stimulate CD8+ T cells and inhibit tumor growth	[132]
4-1BB bispecific aptamer	Agonistic	4-1BB	RNA	2′-fluoro-pyrimidine, conjugated with vascular endothelial growth factor or osteopontin	Enhances the therapeutic index of tumor immunotherapy	[133]
hOX40 aptamer	Agonistic	OX40	RNA	2′-fluoro-pyrimidine and multimerized	Induce proliferation and IFN-γ production in activated human T cells in vitro	[134]
CD40 agonist aptamers	Agonistic	CD40	RNA	2ʹ-fluoropyrimidine	Hastened the improvement of bone marrow aplasia by inducing the reproduction and activation of B cells	[135]
CD40-blockade aptamer	Antagonist	CD40	RNA	2ʹ-fluoropyrimidine	Have a direct antitumor effect on CD40-expressing B-cell lymphoma in vitro and in vivo	[135]
CD40 agonistic aptamer-shRNA chimera	Agonistic	CD40	RNA	2ʹ-fluoropyrimidine, and linked with a short hairpin RNA targeting serine/threonine protein kinase	Enhancing tumor antigenicity by NMD inhibition and improvement in tumor infiltration and overall survival in vivo	[135]
CD28Apt2 and CD28Apt7	Agonistic	CD28	RNA	2ʹ-fluoropyrimidine and dimerization	Increasing the cellular immune system response and prolong the survival of mice	[136]
X-polymers	Antagonistic and Agonistic	CTLA-4 and CD28	RNA	CAR-like multivalent aptamer nanoparticles	Increase T cell proliferation and reverse the inhibitory effect of IL-2, and suppress the growth of mouse melanoma B16 cells both in vitro and in vivo	[137]
APT-β1	Inhibitors of immunosuppressive cytokines	TGF-β1	RNA	Combined with gefitinib	Enhanced the anti-tumor effect, and inhibit the regrowth of lung cancer	[138]
R5A1 aptamer	Inhibitors of immunosuppressive cytokines	IL-10 receptor	RNA	–	Inhibit CT26 tumor growth in mice	[123]