Bifunctional iRGD-anti-CD3 enhances antitumor potency of T cells by facilitating tumor infiltration and T-cell activation

Abstract

BackgroundPoor infiltration and limited activation of transferred T cells are fundamental factors impeding the development of adoptive cell immunotherapy in solid tumors. A tumor-penetrating peptide iRGD has been widely used to deliver drugs deep into tumor tissues. CD3-targeting bispecific antibodies represent a promising immunotherapy which recruits and activates T cells.MethodsT-cell penetration was demonstrated in tumor spheroids using confocal microscope, and in xenografted tumors by histology and in vivo real-time fluorescence imaging. Activation and cytotoxicity of T cells were assessed by flow cytometry and confocal microscope. Bioluminescence imaging was used to evaluate in vivo antitumor effects, and transmission electron microscopy was used for mechanistic studies.ResultsWe generated a novel bifunctional agent iRGD-anti-CD3 which could immobilize iRGD on the surface of T cells through CD3 engaging. We found that iRGD-anti-CD3 modification not only facilitated T-cell infiltration in 3D tumor spheroids and xenografted tumor nodules but also induced T-cell activation and cytotoxicity against target cancer cells. T cells modified with iRGD-anti-CD3 significantly inhibited tumor growth and prolonged survival in several xenograft mouse models, which was further enhanced by the combination of programmed cell death protein 1 (PD-1) blockade. Mechanistic studies revealed that iRGD-anti-CD3 initiated a transport pathway called vesiculovacuolar organelles in the endothelial cytoplasm to promote T-cell extravasation.ConclusionAltogether, we show that iRGD-anti-CD3 modification is an innovative and bifunctional strategy to overcome major bottlenecks in adoptive cell therapy. Moreover, we demonstrate that combination with PD-1 blockade can further improve antitumor efficacy of iRGD-anti-CD3-modified T cells.

Artificial intelligence for quantifying immune infiltrates interacting with stroma in colorectal cancer

“…CD3 + T cells are membrane markers of mature T lymphocytes that can be used to quantify the total number of T lymphocytes [19]. When CD3 + cells was increased, it represented a higher tumor lymphatic infiltration and a higher amount of tumor-killing immune cells, which has a protective effect on the organism [37,38]. This result supports the idea that our proposed Deep-immune score may be sufficient to predict prognosis of CRC.…”

Delivery of Anti-miRNA-221 for Colorectal Carcinoma Therapy Using Modified Cord Blood Mesenchymal Stem Cells-Derived Exosomes

“…Many studies have reported that iRGD peptide accelerates drug delivery into tumor cells ( Tian et al, 2014 ). After its combination with integrins, the enzyme hydrolysate promotes the tissue penetration of the drug ( Zuo, 2019 ; Zhou et al, 2021 ). We found that NRP-1 was highly expressed in colon cancer tissues and cell lines, enabling the iRGD-Exos to be effectively ingested by colon cancer cells.…”

The role of cell‐penetrating peptides in potential anti‐cancer therapy

“…The use of the CPP‐iRGD is the key to facilitating tumour penetration and T‐cell activation. In 2021, bifunctional iRGD‐anti‐CD3 was found to enhance the anti‐tumour potency of T cells by facilitating tumour infiltration and T‐cell activation 259 . Furthermore, the combination therapy with iRGD‐antiCD3 and PD‐1 blockade enhances the anti‐tumour capacity of cord blood‐derived T Cells 260 .…”

“…In 2021, bifunctional iRGD-anti-CD3 was found to enhance the anti-tumour potency of T cells by facilitating tumour infiltration and T-cell activation. 259 Furthermore, the combination therapy with iRGD-antiCD3 and PD-1 blockade enhances the anti-tumour capacity of cord blood-derived T Cells. 260 The mechanism of iRGD is illustrated in Figure 6.…”