Traditional Chinese medicine inhibits PD-1/PD-L1 axis to sensitize cancer immunotherapy: a literature review

Abstract

The Programmed death-1 (PD-1) and its programmed death-ligand 1 (PD-L1) comprise the PD-1/PD-L1 axis and maintain tumor immune evasion. Cancer immunotherapy based on anti-PD-1/PD-L1 antibodies is the most promising anti-tumor treatment available but is currently facing the thorny problem of unsatisfactory outcomes. Traditional Chinese Medicine (TCM), with its rich heritage of Chinese medicine monomers, herbal formulas, and physical therapies like acupuncture, moxibustion, and catgut implantation, is a multi-component and multi-target system of medicine known for enhancing immunity and preventing the spread of disease. TCM is often used as an adjuvant therapy for cancer in clinical practices, and recent studies have demonstrated the synergistic effects of combining TCM with cancer immunotherapy. In this review, we examined the PD-1/PD-L1 axis and its role in tumor immune escape while exploring how TCM therapies can modulate the PD-1/PD-L1 axis to improve the efficacy of cancer immunotherapy. Our findings suggest that TCM therapy can enhance cancer immunotherapy by reducing the expression of PD-1 and PD-L1, regulating T-cell function, improving the tumor immune microenvironment, and regulating intestinal flora. We hope this review may serve as a valuable resource for future studies on the sensitization of immune checkpoint inhibitors (ICIs) therapy.

Integrative Oncology Approaches to Supporting Immune Checkpoint Inhibitor Treatment of Solid Tumours

“…Herbal medicine from multiple traditions is a commonly used immunomodulatory approach in integrative oncology, with CHM (Chinese Herbal Medicine) currently being the most studied herbal approach in general oncology support. Chinese herbal medicine approaches have promising preclinical evidence in supporting immunotherapy treatment [109,110], and the results of a planned multi-centre RCT evaluating the safety and efficacy of Bojungikki-tang (BJIKT) therapy in patients with advanced NSCLC treated with ICIs are eagerly awaited [111].…”

Herb pair of Huangqi‐Danggui exerts anti‐tumor immunity to breast cancer by upregulating PIK3R1

“…Numerous studies have demonstrated that Traditional Chinese Medicine (TCM) has a significant impact on tumor suppression, reduces drug resistance, and enhances the immune response while mitigating adverse reactions 8–10 . In recent years, a breakthrough in TCM has been made through targeting immune checkpoints, such as PD‐1 and PD‐L1, thus offering a novel approach in the treatment of various malignant tumors 11,12 . TCM posits that Qi, the vital energy, is the driving force behind all physiological functions of the human body.…”

“… 8 , 9 , 10 In recent years, a breakthrough in TCM has been made through targeting immune checkpoints, such as PD‐1 and PD‐L1, thus offering a novel approach in the treatment of various malignant tumors. 11 , 12 TCM posits that Qi, the vital energy, is the driving force behind all physiological functions of the human body. It is generated by the combination of the essence of water and grain with the natural atmosphere that is inhaled.…”