Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) are important co-inhibitory molecules, while regulatory T cells (Tregs) are important suppressor cells. The increase of them in tumor microenvironment is closely related to tumor immune escape and tumor development. PD-L1 plays an important role in the development and function of Tregs. The application of PD-1/PD-L1 blockade also affects the proliferation and function of Tregs, which further participates in the occurrence of drug resistance and hyperprogressive disease. Further understanding of the role and correlation of PD-L1 and Tregs in tumor immunity and immunotherapy can provide new ideas for improving the efficacy of PD-1/PD-L1 blockade.

Objective:To explore the medication regularity of Traditional Chinese Medicine (TCM) for diabetic lower extremity arterial disease (DLEAD) based on data mining.Methods:Search for the clinical literature of treating DLEAD in recent 20 years from China Academic Journal Database (Wanfang Data), China National Knowledge Resources Database (CNKI), China Biomedical Literature Service System (SinoMed) and Chinese Science and Technology Journal Database (Chongqing VIP) dated. The frequency analysis, cluster analysis and association analysis for TCM were carried out respectively through Excel 2019, SPSS 25 and SPSS Modeler 18.Results:There are altogher 175 papers mentioning 201 prescriptions and 186 herbs, among which the top 5 herbs that are used frequently are Astragali Radix, Angelicae Sinensis Radix, Chuanxiong Rhizoma, Achyranthis Bidentatae Radix, Carthami Flos. The taste are mainly sweet and the nature is warm, with liver meridian as the most important maridian. The herbs for activating blood circulation and removing blood stasis are frequently used, followed by Qi tonic and blood tonic herbs. Association Rule Analysis suggested that Astragali Radix, Angelicae Sinensis Radix, Chuanxiong Rhizoma are the herbs that are frequently combined together. Conclusions:The medication for treating DLEAD mainly focuses on promoting blood circulation and removing blood stasis and tonifing Qi and blood. At the same time, the treatment should focus on dispelling wind and dispersing cold, warming yang and unblocking collaterals, resolving phlegm and removing dampness, nourishing yin and clearing heat based on different syndromes. Astragali Radix, Angelicae Sinensis Radix, Chuanxiong Rhizoma were the core herbs. It can be combined with Achyranthis Bidentatae Radix, Pheretma, Paeoniae Radix Rubra, Salviae miltiorrhizae Radix et Rhizoma, Peach Kernel, Carthami Flos to improve the curative effect.