The B7/CD28 families of immune checkpoints play vital roles in negatively or positively regulating immune cells in homeostasis and various diseases.Recent basic and clinical studies have revealed novel biology of the B7/CD28 families and new therapeutics for cancer therapy.In this review,we discuss the newly discovered KIR3DL3/TMIGD2/HHLA2 pathways,PD-1/PD-L1 and B7-H3 as metabolic regulators,the glycobiology of PD-1/PD-L1,B7x(B7-H4)and B7-H3,and the recently characterized PD-L1/B7-1 cis-interaction.We also cover the tumor-intrinsic and-extrinsic resistance mechanisms to current anti-PD-1/PD-L1 and anti-CTLA-4 immunotherapies in clinical settings.Finally,we review new immunotherapies targeting B7-H3,B7x,PD-1/PD-L1,and CTLA-4 in current clinical trials.
Marc C.PulancoAnne T.MadsenAnkit TanwarDevin T.CorriganXingxing Zang
Somatic activating mutations in the epidermal growth factor receptor(EGFR)are one of the most common oncogenic drivers in cancers such as non-small-cell lung cancer(NSCLC),metastatic colorectal cancer,glioblastoma,head and neck cancer,pancreatic cancer,and breast cancer.Molecular-targeted agents against EGFR signaling pathways have shown robust clinical efficacy,but patients inevitably experience acquired resistance.Although immune checkpoint inhibitors(ICIs)targeting PD-1/PD-L1 have exhibited durable anti-tumor responses in a subset of patients across multiple cancer types,their efficacy is limited in cancers harboring activating gene alterations of EGFR.Increasing studies have demonstrated that upregulation of new B7/CD28 family members such as B7-H3,B7x and HHLA2,is associated with EGFR signaling and may contribute to resistance to EGFR-targeted therapies by creating an immunosuppressive tumor microenvironment(TME).In this review,we discuss the regulatory effect of EGFR signaling on the PD-1/PD-L1 pathway and new B7/CD28 family member pathways.Understanding these interactions may inform combination therapeutic strategies and potentially overcome the current challenge of resistance to EGFR-targeted therapies.We also summarize clinical data of anti-PD-1/PD-L1 therapies in EGFR-mutated cancers,as well as ongoing clinical trials of combination of EGFR-targeted therapies and anti-PD-1/PD-L1 immunotherapies.
机体特异性免疫应答是一个需要一系列免疫细胞和免疫分子共同参与的异常复杂的过程,这些免疫细胞及分子之间相互调节又相互制约。目前大多数肾脏疾病发病机制尚不明确。B7(CD80)位于调节CD4+和CD8+T细胞的抗原提呈细胞上,通过与细胞上的糖蛋白CD28结合发挥信号传递作用、增强或放大免疫反应的功能,或者与细胞毒性T细胞蛋白-4(cytotoxic T lymphocyte-associated antigen4 CTLA-4)结合后抑制免疫应答。通常肾组织不表达或低表达B7,然而某些肾小球疾病的发生与B7的增加有关,其降低了足细胞附着肾小球基底膜的能力,增加炎症反应及肾脏纤维化。当B7与CTLA-4相结合时,免疫反应就会被减弱。因此通过阻断CD28或增强CTLA-4信号可能阻止疾病的发生。该文就共刺激分子B7/CD28在足细胞损伤、原发性肾小球肾炎、紫癜性肾炎、狼疮性肾炎等肾脏疾病的发病机制中的作用,以及B7阻滞剂在部分肾脏疾病靶向治疗的研究进展进行综述。
