免疫和炎症构成肿瘤微环境的两大核心,但两者之间关系并不清楚。髓源抑制性细胞(myeloid derived suppressorcell,MDSC)和调节性T细胞(regulatory T cell,Treg)等抑制性细胞趋化至肿瘤部位可抑制炎症,而非介导肿瘤免疫逃逸;肥大细胞则通过对MDSC和Treg的调节,介导免疫和炎症的对话;作为肿瘤微环境中基本信号通路的Toll样信号可以直接调节免疫和炎症,并通过微颗粒途径精细调控肿瘤炎症的稳定。不管肿瘤炎症和免疫的关系如何复杂而交错,一般认为,肿瘤微环境的抗肿瘤免疫和炎症呈现出一种负相关关系,即在肿瘤的早期,免疫反应较强而炎症较弱;但在肿瘤的后期,免疫反应较弱而炎症较强。
Chemotherapeutic drugs eliminate tumor cells at relatively high doses and are considered weapons against tumors in clinics and hospitals.However,despite their ability to induce cellular apoptosis,chemotherapeutic drugs should probably be regarded more as a class of cell regulators than cell killers,if the dosage used and the fact that their targets are involved in basic molecular events are considered.Unfortunately,the regulatory properties of chemotherapeutic drugs are usually hidden or masked by the massive cell death induced by high doses.Recent evidence has begun to suggest that low dosages of chemotherapeutic drugs might profoundly regulate various intracellular aspects of normal cells,especially immune cells.Here,we discuss the immune regulatory roles of three kinds of chemotherapeutic drugs under low-dose conditions and propose low dosages as potential new chemotherapeutic weapons on the battlefield of immune-related disease.
