Monoclonal antibodies and their applications

The invention belongs to the technical field of antibody medicines, and in particular relates to a mouse anti-human PD-L1 monoclonal antibody and an application thereof. The antibody derives from mouse hybridoma cells and is subjected to PD-L1 affinity screening. The mouse-derived antibody has excellent affinity and specificity to monkey PD-L1 or/and human PD-L1, and can block the combination of human PD-L1 and human PD-1 in dose dependence, effectively promote T leukomonocyte proliferation and stimulate the secretion of lymphadenoma cell IL-2 and IFN gamma. Meantime, the anti-PD-L1 can promote the proliferation of tumor antigen-specific T cells by blocking PD-1/PD-L1 signals, so as to exert the action of killing tumor cells. The treatment performed by blocking the PD-1 and PD-L1 signal channels is leading immunotherapy due to good treatment effect and safety, thereby being a hot target in the lung cancer treatment field in the last two years.