Abstract: An anti-SIRP? antibody or an antigen-binding fragment thereof, and use thereof are provided. The anti-human SIRP? monoclonal antibody is obtained by means of immunizing mice, and a chimeric antibody and a humanized antibody are further obtained. The provided anti-SIRP? antibody or antigen-binding fragment thereof can bind to the human SIRP? protein, block the CD47-SIRP? signaling pathway, and have immune regulation effects such as enhancing phagocytosis. Further provided are a pharmaceutical composition and a nucleic acid molecule, and the use of the anti-SIRP? antibody or the antigen-binding fragment thereof in the preparation of a drug for inhibiting or treating diseases.

Abstract: A bispecific antibody targeting human claudin and human PDL1 proteins, containing an anti-human claudin18.2 antibody moiety and an anti-PD-L1 antibody moiety. The bispecific antibody can not only bind to human claudin18.2 protein, but also block binding of PD-1/PD-L1, and can not only activate NK cells and kill tumor cells in the innate immunity, but also promote the killing effect of killer T lymphocytes on tumors in the acquired immunity. The bispecific antibody has better anti-tumor efficacy than an anti-claudin18.2 antibody alone.

Abstract: Provided are an anti-PD-L1 nanobody and an Fc fusion protein thereof, and an application thereof. The anti-PD-L1 nanobody and the Fc fusion protein thereof have strong specificity, high affinity, and weak immunogenicity to humans. In addition, same have high stability and a significant anti-tumor effect.

Abstract: Provided are an anti-CLDN18.2 antibody and a pharmaceutical composition thereof and a detection method therefor, wherein the heavy chain of the antibody is selected from any one of SEQ ID NOs: 1-7 or SEQ ID NOs: 15-30, and the light chain of the antibody is selected from any one of SEQ ID NOs: 8-14 or SEQ ID NOs: 31-46. The ability of the antibody to bind to cell lines and tumor tissue cells is more powerful than that of the existing antibody IMAB362, and the anti-tumor effect of the antibody is also more powerful than that of the existing antibody IMAB362.