The present application relates to a chimeric antigen receptor (CAR), comprising a GPC3 binding domain, a transmembrane domain, a costimulatory domain and an intracellular signaling domain, the GPC3 binding domain comprises an antibody or a fragment thereof which specifically binding to GPC3, the antibody comprises a light chain complementary determining region 1 (LCDR1), a light chain complementary determining region 2 (LCDR2) and a light chain complementary determining region 3 (LCDR3), the amino acid sequence of the LCDR1 is as set forth in SEQ ID NO: 16, the amino acid sequence of the LCDR2 is as set forth in SEQ ID NO: 17 and the amino acid sequence of the LCDR3 is as set forth in SEQ ID NO: 18. The present application also relates to an isolated nucleic acid encoding the CAR, a vector comprising the nucleic acid, an immune effector cell comprising the nucleic acid or the vector and a preparation method thereof as well as a use of the CAR.

Lipocalin muteins specific to a predetermined antigen can be transduced into a T cell to bring therapeutic benefits to patients in need. In one example, a lipocalin mutein specific to a predetermined antigen (e.g., a target differentially expressed on the surface of a tumor cell) can be transduced into a T cell membrane to serve as an antigen receptor, offering benefits over conventionally deployed antibody-derived protein moieties such as a single chain variable fragment (scFv). Benefits include a more stable structure, leading to superior target engagement, for example. Further, lipocalin muteins specific to a predetermined antigen (e.g. an immunomodulatory target such as an immune checkpoint or costimulatory molecule) can be transduced into a T cell for secretion thereby, bringing an added therapeutic benefit. Specific examples of such modified T cells and methods of making and using the same are provided herein.

Provided in the present invention is a method for treating tumor. An immune effector cell and a second treatment agent are applied to individual suffering from tumor, wherein the immune effector cell expresses a receptor for recognizing tumor antigen, and wherein the second treatment agent is a compound of formula I or a pharmaceutically acceptable salt thereof.

The present invention provides an antibody against glypican-3 (GPC3) and application thereof, and the antibody comprises a single chain antibody and humanized antibody.