Interleukin-4-induced gene 1 (IL4I1)

Interleukin-4-induced gene 1 (IL4I1) encodes a secreted L-amino acid oxidase enzyme that is upregulated in response to interleukin-4 and is highly expressed in B cells, macrophages, dendritic cells, and certain lymphomas. IL4I1 primarily catalyzes the oxidative deamination of L-phenylalanine and can also act on tryptophan to generate immunosuppressive metabolites. This activity contributes to the modulation of T-cell responses, supporting tumor immune escape and dampening inflammation by impairing cytotoxic T cell activation and promoting regulatory immune cell types. High levels of IL4I1 are associated with cancer progression and immunosuppressive microenvironments, making it a novel potential target for cancer immunotherapy and a biomarker of immune regulation in disease[1][3][4][7][8].

Other names

IL4-induced protein 1L-amino-acid oxidaseFIG1LAAOInterleukin-4-induced protein 1[6]IL4I1 (abbreviation)

Drugs or inhibitors that target IL4I1 would be expected to inhibit its L-amino acid oxidase activity, thus reversing immunosuppression mediated by catabolites such as indole-3-pyruvic acid, indole-3-aldehyde, and H2O2, restoring T cell function and enhancing anti-tumor immunity[1][4][8].