Non-human animal, composition and application method, wherein the non-human animal includes saltant type L- cynruins hydrolase (or kynureninase) gene. The non-human animal can be described, in some embodiments,There is the endogenous kynureninase gene of genetic modification as in, the non-human animal is allowed to express kynurenin enzyme polypeptide, it includes an amino acid replacement, therefore leads to the polypeptide for eliminating the kynureninase epitope, is to be present in nearly 1 gp41. of film perimeter human immunodeficiency virusDetoxic seedling