Masked IL-15 cytokines and cleavage products thereof

The present invention relates to a masked IL-15 cytokine comprising an IL-15 cytokine or a functional fragment thereof, a masking moiety, and a proteolytically cleavable linker. The cleavable linker has a masking portion that masks the IL-15 cytokine or functional fragment thereof, thereby reducing or preventing binding of the IL-15 cytokine or functional fragment thereof to its homologous receptor, but upon proteolytic cleavage of the cleavable linker at a target site, the IL-15 cytokine or functional fragment thereof is activated, thereby reducing or preventing binding of the IL-15 cytokine or functional fragment thereof to its homologous receptor. This enables or even more binding to its homologous receptor. 本发明涉及掩蔽的IL-15细胞因子，所述掩蔽的IL-15细胞因子包括IL-15细胞因子或其功能片段、掩蔽部分和蛋白水解可切割接头。所述掩蔽部分掩蔽所述IL-15细胞因子或其功能片段，由此减少或预防所述IL-细胞因子或其功能片段与其同源受体结合，但在所述可切割接头在靶位点处进行蛋白水解切割后，所述IL-15细胞因子或其功能片段被激活，这使其能够或更能够与其同源受体结合。