Premium
Development of an attenuated interleukin‐2 fusion protein that can be activated by tumour‐expressed proteases
Author(s) -
Puskas John,
Skrombolas Denise,
Sedlacek Abigail,
Lord Edith,
Sullivan Mark,
Frelinger John
Publication year - 2011
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/j.1365-2567.2011.03428.x
Subject(s) - proteases , fusion protein , immune system , protease , cytokine , biology , matrix metalloproteinase , in vivo , microbiology and biotechnology , in vitro , cleavage (geology) , biochemistry , immunology , recombinant dna , enzyme , paleontology , fracture (geology) , gene
Summary The ability to alter the cytokine microenvironment has the potential to shape immune responses in many physiological settings, including the immunotherapy of tumours. We set out to develop a general approach in which cytokines could be functionally attenuated until activated. We report the development and initial characterization of fusion proteins in which human or mouse interleukin‐2 (IL‐2), a potent growth factor for immune cells, is joined to a specific IL‐2 inhibitory binding component separated by a protease site. The rationale is that upon cleavage by a protease the cytokine is free to dissociate from the inhibitory component and becomes biologically more available. We describe the successful development of two attenuation strategies using specific binding: the first uses the mouse IL‐2 receptor alpha chain as the inhibitory binding component whereas the second employs a human antibody fragment (scFv) reactive with human IL‐2. We demonstrated that the fusion proteins containing a prostate‐specific antigen or a matrix metalloproteinase (MMP) protease cleavage site are markedly attenuated in the intact fusion protein but had enhanced bioactivity of IL‐2 in vitro when cleaved. Further, we showed that a fusion protein composed of the IL‐2/IL‐2 receptor alpha chain with an MMP cleavage site reduced tumour growth in vivo in a peritoneal mouse tumour model. This general strategy should be applicable to other proteases and immune modulators allowing site‐specific activation of immunomodulators while reducing unwanted side‐effects.