Henk Pieters

Bio: Henk Pieters is an academic researcher from Takeda Pharmaceutical Company. The author has contributed to research in topics: Receptor tyrosine kinase & Matrix metalloproteinase. The author has an hindex of 8, co-authored 13 publications receiving 908 citations.

Generation of high-affinity human antibodies by combining donor-derived and synthetic complementarity-determining-region diversity

Abstract: Combinatorial libraries of rearranged hypervariable V(H) and V(L) sequences from nonimmunized human donors contain antigen specificities, including anti-self reactivities, created by random pairing of V(H)s and V(L)s. Somatic hypermutation of immunoglobulin genes, however, is critical in the generation of high-affinity antibodies in vivo and occurs only after immunization. Thus, in combinatorial phage display libraries from nonimmunized donors, high-affinity antibodies are rarely found. Lengthy in vitro affinity maturation is often needed to improve antibodies from such libraries. We report the construction of human Fab libraries having a unique combination of immunoglobulin sequences captured from human donors and synthetic diversity in key antigen contact sites in heavy-chain complementarity-determining regions 1 and 2. The success of this strategy is demonstrated by identifying many monovalent Fabs against multiple therapeutic targets that show higher affinities than approved therapeutic antibodies. This very often circumvents the need for affinity maturation, accelerating discovery of antibody drug candidates.

Selective inhibition of matrix metalloproteinase-14 blocks tumor growth, invasion, and angiogenesis.

Abstract: Inhibition of specific matrix metalloproteinases (MMP) is an attractive noncytotoxic approach to cancer therapy. MMP-14, a membrane-bound zinc endopeptidase, has been proposed to play a central role in tumor growth, invasion, and neovascularization. Besides cleaving matrix proteins, MMP-14 activates proMMP-2 leading to an amplification of pericellular proteolytic activity. To examine the contribution of MMP-14 to tumor growth and angiogenesis, we used DX-2400, a highly selective fully human MMP-14 inhibitory antibody discovered using phage display technology. DX-2400 blocked proMMP-2 processing on tumor and endothelial cells, inhibited angiogenesis, and slowed tumor progression and formation of metastatic lesions. The combination of potency, selectivity, and robust in vivo activity shows the potential of a selective MMP-14 inhibitor for the treatment of solid tumors.

Tie complex binding proteins

Abstract: Tie1 and Tie2 are receptor tyrosine kinase proteins that include a transmembrane domain. Tie1 and Tie2 are present on endothelial cells. This disclosure describes agents, such as antibodies, that bind to Tie1, Tie2, and Ang, including ones that inhibit endothelial cell activity and angiogenesis. The agents can be used to treat angiogenesis-associated disorders.

Method and apparatus for washing magnetically responsive particles

Abstract: The invention features apparati and methods for washing magnetically responsive particles such as paramagnetic beads. One exemplary apparatus includes a flow chamber having an inlet and an outlet; and at least a first magnetic field inducer. The apparatus is configured such that a first magnetic field can be selectively applied in the flow chamber. The apparatus can also apply a flow of fluid to the chamber in coordination with the selective application of the magnetic field.

Roles of matrix metalloproteinases in cancer progression and their pharmacological targeting

Abstract: Matrix metalloproteinases (MMPs) consist of a multigene family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases implicated in pathological processes, such as carcinogenesis. In this regard, their activity plays a pivotal role in tumor growth and the multistep processes of invasion and metastasis, including proteolytic degradation of ECM, alteration of the cell-cell and cell-ECM interactions, migration and angiogenesis. The underlying premise of the current minireview is that MMPs are able to proteolytically process substrates in the extracellular milieu and, in so doing, promote tumor progression. However, certain members of the MMP family exert contradicting roles at different stages during cancer progression, depending among other factors on the tumor stage, tumor site, enzyme localization and substrate profile. MMPs are therefore amenable to therapeutic intervention by synthetic and natural inhibitors, providing perspectives for future studies. Multiple therapeutic agents, called matrix metalloproteinase inhibitors (MMPIs) have been developed to target MMPs, attempting to control their enzymatic activity. Even though clinical trials with these compounds do not show the expected results in most cases, the field of MMPIs is ongoing. This minireview critically evaluates the role of MMPs in relation to cancer progression, and highlights the challenges, as well as future prospects, for the design, development and efficacy of MMPIs.

Selecting and screening recombinant antibody libraries

Abstract: During the past decade several display methods and other library screening techniques have been developed for isolating monoclonal antibodies (mAbs) from large collections of recombinant antibody fragments. These technologies are now widely exploited to build human antibodies with high affinity and specificity. Clever antibody library designs and selection concepts are now able to identify mAb leads with virtually any specificity. Innovative strategies enable directed evolution of binding sites with ultra-high affinity, high stability and increased potency, sometimes to a level that cannot be achieved by immunization. Automation of the technology is making it possible to identify hundreds of different antibody leads to a single therapeutic target. With the first antibody of this new generation, adalimumab (Humira, a human IgG1 specific for human tumor necrosis factor (TNF)), already approved for therapy and with many more in clinical trials, these recombinant antibody technologies will provide a solid basis for the discovery of antibody-based biopharmaceuticals, diagnostics and research reagents for decades to come.

Isolating and engineering human antibodies using yeast surface display

Abstract: This protocol describes the process of isolating and engineering antibodies or proteins for increased affinity and stability using yeast surface display Single-chain antibody fragments (scFvs) are first isolated from an existing nonimmune human library displayed on the yeast surface using magnetic-activated cell sorting selection followed by selection using flow cytometry This enriched population is then mutagenized, and successive rounds of random mutagenesis and flow cytometry selection are done to attain desired scFv properties through directed evolution Labeling strategies for weakly binding scFvs are also described, as well as procedures for characterizing and 'titrating' scFv clones displayed on yeast The ultimate result of following this protocol is a panel of scFvs with increased stability and affinity for an antigen of interest

Is there new hope for therapeutic matrix metalloproteinase inhibition

Abstract: Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases that form a family of 24 members in mammals. Evidence of the pathological roles of MMPs in various diseases, combined with their druggability, has made them attractive therapeutic targets. Initial drug discovery efforts focused on the roles of MMPs in cancer progression, and more than 50 MMP inhibitors have been investigated in clinical trials in various cancers. However, all of these trials failed. Reasons for failure include the lack of inhibitor specificity and insufficient knowledge about the complexity of the disease biology. MMPs are also known to be involved in several inflammatory processes, and there are new therapeutic opportunities for MMP inhibitors to treat such diseases. In this Review, we discuss the recent advances made in understanding the role of MMPs in inflammatory diseases and the therapeutic potential of MMP inhibition in those conditions.