| 1. |
- Bass, Tarek
(author)
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Affibody molecules targeting HER3 for cancer therapy
- 2017
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Doctoral thesis (other academic/artistic)abstract
- The development of targeted therapy has contributed tremendously to the treatment of patients with cancer. The use of highly specific affinity proteins to target cancer cells has become a standard in treatment strategies for several different cancers. In light of this, many cancer cell markers are investigated for their potential use in diagnostics and therapy. One such marker is the human epidermal growth factor receptor 3, HER3. It has been established as an important contributor to many cancer types. The function of HER3 is to relay cell growth signals from outside of the cell to the inside. Interfering with- and inhibit- ing the function of HER3 has emerged as an interesting strategy for cancer therapeutics. The studies presented in this thesis aim to target HER3 with small, engineered affinity domain proteins for therapeutic purposes. Monomeric affibody molecules have previously been engineered to bind and inhibit HER3 in vitro. Due to the relatively low expression of HER3, an increase in valency appears promising to strengthen the therapeutic potential. Affibody molecules targeting the receptor were thus linked to form bivalent and bispecific constructs and evaluated both in vitro and in vivo. In the first study of this thesis affibody molecules specific for HER3 and HER2 were fused to an albumin binding domain to form bivalent and bispecific construct. The constructs inhibited ligand-induced receptor phos- phorylation of both HER2 and HER3 more efficiently than monomeric affibody molecules. A second approach to enhance the potential of affibody molecules in tumor targeting is described in the second study, where monomeric HER3-binding affibody molecules were engineered to increase their affinity for HER3. The resulting variants showed a 20-fold in- creased affinity and higher capacity to inhibit cancer cell growth. Combining the findings of the first two studies, the third study describes the evaluation of a HER3-targeting bivalent affibody construct for potential application as a therapeutic. Here, the bivalent construct inhibited cancer cell growth in vitro and was found to slow down tumor growth in mice, while being well tolerated and showing no visible toxicity. The fourth study built upon these findings and compares a very similar bivalent construct to the clinically-investigated HER3-specific monoclonal antibody seribantumab. The affibody construct showed very comparable efficacy with the antibody in terms of decreasing tumor growth rate and ex- tending mouse survival. Collectively, these works describe for the first time the use of alternative affinity protein constructs with therapeutic potential targeting HER3.
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| 2. |
- Borrebaeck, Carl A K, et al.
(author)
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Kinetic analysis of recombinant antibody-antigen interactions : Relation between structural domains and antigen binding
- 1992
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In: Bio/Technology. - : Springer Science and Business Media LLC. - 0733-222X. ; 10:6, s. 697-698
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Journal article (peer-reviewed)abstract
- The relation between domain structures of recombinant monoclonal antibody fragments and their reaction kinetics was studied for the first time using a novel biosensor based on surface plasmon resonance technology. The association and dissociation rate constants of Fab, Fv and single domain (VH fragment) anti-lysozyme antibodies were determined and compared to the intact monoclonal antibody. Fab and Fv fragments showed similar reaction kinetics and had affinity constants of 6 X 109 M-1 and 25 X 109 M-1, respectively. The single domain antibody had significantly different reaction kinetics compared to the fragments consisting of paired heavy and light chain domains. The VH domain had both a higher dissociation and a lower association rate constant, which resulted in an affinity constant approximately 250 times lower than the Fab fragment. This rapid evaluation of antibody reaction kinetics should prove to be an important selection parameter when comparing antibody fragments for their utility in therapeutic or other applications.
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| 3. |
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| 4. |
- Danielsson, L, et al.
(author)
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Human monoclonal antibodies with different fine-specificity for digoxin derivatives: Cloning of heavy and light chain variable region sequences
- 1991
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In: Immunology. - 0019-2805. ; 74:1, s. 50-54
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Journal article (peer-reviewed)abstract
- Human-mouse hybridoma cell lines producing human monoclonal antibodies against the cardiac glycoside digoxin were established after in vitro immunization or direct immortalization of human peripheral blood lymphocytes with digoxin. Three antibodies, designated M06, LH92 and LH 1 14, displayed different patterns of fine specificity against digoxin and several digoxin analogues, as elucidated by inhibition ELISA. All three monoclonal antibodies had p heavy chains, two of them (M06 and LH 114) had K light chains and one (LH92) A light chains. DNA encoding the variable regions of both heavy and light chains of the three antibodies were amplified from cDNA using the polymerase chain reaction (PCR). The nucleotide sequences of the amplified DNA were determined after subcloning of PCR fragments in M13 vectors. The deduced amino acid sequences revealed considerable sequence differences in the complementarity determining regions between the three antibodies.
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| 5. |
- Ellmark, Peter, et al.
(author)
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A novel mammalian display system for the selection of protein-protein interactions by decoy receptor engagement
- 2004
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In: Journal of Molecular Recognition. - : Wiley. - 1099-1352 .- 0952-3499. ; 17:4, s. 316-322
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Journal article (peer-reviewed)abstract
- The emerging field of proteomics has created a need for new high-throughput methodologies for the analysis of gene products. An attractive approach is to develop systems that allow for clonal selection of interacting protein pairs from large molecular libraries. In this study, we have characterized a novel approach for identification and selection of protein-protein interactions, denoted SPIRE (selection of protein interactions by receptor engagement), which is based on a mammalian expression system. We have demonstrated proof of concept by creating a general plasma membrane bound decoy receptor, by displaying a protein or a peptide genetically fused to a trunctated version of the CD40 molecule. When this decoy receptor is engaged by a ligand to the displayed protein/peptide, the receptor expressing cell is rescued from apoptosis. To design a high-throughput system with a highly parallel capacity, we utilized the B cell line WEHI-231, as carrier of the decoy receptor. One specific peptide-displaying cell could be identified and amplified, based on a specific receptor engagement, in a background of 12 500 wild-type cells after four selections. This demonstrates that the approach may serve as a tool in post-genomic research for identifying protein-protein interactions, without prior knowledge of either component. Copyright (C) 2004 John Wiley Sons, Ltd.
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| 6. |
- Ellmark, Peter, et al.
(author)
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In vitro molecular evolution of antibody genes mimicking receptor revision
- 2002
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In: Molecular Immunology. - 1872-9142. ; 39:5-6, s. 349-356
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Journal article (peer-reviewed)abstract
- Antibody evolution in vivo proceeds mainly by stepwise improvements, accomplished by single base pair substitutions. Lately, receptor revision, i.e. exchange of large parts of the V gene for another sequence, has been suggested to provide a complementary route for affinity maturation. By employing a receptor revision like evolution process in vitro using combinatorial libraries and phage display selection, we demonstrate here that maturation of a clone may preferentially proceed through exchange of a large gene segment rather than via minor sequence changes. These modifications of a CD40-specific human antibody fragment outline how receptor revision like events may provide an advantage to a particular clonotype put under selective pressure. (C) 2002 Elsevier Science Ltd. All rights reserved.
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| 7. |
- Ellmark, Peter, et al.
(author)
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Modulation of the CD40-CD40 ligand interaction using human anti-CD40 single-chain antibody fragments obtained from the n-CoDeR phage display library
- 2002
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In: Immunology. - 0019-2805. ; 106:4, s. 456-463
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Journal article (peer-reviewed)abstract
- CD40 plays a central regulatory role in the immune system and antibodies able to modulate CD40 signalling may consequently have a potential in immunotherapy, in particular for treatment of lymphomas and autoimmune disease like multiple sclerosis. As a first step to achieve this goal, we describe the selection and characterization of a novel set of fully human anti-CD40 antibody fragments (scFv) from a phage display library (n-CoDeR). In order to determine their biological potential, these antibody fragments have been analysed for their ability to promote B-cell activation, rescue from apoptosis and to block the CD40-CD40 ligand (CD40L) interaction. The selected cohort of human scFv could be subcategorized, each expressing a distinct functional signature. Thus scFv were generated that induced B-cell proliferation, rescued B cells from apoptosis and blocked the CD40-CD40L interaction to different extents. In particular, one of the scFv clones (F33) had the ability to abrogate completely this interaction. The epitope recognition patterns as well as individual rate constants were also determined and the affinity was shown to vary from low to high nanomolar range. In conclusion, this panel of human anti-CD40 scFv fragments displays a number of distinct properties, which may constitute a valuable source when evaluating candidates for in vivo trials.
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| 8. |
- Ellmark, Peter, et al.
(author)
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Pre-assembly of the extracellular domains of CD40 is not necessary for rescue of mouse B cells from anti-immunoglobulin M-induced apoptosis
- 2003
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In: Immunology. - : Wiley. - 0019-2805 .- 1365-2567. ; 108:4, s. 452-457
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Journal article (peer-reviewed)abstract
- CD40 is a tumour necrosis factor receptor (TNFR) family member of central importance for the adaptive immune system. To elucidate the functional role of the different extracellular domains of CD40, we have created a set of truncated CD40 molecules where domains, or parts of domains, have been removed. These CD40 proteins, which contain a peptide tag in the N-terminal end, have been expressed in a murine B-cell line, WEHI 231. It was found that ligation of these engineered CD40 proteins via the peptide tag, was sufficient to rescue as well as to promote proliferation of apoptotic WEHI 231 cells, even when all the extracellular domains of CD40 were absent. Our results suggest that pre association of CD40 in the cell membrane plays no critical role for the CD40 signalling pathway. Furthermore, our data imply that conformational changes initiated in the extracellular domains of CD40 are not essential for signal transduction.
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| 9. |
- Ellmark, Peter, et al.
(author)
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Tumor-directed immunotherapy can generate tumor-specific T cell responses through localized co-stimulation
- 2017
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In: Cancer Immunology and Immunotherapy. - : Springer Science and Business Media LLC. - 0340-7004 .- 1432-0851. ; 66:1, s. 1-7
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Journal article (peer-reviewed)abstract
- The most important goals for the field of immuno-oncology are to improve the response rate and increase the number of tumor indications that respond to immunotherapy, without increasing adverse side effects. One approach to achieve these goals is to use tumor-directed immunotherapy, i.e., to focus the immune activation to the most relevant part of the immune system. This may improve anti-tumor efficacy as well as reduce immune-related adverse events. Tumor-directed immune activation can be achieved by local injections of immune modulators in the tumor area or by directing the immune modulator to the tumor using bispecific antibodies. In this review, we focus on therapies targeting checkpoint inhibitors and co-stimulatory receptors that can generate tumor-specific T cell responses through localized immune activation.
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| 10. |
- Faber, Catherine, et al.
(author)
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Three-dimensional structure of a human Fab with high affinity for tetanus toxoid
- 1998
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In: Immunotechnology. - 1380-2933. ; 3:4, s. 253-270
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Journal article (peer-reviewed)abstract
- Background: The wide range of antibody specificity and affinity results from the differing shapes and chemical compositions of their binding sites. These shapes range from discrete grooves in antibodies elicited by linear oligomers of nucleotides and carbohydrates to shallow depressions or flat surfaces for accommodation of proteins: peptides and large organic compounds. Objectives: To determine the Fab structure of a high-affinity human antitoxin antibody. To explore structural features which enable the antibody to bind to intact tetanus toxoid, peptides derived from the sequence of the natural immunogen and antigenic mimics identified by combinatorial chemistry. To explain why this Fab shows a remarkable tendency to produce crystals consistently diffracting to d spacings of 1.7-1.8 Å. To use this information to engineer a strong tendency to crystallize into the design of other Fabs. Study design: The protein was crystallized in hanging or sitting drops by a microseeding technique in polyethylene glycol (PEG) 8000. Crystals were subjected to X-ray analysis and the three-dimensional structure of the Fab was determined by the molecular replacement method. Interactive computer graphics were employed to fit models to electron density maps, survey the structure in multiple views and discover the crystal packing motif of the protein. Results: Exceptionally large single crystals of this protein have been obtained, one measuring 5 x 3 x 2 mm (l x w x d). The latter was cut into six irregular pieces, each retaining the features of the original in diffracting to high resolution (1.8 Å) with little decay in the X-ray beam. In an individual Fab, the active site is relatively flat and it seems likely that the protein antigen and derivative peptides are tightly held on the outer surface without significant penetration into the interior. There is no free space to accommodate even a dipeptide between V(H) and V(L). One of the unique features of the B7-15A2 Fab is a large aliphatic ridge dominating the center of the active site. The CDR3 of the H chain contributes significantly to this ridge, as well as to adjoining regions projected to be important for the docking of the antigen. Both the ease of crystallization and the favorable diffraction properties are mainly attributable to the tight packing of the protein molecules in the crystal lattice. Discussion: The B7-15A2 active site provides a stable and well defined platform for high affinity docking of proteins, peptides and their mimotopes. The advantages for future developments are suggested by the analysis of the crystal properties. It should be possible to incorporate the features promoting crystallization, close packing and resistance to radiation damage into engineered human antibodies without altering the desired specificities and affinities of their active sites.
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| 11. |
- Fransson, Johan, et al.
(author)
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Internalising human anti-tumor antibodies.
- 2003
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In: Immunology Letters (Abstracts of the 15th European Immunology Congress (EFIS 2003)). - 1879-0542 .- 0165-2478. ; 87:1-3, s. 02-34
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Conference paper (other academic/artistic)
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| 12. |
- Fransson, Johan, et al.
(author)
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Profiling of internalizing tumor-associated antigens on breast and pancreatic cancer cells by reversed genomics
- 2004
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In: Cancer Letters. - : Elsevier BV. - 1872-7980 .- 0304-3835. ; 208:2, s. 235-242
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Journal article (peer-reviewed)abstract
- Human antibodies directed towards functionally associated tumor antigens have great potentials as adjuvant treatment in cancer therapy. Here we describe an efficient subtractive approach to select single chain Fv (scFv) antibodies, specifically binding to unknown rapidly internalizing tumor-associated antigens (TAA) on human breast and pancreatic carcinoma cell lines. After re-engineering the scFv into intact IgG molecules, these fully human antibodies displayed individual binding profiles to TAAs on breast, pancreatic, colorectal and prostate carcinomas, while showing no reactivity to lymphomas. The ability of the selected antibodies to undergo receptor-mediated internalization was verified by confocal microscopy, thus proving our strategy to provide a unique set of human antibodies, potentially useful in immunotherapy. (C) 2003 Elsevier Ltd. All rights reserved.
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| 13. |
- Furebring, Christina, et al.
(author)
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Antibody-mediated neutralization of cytomegalovirus: modulation of efficacy induced through the IgG constant region.
- 2002
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In: Molecular Immunology. - 1872-9142. ; 38:11, s. 833-840
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Journal article (peer-reviewed)abstract
- Antibodies can neutralize the infectious properties of human cytomegalovirus (CMV). In vivo, the major neutralization determinants are located on glycoprotein B (gB). Recombinant human antibodies, that carry different constant regions (IgG1, IgG3 and the synthetic variant IgG3mA) against two of these epitopes were investigated for their ability to recruit the complement cascade for destruction of the virus. It was shown that all variants of an antibody against the antigenic domain (AD)-2 epitope displayed a similar neutralization activity despite the fact that improved C1q binding was observed for IgG3 and IgG3mA over the IgG1 variant. In contrast, an antibody against the AD-1 epitope carrying the normal IgG3 constant region, was less efficient than its IgG1 counterpart in neutralizing the virus in the absence of complement. However, it restored its activity in the presence of complement to the level of the naturally occurring IgG1 version. The same antibody was substantially more potent in neutralizing the virus in the presence of complement if it carried the IgG3mA constant region. This demonstrates the importance of the constant domain for the biological activity of AD-1 specific antibodies, a factor that should be taken into account when using antibody-based therapeutics or when inducing antibodies by vaccination.
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| 14. |
- Furebring, Christina, et al.
(author)
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Evaluation of novel control elements by construction of eukaryotic expression vectors
- 1997
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In: Gene. - 0378-1119. ; 188:2, s. 191-198
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Journal article (peer-reviewed)abstract
- A novel mammalian eukaryotic expression vector for the production of immunoglobulin heavy chain (IgH) genes has been designed. This expression vector contains the variable heavy chain (VH) promoter, the IgH intron enhancer (μE) and the IgH 3' enhancer (3'E). This construct, designated pTIF-1, was stably transfected into the myeloma cell line J558L. A fivefold increase in the expression level of a rearranged IgH gene was observed when using the pTIF-1 vector containing the 3'E compared to an expression vector lacking this enhancer. Interestingly, this positive effect on the expression level of the 3' enhancer appears to be position independent. The introduction of two recently identified Ig control elements, HS3 and HS4, to the vector cassette did not further elevate the expression level in the cell line tested. The pTIF-1 vector can be used for expression of any antibody specificity, using PCR amplification of the VDJ region of interest. Furthermore, the constant region can easily be exchanged, which further facilitates studies to dissect different effector functions of IgH constant genes.
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| 15. |
- Furebring, Christina
(author)
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Expression of Ig genes. Regulation of transcription and production of human antibodies
- 1996
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Doctoral thesis (other academic/artistic)abstract
- During B lymphocyte development, the transcriptional activity of the IgH locus is subject to spatial and temporal changes. The 3' enhancer (3'E) has been suggested to play an important role in regulation of immunoglobulin gene expression late in B cell development. We have investigated, using transgenic mice, the role of the 3'E in regulating Ig gene expression. Mice harbouring a rearranged IgH gene potentiated by the VH promoter in combination with the IgH intron enhancer (µE), the 3'E or the µE/3'E pair were generated. The 3'E activity is mainly observed in lymphoid tissues and is mainly restricted to the in vivo activated B cells. The 3'E can potentiate Ig gene expression directly in conjunction with the VH promoter. The expression level of the µE/3'E controlled transgene is fivefold higher as compared to the transgene controlled by the µE alone. The aim of my subsequent studies has been to generate and produce human monoclonal antibodies. We have focused our interest on immortalization of the variable region genes, from hybridoma or from a single antigen-specific B cell, using the powerful PCR technique. The variable region genes from single B cells can be immortalized directly or after a cellular amplification step, involving the EL-4 and CD40 cell culture systems. The variable region genes obtained can thereafter be expressed either as Ab fragments, in prokaryotic host cells, or as the entire Ab, in eukaryotic host cells. To allow efficient expression of intact Ab we have optimized a eukaryotic IgH gene expression vector using different combinations of regulatory elements.
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| 16. |
- Gustafsson, Erika, et al.
(author)
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Directed evolution of chemotaxis inhibitory protein of Staphylococcus aureus generates biologically functional variants with reduced interaction with human antibodies
- 2010
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In: Protein Engineering Design & Selection. - : Oxford University Press (OUP). - 1741-0126 .- 1741-0134. ; 23:2, s. 91-101
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Journal article (peer-reviewed)abstract
- Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) is a protein that binds and blocks the C5a receptor (C5aR) and formylated peptide receptor, thereby inhibiting the immune cell recruitment associated with inflammation. If CHIPS was less reactive with existing human antibodies, it would be a promising anti-inflammatory drug candidate. Therefore, we applied directed evolution and computational/rational design to the CHIPS gene in order to generate new CHIPS variants displaying lower interaction with human IgG, yet retaining biological function. The optimization was performed in four rounds: one round of random mutagenesis to add diversity into the CHIPS gene and three rounds of DNA recombination by Fragment INduced Diversity (FIND((R))). Every round was screened by phage selection and/or ELISA for decreased interaction with human IgG and retained C5aR binding. The mean binding of human anti-CHIPS IgG decreased with every round of evolution. For further optimization, new amino acid substitutions were introduced by rational design, based on the mutations identified during directed evolution. Finally, seven CHIPS variants with low interaction with human IgG and retained C5aR blocking capacity could be identified.
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| 17. |
- Gustafsson, Erika, et al.
(author)
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Identification of conformational epitopes for human IgG on chemotaxis inhibitory protein of Staphylococcus aureus
- 2009
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In: BMC Immunology. - : Springer Science and Business Media LLC. - 1471-2172. ; 10:13
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Journal article (peer-reviewed)abstract
- Background The Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS) blocks the Complement fragment C5a receptor (C5aR) and formylated peptide receptor (FPR) and is thereby a potent inhibitor of neutrophil chemotaxis and activation of inflammatory responses. The majority of the healthy human population has antibodies against CHIPS that have been shown to interfere with its function in vitro. The aim of this study was to define potential epitopes for human antibodies on the CHIPS surface. We also initiate the process to identify a mutated CHIPS molecule that is not efficiently recognized by preformed anti-CHIPS antibodies and retains anti-inflammatory activity. Results In this paper, we panned peptide displaying phage libraries against a pool of CHIPS specific affinity-purified polyclonal human IgG. The selected peptides could be divided into two groups of sequences. The first group was the most dominant with 36 of the 48 sequenced clones represented. Binding to human affinity-purified IgG was verified by ELISA for a selection of peptide sequences in phage format. For further analysis, one peptide was chemically synthesized and antibodies affinity-purified on this peptide were found to bind the CHIPS molecule as studied by ELISA and Surface Plasmon Resonance. Furthermore, seven potential conformational epitopes responsible for antibody recognition were identified by mapping phage selected peptide sequences on the CHIPS surface as defined in the NMR structure of the recombinant CHIPS31-121 protein. Mapped epitopes were verified by in vitro mutational analysis of the CHIPS molecule. Single mutations introduced in the proposed antibody epitopes were shown to decrease antibody binding to CHIPS. The biological function in terms of C5aR signaling was studied by flow cytometry. A few mutations were shown to affect this biological function as well as the antibody binding. Conclusions Conformational epitopes recognized by human antibodies have been mapped on the CHIPS surface and amino acid residues involved in both antibody and C5aR interaction could be defined. This information has implications for the development of an effective anti-inflammatory agent based on a functional CHIPS molecule with low interaction with human IgG.
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| 18. |
- Gustafsson, Erika, et al.
(author)
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Purification of truncated and mutated chemotaxis inhibitory protein of Staphylococcus aureus—an anti-inflammatory protein
- 2009
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In: Protein Expression and Purification. - : Elsevier BV. - 1046-5928. ; 63:2, s. 95-101
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Journal article (peer-reviewed)abstract
- The Chemotaxis Inhibitory Protein of Staphylococcus aureus (CHIPS) binds and blocks the C5a receptor (C5aR) and formyl-peptide receptor (FPR). This way, CHIPS is a potent inhibitor of the immune cell recruitment associated with inflammation. Truncation of the protein and the introduction of mutations, shifts the expression towards the insoluble fraction of Escherichia coli, whereas the wild-type protein can be solubly expressed. A protocol for expression and tag independent purification of biologically active CHIPS variants has been established to enable further characterization of an improved CHIPS variant, called ADC-1004. The CHIPS variants were purified by washing of E. coli inclusion bodies followed by refolding and gel filtration. New techniques were utilized to optimize the purification process. Expression in inclusion bodies was increased by the use of Ultra Yield™ flasks and optimal refolding conditions were determined by the use of the iFOLD Refolding System 2™. The folding and biological activity of the purified proteins were analyzed by circular dichroism (CD) spectroscopy and flow cytometry, respectively, and compared to solubly produced CHIPS31–113 and wild-type CHIPS1–121. We show that the CHIPS variants produced in inclusion bodies can be refolded and purified to achieve equal biological activity as solubly produced CHIPS31–113 and wild-type CHIPS1–121. The truncation causes minor structural changes while purification from inclusion bodies or the soluble fraction does not further affect the structure.
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| 19. |
- Malmborg Hager, Ann-Christin, et al.
(author)
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Affinity and Epitope Profiling of Mouse Anti-CD40 Monoclonal Antibodies
- 2003
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In: Scandinavian Journal of Immunology. - : Wiley. - 1365-3083 .- 0300-9475. ; 57:6, s. 517-524
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Journal article (peer-reviewed)abstract
- The CD40-CD40L interaction plays a critical role in both humoral and cellular immune responses and interfering antibodies have been suggested as an effective approach for the treatment of lymphomas and autoimmune diseases. In this study we have profiled a panel of mouse antihuman CD40 monoclonal antibodies (MoAbs), regarding their CD40 binding affinity and epitope-specificity relative to the CD40L binding in relation to their cellular activating potential. Despite a rather similar domain-recognition profile, the MoAbs blocked the CD40L binding to a varying degree, with MoAb 5C3 being the poorest inhibitor. There was no correlation between affinity and cellular activation potential. In contrast, a correlation between the ability to block CD40L-binding and activation potential could be seen. We believe that this analysis of several mouse anti-CD40 antibodies can be used to develop strategies for producing new human anti-CD40 antibodies that can more effectively induce or block B-cell proliferation.
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| 20. |
- Mangsbo, Sara M, et al.
(author)
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The human agonistic CD40 antibody ADC-1013 eradicates bladder tumors and generates T cell dependent tumor immunity.
- 2015
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In: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 21:5, s. 1115-1126
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Journal article (peer-reviewed)abstract
- Purpose: Local administration of immune-activating antibodies may increase the efficacy and reduce the immune-related adverse events associated with systemic immunotherapy of cancer. Here we report the development and affinity maturation of a fully human agonistic CD40 antibody (IgG1), ADC-1013. Experimental Design: We have used molecular engineering to generate an agonistic antibody with high affinity for CD40. The functional activity of ADC-1013 has been investigated in human and murine in vitro models. The in vivo effect has been investigated in two separate bladder cancer models, both using human xenograft tumors in immune deficient NSG mice and using a syngeneic bladder cancer model in a novel human CD40 transgenic mouse. Results: Activation of dendritic cells (DCs) by ADC-1013 results in up-regulation of the co-stimulatory molecules CD80 and CD86, and secretion of IL-12. ADC-1013 also activates dendritic cells from human CD40 transgenic mice, and peptide-pulsed and ADC-1013-stimulated dendritic cells induce antigen-specific T cell proliferation in vitro. In vivo, treatment with ADC-1013 in a syngeneic bladder cancer model, negative for hCD40, induces significant anti-tumor effects and long-term tumor-specific immunity. Further, ADC-1013 demonstrates significant anti-tumor effects in a human bladder cancer transplanted into immunodeficient NSG mice. Conclusions: Our data demonstrate that ADC-1013 induces long-lasting anti-tumor responses and immunological memory mediated by CD40 stimulation. To the best of our knowledge, ADC-1013 represents the first immunomodulatory antibody developed for local immunotherapy of cancer.
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| 21. |
- Nelson, Michelle H., et al.
(author)
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The Bispecific Tumor Antigen-Conditional 4-1BB x 5T4 Agonist, ALG.APV-527, Mediates Strong T-Cell Activation and Potent Antitumor Activity in Preclinical Studies
- 2023
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In: Molecular Cancer Therapeutics. - 1538-8514. ; 22:1, s. 89-101
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Journal article (peer-reviewed)abstract
- 4-1BB (CD137) is an activation-induced costimulatory receptor that regulates immune responses of activated CD8 T and natural killer cells, by enhancing proliferation, survival, cytolytic activity, and IFNγ production. The ability to induce potent antitumor activity by stimulating 4-1BB on tumor-specific cytotoxic T cells makes 4-1BB an attractive target for designing novel immuno-oncology therapeutics. To minimize systemic immune toxicities and enhance activity at the tumor site, we have developed a novel bispecific antibody that stimulates 4-1BB function when co-engaged with the tumor-associated antigen 5T4. ALG.APV-527 was built on the basis of the ADAPTIR bispecific platform with optimized binding domains to 4-1BB and 5T4 originating from the ALLIGATOR-GOLD human single-chain variable fragment library. The epitope of ALG.APV-527 was determined to be located at domain 1 and 2 on 4-1BB using X-ray crystallography. As shown in reporter and primary cell assays in vitro, ALG.APV-527 triggers dose-dependent 4-1BB activity mediated only by 5T4 crosslinking. In vivo, ALG.APV-527 demonstrates robust antitumor responses, by inhibiting growth of established tumors expressing human 5T4 followed by a long-lasting memory immune response. ALG.APV-527 has an antibody-like half-life in cynomolgus macaques and was well tolerated at 50.5 mg/kg. ALG.APV-527 is uniquely designed for 5T4-conditional 4-1BB-mediated antitumor activity with potential to minimize systemic immune activation and hepatotoxicity while providing efficacious tumor-specific responses in a range of 5T4-expressing tumor indications as shown by robust activity in preclinical in vitro and in vivo models. On the basis of the combined preclinical dataset, ALG.APV-527 has potential as a promising anticancer therapeutic for the treatment of 5T4-expressing tumors.
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