scholarly journals Targeting MICA/B with cytotoxic therapeutic antibodies leads to tumor control

2021 ◽  
Vol 1 ◽  
pp. 107
Author(s):  
Mathieu Bléry ◽  
Manel Mrabet-Kraiem ◽  
Ariane Morel ◽  
Florence Lhospice ◽  
Delphine Bregeon ◽  
...  
Keyword(s):  
Solid Tumors ◽  
Tumor Control ◽  
Cytotoxic Lymphocytes ◽  
Drug Conjugates ◽  
Induced Tumors ◽  
Human Igg1 ◽  
Induced Proteins ◽  
Optimal Tumor

Background: MICA and MICB are tightly regulated stress-induced proteins that trigger the immune system by binding to the activating receptor NKG2D on cytotoxic lymphocytes. MICA and MICB are highly polymorphic molecules with prevalent expression on several types of solid tumors and limited expression in normal/healthy tissues, making them attractive targets for therapeutic intervention. Methods: We have generated a series of anti-MICA and MICB cross-reactive antibodies with the unique feature of binding to the most prevalent isoforms of both these molecules. Results: The anti-MICA and MICB antibody MICAB1, a human IgG1 Fc-engineered monoclonal antibody (mAb), displayed potent antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) of MICA/B-expressing tumor cells in vitro. However, it showed insufficient efficiency against solid tumors in vivo, which prompted the development of antibody-drug conjugates (ADC). Indeed, optimal tumor control was achieved with MICAB1-ADC format in several solid tumor models, including patient-derived xenografts (PDX) and carcinogen-induced tumors in immunocompetent MICAgen transgenic mice. Conclusions: These data indicate that MICA and MICB are promising targets for cytotoxic immunotherapy.

scholarly journals Targeting MICA/B with cytotoxic therapeutic antibodies leads to tumor control

2021 ◽  
Vol 1 ◽  
pp. 107
Author(s):  
Mathieu Bléry ◽  
Manel Mrabet-Kraiem ◽  
Ariane Morel ◽  
Florence Lhospice ◽  
Delphine Bregeon ◽  
...  
Keyword(s):  
Solid Tumors ◽  
Tumor Control ◽  
Cytotoxic Lymphocytes ◽  
Drug Conjugates ◽  
Induced Tumors ◽  
Human Igg1 ◽  
Induced Proteins ◽  
Optimal Tumor

Background: MICA and MICB are tightly regulated stress-induced proteins that trigger the immune system by binding to the activating receptor NKG2D on cytotoxic lymphocytes. MICA and MICB are highly polymorphic molecules with prevalent expression on several types of solid tumors and limited expression in normal/healthy tissues, making them attractive targets for therapeutic intervention. Methods: We have generated a series of anti-MICA and MICB cross-reactive antibodies with the unique feature of binding to the most prevalent isoforms of both these molecules. Results: The anti-MICA and MICB antibody MICAB1, a human IgG1 Fc-engineered monoclonal antibody (mAb), displayed potent antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) of MICA/B-expressing tumor cells in vitro. However, it showed insufficient efficiency against solid tumors in vivo, which prompted the development of antibody-drug conjugates (ADC). Indeed, optimal tumor control was achieved with MICAB1-ADC format in several solid tumor models, including patient-derived xenografts (PDX) and carcinogen-induced tumors in immunocompetent MICAgen transgenic mice. Conclusions: These data indicate that MICA and MICB are promising targets for cytotoxic immunotherapy.

scholarly journals Drug Conjugates of Antagonistic RSPO4 Mutant For Simultaneous Targeting of LGR4/5/6 for Cancer Treatment

2021 ◽  
Author(s):  
Jie Cui ◽  
Soohyun Park ◽  
Wangsheng Yu ◽  
Kendra Carmon ◽  
Qingyun J. Liu
Keyword(s):  
Wnt Signaling ◽  
G Protein Coupled Receptors ◽  
Cytotoxic Effects ◽  
Drug Conjugates ◽  
Novel Approach ◽  
Human Igg1 ◽  
G Protein Coupled ◽  
Different Levels

AbstractLGR4-6 (Leucine-rich repeating containing, G-protein-coupled receptors 4, 5, and 6) are three related receptors with distinct roles in organ development and stem cell survival. All three receptors are upregulated in gastrointestinal cancers to different levels, and LGR5 has been shown to be enriched in cancer stem cells. Antibody-drug conjugates (ADCs) targeting LGR5 showed robust antitumor effect in vivo but could not eradicate tumors due to plasticity of LGR5-positive cancer cells. As LGR5-negative cells often express LGR4 or LGR6 or both, we reasoned that simultaneous targeting of all three LGRs may provide a more effective approach. R-spondins (RSPOs) bind to LGR4-6 with high affinity and potentiate Wnt signaling. We identified an RSPO4 mutant (Q65R) that retains potent LGR binding but no longer potentiates Wnt signaling. The RSPO4 mutant was fused to the N-terminus of human IgG1-Fc to create a peptibody which was then conjugated with cytotoxins monomethyl auristatin or duocarmycin by site-specific conjugation. The resulting peptibody drug conjugates (PDCs) showed potent cytotoxic effects on cancer cell lines expressing any LGR in vitro and suppressed tumor growth in vivo without inducing intestinal enlargement or other adverse effects. These results suggest that RSPO-derived PDCs may provide a novel approach to the treatment of cancers with high LGR expression.

scholarly journals Single Domain Antibodies as Carriers for Intracellular Drug Delivery: A Proof of Principle Study

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 927
Author(s):  
Sebas D. Pronk ◽  
Erik Schooten ◽  
Jurgen Heinen ◽  
Esra Helfrich ◽  
Sabrina Oliveira ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Targeted Delivery ◽  
Single Domain ◽  
Drug Conjugates ◽  
Intracellular Drug Delivery ◽  
Internalization Rate ◽  
Single Domain Antibodies ◽  
Different Characteristics

Antibody-drug conjugates (ADCs) are currently used for the targeted delivery of drugs to diseased cells, but intracellular drug delivery and therefore efficacy may be suboptimal because of the large size, slow internalization and ineffective intracellular trafficking of the antibody. Using a phage display method selecting internalizing phages only, we developed internalizing single domain antibodies (sdAbs) with high binding affinity to rat PDGFRβ, a receptor involved in different types of diseases. We demonstrate that these constructs have different characteristics with respect to internalization rates but all traffic to lysosomes. To compare their efficacy in targeted drug delivery, we conjugated the sdAbs to a cytotoxic drug. The conjugates showed improved cytotoxicity correlating to their internalization speed. The efficacy of the conjugates was inhibited in the presence of vacuolin-1, an inhibitor of lysosomal maturation, suggesting lysosomal trafficking is needed for efficient drug release. In conclusion, sdAb constructs with different internalization rates can be designed against the same target, and sdAbs with a high internalization rate induce more cell killing than sdAbs with a lower internalization rate in vitro. Even though the overall efficacy should also be tested in vivo, sdAbs are particularly interesting formats to be explored to obtain different internalization rates.

scholarly journals In Vitro and In Vivo Comparison of Lymphocytes Transduced with a Human CD16 or with a Chimeric Antigen Receptor Reveals Potential Off-Target Interactions due to the IgG2 CH2-CH3 CAR-Spacer

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Béatrice Clémenceau ◽  
Sandrine Valsesia-Wittmann ◽  
Anne-Catherine Jallas ◽  
Régine Vivien ◽  
Raphaël Rousseau ◽  
...  
Keyword(s):  
Chimeric Antigen Receptor ◽  
Tumor Regression ◽  
Critical Role ◽  
Antigen Receptor ◽  
Target Cells ◽  
Cytotoxic Lymphocytes ◽  
Her2 Positive ◽  
Positive Target

The present work was designed to compare two mechanisms of cellular recognition based on Ab specificity: firstly, when the anti-HER2 mAb trastuzumab bridges target cells and cytotoxic lymphocytes armed with a Fc receptor (ADCC) and, secondly, when HER2 positive target cells are directly recognized by cytotoxic lymphocytes armed with a chimeric antigen receptor (CAR). To compare these two mechanisms, we used the same cellular effector (NK-92) and the same signaling domain (FcεRIγ). The NK-92 cytotoxic cell line was transfected with either a FcγRIIIa-FcεRIγ(NK-92CD16) or a trastuzumab-based scFv-FcεRIγchimeric receptor (NK-92CAR). In vitro, the cytotoxic activity against HER2 positive target cells after indirect recognition byNK-92CD16was always inferior to that observed after direct recognition byNK-92CAR. In contrast, and somehow unexpectedly, in vivo, adoptive transfer ofNK-92CD16+ trastuzumab but not ofNK-92CARinduced tumor regression. Analysis of the in vivo xenogeneic system suggested that the human CH2-CH3 IgG2 used as a spacer in our construct was able to interact with the FcR present at the cell surface of the few NSG-FcR+ remaining immune cells. This interaction, leading to blockage of theNK-92CARin the periphery of the engrafted tumor cells, stresses the critical role of the composition of the spacer domain.

scholarly journals Targeting human leukocyte antigen G with chimeric antigen receptors of natural killer cells convert immunosuppression to ablate solid tumors

2021 ◽  
Vol 9 (10) ◽  
pp. e003050
Author(s):  
Chia-Ing Jan ◽  
Shi-Wei Huang ◽  
Peter Canoll ◽  
Jeffrey N Bruce ◽  
Yu-Chuan Lin ◽  
...  
Keyword(s):  
Human Leukocyte Antigen ◽  
Natural Killer ◽  
Solid Tumors ◽  
Low Dose ◽  
Human Leukocyte ◽  
Leukocyte Antigen ◽  
Low Dose Chemotherapy ◽  
Human Leukocyte Antigen G

BackgroundImmunotherapy against solid tumors has long been hampered by the development of immunosuppressive tumor microenvironment, and the lack of a specific tumor-associated antigen that could be targeted in different kinds of solid tumors. Human leukocyte antigen G (HLA-G) is an immune checkpoint protein (ICP) that is neoexpressed in most tumor cells as a way to evade immune attack and has been recently demonstrated as a useful target for chimeric antigen receptor (CAR)-T therapy of leukemia by in vitro studies. Here, we design and test for targeting HLA-G in solid tumors using a CAR strategy.MethodsWe developed a novel CAR strategy using natural killer (NK) cell as effector cells, featuring enhanced cytolytic effect via DAP12-based intracellular signal amplification. A single-chain variable fragment (scFv) against HLA-G is designed as the targeting moiety, and the construct is tested both in vitro and in vivo on four different solid tumor models. We also evaluated the synergy of this anti-HLA-G CAR-NK strategy with low-dose chemotherapy as combination therapy.ResultsHLA-G CAR-transduced NK cells present effective cytolysis of breast, brain, pancreatic, and ovarian cancer cells in vitro, as well as reduced xenograft tumor growth with extended median survival in orthotopic mouse models. In tumor coculture assays, the anti-HLA-G scFv moiety promotes Syk/Zap70 activation of NK cells, suggesting reversal of the HLA-G-mediated immunosuppression and hence restoration of native NK cytolytic functions. Tumor expression of HLA-G can be further induced using low-dose chemotherapy, which when combined with anti-HLA-G CAR-NK results in extensive tumor ablation both in vitro and in vivo. This upregulation of tumor HLA-G involves inhibition of DNMT1 and demethylation of transporter associated with antigen processing 1 promoter.ConclusionsOur novel CAR-NK strategy exploits the dual nature of HLA-G as both a tumor-associated neoantigen and an ICP to counteract tumor spread. Further ablation of tumors can be boosted when combined with administration of chemotherapeutic agents in clinical use. The readiness of this novel strategy envisions a wide applicability in treating solid tumors.

scholarly journals TArget-Responsive Subcellular Catabolism Analysis for Early-stage Antibody-Drug Conjugates Screening and Assessment

2020 ◽  
Author(s):  
Hua Sang ◽  
Jiali Liu ◽  
Fang Zhou ◽  
Xiaofang Zhang ◽  
Jingwei Zhang ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Therapeutic Efficacy ◽  
High Throughput Screening ◽  
Early Stage ◽  
Cellular Level ◽  
Drug Conjugates ◽  
Therapeutic Outcomes ◽  
Lysosomal Proteolysis

<p></p><p>Key events including antibody-antigen affinity, ADC internalization, trafficking and lysosomal proteolysis-mediated payload release combinatorially determine the therapeutic efficacy and safety for ADCs. Nevertheless, a universal technology that efficiently and conveniently evaluates the involvement of these above elements to ADC payload release and hence the final therapeutic outcomes for mechanistic studies and quality assessment is lacking. Considering the plethora of ADC candidates under development owing to the ever-evolving linker and drug chemistry, we developed a TArget-Responsive Subcellular Catabolism (TARSC) approach that measures catabolites kinetics for given ADCs and elaborates how each individual step ranging from antigen binding to lysosomal proteolysis affects ADC catabolism by targeted interferences. Using a commercial and a biosimilar ado-trastuzumab emtansine (T-DM1) as model ADCs, we recorded unequivocal catabolites kinetics for the two T-DM1s in the presence and absence of the targeted interferences. Their negligible differences in TARSC profiles fitting with their undifferentiated therapeutic outcomes suggested by <i>in vitro</i> viability assays and <i>in vivo</i> tumor growth assays, highlighting TARSC analysis as a good indicator of ADC efficacy and bioequivalency. Lastly, we demonstrated the use of TARSC in assessing payload release efficiency for a new Trastuzumab-toxin conjugate. Collectively, we demonstrated the use of TARSC in characterizing ADC catabolism at (sub)cellular level, and in systematically depicting whether given target proteins affect ADC payload release and hence therapeutic efficacy. We anticipate its future use in high-throughput screening, quality assessment and mechanistic understanding of ADCs for drug R&D before proceeding to costly <i>in vivo</i> experiments.</p><br><p></p>

scholarly journals Biodegradable multi-walled carbon nanotubes trigger anti-tumoral effects

Nanoscale ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 11013-11020 ◽  
Author(s):  
E. González-Lavado ◽  
N. Iturrioz-Rodríguez ◽  
E. Padín-González ◽  
J. González ◽  
L. García-Hevia ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Malignant Melanoma ◽  
Solid Tumors ◽  
Mild Oxidation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Mild oxidation treatments improve the in vitro and in vivo macrophage biodegradation of carbon nanotubes that trigger remarkable anti-tumoral effects in malignant melanoma solid tumors produced in mice.

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