Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma Cells
The nucleotides ATP and NAD<sup>+</sup> are released from stressed cells as endogenous danger signals. Ecto-enzymes in the tumor microenvironment hydrolyze these inflammatory nucleotides to immunosuppressive adenosine, thereby, hampering anti-tumor immune responses. The NAD<sup>+&l...
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| Format: | Article |
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MDPI AG
2020-12-01
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| Series: | Cancers |
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| Online Access: | https://www.mdpi.com/2072-6694/13/1/76 |
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| author | Natalie Baum Ralf Fliegert Andreas Bauche Julia Hambach Stephan Menzel Friedrich Haag Peter Bannas Friedrich Koch-Nolte |
| author_facet | Natalie Baum Ralf Fliegert Andreas Bauche Julia Hambach Stephan Menzel Friedrich Haag Peter Bannas Friedrich Koch-Nolte |
| author_sort | Natalie Baum |
| collection | DOAJ |
| description | The nucleotides ATP and NAD<sup>+</sup> are released from stressed cells as endogenous danger signals. Ecto-enzymes in the tumor microenvironment hydrolyze these inflammatory nucleotides to immunosuppressive adenosine, thereby, hampering anti-tumor immune responses. The NAD<sup>+</sup> hydrolase CD38 is expressed at high levels on the cell surface of multiple myeloma (MM) cells. Daratumumab, a CD38-specific monoclonal antibody promotes cytotoxicity against MM cells. With long CDR3 loops, nanobodies and nanobody-based heavy chain antibodies (hcAbs) might bind to cavities on CD38 and thereby inhibit its enzyme activity more potently than conventional antibodies. The goal of our study was to establish assays for monitoring the enzymatic activities of CD38 on the cell surface of tumor cells and to assess the effects of CD38-specific antibodies on these activities. We monitored the enzymatic activity of CD38-expressing MM and other tumor cell lines, using fluorometric and HPLC assays. Our results showed that daratumumab and hcAb MU1067 inhibit the ADPR cyclase but not the NAD<sup>+</sup> hydrolase activity of CD38-expressing MM cells. We conclude that neither clinically approved daratumumab nor recently developed nanobody-derived hcAbs provide a second mode of action against MM cells. Thus, there remains a quest for “double action” CD38-inhibitory antibodies. |
| first_indexed | 2024-03-10T13:40:21Z |
| format | Article |
| id | doaj.art-1b926f34243d43058f87f16abfae501b |
| institution | Directory Open Access Journal |
| issn | 2072-6694 |
| language | English |
| last_indexed | 2024-03-10T13:40:21Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Cancers |
| spelling | doaj.art-1b926f34243d43058f87f16abfae501b2023-11-21T03:03:01ZengMDPI AGCancers2072-66942020-12-011317610.3390/cancers13010076Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma CellsNatalie Baum0Ralf Fliegert1Andreas Bauche2Julia Hambach3Stephan Menzel4Friedrich Haag5Peter Bannas6Friedrich Koch-Nolte7Institute of Immunology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyDepartment of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyDepartment of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyInstitute of Immunology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyInstitute of Immunology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyInstitute of Immunology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyDepartment of Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyInstitute of Immunology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, GermanyThe nucleotides ATP and NAD<sup>+</sup> are released from stressed cells as endogenous danger signals. Ecto-enzymes in the tumor microenvironment hydrolyze these inflammatory nucleotides to immunosuppressive adenosine, thereby, hampering anti-tumor immune responses. The NAD<sup>+</sup> hydrolase CD38 is expressed at high levels on the cell surface of multiple myeloma (MM) cells. Daratumumab, a CD38-specific monoclonal antibody promotes cytotoxicity against MM cells. With long CDR3 loops, nanobodies and nanobody-based heavy chain antibodies (hcAbs) might bind to cavities on CD38 and thereby inhibit its enzyme activity more potently than conventional antibodies. The goal of our study was to establish assays for monitoring the enzymatic activities of CD38 on the cell surface of tumor cells and to assess the effects of CD38-specific antibodies on these activities. We monitored the enzymatic activity of CD38-expressing MM and other tumor cell lines, using fluorometric and HPLC assays. Our results showed that daratumumab and hcAb MU1067 inhibit the ADPR cyclase but not the NAD<sup>+</sup> hydrolase activity of CD38-expressing MM cells. We conclude that neither clinically approved daratumumab nor recently developed nanobody-derived hcAbs provide a second mode of action against MM cells. Thus, there remains a quest for “double action” CD38-inhibitory antibodies.https://www.mdpi.com/2072-6694/13/1/76multiple myelomaCD38ecto-enzymeNAD<sup>+</sup> hydrolaseantibodiesheavy-chain antibodies |
| spellingShingle | Natalie Baum Ralf Fliegert Andreas Bauche Julia Hambach Stephan Menzel Friedrich Haag Peter Bannas Friedrich Koch-Nolte Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma Cells Cancers multiple myeloma CD38 ecto-enzyme NAD<sup>+</sup> hydrolase antibodies heavy-chain antibodies |
| title | Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma Cells |
| title_full | Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma Cells |
| title_fullStr | Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma Cells |
| title_full_unstemmed | Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma Cells |
| title_short | Daratumumab and Nanobody-Based Heavy Chain Antibodies Inhibit the ADPR Cyclase but not the NAD<sup>+</sup> Hydrolase Activity of CD38-Expressing Multiple Myeloma Cells |
| title_sort | daratumumab and nanobody based heavy chain antibodies inhibit the adpr cyclase but not the nad sup sup hydrolase activity of cd38 expressing multiple myeloma cells |
| topic | multiple myeloma CD38 ecto-enzyme NAD<sup>+</sup> hydrolase antibodies heavy-chain antibodies |
| url | https://www.mdpi.com/2072-6694/13/1/76 |
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