TNB-738, a biparatopic antibody, boosts intracellular NAD+ by inhibiting CD38 ecto-enzyme activity.
Ugamraj, H.S., Dang, K., Ouisse, L.H., Buelow, B., Chini, E.N., Castello, G., Allison, J., Clarke, S.C., Davison, L.M., Buelow, R., Deng, R., Iyer, S., Schellenberger, U., Manika, S.N., Bijpuria, S., Musnier, A., Poupon, A., Cuturi, M.C., van Schooten, W., Dalvi, P.(2022) MAbs 14: 2095949-2095949
- PubMed: 35867844 
- DOI: https://doi.org/10.1080/19420862.2022.2095949
- Primary Citation of Related Structures:  
7VKE - PubMed Abstract: 
Cluster of differentiation 38 (CD38) is an ecto-enzyme expressed primarily on immune cells that metabolize nicotinamide adenine dinucleotide (NAD+) to adenosine diphosphate ribose or cyclic ADP-ribose and nicotinamide. Other substrates of CD38 include nicotinamide adenine dinucleotide phosphate and nicotinamide mononucleotide, a critical NAD+ precursor in the salvage pathway. NAD+ is an important coenzyme involved in several metabolic pathways and is a required cofactor for the function of sirtuins (SIRTs) and poly (adenosine diphosphate-ribose) polymerases. Declines in NAD+ levels are associated with metabolic and inflammatory diseases, aging, and neurodegenerative disorders. To inhibit CD38 enzyme activity and boost NAD+ levels, we developed TNB-738, an anti-CD38 biparatopic antibody that pairs two non-competing heavy chain-only antibodies in a bispecific format. By simultaneously binding two distinct epitopes on CD38, TNB-738 potently inhibited its enzymatic activity, which in turn boosted intracellular NAD+ levels and SIRT activities. Due to its silenced IgG4 Fc, TNB-738 did not deplete CD38-expressing cells, in contrast to the clinically available anti-CD38 antibodies, daratumumab, and isatuximab. TNB-738 offers numerous advantages compared to other NAD-boosting therapeutics, including small molecules, and supplements, due to its long half-life, specificity, safety profile, and activity. Overall, TNB-738 represents a novel treatment with broad therapeutic potential for metabolic and inflammatory diseases associated with NAD+ deficiencies. Abbreviations: 7-AAD: 7-aminoactinomycin D; ADCC: antibody dependent cell-mediated cytotoxicity; ADCP: antibody dependent cell-mediated phagocytosis; ADPR: adenosine diphosphate ribose; APC: allophycocyanin; cADPR: cyclic ADP-ribose; cDNA: complementary DNA; BSA: bovine serum albumin; CD38: cluster of differentiation 38; CDC: complement dependent cytotoxicity; CFA: Freund's complete adjuvant; CHO: Chinese hamster ovary; CCP4: collaborative computational project, number 4; COOT: crystallographic object-oriented toolkit; DAPI: 4',6-diamidino-2-phenylindole; DNA: deoxyribonucleic acid; DSC: differential scanning calorimetry; 3D: three dimensional; εNAD+: nicotinamide 1,N 6 -ethenoadenine dinucleotide; ECD: extracellular domain; EGF: epidermal growth factor; FACS: fluorescence activated cell sorting; FcγR: Fc gamma receptors; FITC: fluorescein isothiocyanate; HEK: human embryonic kidney; HEPES: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; IgG: immunoglobulin; IFA: incomplete Freund's adjuvant; IFNγ: Interferon gamma; KB: kinetic buffer; kDa: kilodalton; KEGG: kyoto encyclopedia of genes and genomes; LDH: lactate dehydrogenase; M: molar; mM: millimolar; MFI: mean fluorescent intensity; NA: nicotinic acid; NAD: nicotinamide adenine dinucleotide; NADP: nicotinamide adenine dinucleotide phosphate; NAM: nicotinamide; NGS: next-generation sequencing; NHS/EDC: N-Hydroxysuccinimide/ ethyl (dimethylamino propyl) carbodiimide; Ni-NTA: nickel-nitrilotriacetic acid; nL: nanoliter; NK: natural killer; NMN: nicotinamide mononucleotide; OD: optical density; PARP: poly (adenosine diphosphate-ribose) polymerase; PBS: phosphate-buffered saline; PBMC: peripheral blood mononuclear cell; PDB: protein data bank; PE: phycoerythrin; PISA: protein interfaces, surfaces, and assemblies: PK: pharmacokinetics; mol: picomolar; RNA: ribonucleic acid; RLU: relative luminescence units; rpm: rotations per minute; RU: resonance unit; SEC: size exclusion chromatography; SEM: standard error of the mean; SIRT: sirtuins; SPR: surface plasmon resonance; µg: microgram; µM: micromolar; µL: microliter.
Organizational Affiliation: 
Teneobio, Newark, California, USA.