| 2. |
- Bar, Laure, et al.
(författare)
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Impact of antigen density on recognition by monoclonal antibodies
- 2020
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Ingår i: Analytical Biochemistry. - : American Chemical Society (ACS). - 0003-2697 .- 1096-0309 .- 0003-2700 .- 1520-6882. ; 92:7, s. 5396-5403
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Tidskriftsartikel (refereegranskat)abstract
- Understanding antigen–antibody interactions is important to many emerging medical and bioanalytical applications. In particular, the levels of antigen expression at the cell surface may determine antibody-mediated cell death. This parameter has a clear effect on outcome in patients undergoing immunotherapy. In this context, CD20 which is expressed in the membrane of B cells has received significant attention as target for immunotherapy of leukemia and lymphoma using the monoclonal antibody rituximab. To systematically study the impact of CD20 density on antibody recognition, we designed self-assembled monolayers that display tunable CD20 epitope densities. For this purpose, we developed in situ click chemistry to functionalize SPR sensor chips. We find that the rituximab binding affinity depends sensitively and nonmonotonously on CD20 surface density. Strongest binding, with an equilibrium dissociation constant (KD = 32 nM) close to values previously reported from in vitro analysis with B cells (apparent KD between 5 and 19 nM), was obtained for an average inter-antigen spacing of 2 nm. This distance is required for improving rituximab recognition, and in agreement with the known requirement of CD20 to form clusters to elicit a biological response. More generally, this study offers an interesting outlook in the understanding of the necessity of epitope clusters for effective mAb recognition.
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| 4. |
- Dircksen, Heinrich, 1954-, et al.
(författare)
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Genomics, transcriptomics and peptidomics of Daphnia pulex neuropeptides and protein hormones
- 2011
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 10:10, s. 4478-4504
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Tidskriftsartikel (refereegranskat)abstract
- We report 43 novel genes in the water flea Daphnia pulex encoding 73 predicted neuropeptide and protein hormones as partly confirmed by RT-PCR. MALDI-TOF mass spectrometry identified 40 neuropeptides by mass matches and 30 neuropeptides by fragmentation sequencing. Single genes encode adipokinetic hormone, allatostatin-A, allatostatin-B, a first crustacean allatotropin, Ala7-CCAP, one CCHamide, Arg7-corazonin, CRF-like (DH52) and calcitonin-like (DH31) diuretic hormones, two ecdysis-triggering hormones, two FIRFamides, one insulin- and one each of three IGF-related peptides, two alternative splice forms of short and long ion transport peptide (ITP), one each of two N-terminally elongated ITPs, myosuppressin, neuroparsin, two neuropeptide-F splice forms, three periviscerokinins (but no pyrokinins), pigment dispersing hormone, proctolin, Met4-proctolin, one novel short neuropeptide-F, three RYamides, SIFamide, two sulfakinins, three tachykinins. Two genes encode orcokinins, three genes different allatostatins-C. Paired gene clusters occur for two novel eclosion hormones; bursicons alpha, beta; glycoproteins GPA2, GPB5; and two of the allatostatin-C genes. Detailed comparisons of genes or their products with those from insects and decapod crustaceans revealed that the D. pulex peptides are often closer to their insect than to their decapod crustacean homologues, confirming that branchiopods, to which Daphnia belongs, are the ancestor group of insects.
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