A linear epitope coupled to DsRed provides an affinity ligand for the capture of monoclonal antibodies

Monoclonal antibodies (mAbs) dominate the market for biopharmaceutical proteins because they provide active and passive immunotherapies for many different diseases. However, for most mAbs, two expensive manufacturing platforms are required. These are mammalian cell cultures for upstream production and Protein A chromatography for product capture during downstream processing. Here we describe a novel affinity ligand based on the fluorescent protein DsRed as a carrier for the linear epitope ELDKWA, which can capture the HIV-neutralizing antibody 2F5. We produced the DsRed-2F5-Epitope (DFE) in transgenic tobacco (Nicotiana tabacum) plants and purified it using a combination of heat treatment and immobilized metal-ion affinity chromatography, resulting in a yield of 24 mg kg-1 at 90% purity.
Using a design-of-experiments approach, we coupled up to 15 mg DFE per mL Sepharose. The resulting affinity resin was able to capture 2F5 from the clarified extract of N. benthamiana plants, achieving a purity of 97%, a recovery of >95% and an initial dynamic binding capacity at 10% product breakthrough of 4 mg mL-1 after a contact time of 2 min. The resin capacity declined to 15% of the starting value within 25 cycles when 1.25 M magnesium chloride was used for elution.
We confirmed the binding activity of the 2F5 product by surface plasmon resonance spectroscopy. DFE is not yet optimized, and a cost analysis revealed that boosting DFE expression and increasing its capacity by fourfold will make the resin cost-competitive with some Protein A counterparts. The affinity resin can also be exploited to purify idiotype-specific mAbs.

One Injection of DsRed Followed by Bites from Transgenic Mosquitoes Producing DsRed in the Saliva Elicits a High Titer of Antibody in Mice

It has been proposed that transgenic mosquitoes can be used as a “flying syringe” for infectious disease control. We succeeded in generating a transgenic (TG) mosquito, Anopheles stephensi, excreting and discharging DsRed in saliva. DsRed was deposited on the membrane where the TG mosquito probed with its proboscis. Repeated feeding by the TG mosquitoes induced anti-DeRed as well as anti-SG antibodies in mice. This indicates that the TG mosquitoes can immunize the animal. Moreover, in this report, we employed a pre-immunization method before exposing mice to the TG mosquitoes.
We injected DsRed to mice to prepare memory B cells and exposed the mice to bites by the TG mosquitoes excreting DsRed. The mice produced a higher titer of antibody to DsRed, suggesting that the bites from TG mosquitoes act as a booster and that primary immunization with a vaccine protein and exposure to TG mosquitoes excreting the vaccine protein in the saliva produces a synergistic effect.

RFP (dsRed) Antibody

3993-100 Biovision 430 EUR

RFP (dsRed) Antibody

3993-30T Biovision 185 EUR

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DsRed- rab7 WT

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dsRed Fluorescent Protein

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PVT1229 Lifescience Market 2 ug 241 EUR

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PD1 ELISA Matched Antibody Pair (Risk Free)

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