Antitumor effects of immobilized protein A and staphylococcal products: Linkage between toxicity and efficacy, and identification of potential tumoricidal reagents

Terman, David S.; Bertram, Juergen H.

doi:10.1016/0277-5379(85)90001-x

Cited by 36 publications

(13 citation statements)

References 27 publications

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“…HIV-1 neutralization was assessed by using a syncytium inhibition assay. Ten twofold serial dilutions (start concentration: 100 g/ml) of Zm 2G12, CHO 2G12, and a nonneutralizing control were preincubated with HIV-1 RF at 10 half-maximum tissue culture infectious dose (2,42) per milliliter for 1 h at 37°C. CD4-positive human AA-2 cells were added at a density of 4 ϫ 10 5 cells per milliliter and incubated for a further 5 days.…”

Section: Methodsmentioning

confidence: 99%

“…Protein A binds with great affinity and specificity to the Fc portion of full-length antibodies and is widely used in commercial antibody production. However, the resin is very expensive (particularly when used in industrial scale chromatography columns) and can undergo degradation (41) and leach into the final product, causing toxicity (42). However, conventional chromatographic methods are suitable for large-scale processes because they are less expensive, easier to use, and largely resistant to chemical and biological degradation (43,44).…”

Section: Applied Biological Sciencesmentioning

confidence: 99%

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Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Ramessar

Rademacher

Sack

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

150

124

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A series of small-molecule microbicides has been developed for vaginal delivery to prevent heterosexual HIV transmission, but results from human clinical trials have been disappointing. Proteinbased microbicides, such as HIV-specific monoclonal antibodies, have been considered as an alternative approach. Despite their promising safety profile and efficacy, the major drawback of such molecules is the economy of large-scale production in mammalian cells, the current system of choice. Here, we show that an alternative biomanufacturing platform is now available for one of the most promising anti-HIV antibodies (2G12). Our data show that the HIV-neutralization capability of the antibody is equal to or superior to that of the same antibody produced in CHO cells. We conclude that this protein production system may provide a means to achieve microbicide ingredient manufacture at costs that would allow product introduction and manufacture in the developing world.

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Section: Methodsmentioning

confidence: 99%

Section: Applied Biological Sciencesmentioning

confidence: 99%

Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Ramessar

Rademacher

Sack

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

150

124

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“…However, it suffers from problems regarding ligand stability and cost, since protein A resin is very expensive and readily amenable to chemical and biological degradation. In addition, protein A leaching is a serious concern (Carter-Franklin et al, 2007), since protein A is known to cause severe immunogenic responses in humans (Terman and Bertram, 1985;. Non-affinity-based purification schemes for mAbs have also been the focus of much discussion in the literature (Li et al, 1998;Teng et al, 1999;Boschetti, 2001;Vancan et al, 2002;Follman and Fahrner, 2004;Ghose et al, 2006;Bak and Thomas, 2007;Ramessar et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Combinatorial de novo design and application of a biomimetic affinity ligand for the purification of human anti‐HIV mAb 4E10 from transgenic tobacco

Platis

Maltezos

K‐C.

et al. 2009

J of Molecular Recognition

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Monoclonal anti-HIV antibody 4E10 (mAb 4E10) is one of the most broadly neutralizing antibodies against HIV, directed against a specific epitope on envelope protein gp41. In the present study, a combinatorial de novo design approach was used for the development of a biomimetic ligand for the affinity purification of mAb 4E10 from tobacco transgenic extract in a single chromatographic step. The biomimetic ligand (4E10lig) was based on a L-Phe/beta-Ala bi-substituted 1,3,5-triazine (Trz) scaffold (beta-Ala-Trz-L-Phe, 4E10lig) which potentially mimics the more pronounced electrostatic and hydrophobic interactions of mAb 4E10-binding sequence determined by screening of a random peptide library. This library was comprised of Escherichia coli cells harboring a plasmid (pFlitrx) engineered to express a fusion protein containing random dodecapeptides that were inserted into the active loop of thioredoxin, which itself was inserted into the dispensable region of the flagellin gene. Adsorption equilibrium studies with this biomimetic ligand and mAb 4E10 determined a dissociation constant (K(D)) of 0.41 +/- 0.05 microM. Molecular modeling studies of the biomimetic ligand revealed that it can potentially occupy the same binding site as the natural binding core peptide epitope. The biomimetic affinity adsorbent was exploited in the development of a facile mAb 4E10 purification protocol, affording mAb 4E10 of high purity (approximately 95%) with good overall yield (60-80%). Analysis of the antibody preparation by SDS-PAGE, enzyme-linked immunosorbent assays (ELISA), and western blot showed that the mAb 4E10 was fully active and free of degraded variants, polyphenols, and alkaloids.

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“…Leaching of the proteinaceous ligands is another problem associated with this mode of chromatography. This is a serious concern because these proteins are known to cause immunogenic responses in humans and have proven toxic in a number of clinical studies [10]. In addition, requirement for efficient cleaning and lack of alkaline stability are some other drawbacks.…”

Section: Introductionmentioning

confidence: 99%

Affinity chromatography for the purification of therapeutic proteins from transgenic maize using immobilized histamine

Platis

Labrou²

2008

J of Separation Science

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Plant molecular pharming is a technology that uses plants as bioreactors to produce recombinant molecules of medical and veterinary importance. In the present study, we evaluated the ability of histamine (HIM), tryptamine (TRM), phenylamine (PHEM) and tyramine (TYRM) coupled to Sepharose CL-4B via a 1,4-butanediol diglycidyl ether spacer to bind and purify human monoclonal anti-HIV antibody 2F5 (mAb 2F5) from spiked maize seed and tobacco leaf extracts. Detailed studies were carried out to determine the factors that affect the chromatographic behaviour of mAb 2F5 and also maize seed and tobacco leaf proteins. All affinity adsorbents showed a reduced capacity to bind and a reduced ability to purify proteins from tobacco extract compared to maize extract. Under optimal conditions, HIM exhibited high selectivity for mAb 2F5 and allowed a high degree of purification (>95% purity) and recovery (>90%) in a single step with salt elution (0.4 M KCl) from spiked maize seed extract. Analysis of the purified antibody fraction by ELISA and Western blot showed that the antibody was fully active and free of degraded variants or modified forms. The efficacy of the system was assessed further using a second therapeutic antibody (human monoclonal anti-HIV antibody mAb 2G12) and a therapeutic enzyme (alpha-chymotrypsin). HIM may find application in the purification of a wide range of biopharmaceuticals from transgenic plants.

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Antitumor effects of immobilized protein A and staphylococcal products: Linkage between toxicity and efficacy, and identification of potential tumoricidal reagents

Cited by 36 publications

References 27 publications

Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Cost-effective production of a vaginal protein microbicide to prevent HIV transmission

Combinatorial de novo design and application of a biomimetic affinity ligand for the purification of human anti‐HIV mAb 4E10 from transgenic tobacco

Affinity chromatography for the purification of therapeutic proteins from transgenic maize using immobilized histamine

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