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Recombinant antibody production evolves into multiple options aimed at yielding reagents suitable for application-specific needs.

de Marco A - Microb. Cell Fact. (2015)

Bottom Line: These have been illustrated with some significant examples and, when possible, compared with the existing alternatives.Space has also been given to those solutions that might represent interesting opportunities or that investigate critical aspects of the production optimization but for which the available data as yet do not allow for a definitive judgment.The take-home message is that there is a clear process of progressive diversification concerning the antibody expression platforms and an effort to yield directly application-adapted immune-reagents rather than generic naked antibodies that need further in vitro modification steps before becoming usable.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences and Engineering, University of Nova Gorica, Glavni Trg 9, 5261, Vipava, Slovenia. Ario.DeMarco@ung.si.

ABSTRACT

Background: Antibodies have been a pillar of basic research, while their relevance in clinical diagnostics and therapy is constantly growing. Consequently, the production of both conventional and fragment antibodies constantly faces more demanding challenges for the improvement of their quantity and quality. The answer to such an increasing need has been the development of a wide array of formats and alternative production platforms. This review offers a critical comparison and evaluation of the different options to help the researchers interested in expressing recombinant antibodies in their choice.

Results: Rather than the compilation of an exhaustive list of the recent publications in the field, this review intendeds to analyze the development of the most innovative or fast-growing strategies. These have been illustrated with some significant examples and, when possible, compared with the existing alternatives. Space has also been given to those solutions that might represent interesting opportunities or that investigate critical aspects of the production optimization but for which the available data as yet do not allow for a definitive judgment.

Conclusions: The take-home message is that there is a clear process of progressive diversification concerning the antibody expression platforms and an effort to yield directly application-adapted immune-reagents rather than generic naked antibodies that need further in vitro modification steps before becoming usable.

No MeSH data available.


Related in: MedlinePlus

Salmonella as a tumor-targetable cargo. Salmonella can be transformed for displaying recombinant antibodies specific for tumor cell antigens and for secreting enzymes able to activate pro-drugs. The antibodies assure the selective accumulation of systematically provided bacteria in the antigen-expressing target tissue and there the secreted enzymes will trigger the local conversion of inactive pro-drug into toxic compounds with anti-tumor activity
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Fig5: Salmonella as a tumor-targetable cargo. Salmonella can be transformed for displaying recombinant antibodies specific for tumor cell antigens and for secreting enzymes able to activate pro-drugs. The antibodies assure the selective accumulation of systematically provided bacteria in the antigen-expressing target tissue and there the secreted enzymes will trigger the local conversion of inactive pro-drug into toxic compounds with anti-tumor activity

Mentions: Antibodies are too often considered as reagents that must be first expressed and purified before being used. Further biotechnological steps such as their functionalization with appropriate molecules may be necessary to enable their final application, as for instance their use as capture binders on chip surfaces or their complexation to nanoparticles. However, there are examples—as in cases mentioned above [31, 33, 35]—showing that some of these tedious and expensive steps can be avoided by expressing recombinant antibodies as displayed reagents exposed on the surface of bacteria. The therapeutic application of attenuated strains of VHH-displaying Salmonellatyphimurium has been demonstrated recently [45]. The rationale behind the experiment is that several bacterial strains can contribute to tumor eradication in mouse models because they may induce anti-tumor immune-response after direct local injection. Bacteria show also a certain natural tropism for tumors but it is insufficient for effective targeted accumulation after systemic treatment. To improve their tumor-delivery specificity, Salmonella has been engineered for displaying an anti-CD20 nanobody. Such engineered bacteria accumulated selectively in CD20-positive tumor xenografts when applied systematically in mice and were successfully used as a cargo to deliver an enzyme able to convert in situ pro-drugs into active compounds (Fig. 5). The efficient nanobody-mediated bacterial targeting resulted in a significant tumor rejection in vivo even in immune-compromised models [45]. A similar approach has been applied also to Lactobacillus plantarum to exploit it as a cargo to deliver cDNA to mammalian cells [46]. Specifically, lactobacilli were transformed to display a scFv selective for the dendritic cell marker receptor DEC-205. The resulting lactobacilli were effectively internalized in vitro and in vivo by dendritic cells and transferred efficiently a GFP plasmid to them.Fig. 5


Recombinant antibody production evolves into multiple options aimed at yielding reagents suitable for application-specific needs.

de Marco A - Microb. Cell Fact. (2015)

Salmonella as a tumor-targetable cargo. Salmonella can be transformed for displaying recombinant antibodies specific for tumor cell antigens and for secreting enzymes able to activate pro-drugs. The antibodies assure the selective accumulation of systematically provided bacteria in the antigen-expressing target tissue and there the secreted enzymes will trigger the local conversion of inactive pro-drug into toxic compounds with anti-tumor activity
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4557595&req=5

Fig5: Salmonella as a tumor-targetable cargo. Salmonella can be transformed for displaying recombinant antibodies specific for tumor cell antigens and for secreting enzymes able to activate pro-drugs. The antibodies assure the selective accumulation of systematically provided bacteria in the antigen-expressing target tissue and there the secreted enzymes will trigger the local conversion of inactive pro-drug into toxic compounds with anti-tumor activity
Mentions: Antibodies are too often considered as reagents that must be first expressed and purified before being used. Further biotechnological steps such as their functionalization with appropriate molecules may be necessary to enable their final application, as for instance their use as capture binders on chip surfaces or their complexation to nanoparticles. However, there are examples—as in cases mentioned above [31, 33, 35]—showing that some of these tedious and expensive steps can be avoided by expressing recombinant antibodies as displayed reagents exposed on the surface of bacteria. The therapeutic application of attenuated strains of VHH-displaying Salmonellatyphimurium has been demonstrated recently [45]. The rationale behind the experiment is that several bacterial strains can contribute to tumor eradication in mouse models because they may induce anti-tumor immune-response after direct local injection. Bacteria show also a certain natural tropism for tumors but it is insufficient for effective targeted accumulation after systemic treatment. To improve their tumor-delivery specificity, Salmonella has been engineered for displaying an anti-CD20 nanobody. Such engineered bacteria accumulated selectively in CD20-positive tumor xenografts when applied systematically in mice and were successfully used as a cargo to deliver an enzyme able to convert in situ pro-drugs into active compounds (Fig. 5). The efficient nanobody-mediated bacterial targeting resulted in a significant tumor rejection in vivo even in immune-compromised models [45]. A similar approach has been applied also to Lactobacillus plantarum to exploit it as a cargo to deliver cDNA to mammalian cells [46]. Specifically, lactobacilli were transformed to display a scFv selective for the dendritic cell marker receptor DEC-205. The resulting lactobacilli were effectively internalized in vitro and in vivo by dendritic cells and transferred efficiently a GFP plasmid to them.Fig. 5

Bottom Line: These have been illustrated with some significant examples and, when possible, compared with the existing alternatives.Space has also been given to those solutions that might represent interesting opportunities or that investigate critical aspects of the production optimization but for which the available data as yet do not allow for a definitive judgment.The take-home message is that there is a clear process of progressive diversification concerning the antibody expression platforms and an effort to yield directly application-adapted immune-reagents rather than generic naked antibodies that need further in vitro modification steps before becoming usable.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Sciences and Engineering, University of Nova Gorica, Glavni Trg 9, 5261, Vipava, Slovenia. Ario.DeMarco@ung.si.

ABSTRACT

Background: Antibodies have been a pillar of basic research, while their relevance in clinical diagnostics and therapy is constantly growing. Consequently, the production of both conventional and fragment antibodies constantly faces more demanding challenges for the improvement of their quantity and quality. The answer to such an increasing need has been the development of a wide array of formats and alternative production platforms. This review offers a critical comparison and evaluation of the different options to help the researchers interested in expressing recombinant antibodies in their choice.

Results: Rather than the compilation of an exhaustive list of the recent publications in the field, this review intendeds to analyze the development of the most innovative or fast-growing strategies. These have been illustrated with some significant examples and, when possible, compared with the existing alternatives. Space has also been given to those solutions that might represent interesting opportunities or that investigate critical aspects of the production optimization but for which the available data as yet do not allow for a definitive judgment.

Conclusions: The take-home message is that there is a clear process of progressive diversification concerning the antibody expression platforms and an effort to yield directly application-adapted immune-reagents rather than generic naked antibodies that need further in vitro modification steps before becoming usable.

No MeSH data available.


Related in: MedlinePlus