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Design and evaluation of a peptide-based immunotoxin for breast cancer therapeutics.

Weigel KJ, Shen L, Thomas CL, Alber D, Drapalik L, Schafer ZT, Lee SW - FEBS Open Bio (2015)

Bottom Line: ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients.Immunotoxin candidates were designed to incorporate a targeting ligand with affinity for ErbB2 along with a membrane lysin-based toxin domain.Our findings hold significant promise for the use of effective immunotoxins in cancer therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.

ABSTRACT
Immunotoxins are chimeric proteins comprising a specific cellular targeting domain linked to a cytotoxic factor. Here we describe the design and use of a novel, peptide-based immunotoxin that can initiate selective cytotoxicity on ErbB2-positive cells. ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients. Immunotoxin candidates were designed to incorporate a targeting ligand with affinity for ErbB2 along with a membrane lysin-based toxin domain. One particular peptide candidate, NL1.1-PSA, demonstrated selective cytotoxicity towards ErbB2-overexpressing cell lines. We utilized a bioengineering strategy to show that recombinant NL1.1-PSA immunotoxin expression by Escherichia coli also conferred selective cytotoxicity towards ErbB2-overexpressing cells. Our findings hold significant promise for the use of effective immunotoxins in cancer therapeutics.

No MeSH data available.


Related in: MedlinePlus

Design of ErbB2-targeting immunotoxins. Schematic of the immunotoxin design. Any combination of one ligand moiety and one toxin moiety from the lists can be inserted into the diagram to demonstrate how the pairs can be conjugated together. Of note, the location on the amino- and carboxy-terminal ends may be exchanged to create two different immunotoxins from the same two moieties (A). Table listing the amino acid sequences of the moieties denoted in panel A (B). Please see the references associated with each of the following characters: α [28], ♭[29], + [26], ¥ [31].
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f0005: Design of ErbB2-targeting immunotoxins. Schematic of the immunotoxin design. Any combination of one ligand moiety and one toxin moiety from the lists can be inserted into the diagram to demonstrate how the pairs can be conjugated together. Of note, the location on the amino- and carboxy-terminal ends may be exchanged to create two different immunotoxins from the same two moieties (A). Table listing the amino acid sequences of the moieties denoted in panel A (B). Please see the references associated with each of the following characters: α [28], ♭[29], + [26], ¥ [31].

Mentions: Although ErbB2 has no known ligand [27], previous studies have identified small peptide fragments with a strong affinity for the ErbB2 receptor [28,29]. In our immunotoxin design strategy we therefore conjugated these ErbB2 receptor targeting ligands to several peptide sequence candidates that were previously demonstrated to have intrinsic ability to lyse cellular membranes. In particular, the three peptide toxins tested were composed of: 1. SP – a proline-substituted derivative of the Streptolysin S hemolysin from Group A Streptococcus that was shown to have intrinsic cytolytic activity as a peptide [30]; 2. PSA, an 18-residue peptide adapted from the N-terminus of the Pardaxin hemolysin [31]; 3. S32, a synthetically designed toxin from our bacteriocin screening library that was found to exert hemolytic activity ([26]; Lee, SW, unpublished data). Based on this template, we designed a series of immunotoxin-based synthetic peptides with two components: an ErbB2 targeting moiety and a toxin moiety. The toxin and targeting moieties were paired in various combinations, some with the targeting moiety at the amino-terminus and toxin moiety on the carboxy-terminus (Fig. 1A), others with the two moieties inverted on terminal ends. These immunotoxin peptide candidates were then synthesized as lyophilized peptides from Genscript at a >70% purity, and dissolved in DMSO prior to testing.


Design and evaluation of a peptide-based immunotoxin for breast cancer therapeutics.

Weigel KJ, Shen L, Thomas CL, Alber D, Drapalik L, Schafer ZT, Lee SW - FEBS Open Bio (2015)

Design of ErbB2-targeting immunotoxins. Schematic of the immunotoxin design. Any combination of one ligand moiety and one toxin moiety from the lists can be inserted into the diagram to demonstrate how the pairs can be conjugated together. Of note, the location on the amino- and carboxy-terminal ends may be exchanged to create two different immunotoxins from the same two moieties (A). Table listing the amino acid sequences of the moieties denoted in panel A (B). Please see the references associated with each of the following characters: α [28], ♭[29], + [26], ¥ [31].
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4382514&req=5

f0005: Design of ErbB2-targeting immunotoxins. Schematic of the immunotoxin design. Any combination of one ligand moiety and one toxin moiety from the lists can be inserted into the diagram to demonstrate how the pairs can be conjugated together. Of note, the location on the amino- and carboxy-terminal ends may be exchanged to create two different immunotoxins from the same two moieties (A). Table listing the amino acid sequences of the moieties denoted in panel A (B). Please see the references associated with each of the following characters: α [28], ♭[29], + [26], ¥ [31].
Mentions: Although ErbB2 has no known ligand [27], previous studies have identified small peptide fragments with a strong affinity for the ErbB2 receptor [28,29]. In our immunotoxin design strategy we therefore conjugated these ErbB2 receptor targeting ligands to several peptide sequence candidates that were previously demonstrated to have intrinsic ability to lyse cellular membranes. In particular, the three peptide toxins tested were composed of: 1. SP – a proline-substituted derivative of the Streptolysin S hemolysin from Group A Streptococcus that was shown to have intrinsic cytolytic activity as a peptide [30]; 2. PSA, an 18-residue peptide adapted from the N-terminus of the Pardaxin hemolysin [31]; 3. S32, a synthetically designed toxin from our bacteriocin screening library that was found to exert hemolytic activity ([26]; Lee, SW, unpublished data). Based on this template, we designed a series of immunotoxin-based synthetic peptides with two components: an ErbB2 targeting moiety and a toxin moiety. The toxin and targeting moieties were paired in various combinations, some with the targeting moiety at the amino-terminus and toxin moiety on the carboxy-terminus (Fig. 1A), others with the two moieties inverted on terminal ends. These immunotoxin peptide candidates were then synthesized as lyophilized peptides from Genscript at a >70% purity, and dissolved in DMSO prior to testing.

Bottom Line: ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients.Immunotoxin candidates were designed to incorporate a targeting ligand with affinity for ErbB2 along with a membrane lysin-based toxin domain.Our findings hold significant promise for the use of effective immunotoxins in cancer therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.

ABSTRACT
Immunotoxins are chimeric proteins comprising a specific cellular targeting domain linked to a cytotoxic factor. Here we describe the design and use of a novel, peptide-based immunotoxin that can initiate selective cytotoxicity on ErbB2-positive cells. ErbB2 is a receptor tyrosine kinase that is overexpressed in the tumor cells of approximately 30% of breast cancer patients. Immunotoxin candidates were designed to incorporate a targeting ligand with affinity for ErbB2 along with a membrane lysin-based toxin domain. One particular peptide candidate, NL1.1-PSA, demonstrated selective cytotoxicity towards ErbB2-overexpressing cell lines. We utilized a bioengineering strategy to show that recombinant NL1.1-PSA immunotoxin expression by Escherichia coli also conferred selective cytotoxicity towards ErbB2-overexpressing cells. Our findings hold significant promise for the use of effective immunotoxins in cancer therapeutics.

No MeSH data available.


Related in: MedlinePlus