Immunotoxin-αCD40 therapy activates innate and adaptive immunity and generates a durable antitumor response in glioblastoma models.

D2C7-immunotoxin (IT), a dual-specific IT targeting wild-type epidermal growth factor receptor (EGFR) and mutant EGFR variant III (EGFRvIII) proteins, demonstrates encouraging survival outcomes in a subset of patients with glioblastoma. We hypothesized that immunosuppression in glioblastoma limits D2C7-IT efficacy. To improve the response rate and reverse immunosuppression, we combined D2C7-IT tumor cell killing with αCD40 costimulation of antigen-presenting cells.

Improved efficacy against malignant brain tumors with EGFRwt/EGFRvIII targeting immunotoxin and checkpoint inhibitor combinations.

Background: D2C7-IT is a novel immunotoxin (IT) targeting wild-type epidermal growth factor receptor (EGFRwt) and mutant EGFR variant III (EGFRvIII) proteins in glioblastoma. In addition to inherent tumoricidal activity, immunotoxins induce secondary immune responses through the activation of T cells. However, glioblastoma-induced immune suppression is a major obstacle to an effective and durable immunotoxin-mediated antitumor response.

Synergistic antitumor effects of 9.2.27-PE38KDEL and ABT-737 in primary and metastatic brain tumors.

Standard treatment, unfortunately, yields a poor prognosis for patients with primary or metastatic cancers in the central nervous system, indicating a necessity for novel therapeutic agents. Immunotoxins (ITs) are a class of promising therapeutic candidates produced by fusing antibody fragments with toxin moieties. In this study, we investigated if inherent resistance to IT cytotoxicity can be overcome by rational combination with pro-apoptotic enhancers.

Production and quality control assessment of a GLP-grade immunotoxin, D2C7-(scdsFv)-PE38KDEL, for a phase I/II clinical trial.

D2C7-(scdsFv)-PE38KDEL (D2C7-IT) is a novel recombinant Pseudomonas exotoxin A-based immunotoxin (IT), targeting both wild-type epidermal growth factor receptor (EGFRwt) and mutant EGFR variant III (EGFRvIII) proteins overexpressed in glioblastomas. Initial pre-clinical testing demonstrated the anti-tumor efficacy of D2C7-IT against orthotopic glioblastoma xenograft models expressing EGFRwt, EGFRvIII, or both EGFRwt and EGFRvIII. A good laboratory practice (GLP) manufacturing process was developed to produce sufficient material for a phase I/II clinical trial.

Preclinical toxicity evaluation of a novel immunotoxin, D2C7-(scdsFv)-PE38KDEL, administered via intracerebral convection-enhanced delivery in rats.

D2C7-(scdsFv)-PE38KDEL (D2C7-IT) is a novel immunotoxin that reacts with wild-type epidermal growth factor receptor (EGFRwt) and mutant EGFRvIII proteins overexpressed in glioblastomas. This study assessed the toxicity of intracerebral administration of D2C7-IT to support an initial Food and Drug Administration Investigational New Drug application. After the optimization of the formulation and administration, two cohorts (an acute and chronic cohort necropsied on study days 5 and 34) of Sprague-Dawley (SD) rats (four groups of 5 males and 5 females) were infused with the D2C7-IT formulation at total doses of 0, 0.

Tofacitinib suppresses antibody responses to protein therapeutics in murine hosts.

Immunogenicity remains the "Achilles' heel" of protein-based therapeutics. Anti-drug Abs produced in response to protein therapeutics can severely limit both the safety and efficacy of this expanding class of agent. In this article, we report that monotherapy of mice with tofacitinib (the JAK inhibitor) quells Ab responses to an immunotoxin derived from the bacterial protein Pseudomonas exotoxin A, as well as to the model Ag keyhole limpet hemocyanin.

Affinity-matured recombinant immunotoxin targeting gangliosides 3'-isoLM1 and 3',6'-isoLD1 on malignant gliomas.

About 60 percent of glioblastomas highly express the gangliosides 3'-isoLM1 and 3',6'-isoLD1 on the cell surface, providing ideal targets for brain tumor immunotherapy. A novel recombinant immunotoxin, DmAb14m-(scFv)-PE38KDEL (DmAb14m-IT), specific for the gangliosides 3'-isoLM1 and 3',6'-isoLD1, was constructed with improved affinity and increased cytotoxicity for immunotherapeutic targeting of glioblastoma. We isolated an scFv parental clone from a previously established murine hybridoma, DmAb14, that is specific to both 3'-isoLM1 and 3',6'-isoLD1.

Construction of an immunotoxin, D2C7-(scdsFv)-PE38KDEL, targeting EGFRwt and EGFRvIII for brain tumor therapy.

Purpose: The EGF receptor gene (EGFR) is most frequently amplified and overexpressed, along with its deletion mutant, EGFRvIII, in glioblastoma. We tested the preclinical efficacy of the recombinant immunotoxin, D2C7-(scdsFv)-PE38KDEL, which is reactive with a 55-amino acid (AA) region present in the extracellular domain of both EGFRwt (583-637 AAs) and EGFRvIII (292-346 AAs) proteins.

Experimental Design: The binding affinity and specificity of D2C7-(scdsFv)-PE38KDEL for EGFRwt and EGFRvIII were measured by surface-plasmon resonance and flow cytometry.

Anti-CD22-chimeric antigen receptors targeting B-cell precursor acute lymphoblastic leukemia.

Immune targeting of B-cell malignancies using chimeric antigen receptors (CARs) is a promising new approach, but critical factors impacting CAR efficacy remain unclear. To test the suitability of targeting CD22 on precursor B-cell acute lymphoblastic leukemia (BCP-ALL), lymphoblasts from 111 patients with BCP-ALL were assayed for CD22 expression and all were found to be CD22-positive, with median CD22 expression levels of 3500 sites/cell. Three distinct binding domains targeting CD22 were fused to various TCR signaling domains ± an IgG heavy chain constant domain (CH2CH3) to create a series of vector constructs suitable to delineate optimal CAR configuration.

Recombinant anti-podoplanin (NZ-1) immunotoxin for the treatment of malignant brain tumors.

Our study demonstrates the glioma tumor antigen podoplanin to be present at very high levels (>90%) in both glioblastoma (D2159MG, D08-0308MG and D08-0493MG) and medulloblastoma (D283MED, D425MED and DAOY) xenografts and cell line. We constructed a novel recombinant single-chain antibody variable region fragment (scFv), NZ-1, specific for podoplanin from the NZ-1 hybridoma. NZ-1-scFv was then fused to Pseudomonas exotoxin A, carrying a C-terminal KDEL peptide (NZ-1-PE38KDEL).

Anoctamin and transmembrane channel-like proteins are evolutionarily related.

The anoctamin (ANO) family of proteins, consisting of 10 members in mammals, are transmembrane proteins that have Ca2+-activated Cl- channel activity. The transmembrane channel-like (TMC) family of proteins, consisting of 8 members in mammals, are also transmembrane proteins of which mutations are implicated in various human conditions, such as hearing loss and epidermodysplasia verruciformis. Here we show that ANO and TMC proteins share high sequence similarity and probably the same membrane topology, indicating that these proteins are evolutionarily related.

EGFRvIII-targeted immunotoxin induces antitumor immunity that is inhibited in the absence of CD4+ and CD8+ T cells.

Purpose: Immunotoxins as anti-cancer therapeutics have several potential advantages over conventional agents including a high specificity, extraordinary potency, and a lack of an identified mechanism for resistance. It has been clearly demonstrated that Pseudomonas-based immunotoxins have a direct cytotoxic effect. However, delayed and often dramatic antitumor responses seen in human studies with targeted toxins led us to hypothesize that immunologic responses may be a secondary mechanism that enhances the therapeutic efficacy of these novel drugs.

Duplication and extensive remodeling shaped POTE family genes encoding proteins containing ankyrin repeat and coiled coil domains.

The POTE family genes encode a highly homologous group of primate-specific proteins that contain ankyrin repeats and coiled coil domains. At least 13 paralogous POTE family genes are found on 8 human chromosomes (2, 8, 13, 14, 15, 18, 21 and 22), which can be sorted into 3 groups based on sequence similarity. We identified by a database search a group of additional human ankyrin repeat domain proteins, of which ANKRD26 and ANKRD30A are the best characterized; these are more distant homologs of POTE family proteins.

Finding fusion genes resulting from chromosome rearrangement by analyzing the expressed sequence databases.

Chromosomal rearrangements resulting in gene fusions are frequently involved in carcinogenesis. Here, we describe a semiautomatic procedure for identifying fusion gene transcripts by using publicly available mRNA and EST databases. With this procedure, we have identified 96 transcript sequences that are derived from 60 known fusion genes.

TEPP, a new gene specifically expressed in testis, prostate, and placenta and well conserved in chordates.

We have combined computer-based screening and experimental expression analysis to identify genes that are expressed in normal prostate and/or prostate cancer but not in essential human tissues. Using this approach we identified a new gene that is specifically expressed in testis, prostate, and placenta. The gene has one major transcript of 1.

Cloning, molecular characterization, and expression analysis of Copine 8.

Copines are ubiquitously expressed, phospholipid-binding proteins that have been conserved through evolution. In this paper, we report the cloning and molecular characterization of a new member of the Copine family, Copine 8. This gene has been isolated and characterized using a combination of bioinformatic and experimental approaches.