Interstitial Infusion of Glioma-Targeted Recombinant Immunotoxin 8H9scFv-PE38

Prostate cancer (PCa) is the second most common cancer in men, causing more than 300,000 deaths every year worldwide. Due to their superior cell-killing ability and the relative simplicity of their preparation, immunotoxin molecules have great potential in the clinical treatment of cancer, and several such molecules have been approved for clinical application. In this study, we adopted a relatively simple strategy based on a single-domain antibody (sdAb) and an improved Pseudomonas exotoxin A (PE) toxin (PE24X7) to prepare a safer immunotoxin against prostate-specific membrane antigen (PSMA) for PCa treatment. The designed anti-PSMA immunotoxin, JVM-PE24X7, was conveniently prepared in its soluble form in an Escherichia coli (E. coli) system, avoiding the complex renaturation process needed for immunotoxin preparation by the conventional strategy. The product was very stable and showed a very strong ability to bind the PSMA receptor. Cytotoxicity assays showed that this molecule at a very low concentration could kill PSMA-positive PCa cells, with an EC50 value (concentration at which the cell viability decreased by 50%) of 15.3 pM against PSMA-positive LNCaP cells. Moreover, this molecule showed very good killing selectivity between PSMA-positive and PSMA-negative cells, with a selection ratio of more than 300-fold. Animal studies showed that this molecule at a very low dosage (5 × 0.5 mg/kg once every three days) completely inhibited the growth of PCa tumors, and the maximum tolerable dose (MTD) was more than 15 mg/kg, indicating its very potent tumor-treatment ability and a wide therapeutic window. Use of the new PE toxin, PE24X7, as the effector moiety significantly reduced off-target toxicity and improved the therapeutic window of the immunotoxin. The above results demonstrate that the designed anti-PSMA immunotoxin, JVM-PE24X7, has good application value for the treatment of PCa.

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Design, Expression, Purification and Characterization of the Recombinant Immunotoxin 4D5 scFv-TRAIL

International Journal of Peptide Research and Therapeutics ◽

10.1007/s10989-019-09894-4 ◽

2019 ◽

Vol 26 (2) ◽

pp. 889-897

Author(s):

Zhanqing Wang ◽

Lili Chi ◽

Yaling Shen

Keyword(s):

Purification And Characterization ◽

Recombinant Immunotoxin

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Role of renal medullary adenosine in the control of blood flow and sodium excretion

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1999.276.3.r790 ◽

1999 ◽

Vol 276 (3) ◽

pp. R790-R798 ◽

Cited By ~ 40

Author(s):

Ai-Ping Zou ◽

Kasem Nithipatikom ◽

Pin-Lan Li ◽

Allen W. Cowley

Keyword(s):

Blood Flow ◽

Sodium Excretion ◽

Renal Medulla ◽

Urine Flow ◽

Doppler Flowmetry ◽

Blood Flows ◽

Medullary Blood Flow ◽

Adenosine Concentration ◽

Interstitial Infusion

This study determined the levels of adenosine in the renal medullary interstitium using microdialysis and fluorescence HPLC techniques and examined the role of endogenous adenosine in the control of medullary blood flow and sodium excretion by infusing the specific adenosine receptor antagonists or agonists into the renal medulla of anesthetized Sprague-Dawley rats. Renal cortical and medullary blood flows were measured using laser-Doppler flowmetry. Analysis of microdialyzed samples showed that the adenosine concentration in the renal medullary interstitial dialysate averaged 212 ± 5.2 nM, which was significantly higher than 55.6 ± 5.3 nM in the renal cortex ( n = 9). Renal medullary interstitial infusion of a selective A1antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 300 pmol ⋅ kg−1 ⋅ min−1, n = 8), did not alter renal blood flows, but increased urine flow by 37% and sodium excretion by 42%. In contrast, renal medullary infusion of the selective A2 receptor blocker 3,7-dimethyl-1-propargylxanthine (DMPX; 150 pmol ⋅ kg−1 ⋅ min−1, n = 9) decreased outer medullary blood flow (OMBF) by 28%, inner medullary blood flows (IMBF) by 21%, and sodium excretion by 35%. Renal medullary interstitial infusion of adenosine produced a dose-dependent increase in OMBF, IMBF, urine flow, and sodium excretion at doses from 3 to 300 pmol ⋅ kg−1 ⋅ min−1( n = 7). These effects of adenosine were markedly attenuated by the pretreatment of DMPX, but unaltered by DPCPX. Infusion of a selective A3receptor agonist, N 6-benzyl-5′-( N-ethylcarbonxamido)adenosine (300 pmol ⋅ kg−1 ⋅ min−1, n = 6) into the renal medulla had no effect on medullary blood flows or renal function. Glomerular filtration rate and arterial pressure were not changed by medullary infusion of any drugs. Our results indicate that endogenous medullary adenosine at physiological concentrations serves to dilate medullary vessels via A2 receptors, resulting in a natriuretic response that overrides the tubular A1 receptor-mediated antinatriuretic effects.

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Recombinant Immunotoxin Containing a Disulfide-Stabilized Fv Directed at erbB2 That Does Not Require Proteolytic Activation

Biochemistry ◽

10.1021/bi952047g ◽

1996 ◽

Vol 35 (9) ◽

pp. 2872-2877 ◽

Cited By ~ 9

Author(s):

Chien-Tsun Kuan ◽

Ira Pastan

Keyword(s):

Proteolytic Activation ◽

Recombinant Immunotoxin

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Phase I study of mesothelin-targeted immunotoxin LMB-100 in combination with tofacitinib in patients with advanced pancreatobiliary cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.3051 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. 3051-3051

Author(s):

Nebojsa Skorupan ◽

Mehwish Iqra Ahmad ◽

Guillaume Joe Pegna ◽

Cody J. Peer ◽

Jane B. Trepel ◽

...

Keyword(s):

Solid Tumors ◽

Dose Level ◽

Dose Escalation ◽

Single Agent ◽

Primary Objective ◽

Pseudomonas Exotoxin A ◽

Recombinant Immunotoxin ◽

Level 1 ◽

Expansion Cohort ◽

Almost All

3051 Background: LMB-100 recombinant immunotoxin consists of a mesothelin-binding Fab for targeting a modified Pseudomonas exotoxin A payload to tumors. Previous clinical trials demonstrated that almost all patients formed anti-drug-antibodies (ADAs) to LMB-100 that made administration beyond cycle 2 ineffective. Tofacitinib is an oral JAK inhibitor that prevented formation of ADAs against a closely related immunotoxin in pre-clinical studies. The primary objective of the dose escalation cohort was assessment of safety and tolerability of LMB-100 given with tofacitinib to patients with mesothelin-expressing solid tumors. The primary objective of the expansion cohort was to determine whether co-administration of tofacitinib delays formation of neutralizing LMB-100 ADAs. Methods: Patients (n = 13) with pancreatic adenocarcinoma and other mesothelin-expressing solid tumors (n = 3; cholangiocarcinoma, appendix, cystadenocarcinoma) were treated for up to 3 cycles with LMB-100 as a 30-minute infusion on days 4, 6, and 8 at two dose levels (100 and 140 mcg/kg) and co-treated with oral tofacitinib for the first 10 days of the cycle (10 mg BID). Results: Dose level 1 of LMB-100 was started at 100 mcg/kg one dose level below the single agent MTD. Dose escalation to 140 mcg/kg (dose level 2) resulted in DLTs in 2 of the 3 patients treated: grade 3 cardiac toxicity and grade 4 hyponatremia, both attributed to capillary leak syndrome. Ultimately, 7 patients were treated at dose level 1 without DLTs and 100 mcg/kg was chosen as the LMB-100 dose for the expansion cohort. The last of 6 patients treated in the expansion cohort developed grade 4 pericardial effusion leading to early closure of the study for toxicity. No objective responses were seen. Of the 8 patients who received two cycles of treatment at MTD, 4 met prespecified criteria for ADA prevention, and 2 patients who went on to receive cycle 3 had detectable LMB-100 plasma drug levels after administration. Conclusions: LMB-100 was unable to be co-administered safely with tofacitinib. ADA formation was prevented in 2 patients through 3 cycles, a rare occurrence. Clinical trial information: NCT04034238.

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Design of a recombinant immunotoxin against the human granulocyte-colony stimulating factor receptor

Molecular Biology Reports ◽

10.1007/s11033-018-4567-z ◽

2018 ◽

Vol 46 (1) ◽

pp. 1093-1097 ◽

Cited By ~ 2

Author(s):

E. Babavalian ◽

M. Zeinoddini ◽

A. R. Saeedinia ◽

R. Mohammadi ◽

N. Xodadadi

Keyword(s):

Granulocyte Colony Stimulating Factor ◽

Colony Stimulating Factor ◽

Recombinant Immunotoxin ◽

Stimulating Factor

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Recombinant Immunotoxin 4D5scFv-PE40 for Targeted Therapy of HER2-Positive Tumors

Acta Naturae ◽

10.32607/20758251-2015-7-4-93-96 ◽

2015 ◽

Vol 7 (4) ◽

pp. 93-96 ◽

Cited By ~ 2

Author(s):

E. A. Sokolova ◽

O. A. Stremovskiy ◽

T. A. Zdobnova ◽

I. V. Balalaeva ◽

S. M. Deyev

Keyword(s):

Targeted Therapy ◽

Tumor Marker ◽

Cancer Cells ◽

Therapeutic Index ◽

Molecular Profile ◽

Her2 Positive ◽

Pseudomonas Exotoxin A ◽

Recombinant Immunotoxin ◽

Long Run

Recombinant immunotoxins are extremely promising agents for the targeted therapy of tumors with a certain molecular profile. In this work, we studied the properties of a new recombinant HER2-specific immunotoxin composed of the scFv antibody and a fragment of Pseudomonas exotoxin A (4D5scFv-PE40). High affinity of the immunotoxin for the HER2 tumor marker, its selective cytotoxicity against HER2-overexpressing cells, and its storage stability were demonstrated. The 50% inhibitory concentration (IC50) of the 4D5scFv-PE40 immunotoxin for HER2-overexpressing cancer cells was 2.5-3 orders of magnitude lower compared to that for CHO cells not expressing this tumor marker and was 2.5-3 orders of magnitude lower than IC50 of free PE40 for HER2-overexpressing cancer cells. These findings provide a basis for expecting in the long run high therapeutic index values of the 4D5scFv-PE40 immunotoxin for its use in vivo.

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