journal contribution
posted on 2024-04-01, 07:21 authored by Abhay K. Singh, Calvin D. Lewis, Cristian A.W.V. Boas, Philipp Diebolder, Prashant N. Jethva, Aaron Rhee, Jong Hee Song, Young Ah Goo, Shunqian Li, Michael L. Nickels, Yongjian Liu, Buck E. Rogers, Vaishali Kapoor, Dennis E. Hallahan Supplementary Figure 11. Specific uptake of the [89Zr]Zr-DFO-L111 in tumors in vivo. Bar graph showing the uptake of the [89Zr]Zr-DFO-Isotype or [89Zr]Zr-DFO-L111 at days 2 and 5 in nude mice bearing A549 tumors in the hindlimb (n=4). Tumors were irradiated with three doses of 3Gy over 24h, followed by injection with radiolabeled antibodies. Cold anti-TIP1 Ab was injected before injecting the radiolabeled for the blocking study. Bar graphs represent %ID/gm. *P<0.05, **P<0.01
Funding
National Institutes of Health (NIH)
Alvin J. Siteman Cancer Center (Siteman Cancer Center)
Elizabeth and James McDonnell endowment
History
ARTICLE ABSTRACT
Tax-interacting protein 1 (TIP1) is a cancer-specific radiation-inducible cell surface antigen that plays a role in cancer progression and resistance to therapy. This study aimed to develop a novel anti-TIP1 human antibody for noninvasive PET imaging in patients with cancer.
A phage-displayed single-chain variable fragment (scFv) library was created from healthy donors’ blood. High-affinity anti-TIP1 scFvs were selected from the library and engineered to human IgG1. Purified Abs were characterized by size exclusion chromatography high-performance liquid chromatography (SEC-HPLC), native mass spectrometry (native MS), ELISA, BIAcore, and flow cytometry. The labeling of positron emitter [89Zr]Zr to the lead Ab, L111, was optimized using deferoxamine (DFO) chelator. The stability of [89Zr]Zr-DFO-L111 was assessed in human serum. Small animal PET studies were performed in lung cancer tumor models (A549 and H460).
We obtained 95% pure L111 by SEC-HPLC. Native MS confirmed the intact mass and glycosylation pattern of L111. Conjugation of three molar equivalents of DFO led to the optimal DFO-to-L111 ratio of 1.05. Radiochemical purity of 99.9% and specific activity of 0.37 MBq/μg was obtained for [89Zr]Zr-DFO-L111. [89Zr]Zr-DFO-L111 was stable in human serum over 7 days. The immunoreactive fraction in cell surface binding studies was 96%. In PET, preinjection with 4 mg/kg cold L111 before [89Zr]Zr-DFO-L111 (7.4 MBq; 20 μg) significantly (P < 0.01) enhanced the tumor-to-muscle standard uptake values (SUVmax) ratios on day 5 compared with day 2 postinjection.
L111 Ab targets lung cancer cells in vitro and in vivo. [89Zr]Zr-DFO-L111 is a human antibody that will be evaluated in the first in-human study of safety and PET imaging.
