HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Thakur, M.L. Articles by White, F.W. Search for Related Content PubMed PubMed Citation Articles by Thakur, M.L. Articles by White, F.W., III

Monoclonal Antibodies as Agents for Selective Radiolabeling of Human Neutrophils

Department of Radiation Oncology and Nuclear Medicine, Division of Nuclear Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania

Correspondence: For reprints contact: M. L. Thakur, PhD, Div. of Nuclear Medicine, Dept. of Radiation Oncology and Nuclear Medicine, 804 Main Building, Thomas Jefferson University, Philadelphia, PA 19107.

ABSTRACT

Ten monoclonal antibodies (MAbs) have been evaluated as agents for selective radiolabeling of human neutrophils(PMNs). Four bifunctional chelating agents(BFCA)have been compared in order to determine the one that gives the best labeling of MAbs with radionuclides. Of these,the cyclic anhydride of diethylenetriaminepentaacetic acid (DTPA)has been chosen for routine use since it incorporated ¹¹¹In efficiently, and only minimally altered the immunoreactivity of the MAb. Two [¹¹¹In]DTPA MAbs (1 µg or less, anti-SSEA-1 and B.37.2.1) incorporated 80 ±5% and 72 ± 6% of the added radioactivity with 10⁷separated PMNs in 0.5 ml plasma. In whole blood these values were 27 ± 5% and 38 ±9%, respectively. Using the other three BFCAs with anti-SSEA-1, the corresponding values of 70%–80% and 3%–5%, respectively were obtained. Polyacrylamide gel electrophoretic examinations of the radioactivity that did not bind to blood cells revealed that when DTPA was used as the BFCA, 21% of the radioactivity was associated with a plasma protein of mol wt 60–80 kD and 57% remained bound to the MAb (mol wt 900 kD). When the other three BFCAs were employed, these values were >42% and <19%, respectively. When up to 4% of the PMN surface antigens were MAb bound, the PMNs physiologic function remained unaltered. For two MAbs, anti-SSEA-i , and B 37.2.1 , the PMN specificity was found to be 1.6 x 10^–11M and 2 x 10^–11M, respectively,and the number of cell surface antigens was estimated to be 5.1 x 10⁵ and 7.8 x 10⁵, respectively. For ^99mTc labeling of MAbS, the use of four different reducing agents were examined. One agent, sodium-dithionite(Na₂S₂O₄), at a concentration of 0.2 mg/ml reaction mixture and with a molar ratio 3 x 10³:1 to the Mab, gave us results that were comparable to those obtained with [¹¹¹In]Mab. We conclude that at least two of the ten Mabs, anti-SSEA-1 and B.37.2.1 are worthy of evaluation in humans.

This article has been cited by other articles:

				M. Tulchinsky and A. M. Peters Leukocyte Receptor-Binding Radiopharmaceuticals for Infection and Inflammation Scintigraphy J. Nucl. Med., May 1, 2005; 46(5): 718 - 721. [Full Text] [PDF]

				C. Love and C. J. Palestro Radionuclide Imaging of Infection J. Nucl. Med. Technol., June 1, 2004; 32(2): 47 - 57. [Abstract] [Full Text] [PDF]