Manikwar, PrakashTejo, Bimo A.Shinogle, Heather E.Moore, David S.Zimmerman, TahlBlanco, FranciscoSiahaan, Teruna J.2011-06-152011-06-152010-05-10Manikwar P, Tejo BA, Shinogle H, Moore DS, Zimmerman T, Blanco F, Siahaan TJ. Utilization of I-domain of LFA-1 to Target Drug and Marker Molecules to Leukocytes. Theranostics 2011; 1:277-289.https://hdl.handle.net/1808/7609The long-term objective of this project is to utilize the I-domain protein for the -subunit of LFA-1 to target drugs to lymphocytes by binding to ICAM receptors on the cell surface. The short-term goal is to provide proof-of-concept that I-domain conjugated to small molecules can still bind to and uptake by ICAM-1 on the surface of lymphocytes (i.e., Raji cells). To accomplish this goal, the I-domain protein was labeled with FITC at several lysine residues to produce the FITC-I-domain and CD spectroscopy showed that the FITC-I-domain has a secondary structure similar to that of the parent I-domain. The FITC-I-domain was taken up by Raji cells via receptor-mediated endocytosis and its uptake can be blocked by anti-I-domain mAb but not by its isotype control. Antibodies to ICAM-1 enhance the binding of I-domain to ICAM-1, suggesting it binds to ICAM-1 at different sites than the antibodies. The results in-dicate that fluorophore modification does not alter the binding and uptake properties of the I-domain protein. Thus, I-domain could be useful as a carrier of drug to target ICAM-1-expressing lymphocytes.en-US© Ivyspring International Publisher. This is an open-access article distributed under the terms of the Creative Commons License (http://creativecommons.org/ licenses/by-nc-nd/3.0/). Reproduction is permitted for personal, noncommercial use, provided that the article is in whole, unmodified, and properly cited.http://creativecommons.org/ licenses/by-nc-nd/3.0/Icam-1Fitc-i-domainBindingEndocytosisRaji cellsArticle10.7150/thno/v01p0277openAccess