Normal T-cell response and in vivo magnetic resonance imaging of T cells loaded with HIV transactivator-peptide-derived superparamagnetic nanoparticles.
The present study analyzed the feasibility of using magnetic resonance imaging (MRI) to monitor T-cell homing in vivo after loading T cells with superparamagnetic iron oxide (CLIO) nanoparticles derivatized with a peptide sequence from the transactivator protein (Tat) of HIV-1. T cells were isolated from C57BL/6 (B6) mice and loaded with 0, 400, 800, 1600, or 8000 ng/ml of FITC conjugated CLIO-Tat (FITC-CLIO-Tat). There was a dose-dependent uptake of FITC-CLIO-Tat by T cells. Stimulation of FITC-CLIO-Tat loaded T cells with anti-CD3 (0.1 microg/ml) plus IL-2 (5 ng/ml) elicited normal activation and activation-induced cell death (AICD) responses, and normal upregulation of CD69, ICAM-1 (CD54), L-selectin (CD62L), and Fas. The FITC-CLIO-Tat loaded T cells (3 x 10(7)) were transferred intravenously (i.v.) into B6 mice and the in vivo MRI of mice was acquired using a spin-echo pulse sequence at 4.7 T with a Bruker Biospec system. Homing of T cells into the spleen was observed by a decrease in MRI signal intensity within 1 h after the transfer, which remained decreased for 2-24 h after transfer. These homing data were confirmed by FACS analysis and biodistribution analysis using 125I-CLIO-Tat. Thus, T cells can be efficiently loaded with FITC-CLIO-Tat without interfering with their normal activation and AICD, or homing to the spleen, and the biodistribution of FITC-CLIO-Tat loaded T cells can be monitored in vivo over time by MRI.
Dodd
C H
CH
Division of Clinical Immunology and Rheumatology, Department of Medicine, The University of Alabama at Birmingham, 35294, USA.
Hsu
H C
HC
Chu
W J
WJ
Yang
P
P
Zhang
H G
HG
Mountz
J D
JD
Zinn
K
K
Forder
J
J
Josephson
L
L
Weissleder
R
R
Mountz
J M
JM
Mountz
J D
JD
D000818:Animals; D017209:Apoptosis; D002465:Cell Movement; D002478:Cells, Cultured; D005260:Female; D005290:Ferric Compounds / Q000737:chemistry*; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D015696:Gene Products, tat / Q000737:chemistry*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D019041:L-Selectin / Q000378:metabolism; D008213:Lymphocyte Activation; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008810:Mice, Inbred C57BL; D010455:Peptides / Q000737:chemistry; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000737:chemistry / Q000166:cytology / Q000276:immunology*; D018800:Thy-1 Antigens / Q000032:analysis; D019014:fas Receptor / Q000378:metabolism
D005290:Ferric Compounds; D015696:Gene Products, tat; D010455:Peptides; D018800:Thy-1 Antigens; D019014:fas Receptor; D018799:Intercellular Adhesion Molecule-1; D019041:L-Selectin; C000499:ferric oxide; D016650:Fluorescein-5-isothiocyanate