Monoclonal Antibodies Conjugated with Superparamagnetic Iron Oxide Particles Allow Magnetic Resonance Imaging Detection of Lymphocytes in the Mouse Brain.

Luchetti, Alessandro; Milani, Davide; Ruffini, Francesca; Galli, Rossella; Falini, Andrea; Quattrini, Angelo; Scotti, Giuseppe; Comi, Giancarlo; Martino, Gianvito; Furlan, Roberto; Politi, Letterio S.

We investigated the potential of antibody-vectorialized superparamagnetic iron oxide (SPIO) particles as cellular specific magnetic resonance contrast agents to image lymphocyte populations within the central nervous system (CNS), with the final goal of obtaining a reliable tool for noninvasively detecting and tracking specific cellular populations in vivo. We used superparamagnetic particles bound to a monoclonal antibody. The particle is the contrast agent, by means of its T2 relaxation properties; the antibody is the targeting vector, responsible for homing the particle to target a surface antigen. To investigate the efficiency of particle vectorialization by these antibodies, we compared two types of antibody-vectorialized CD3-specific particles in vivo. We successfully employed vectorialized SPIO particles to image B220 cells in a murine model of B-cell lymphoma. Likewise, we were able to identify CD3 infiltrates in amurinemodel ofmultiple sclerosis. The specificity of the technique was confirmed by immunohistochemistry and electron microscopy of corresponding sections. Our findings suggest that indirect binding of the antibody to a streptavidinated particle allows for enhanced particle vectorialization compared to covalent binding of the antibody to the particle.

MONOCLONAL antibodies; IRON oxides; MAGNETIC resonance imaging; LYMPHOCYTES; IMMUNOHISTOCHEMISTRY; LABORATORY mice; CENTRAL nervous system

Molecular Imaging, 2012, Vol 11, Issue 2, p114

1535-3508

Academic Journal

10.2310/7290.2011.00032