Receptor-Mediated Labeling of CD4 T cells for Longitudinal Tracking of Distribution Following Systemic Injection in Mouse

Motivation: This study aims to address the challenge of in vivo tracking of CD4+ T-cells by MRI, focusing on biodistribution monitoring in adoptive cell therapies. Goal(s): To develop and optimize a receptor-mediated labeling method of CD4+ T-cells with CD4-microbeads that enables in vivo MRI tracking. Approach: CD4+ T-cells were labeled with CD4-microbeads; internalization and signal attenuation were analyzed via Iron staining, electron microscopy, and MRI. Microbead-labeled cells were injected intravenously, followed by longitudinal MRI tracking and histological analyses. Results: Internalized CD4-microbeads in T-cells resulted in significant MRI signal reduction, and confirmed the feasibility of tracking labeled T-cells in liver tissue up to 72-hours post-injection. Impact: The CD4-targeted microbead approach to track CD4+ T cells in vivo with MRI is safe, specific and sensitive. This technique will allow rapid assessment of the efficacy of adoptive cell therapies in conditions such as transplantation and diabetes.