查看文章

Antibody-based PET (immunoPET) with radiotracers that recognize specific cells of the immune system provides an opportunity to monitor immune cell trafficking at the organismal scale. We previously reported the visualization of human CD8⁺ T cells, including CD8⁺ tumor-infiltrating lymphocytes (TIL), in mice using a humanized CD8-targeted minibody. Given the important role of CD4⁺ T cells in adaptive immune responses of health and disease including infections, tumors, and autoimmunity, we explored immunoPET using an anti-human-CD4 minibody. We assessed the ability of [⁶⁴Cu]Cu-NOTA-IAB41 to bind to various CD4⁺ T-cell subsets in vitro. We also determined the effect of the CD4-targeted minibody on CD4⁺ T-cell abundance, proliferation, and activation state in vitro. We subsequently evaluated the ability of the radiotracer to visualize CD4⁺ T cells in T-cell rich organs and orthotopic brain tumors …