1. Immuno-PET of Murine T Cell Reconstitution Postadoptive Stem Cell Transplantation Using Anti-CD4 and Anti-CD8 Cys-Diabodies
- Author
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Tavaré, Richard, McCracken, Melissa N, Zettlitz, Kirstin A, Salazar, Felix B, Olafsen, Tove, Witte, Owen N, and Wu, Anna M
- Subjects
Biomedical and Clinical Sciences ,Immunology ,Transplantation ,Biomedical Imaging ,Regenerative Medicine ,5.2 Cellular and gene therapies ,Development of treatments and therapeutic interventions ,Inflammatory and immune system ,Animals ,CD4 Antigens ,CD8 Antigens ,CD8-Positive T-Lymphocytes ,Cell Proliferation ,Chromatography ,Affinity ,Hematopoietic Stem Cell Transplantation ,Immunotherapy ,Maleimides ,Mice ,Mice ,Inbred C57BL ,Positron-Emission Tomography ,Single-Chain Antibodies ,T-Lymphocytes ,Time Factors ,Tissue Distribution ,Zirconium ,immuno-PET ,CD4(+) and CD8(+) T cells ,antibody fragments ,hematopoietic stem cell transplantation ,Zr-89 ,89Zr ,CD4+ and CD8+ T cells ,Clinical Sciences ,Nuclear Medicine & Medical Imaging ,Clinical sciences - Abstract
UnlabelledThe proliferation and trafficking of T lymphocytes in immune responses are crucial events in determining inflammatory responses. To study whole-body T lymphocyte dynamics noninvasively in vivo, we generated anti-CD4 and -CD8 cys-diabodies (cDbs) derived from the parental antibody hybridomas GK1.5 and 2.43, respectively, for (89)Zr-immuno-PET detection of helper and cytotoxic T cell populations.MethodsAnti-CD4 and -CD8 cDbs were engineered, produced via mammalian expression, purified using immobilized metal affinity chromatography, and characterized for T cell binding. The cDbs were site-specifically conjugated to maleimide-desferrioxamine for (89)Zr radiolabeling and subsequent small-animal PET/CT acquisition and ex vivo biodistribution in both wild-type mice and a model of hematopoietic stem cell (HSC) transplantation.ResultsImmuno-PET and biodistribution studies demonstrate targeting and visualization of CD4 and CD8 T cell populations in vivo in the spleen and lymph nodes of wild-type mice, with specificity confirmed through in vivo blocking and depletion studies. Subsequently, a murine model of HSC transplantation demonstrated successful in vivo detection of T cell repopulation at 2, 4, and 8 wk after HSC transplantation using the (89)Zr-radiolabeled anti-CD4 and -CD8 cDbs.ConclusionThese newly developed anti-CD4 and -CD8 immuno-PET reagents represent a powerful resource to monitor T cell expansion, localization, and novel engraftment protocols. Future potential applications of T cell-targeted immuno-PET include monitoring immune cell subsets in response to immunotherapy, autoimmunity, and lymphoproliferative disorders, contributing overall to preclinical immune cell monitoring.
- Published
- 2015