In Vivo Tracking of Th1 Cells by PET Reveals Quantitative and Temporal Distribution and Specific Homing in Lymphatic Tissue

Journal of Nuclear Medicine

Andreas Schmid¹  Stefan Wiehr¹  Martin Röcken¹  Birgit Fehrenbacher¹  Gerald Reischl¹  Julie L. Sutcliffe¹  Rainer Kehlbach¹  Manfred Kneilling¹  Martin Schaller¹  Martin Eichner¹  Funda Cay¹  Daniel Bukala¹  Walter Ehrlichmann¹  Simon R. Cherry¹  Rüdiger Bantleon¹  Christoph M. Griessinger¹  Heidi Braumüller¹  Oliver Eibl¹  Bernd J. Pichler¹ 

关键词: ⁶⁴Cu-PTSM;    murine Th1 cells;    small animal PET;    in vivo cell tracking;   

DOI  :  10.2967/jnumed.113.126318

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Although T cells can be labeled for noninvasive in vivo imaging, little is known about the impact of such labeling on T-cell function, and most imaging methods do not provide holistic information about trafficking kinetics, homing sites, or quantification. Methods: We developed protocols that minimize the inhibitory effects of 64Cu-pyruvaldehyde-bis(N4-methylthiosemicarbazone) (64Cu-PTSM) labeling on T-cell function and permit the homing patterns of T cells to be followed by PET. Thus, we labeled ovalbumin (OVA) T-cell receptor transgenic interferon (IFN)-γ–producing CD4+ T (Th1) cells with 0.7–2.2 MBq of 64Cu-PTSM and analyzed cell viability, IFN-γ production, proliferation, apoptosis, and DNA double-strand breaks and identified intracellular 64Cu accumulation sites by energy dispersive x-ray analysis. To elucidate the fate of Th1 cell homing by PET, 107 64Cu-OVA-Th1 cells were injected intraperitoneally or intravenously into healthy mice. To test the functional capacities of 64Cu-OVA-Th1 cells during experimental OVA-induced airway hyperreactivity, we injected 107 64Cu-OVA-Th1 cells intraperitoneally into OVA-immunized or nonimmunized healthy mice, which were challenged with OVA peptide or phosphate-buffered saline or remained untreated. In vivo PET investigations were followed by biodistribution, autoradiography, and fluorescence-activated cell sorting analysis. Results: PET revealed unexpected homing patterns depending on the mode of T-cell administration. Within 20 min after intraperitoneal administration, 64Cu-OVA-Th1 cells homed to the perithymic lymph nodes (LNs) of naive mice. Interestingly, intravenously administered 64Cu-OVA-Th1 cells homed predominantly into the lung and spleen but not into the perithymic LNs. The accumulation of 64Cu-OVA-Th1 cells in the pulmonary LNs (6.8 ± 1.1 percentage injected dose per cubic centimeter [%ID/cm3]) 24 h after injection was highest in the OVA-immunized and OVA-challenged OVA airway hyperreactivity–diseased littermates 24 h after intraperitoneal administration and lowest in the untreated littermates (3.7 ± 0.4 %ID/cm3). As expected, 64Cu-OVA-Th1 cells also accumulated significantly in the pulmonary LNs of nonimmunized OVA-challenged animals (6.1 ± 0.5 %ID/cm3) when compared with phosphate-buffered saline–challenged animals (4.6 ± 0.5 %ID/cm3). Conclusion: Our protocol permits the detection of Th1 cells in single LNs and enables temporal in vivo monitoring of T-cell homing over 48 h. This work enables future applications for 64Cu-PTSM–labeled T cells in clinical trials and novel therapy concepts focusing on T-cell–based immunotherapies of autoimmune diseases or cancer.

【 授权许可】

Unknown