尽管已广泛研究了树突状细胞（DC）基于癌症免疫疗法，但DC在注射后的体内命运仍然大部分是未知的。由于缺乏可定量成像的手段，这一点令人担忧，因为DC迁移至淋巴器官的量与治疗效果相关。磁性颗粒成像（MPI）已成为定量监测超顺磁性氧化铁（SPIO）标记的DC在体内迁移的合适手段。在这里，我们描述了一个以足弓淋巴结（pLN）为焦点的MPI扫描，以准确和一致地量化DC的体内迁移。通过对腓骨前示导腺病毒（Ad）转导的SPIO+（Ad SPIO+）和SPIO+ C57BL/6骨髓源DC生成，进行存活率和表型评估，然后进行荧光标记并注射到小鼠后足跖（n = 6）。两天后，使用全动物、重点检测pLN和体外pLN的MPI扫描量化DC的体内迁移。Ad SPIO+和SPIO+ DC的存活率、表型和体内pLN迁移没有显著差异。二天后，重点检测的MPI扫描在所有情况下都量化了DC的迁移，而全动物MPI仅在75％的情况下定量了pLN的迁移。体外MPI和荧光显微镜证实pLN的MPI信号是由最初注射的Ad SPIO+和SPIO+ DC引起的。我们通过使用以pLN为焦点的MPI扫描克服了MPI的一种已报道的局限性，可以在100％的情况下量化pLN迁移的Ad SPIO+和SPIO+ DC，并检测到数量为1000个DC（4.4ng Fe）的体内存在。对于评估基于DC的癌症免疫疗效，MPI是一种合适的临床前成像模式。使用非侵入性可定量的磁性颗粒成像追踪DC的体内命运可能作为治疗效果的替代标志物。•改性腺病毒转导和铁氧化物标记的树突状细胞具有体内迁移能力。•磁性颗粒成像是一种适合定量监测体内树突状细胞迁移的模式。•磁性颗粒成像的重点检测视野克服了动态范围的局限性。© 2023年。作者。

Despite widespread study of dendritic cell (DC)-based cancer immunotherapies, the in vivo postinjection fate of DC remains largely unknown. Due in part to a lack of quantifiable imaging modalities, this is troubling as the amount of DC migration to secondary lymphoid organs correlates with therapeutic efficacy. Magnetic particle imaging (MPI) has emerged as a suitable modality to quantify in vivo migration of superparamagnetic iron oxide (SPIO)-labeled DC. Herein, we describe a popliteal lymph node (pLN)-focused MPI scan to quantify DC in vivo migration accurately and consistently.Adenovirus (Ad)-transduced SPIO+ (Ad SPIO+) and SPIO+ C57BL/6 bone marrow-derived DC were generated and assessed for viability and phenotype, then fluorescently labeled and injected into mouse hind footpads (n = 6). Two days later, in vivo DC migration was quantified using whole animal, pLN-focused, and ex vivo pLN MPI scans.No significant differences in viability, phenotype and in vivo pLN migration were noted for Ad SPIO+ and SPIO+ DC. Day 2 pLN-focused MPI quantified DC migration in all instances while whole animal MPI only quantified pLN migration in 75% of cases. Ex vivo MPI and fluorescence microscopy confirmed that pLN MPI signal was due to originally injected Ad SPIO+ and SPIO+ DC.We overcame a reported limitation of MPI by using a pLN-focused MPI scan to quantify pLN-migrated Ad SPIO+ and SPIO+ DC in 100% of cases and detected as few as 1000 DC (4.4 ng Fe) in vivo. MPI is a suitable preclinical imaging modality to assess DC-based cancer immunotherapeutic efficacy.Tracking the in vivo fate of DC using noninvasive quantifiable magnetic particle imaging can potentially serve as a surrogate marker of therapeutic effectiveness.• Adenoviral-transduced and iron oxide-labeled dendritic cells are in vivo migration competent. • Magnetic particle imaging is a suitable modality to quantify in vivo dendritic cell migration. • Magnetic particle imaging focused field of view overcomes dynamic range limitation.© 2023. The Author(s).