The activation of the immune system is critical for cancer
immunotherapy
and treatments of inflammatory diseases. Non-invasive visualization
of immunoactivation is designed to monitor the dynamic nature of the
immune response and facilitate the assessment of therapeutic outcomes,
which, however, remains challenging. Conventional imaging modalities,
such as positron emission tomography, computed tomography, etc., were utilized for imaging immune-related biomarkers.
To explore the dynamic immune monitoring, probes with signals correlated
to biomarkers of immune activation or prognosis are urgently needed.
These emerging molecular probes, which turn on the signal only in
the presence of the intended biomarker, can improve the detection
specificity. These probes with “turn on” signals enable
non-invasive, dynamic, and real-time imaging with high sensitivity
and efficiency, showing significance for multifunctionality/multimodality
imaging. As a result, more and more innovative engineered nanoprobes
combined with diverse imaging modalities were developed to assess
the activation of the immune system. In this work, we comprehensively
review the recent and emerging advances in engineered nanoprobes for
monitoring immune activation in cancer or other immune-mediated inflammatory
diseases and discuss the potential in predicting the efficacy following
treatments. Research on real-time in vivo immunoimaging
is still under exploration, and this review can provide guidance and
facilitate the development and application of next-generation imaging
technologies.