CyCLoPs: A approach for detecting immune responses with in vivo labeling of cytokine activity

However, it is largely unknown which cell types respond to cytokines. Herein, we developed a reporter system, Cytokine-Cellular-Locating-Platforms (CyCLoPs), that transforms the cytokine and its receptor engagement into a genetically tractable signal.

In vitro, CyCLoPs exhibited remarkable specificity, a high signal-to-background ratio, and broad applicability to probe interactions between cytokines and their receptors. In vivo, the IL-17A-CyCLoPs reporter mouse enabled the detection of IL-17A-responsive cells in the ilea, primarily located at the villi rather than the crypt, following colonization by a commensal bacterium. In addition, the IFN-γ-CyCLoPs mouse facilitated the identification of IFN-γ-exposed CD8+ T cells in tumors with reduced effector function.