Immune system – indirect modulation via secreted cytokines and exosomes

Immune system – indirect modulation via secreted cytokines and exosomes refers to a biological process where cells communicate with and regulate the immune system through paracrine signaling rather than direct cell-to-cell contact. This mechanism involves the secretion of cytokines—small signaling proteins like interleukins and interferons—and exosomes, which are nanometer-sized extracellular vesicles containing proteins, lipids, and RNA (Wiklander et al., 2019, Nature Communications). These factors can travel through the extracellular space or systemic circulation to bind to receptors on distant immune cells, such as T cells and macrophages, thereby altering their activation state or function (Galipeau & Sensébé, 2018, Nature). In therapeutic contexts, this mechanism is frequently associated with mesenchymal stem cells (MSCs) and exosome-based therapies aimed at treating inflammatory and autoimmune disorders. Conversely, in oncology, tumors often exploit this pathway to secrete immunosuppressive factors that help them evade immune detection (Whiteside, 2016, Essays in Biochemistry). Because this term encompasses a vast array of distinct signaling molecules and pathways, it is considered a therapeutic mechanism or a mode of action rather than a single, discrete molecular target.

Other names

Paracrine immunomodulationExosome-mediated immune signalingCytokine-mediated immune regulationIndirect immune modulation

Modulation of immune cell activity through the secretion of soluble cytokines and extracellular vesicles (exosomes) that carry bioactive cargo to recipient cells.