EVs, which are lipid-membrane structured vesicles measuring in nanoscale, are produced by nearly all types of cells [1], [2]. Initially, it was commonly assumed that EVs mainly participate in eliminating cellular waste, recent investigations have brought to light their role as transporters of biologically active compounds, including DNA/RNA, proteins, and lipids, from the originating cell to target cells [3], [4]. EVs can be detected from various bodily fluids, and enter the systemic circulation. They can then affect receptor cell function through mechanisms like direct membrane fusion, endocytosis, and ligand-receptor interactions [5], [6]. Depending on their cellular origins, EVs have different biological activities and play various roles, including inducing reprogramming of target cells and delivering functional signals and molecules to recipient cells [7]. Consequently, the role of EVs in physiology and pathology, including cancer therapy, has gained significant attention. Tumor growth, metastasis, and drug resistance are regulated by immune cells EVs, which exhibit both promotive and inhibitory effects [8], [9], [10]. The tumor microenvironment (TME), consisting of immune cells, fibroblasts, the extracellular matrix, peripheral blood vessels, and signaling molecules, plays a pivotal role in governing tumor progression and metastasis. The modification of TME occurs through the transmission of signals by immune cell-derived EVs, which demonstrate similar characteristics as their parent cells. The mounting evidence suggests that these EVs actively participate in facilitating the immune responses in tumor regulation [11], [12], providing a new platform for the advancement of tumor immunotherapy.

Cancer immunotherapy has become a hot research topic by mobilizing systemic immunity against tumors [13], [14]. The exploration of the taxonomic identification and biological capabilities of EVs has significantly contributed to their potential as versatile therapeutic strategies with translational implications in clinical settings [2], [15]. This review provides a comprehensive overview of the formation and categorization of EVs, emphasizing the examination and utilization of EVs originating from both inherent immune cells and adaptable immune cells. The focus is on the current situation and future potential of EVs derived from immune cells concerning tumor vaccines and targeted nano delivery systems (Fig. 1).