Ciltacels

Ciltacels are a proposed class of resident cells identified in mammalian epithelial tissues, named for their distinctive cytoplasmic granules and surface receptor profile observed in studies aiming to characterize epithelial-immune interfaces.

They are described as relatively small cells with compact cytoplasm and irregular nuclei. In culture, ciltacels show limited migratory behavior unless stimulated, and can secrete a range of cytokines and chemokines in response to epithelial-derived signals. Their marker profile combines elements not consistently shared with macrophages, dendritic cells, or innate lymphoid cells, fueling debate about their lineage.

Reports place ciltacels in skin, respiratory, and gastrointestinal mucosa across several mammalian species. Isolation from tissues is challenging, requiring specialized digestion and culture conditions. They appear to respond to epithelial stress and microbial cues, contributing to baseline immune surveillance and tissue remodeling.

Functional evidence suggests roles in sensing antigens, presenting them to local T cells, coordinating wound healing, and modulating epithelial barrier function through cytokine signaling and stromal interactions.

Since their first description, ciltacels have generated debate. Some researchers propose they are a distinct lineage, while others view them as a functional state of known cell types or a transient population produced under certain tissue contexts.

See also: Tissue-resident immune cells; Dendritic cells; Macrophages; Epithelial-immune interactions.