Antigen-presenting cells (oral and gut-associated) (APCs)

Oral and gut-associated antigen-presenting cells (APCs) are a specialized group of immune cells, including dendritic cells, macrophages, and B cells, that reside in the mucosal tissues of the mouth and the gastrointestinal tract (PMID: 30333453). These cells play a pivotal role in maintaining immunological homeostasis by sampling antigens from the environment and determining whether to initiate a protective immune response or induce systemic tolerance (PMID: 28920588). In the gut-associated lymphoid tissue (GALT), APCs like CD103+ dendritic cells are essential for the generation of regulatory T cells (Tregs) that prevent hypersensitivity to dietary proteins (PMID: 31103335). Dysregulation of these cells is implicated in the pathogenesis of food allergies, celiac disease, and inflammatory bowel diseases, where the balance between tolerance and inflammation is lost (PMID: 25907459). Therapeutic strategies such as oral immunotherapy (OIT) and mucosal vaccines specifically target these APCs to modulate the immune system, either to desensitize patients to allergens like peanuts or to provide immunity against enteric pathogens (PMID: 32037114). While not a single molecular target, these cells are the functional units through which oral biologics and allergens exert their systemic effects. Monitoring the activity of these cells often involves assessing the expansion of FoxP3+ regulatory T cells or changes in cytokine profiles such as IL-10 and TGF-beta. Safety concerns associated with modulating these cells include the risk of systemic allergic reactions or the development of localized eosinophilic inflammation in the esophagus.

Other names

Oral antigen-presenting cellsGut-associated antigen-presenting cellsMucosal antigen-presenting cellsGALT-associated APCsDendritic cellsMacrophagesLangerhans cells

Induction of immune tolerance or protective immunity via antigen presentation to T-lymphocytes in mucosal tissues (PMID: 32037114).