Host antigen-presenting cells and immune system components (Host APCs)

Host antigen-presenting cells (APCs), including dendritic cells, macrophages, and B cells, are specialized immune cells responsible for capturing, processing, and presenting antigens to T lymphocytes via major histocompatibility complex (MHC) molecules (StatPearls: NBK546619). This process, supported by costimulatory signals such as CD80 and CD86, is fundamental to the initiation of adaptive immune responses. In clinical contexts such as allogeneic hematopoietic stem cell transplantation, host APCs are critical mediators of Graft-versus-Host Disease (GvHD), as they present host-derived alloantigens to donor T cells (Nature Reviews Immunology, 2007). While various immunosuppressive drugs target the molecular interactions between APCs and T cells, the term itself refers to a heterogeneous cellular population and systemic network rather than a single molecular entity. Consequently, it is categorized as a broad biological system rather than a discrete therapeutic target like a specific receptor or enzyme.

Other names

Professional antigen-presenting cellsHost APCsImmune system components

Pharmacological modulation of this system typically involves the inhibition of T-cell costimulation (e.g., blocking the CD80/86-CD28 interaction) or the suppression of intracellular signaling pathways required for T-cell activation following antigen presentation (StatPearls: NBK546619).