Host antigen-presenting cells (Host APCs)

Host antigen-presenting cells (APCs) are a heterogeneous group of immune cells, primarily consisting of dendritic cells, macrophages, and B cells, that play a fundamental role in bridging innate and adaptive immunity (StatPearls, 2023). These cells are responsible for internalizing pathogens or foreign proteins, processing them into peptides, and displaying them on their surface via major histocompatibility complex (MHC) molecules to T-cell receptors (Janeway's Immunobiology, 2017). This interaction, supplemented by co-stimulatory signals such as CD80 and CD86, is essential for the activation and clonal expansion of T cells (NCBI, 2022). In clinical medicine, host APCs are central to the pathogenesis of graft-versus-host disease (GvHD), where they present host antigens to donor T cells, triggering an immune attack (Blood Journal, 2014). Consequently, many immunosuppressive therapies aim to modulate the activity of these cells or the signaling pathways they initiate to treat transplant rejection and various autoimmune conditions (Nature Reviews Immunology, 2021). Because this entry refers to a broad cellular population and systemic component rather than a specific molecular target or receptor, it is classified as an incorrect target designation for molecular pharmacology purposes.

Other names

Professional antigen-presenting cellsHost immune systemAPCsAntigen-presenting cells

Modulation of T-cell activation by interfering with the interaction between antigen-presenting cells and T-lymphocytes, typically by blocking co-stimulatory signals (e.g., CD80/86) or inhibiting the intracellular signaling required for cytokine release and cellular proliferation.