Host antigen-presenting cells and lymphocytes

Host antigen-presenting cells (APCs) and lymphocytes constitute the primary cellular components of the recipient's immune system involved in recognizing and responding to foreign or self-antigens. APCs, including dendritic cells, macrophages, and B cells, capture and process antigens to present them via Major Histocompatibility Complex (MHC) molecules to T lymphocytes, thereby initiating the adaptive immune response (NIH, 2023). In clinical settings such as hematopoietic stem cell transplantation, host APCs are pivotal in the pathogenesis of graft-versus-host disease (GvHD) by activating donor-derived T cells (Shlomchik et al., Science, 1999). Conversely, host lymphocytes can mediate the rejection of transplanted organs by recognizing donor alloantigens (StatPearls, 2023). Because this term describes a broad cellular collective rather than a single protein or receptor, it is not classified as a specific molecular drug target, though its constituent pathways are heavily targeted by immunosuppressive pharmacology. Therapeutic strategies often focus on inhibiting lymphocyte proliferation or blocking the costimulatory signals required for APC-T cell interaction.

Other names

Host immune cellsRecipient antigen-presenting cells and lymphocytesHost-derived immune cells

Immunosuppressive agents modulate these cells by inhibiting intracellular signaling (e.g., calcineurin or mTOR pathways), blocking costimulatory signals, or depleting specific cell populations to prevent immune-mediated damage.