Chapter 23 Cross-talk between nervous and immune systems in response to injury

Potential for cross-talk between the nervous system and the immune system exists at many levels, through anatomical proximity and also by more distant humoral interactions. The growing lay popularity of psychoneuroimmunology implies that there may also be a sociological interaction between the nervous system and immune system. Cells intrinsic to the immune system and the nervous system are characteristically highly adaptable to environmental stimuli. They can rapidly upregulate and downregulate ion channels and receptors for cytokines, growth factors, hormones and neurotransmitters. Structural and functional analogies between the two systems are illustrated by the complex molecular interactions through which a foreign antigen activates T lymphocytes. After initially processing the antigen, a professional antigen-presenting cell displays peptide fragments of the antigenic protein on its surface major histocompatibility complex molecules (MHC) for recognition by a specific antigen receptor complex on the surface of a T lymphocyte. The ensuing transient formation of intimate cellcell contacts, reminiscent of synapses, between antigen-presenting cell and responding T cell involves complementary surface molecules of both cells.