Helping The Body To Cure Itself: Immune Modulation By Therapeutic Vaccination For Spinal Cord Injury.

Spinal cord injury often has devastating consequences, due to the poor regenerative capacity of the central nervous system (CNS), and because the injury triggers self-destructive processes that lead to degeneration of directly injured fibers, and fibers that survived the lesion but subsequently undergo "secondary degeneration." The highly complex, multifaceted dialogue between the immune system and the damaged spinal cord is complicated further by factors related to species, strain, and gender. It is suggested that following an injury to the CNS, the resident and systemic immune cells are recruited and activated, to reduce the self-destruction and facilitate the repair of the damaged nerve. Both of these functions can benefit from a well-controlled immune response that critically involves the innate and adaptive arms of the immune system, represented by macrophages/ microglia and autoimmune T cells, respectively. A poorly controlled immune response can be non-efficient or even destructive, leading in extreme cases even to autoimmune disease. The beneficial autoimmune response can be boosted by posttraumatic T cell-based vaccination with peptides that activate weak self-reactive T cells, thereby ensuring timely and adequate immune activation without the risk of autoimmune disease. It is proposed that the notion of "bad" or "good" inflammation be replaced by a concept that views inflammation in the CNS as a repair mechanism and thus as beneficial if well regulated, and supports therapy for spinal cord and other CNS injuries by immunomodulation.