title: The gateway theory: bridging neural and immune interactions in the CNS.
abstract: The central nervous system (CNS) is considered an immune-privileged tissue protected by a specific vessel structure, the blood-brain barrier (BBB). Upon infection or traumatic injury in the CNS, the BBB is breached, and various immune cells are recruited to the affected area. In the case of autoimmune diseases in the CNS like multiple sclerosis (MS), autoreactive T cells against some CNS-specific antigens can theoretically attack neurons throughout the CNS. The affected CNS regions in MS patients can be detected as multiple focal plaques in the cerebrum, thoracic cord, and other regions. Vision problems are often associated with the initial phase of MS, suggesting a disturbance in the optic nerves. These observations raise the possibility that there exist specific signals that direct autoreactive T cells past the BBB and into particular sites of the CNS. Using a mouse model of MS, experimental autoimmune encephalomyelitis (EAE), we recently defined the mechanism of the pathogenesis in which regional neural stimulations modulate the status of the blood vessel endothelium to allow the invasion of autoreactive T cells into specific sites of the CNS via the fifth lumbar cord. This gate for autoreactive T cells can be artificially manipulated by removing gravity forces on the hind legs or by electric pulses to the soleus muscles, quadriceps, and triceps of mice, resulting in an accumulation of autoreactive T cells in the intended regions via the activation of regional neurons. Gating blood vessels by regional neural stimulations, a phenomenon we call the gateway theory, has potential therapeutic value not only in preventing autoimmunity, but also in augmenting the effects of cancer immunotherapies.
authors.affiliation: JST-CREST, WPI Immunology Frontier Research Center, Graduate School of Frontier Biosciences, Graduate School of Medicine, Osaka University Suita, Osaka, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kamimura
authors.forename: Moe
authors.initials: M
authors.lastname: Yamada
authors.forename: Masaya
authors.initials: M
authors.lastname: Harada
authors.forename: Lavannya
authors.initials: L
authors.lastname: Sabharwal
authors.forename: Jie
authors.initials: J
authors.lastname: Meng
authors.forename: Hidenori
authors.initials: H
authors.lastname: Bando
authors.forename: Hideki
authors.initials: H
authors.lastname: Ogura
authors.forename: Toru
authors.initials: T
authors.lastname: Atsumi
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Arima
authors.forename: Masaaki
authors.initials: M
authors.lastname: Murakami
keywords: autoimmune diseases; blood-brain barrier; cytokines; gateway theory; inflammation; inflammatory diseases; multiple sclerosis; neural activation