Stage-dependent immunity orchestrates AQP4 antibody-guided NMOSD pathology: a role for netting neutrophils with resident memory T cells in situ.

Abstract

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the CNS characterized by the production of disease-specific autoantibodies against aquaporin-4 (AQP4) water channels. Animal model studies suggest that anti-AQP4 antibodies cause a loss of AQP4-expressing astrocytes, primarily via complement-dependent cytotoxicity. Nonetheless, several aspects of the disease remain unclear, including: how anti-AQP4 antibodies cross the blood-brain barrier from the periphery to the CNS; how NMOSD expands into longitudinally extensive transverse myelitis or optic neuritis; how multiphasic courses occur; and how to prevent attacks without depleting circulating anti-AQP4 antibodies, especially when employing B-cell-depleting therapies. To address these knowledge gaps, we conducted a comprehensive 'stage-dependent' investigation of immune cell elements in situ in human NMOSD lesions, based on neuropathological techniques for autopsied/biopsied CNS materials. The present study provided three major findings. First, activated or netting neutrophils and melanoma cell adhesion molecule-positive (MCAM+) helper T (TH) 17/cytotoxic T (TC) 17 cells are prominent, and the numbers of these correlate with the size of NMOSD lesions in the initial or early-active stages. Second, forkhead box P3-positive (FOXP3+) regulatory T (Treg) cells are recruited to NMOSD lesions during the initial, early-active or late-active stages, suggesting rapid suppression of proinflammatory autoimmune events in the active stages of NMOSD. Third, compartmentalized resident memory immune cells, including CD103+ tissue-resident memory T (TRM) cells with long-lasting inflammatory potential, are detected under "standby" conditions in all stages. Furthermore, CD103+ TRM cells express high levels of granzyme B/perforin-1 in the initial or early-active stages of NMOSD in situ. We infer that stage-dependent compartmentalized immune traits orchestrate the pathology of anti-AQP4 antibody-guided NMOSD in situ. Our work further suggests that targeting activated/netting neutrophils, MCAM+ TH17/TC17 cells, and CD103+ TRM cells, as well as promoting the expansion of FOXP3+ Treg cells, may be effective in treating and preventing relapses of NMOSD.

• Authors: Akihiro Nakajima, Fumihiro Yanagimura, Etsuji Saji, Hiroshi Shimizu, Yasuko Toyoshima, Kaori Yanagawa, Musashi Arakawa, Mariko Hokari, Akiko Yokoseki, Takahiro Wakasugi, Kouichirou Okamoto, Hirohide Takebayashi, Chihiro Fujii, Kyoko Itoh, Yo-Ichi Takei, Shinji Ohara, Mitsunori Yamada, Hitoshi Takahashi, Masatoyo Nishizawa, Hironaka Igarashi, Akiyoshi Kakita, Osamu Onodera, Izumi Kawachi
• Journal: Acta neuropathologica (Acta Neuropathol) Vol. 147 Issue 1 Pg. 76 (Apr 24 2024) ISSN: 1432-0533 [Electronic] Germany
• PMID: 38658413 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Chemical References

• Aquaporin 4
• Autoantibodies
• AQP4 protein, human

Topics

• Neuromyelitis Optica (immunology, pathology)
• Aquaporin 4 (immunology)
• Humans
• Neutrophils (immunology, pathology)
• Female
• Autoantibodies (immunology)
• Male
• Middle Aged
• Immunologic Memory
• Adult
• Aged
• Th17 Cells (immunology, pathology)