title: A(H1N1) vaccination recruits T lymphocytes to the choroid plexus for the promotion of hippocampal neurogenesis and working memory in pregnant mice.
abstract: We previously demonstrated that A(H1N1) influenza vaccine (AIV) promoted hippocampal neurogenesis and working memory in pregnant mice. However, the underlying mechanism of flu vaccination in neurogenesis and memory has remained unclear. In this study, we found that T lymphocytes were recruited from the periphery to the choroid plexus (CP) of the lateral and third (3rd) ventricles in pregnant mice vaccinated with AIV (Pre+AIV). Intracerebroventricular delivery of anti-TCR antibodies markedly decreased neurogenesis and the working memory of the Pre+AIV mice. Similarly, intravenous delivery of anti-CD4 antibodies to the periphery also down-regulated neurogenesis. Furthermore, AIV vaccination caused microglia to skew toward an M2-like phenotype (increased Arginase-1 and Ym1 mRNA levels), and elevated levels of brain-derived growth factor (BDNF) and insulin-like growth factor-1 (IGF-1) were found in the hippocampus, whereas these effects were offset by anti-TCR antibody treatment. Additionally, in the CP, the expression level of adhesion molecules and chemokines, which assist leukocytes in permeating into the brain, were also elevated after AIV vaccination of pregnant mice. Collectively, the results suggested that the infiltrative T lymphocytes in the CP contribute to the increase in hippocampal neurogenesis and working memory caused by flu vaccination, involving activation of the brain's CP, M2 microglial polarization and neurotrophic factor expression.
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, PR China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Qi
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, PR China.
authors.forename: Junhua
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, PR China.
authors.forename: Yucen
authors.initials: Y
authors.lastname: Xia
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, PR China.
authors.forename: Qunfang
authors.initials: Q
authors.lastname: Yuan
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, PR China.
authors.forename: Kaihua
authors.initials: K
authors.lastname: Guo
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, PR China.
authors.forename: Juntao
authors.initials: J
authors.lastname: Zou
authors.affiliation: Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, PR China; Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, PR China. Electronic address: yao.zb@163.com.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Yao
mesh_terms: D000818:Animals; D018925:Chemokines / Q000276:immunology; D002831:Choroid Plexus / Q000276:immunology*; D005260:Female; D006624:Hippocampus / Q000276:immunology*; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology / Q000494:pharmacology*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000276:immunology; D055495:Neurogenesis / Q000276:immunology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
chemical_list: D018925:Chemokines; D007252:Influenza Vaccines
keywords: Chemokine; M2 polarization; Microglia; T cell; TCR; Trafficking