title: PD1 negative and PD1 positive CD4+ T regulatory cells in mild cognitive impairment and Alzheimer's disease.
abstract: Regulatory T lymphocytes (Treg) play a fundamental importance in modulating the relative balance between inflammation and immune tolerance, and alterations of these cells are observed in inflammatory diseases. To better characterize the neuroinflammatory processes suggested to be associated with Alzheimer's disease (AD) and to clarify the possible role of Treg cells in this process, we extensively analyzed these cells (CD4 + CD25highFoxp3+) in patients with either severe AD (n=25) or mild cognitive impairment (MCI) (n=25), comparing the results with those of two groups of healthy controls (HC) (n=55). Because the intra- or extracellular expression of programmed death receptor 1 (PD1) identifies functionally diverse subsets of Treg we also analyzed such subpopulations. Results showed that, whereas both Treg and PD1pos Treg are increased in MCI and AD patients compared to HC, PD1neg Treg, the subpopulation of Treg cells endowed with the strongest suppressive ability, are significantly augmented in MCI patients alone. In these patients amyloid-β-stimulated-T cells proliferation was reduced and Treg-mediated suppression was more efficient compared to both AD and HC. The observation that PD1neg Treg, cells are increased in MCI patients reinforces the inflammatory origin of AD and supports a possible beneficial role of these cells in MCI that is lost in patients with full-blown AD.
authors.affiliation: Laboratory of Molecular Medicine and Biotechnology, Don C. Gnocchi ONLUS Foundation IRCCS, Milano, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Saresella
authors.forename: Elena
authors.initials: E
authors.lastname: Calabrese
authors.forename: Ivana
authors.initials: I
authors.lastname: Marventano
authors.forename: Federica
authors.initials: F
authors.lastname: Piancone
authors.forename: Andrea
authors.initials: A
authors.lastname: Gatti
authors.forename: Maria Gaetana
authors.initials: MG
authors.lastname: Calvo
authors.forename: Raffaello
authors.initials: R
authors.lastname: Nemni
authors.forename: Mario
authors.initials: M
authors.lastname: Clerici
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000276:immunology* / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D049109:Cell Proliferation; D003072:Cognition Disorders / Q000276:immunology* / Q000378:metabolism; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D008875:Middle Aged; D009483:Neuropsychological Tests; D061026:Programmed Cell Death 1 Receptor; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D051017:Apoptosis Regulatory Proteins; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C105992:PDCD1 protein, human; D061026:Programmed Cell Death 1 Receptor