Multiple Sclerosis (MS) is a chronic, inflammatory, neurodegenerative and demyelinating disease that affect the central nervous system (CNS). During MS immune cells from the periphery become able to enter in the CNS through blood brain barrier (BBB) breakdowns; Once entered in the CNS, the immune cells establish, with the help of tissue resident cells, an inflamed environment that leads to the destruction of myelin and later of the neurons. The key role of the immune system as initiator and mediator of the inflammation observed in CNS during MS has been fully described, especially for the adaptive immune system (i.e. CD4+T cells, B cells and macrophages). This role is especially prominent during the first stages of the disease, where the inflammation in the CNS is still not compartmentalized but there is an interaction between periphery and the CNS. In the last decades, there has been also evidence of the involvement of the innate immune system in the mechanisms underlying MS pathology. Here, in this exploratory study we investigated the changes in the innate lymphoid cells (ILCs) and in the NK cells from peripheral blood of early MS patients, diagnosed as clinically isolated syndrome (CIS), both in active and stable phase of the disease from the same patient. Our data from flow cytometry characterization and gene expression analysis showed difference in frequency between active and stable phase of the disease and furthermore compared to the literature. We showed that ILC1s seem to increase in active phase and this is further confirmed by the decrease of aryl hydrocarbon receptor (AHR), expressed by ILC3s, that is linked to a phenotypical switch from ILC3 to ILC1; thus we hypothesized that ILC1s in active phase may increase due to an higher migration from the tissue of origin and additionally because of a phenotypical switch of ILC3s. Furthermore, we obtained no differences in the NK cells frequencies between active and stable phase, however we showed differences related to CX3CR1 and CD160, marker of mature NK cells and marker for high cytotoxic NK cells respectively. Thus, due to the decrease of CX3CR1 in active phase we hypothesized an increase of immature NK cells that may migrate to the CNS leading to a slower resolution of the inflammation. Furthermore, we reported the increase of CD160 in active phase, linked to the increase of the cytotoxicity. Nevertheless, due to the small size of our cohort, future studies are needed to explore the significance of our results.
La Sclerosi Multipla (SM) è una malattia cronica, infiammatoria, neurodegenerativa e demielinizzante che affligge il sistema nervoso centrale. Durante la SM cellule dalla periferia acquisiscono l’abilità di penetrare nel sistema nervoso centrale attraverso rotture della barriera ematoencefalica; una volta entrate nel SNC, le cellule immunitarie instaurano un’ambiente infiammatorio che determina inizialmente la distruzione della mielina e in fasi successive morte neuronale. Il ruolo chiave del sistema immunitario nello sviluppo e nel mantenimento della SM, in particolare quello innato (es. CD4+cellule T, cellule B and macrofagi), è stato descritto ampiamente in letteratura nonostante ancora oggi non sia stata fatta completamente chiarezza su tutti i meccanismi. Il ruolo del sistema immunitario è importante soprattutto durante le prima fasi della malattia, dove l’infiammazione a livello del SNC non è ancora compartimentalizzata ma vi è un’interazione tra periferia e SNC. Negli ultimi decenni vi sono state ulteriori scoperte per quel che riguarda il sistema immunitario innato ed il suo coinvolgimento nella SM. In questo studio preliminare abbiamo esplorato i cambiamenti in frequenza e funzionalità delle cellule innate linfoidi (ILCs) e delle cellule NK in sangue periferico di pazienti in fase precoce di SM (sindrome clinicamente isolata, CIS) comparando fase attiva e fase stabile della malattia. I risultati ottenuti dall’analisi di citofluorimetria e dall’espressione genica mostrano differenze in frequenza tra fase attiva e fase stabile, inoltre queste differenze sono state riscontrate anche in comparazione con la letteratura scientifica. Abbiamo dimostrato che le ILC1 sembrano aumentare in fase attiva, questo è ulteriormente confermato dalla diminuzione del recettore per gli idrocarburi arilici, espresso dalle ILC3, che è correlato ad uno switch fenotipico da ILC3 a ILC1. Di conseguenza, abbiamo ipotizzato che le ILC1 in fase attiva possano aumentare sia a causa di una maggiore migrazione dal tessuto di origine, sia a causa di uno switch fenotipico delle ILC3 in ILC1. Inoltre, non abbiamo rivelato differenze in frequenza tra cellule NK in fase attiva e fase stabile, ma abbiamo ottenuto differenze correlate a CX3CR1 e CD160, rispettivamente un marker per cellule NK mature e un marker per cellule NK altamente citotossiche. Quindi a causa della diminuzione di CX3CR1 in fase attiva, abbiamo ipotizzato un aumento di cellule NK immature che potrebbero migrare al SNC determinando un rallentamento nella risoluzione dell’infiammazione. Inoltre, l’aumento di CD160 in fase attiva potrebbe essere correlato con un aumento della citotossicità di una sottopopolazione di cellule NK. Tuttavia, a causa del piccolo numero di campioni sono necessari studi ulteriori per confermare la significatività dei risultati.
Cambiamenti in frequenza e funzionalità delle cellule innate linfoidi durante fasi preoci di sclerosi multipla
CESTARI, SARA
2020/2021
Abstract
Multiple Sclerosis (MS) is a chronic, inflammatory, neurodegenerative and demyelinating disease that affect the central nervous system (CNS). During MS immune cells from the periphery become able to enter in the CNS through blood brain barrier (BBB) breakdowns; Once entered in the CNS, the immune cells establish, with the help of tissue resident cells, an inflamed environment that leads to the destruction of myelin and later of the neurons. The key role of the immune system as initiator and mediator of the inflammation observed in CNS during MS has been fully described, especially for the adaptive immune system (i.e. CD4+T cells, B cells and macrophages). This role is especially prominent during the first stages of the disease, where the inflammation in the CNS is still not compartmentalized but there is an interaction between periphery and the CNS. In the last decades, there has been also evidence of the involvement of the innate immune system in the mechanisms underlying MS pathology. Here, in this exploratory study we investigated the changes in the innate lymphoid cells (ILCs) and in the NK cells from peripheral blood of early MS patients, diagnosed as clinically isolated syndrome (CIS), both in active and stable phase of the disease from the same patient. Our data from flow cytometry characterization and gene expression analysis showed difference in frequency between active and stable phase of the disease and furthermore compared to the literature. We showed that ILC1s seem to increase in active phase and this is further confirmed by the decrease of aryl hydrocarbon receptor (AHR), expressed by ILC3s, that is linked to a phenotypical switch from ILC3 to ILC1; thus we hypothesized that ILC1s in active phase may increase due to an higher migration from the tissue of origin and additionally because of a phenotypical switch of ILC3s. Furthermore, we obtained no differences in the NK cells frequencies between active and stable phase, however we showed differences related to CX3CR1 and CD160, marker of mature NK cells and marker for high cytotoxic NK cells respectively. Thus, due to the decrease of CX3CR1 in active phase we hypothesized an increase of immature NK cells that may migrate to the CNS leading to a slower resolution of the inflammation. Furthermore, we reported the increase of CD160 in active phase, linked to the increase of the cytotoxicity. Nevertheless, due to the small size of our cohort, future studies are needed to explore the significance of our results.È consentito all'utente scaricare e condividere i documenti disponibili a testo pieno in UNITESI UNIPV nel rispetto della licenza Creative Commons del tipo CC BY NC ND.
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https://hdl.handle.net/20.500.14239/13272