AUTHOR=Acquaviva Massimo , Bassani Claudia , Sarno Nicole , Dalla Costa Gloria , Romeo Marzia , Sangalli Francesca , Colombo Bruno , Moiola Lucia , Martinelli Vittorio , Comi Giancarlo , Farina Cinthia 

TITLE=Loss of Circulating CD8+ CD161high T Cells in Primary Progressive Multiple Sclerosis

JOURNAL=Frontiers in Immunology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.01922

DOI=10.3389/fimmu.2019.01922

ISSN=1664-3224

ABSTRACT=<p>Recent evidence suggests that the primary progressive form of multiple sclerosis (PP-MS) may present with specific immunological alterations. In this study we focused our attention on CD161, an NK and T cell marker upregulated in relapsing-remitting MS, and investigated its transcript and protein levels in blood cells from PP-MS and healthy individuals. We demonstrated transcriptional downregulation of CD161 in PP-MS and described concomitant mRNA reduction for RORgt, CCR6, CXCR6, KLRK1/NKG2D and many other markers typical of mucosa associated invariant T (MAIT) cells. Targeted multiparametric flow cytometry on fresh blood cells from an independent cohort of case-control subjects confirmed the selective loss of circulating CD8 CD161<sup>high</sup> T cells, which consist mainly of MAIT cells, and not of CD8 CD161<sup>int</sup> T cells in PP-MS. These data demonstrate alterations in a specific circulating immune cell subset in MS patients with progressive onset.</p>