Expression of NKG2D and CD107 in CD8(+) effector memory lymphocytes in Churg-Strauss syndrome

• Published in: Clinical and experimental rheumatology Vol. 30; no. 1 Suppl 70; p. S57
• Main Authors: Boita, Monica, Rolla, Giovanni, Mallone, Roberto, Martinuzzi, Emanuela, Heffler, Enrico, Circosta, Paola, Elia, Angela Rita, Cignetti, Alessandro, Caillat-Zucman, Sophie, de Menthon, Mathilde, Guida, Giuseppe
• Format: Journal Article
• Language: English
• Published: Italy 01.01.2012
• Subjects: Adult; Aged; Biomarkers - analysis; Case-Control Studies; CD28 Antigens - analysis; CD4-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - immunology; Churg-Strauss Syndrome - immunology; E-Selectin - analysis; Female; Flow Cytometry; Humans; Immunologic Memory; Immunophenotyping - methods; Italy; Leukocyte Common Antigens - analysis; Lymphocyte Activation; Lysosomal Membrane Proteins - analysis; Male; Middle Aged; NK Cell Lectin-Like Receptor Subfamily K - analysis; Paris; Phenotype; Receptors, Antigen, T-Cell, alpha-beta - analysis
• ISSN: 0392-856X

Churg-Strauss syndrome (CSS) is a necrotising vasculitis of small vessels in which oligoclonally expanded TCR Vβ CD8+ effector memory T cells populations (TEM) may be involved in vasculitic damage. The aim of this study was to assess the functional role of CD8+ T cells in CSS patients by flow cytometry analysis of membrane expression of cytotoxic markers NKG2D and CD107a. Immunostaining of peripheral T cells and effector memory lymphocytes (TEM) from CSS patients and controls was performed by gating CD28 and CD45RA in the CD8+NKG2D+ and CD4+NKG2D+ populations. CD107a expression was evaluated in both whole CD8+ and CD4+ and the TEM cells by gating CD62 and CD45RA following polyclonal stimulation. NKG2D expression was shifted toward the CD8+CD28- fraction of T cells in CSS patients compared to healthy controls (56.1±25.8% versus 17.2±7.3%, respectively, p=0.002). CD8+Vβ+ expanded T cells showed a significantly increased expression of NKG2D compared to the whole CD8+ T cell population (91.4±1.9% versus 79.7±3.8%, respectively, p=0.015). Moreover the CD8+ population from CSS upregulates CD107a on its surface upon polyclonal stimulation in a significantly higher proportion than healthy subjects (26.2±10.8% versus 8.2±2.9%, p=0.0031) and the majority CD8+ CD107+ cells from CSS patients showed a TEM phenotype compared to controls (64.8±4.9% vs. 19.8±2.9, respectively, p<0.001). In CSS, CD8+ TEM lymphocytes show markers of cytotoxic activity, which suggests a role for these cells in vasculitic damage.