Objectives: The aim of the study was to analyse the cytokine memory of T-cells derived from systemic lupus erythematosus (SLE) patients and healthy donors enriched for autoantigen-specific T-cells by in vitro stimulation with SmD1(83-119), a common autoantigen in SLE.
Methods: Autoreactive CD3+ T-cells derived from 37 SLE patients and 14 healthy donors were enriched by repetitive ex vivo stimulation of peripheral blood mononuclear cells (PBMCs) with SmD1(83-119). For control, PBMCs were stimulated only with interleukin-2 (IL-2). After two rounds of antigenic stimulation, cultures were stimulated with PMA/ionomycin to probe the cytokine memory by intracellular cytokine staining. Frequencies of cytokine-expressing T-cells were analysed and, in SLE patients, compared with disease activities and autoantibody levels.
Results: Comparing the cytokine memory in the cultures, SLE patients displayed higher frequencies of tumour necrosis factor-alpha (TNF-alpha)+ T-cells than healthy donors and the frequencies correlated with disease activity. Frequencies of SmD1(83-119)-specific TNF-alpha+ T-cells and of memory T-cells expressing interferon-gamma (IFN-gamma) correlated with serum anti-dsDNA antibody levels. The frequencies of IL-10 expressing SmD1(83-119)-specific T-cells were lower among PBMCs of SLE patients. Relatively higher frequencies of IL-10+ T-cells in SLE patients correlated with low disease activities, and low anti-dsDNA and anti-SmD1(83-119) antibody concentrations in culture supernatants.
Conclusions: The memory of autoreactive SmD1(83-119)-specific and unspecific stimulated peripheral Th cells for re-expression of cytokines is shifted towards more cells expressing TNF-alpha and less IL-10+ cells, when compared SLE patients with normal donors. This shift towards proinflammatory memory effector Th cells correlates with disease severity and humoral autoimmunity.