CD5 expressing CD8+ T cell subsets differ between children with Type 1
Diabetes and controls
Abstract
Different lymphocyte subsets are involved in autoimmune pathogenesis of
Type 1 Diabetes (T1D). Previous studies suggested a role of CD5
expressing T and B cells including rare unconventional lymphocytes with
combined T- and B-cell features (DE cells). We performed
algorithm-supported multi-parameter flow cytometry and quantitative PCR
to investigate immune cell subsets and DE cells in children with T1D
(n=20) and matched controls (n=20). Comparisons of conventional immune
cells detected increased proportions of CD3+ T cells in T1D patients
whereas CD19+ B cell proportions were comparable to controls.
Self-organizing maps for flow cytometry analyses (FlowSOM) showed highly
similar CD5 expressing B-cell subsets and no differences for DE cells
were detected between the study groups by flow cytometry or specific
quantitative PCR. Notably, differences in CD8 positive T cells were
indicated by FlowSOM and similarity-based tSNE analyses. Study group
comparison confirmed significantly reduced CD8+ T-cell proportions with
moderate or low CD5 expression in T1D patients. Finally, In vitro
experiments showed stable CD5 expression differences of CD8+ T cells
after T-cell activation, cytokine stimulation and culture. We observed
differences of T-cell co-receptor CD5 expression in T1D patients with
potential relevance for immune regulation of CD8+ T-cell activation.