CD5-expressing CD8⁺ T-cell subsets differ between children with type 1 diabetes and controls

Area of Science:

• Immunology
• Endocrinology
• Autoimmunity

Background:

• Type 1 diabetes (T1D) pathogenesis involves various lymphocyte subsets.
• Previous research indicated a role for CD5-expressing T and B cells, including dual-expressing (DE) cells.

Purpose of the Study:

• To investigate immune cell subsets and DE cells in children with T1D compared to controls.
• To analyze CD5 expression on T and B cells in T1D patients.

Main Methods:

• Algorithm-supported multiparameter flow cytometry and quantitative PCR were used.
• Self-organizing maps (FlowSOM) and t-distributed stochastic neighbor embedding (tSNE) analyses were applied.
• In vitro experiments assessed CD5 expression stability after T-cell activation and stimulation.

Main Results:

• Increased CD3+ T cells were observed in T1D patients, while CD19+ B-cell proportions were similar to controls.
• No significant differences in CD5-expressing B-cell subsets or DE cells were found between groups.
• Significantly reduced CD8+ T-cell proportions with moderate or low CD5 expression were identified in T1D patients.
• In vitro studies confirmed stable CD5 expression differences in CD8+ T cells post-activation.

Conclusions:

• T1D patients exhibit distinct CD8+ T-cell populations characterized by reduced CD5 expression.
• Altered CD5 expression on CD8+ T cells may play a role in T1D immune regulation and pathogenesis.