Il-10 Production in Peripheral B-Cells in Autoimmune Disorders

Objectives: Recent evidence suggests that circulating B-cells, traditionally noted for antibody production, contribute a regulatory role through the production of immunosuppressive cytokines such as IL-10. We describe IL-10 secretion in peripheral B-cells in Sjogrens Syndrome (SS) patients, healthy patients and Systemic Lupus Erythematosus (SLE) patients. The information will be incorporated with further aims of describing the nature of the salivary infiltration by autoimmune memory B-cells.

Methods: Peripheral blood was obtained from patients with positive diagnosis of the autoimmune diseases Sjogren's Syndrome and Systemic Lupus Erythematosus and healthy patients. Peripheral Blood Mononuclear Cells (PBMC) were isolated and cultured. PBMC populations were stimulated in vitro and an IL-10 secretion-capture reagent was used to capture and affix the cytokine to the secreting cell. Cells were stained and analyzed via flow cytometry.

Results: PBMC cells were stained to determine viability. In order to isolate B-cells from T-cells, cells will be gated CD19+ and CD3-. The membrane-affixed IL-10 is stained to localize the cytokine secreting isotype. Cytokine production of IL-10 differed between the three groups. The ability to stimulate B-cells to make IL-10 in vitro is decreased in Sjogrens Syndrome and Systemic Lupus Erythematosus patients compared to healthy patients. IL-10 production in B-cells after stimulation was from IgD+ CD27- (>56%) suggestive of possibly Naïve or Transitional B-cell populations.

Conclusions: An early explanation could be that the lack of regulation by IL-10 producing B-cells contributes to the autoimmune reactions and offers a protective role in healthy controls. This data as well as on-going experiments will be presented.

This research was supported by the Sjogren's Syndrome Foundation and through NIH-NIDCR T32 DE007202-16