POS1000 EXPRESSION OF GLYCOSYLATED DSRNA ON THE SURFACE OF MONOCYTES IN PATIENTS WITH SJOGREN SYNDROME

Background:

Recent studies have demonstrated that different types of cells express surface glycosylated RNA (glicoRNA). Through this mechanism, they are exposed to the extracellular space and, consequently, to the immune system. In particular, a glycosylated surface ds-RNA (glico-dsRNA) has been identified using the anti-dsRNA J2 antibody.

Objectives:

The purpose of this study was to evaluate the monocytic expression of the glico-dsRNA and correlate it with the clinical and laboratory characteristics of patients with Sjogren Syndrome (SjS).

Methods:

Ten patients diagnosed with SSj and ten healthy control donors (HD) matched for sex and age were evaluated. Demographic and clinical data were collected from these patients, and venous blood was drawn. Mononuclear cells from peripheral blood (PBMC) were isolated from the blood. RNase A was added to the sample and incubated. After washing, the cells were incubated with anti-dsRNA J2 antibody. Subsequently, the cells were incubated with Goat anti-Mouse-IR 680 antibody. Finally, acquisition was performed using a FACS Calibur flow cytometer and 20,000 events per sample were evaluated. The data were analyzed using Cell Quest Pro software. Titers of anti-Ro60 and Ro52 antibodies were measured using ELISA.

Results:

The clinical and laboratory characteristics of the patients are summarized in Table 1. Our study revealed that patients with SSj express a higher percentage of glyco-dsRNA on the surface of monocytes (median=38; σ=27.2) compared to HD (median=11; σ=6.1) (p= 0.001) (Figure 1 and 3), and that monocytic expression of glyco-dsRNA correlates with disease activity assessed by ESSDAI (p=0.0001) (Figure 2). Finally, we demonstrated that the expression of glyco-dsRNA on monocytes does not correlate with the antibody titers of antiRo60 (p-value=0.3) and antiRo52 (p-value=0.8).

Conclusion:

The results demonstrate that the expression of glyco-dsRNA on the cell surface of monocytes is increased in patients with SSj compared to HD and that this expression correlates with disease activity. Therefore, glyco-dsRNA could potentially represent a new surface antigen involved in the pathogenesis of these diseases and serve as a new marker of disease activity.

REFERENCES:

[1] Small RNAs are modified with N-glycans and displayed on the surface of living cells. Flynn R. et al. Cell 2021 Jun 10;184(12):3109-3124.e22.

Acknowledgements:

NIL.

Disclosure of Interests:

None declared.