The Effect Of Oligodeoxynucleotides On The Expression Of Toll-like9in Peripheral Blood B Cells And The Secretion Of Type Ⅰ Interferon In The Patients With Systemic Lupus Erythematosus

Objective: To investigate the immunity regulation effect of immunostimulatoryCpG-containing oligodeoxynucleotides (CpG–ODN) and immunosuppressive ODNon the expression of Toll like receptor9(TLR9) on peripheral blood B lymphocytesand the secretion of type I interferon (IFN) in vitro. We also wish this study couldcontribute to the new strategy for systemic lupus erythematosus (SLE) by exploring thepossible mechanisms of the effect.Methods: Isolated and collected peripheral blood mononuclear cell (PBMC) fromSLE and health control.60cases with SLE (study group) and20cases healthy donorswere enrolled. The PBMC were incubated with RPMI-1640, CpG-ODN andCpG-ODN+immunosuppressive-ODN for48hours in vitro. Then we detected theexpression of TLR9on peripheral blood CD19+B lymphocytes by flow cytometry. Atthe same time the cell-free supernatants were collected and assayed for IFN-α byenzyme-linked immunosorbent assay (ELISA). Compared the differences of the threegroups. According to the SLE Disease Aetivity Index (SLEDAI), SLE patients weredivided into two groups: the slightly active group (S group, n=30, SLEDAI score<10)and the disease moderately/highly active group (MH group, n=30, SLEDAI score≥10). The differences of intracellular TLR9expression and IFN-α level in three groupswere further compared on the basis of the SLEDAI.Results:1.①In the SLE patients, compared with CpG-ODN group, the RPMI-1640group of the proportion of B cells expressing TLR9was lower (mean±SD:11.71±9.62vs19.51±11.23, P<0.001), immunosuppressive-ODN group was also lower(15.04±7.91vs19.51±11.23, P=0.011), although immunosuppressive-ODN groupwas higher than the RPMI-1640group, there was no significant difference betweentwo groups(P=0.057); the mean fluorescence intensity (MFI) was no significant difference among three groups (P>0.05);②In the slightly active patients, comparedwith CpG-ODN group, the RPMI-1640group of the proportion of B cells expressingTLR9was lower (9.19±5.24vs15.92±7.82, P<0.001), immunosuppressive-ODNgroup was also lower (12.54±6.18vs15.92±7.82, P=0.049), althoughimmunosuppressive-ODN group was higher than the RPMI-1640group, and therewas also no significant difference between the two groups(P=0.064); the MFI was nosignificant difference among three groups (P>0.05); In the moderately/highly activepatients, the consequences were similar to the slightly active patients;③In the health people,the CpG-ODN group of the proportion of B cells expressing TLR9was higher thanthe RPMI-1640group (11.59±4.83vs5.43±3.33, P<0.001), also higher than theimmunosuppressive-ODN group (11.59±4.83vs7.77±4.49, P=0.006); to the MFI,both the CpG-ODN group and immunosuppressive-ODN group were higher than theRPMI-1640group, and there was different.(P=0.026, P=0.019).2.The secretion ofIFN-α in the supernatants:①In the SLE patients, the IFN-α level of with CpG-ODNgroup was higher than RPMI-1640group (6.98±0.39vs4.53±0.32, P<0.001), andimmunosuppressive-ODN group was lower than CpG-ODN group(4.63±0.34vs6.98±0.39, P<0.001), but the between the immunosuppressive-ODN group andRPMI-1640group was no statistics difference(P=0.102);②In the slightly activepatients, compared with CpG-ODN group, the RPMI-1640group of the IFN-α waslower (4.37±0.25vs6.82±0.24, P<0.001), and the immunosuppressive-ODN groupwas still lower (4.48±0.27vs6.82±0.24, P<0.001). In the moderately/highly activepatients, the consequences were similar to the slightly active patients.③In the health people,the CpG-ODN group was higher than the other groups and the differences weresignificant.(4.06±0.19vs1.44±0.15, P<0.001;4.06±0.19vs1.55±0.19, P<0.001),but there was no difference between the RPMI-1640group and immunosuppressive-ODNgroup(P=0.060).3.The expression of TLR9on peripheral blood B lymphocytes waspositive correlated with the secretion of IFN-α in PBMC.(Pearson r=0.332, P <0.001).Conclusions: In vitro, our data indicate immunosuppressive-ODN can significantinhibit the expression of TLR9on peripheral blood B lymphocytes and the IFN-αrelease form the supernants induced by CpG-ODN. Suggesting that the mechanism may be related to TLR9on peripheral blood mononuclear cell. Modulating theCpG-ODN–TLR9pathway may offer new opportunities for the understanding andtreatment of systemic lupus erythematosus.