Mechanisms Of Oligodeoxynucleotides Inhibit Atherosclerosis In Apolipoprotein E Knockout Mice

Objective To explore the effect of oligodeoxynucleotides (ODN A151) containing TTAGGG motifs on the cytokines secreted by splenetic lymphocytes of mice.Methods CD4+ T cells were isolated from spleen of C57BL/6J mice by magnetic-activated cell sorting (MACS), then simulated with anti-CD3 and anti-CD28, with or without 1, 5, 10μM ODN A151 and 10μM ODN 1612 for 3 days, and anti-CD3 for another 48 hours. IFN-γ, TNF-α, IL-4 and IL-10 in supernatants were detected by ELISA.Results ODN A151 significantly inhibited production of Th1 cytokines IFN-γand TNF-α, and increased Th2 cytokines IL-4 and IL-10 (P<0.01);ODN A151 also significantly decrease IFN-γ/IL-4 on the concentration above 5μM. ODN 1612 had no effect on production of cytokines.Conclusion ODN A151 regulated differentiation of Th lymphocytes and skewing Th1/Th2 balance toward Th2 type cytokine production. Objective In current research, we hypothesized that suppressive ODN may alter the development of atherosclerosis and investigated involved mechanisms.Methods Eight-week-old homozygous apoE-/- male mice were injected with 300μg ODN A151 (TTAGGG) or nonspecific ODN 1612 dissolved in 300μl PBS every other week while control group was treated with 300μl PBS for 16 weeks. Atherosclerotic lesion sizes were evaluated by 3 approaches: gross apperance, paraffin and frozen histological section analysis. MCP-1, VCAM-1 and the primary signal transduction proteins for Th differentiation (Th1: T-bet, STAT1, 4 and phosphorylation; Th2: GATA-3, STAT6 and phosphorylation) expressions in arteries were measured by western blot. The percentages of Th subsets (Th1 and Th2) indicating Th cell functions, were detected by FACS analysis.Results ODN A151 but not ODN 1612 treatment significantly reduced atherosclerotic plaque size by 49%, effectively inhibited the expression of MCP-1 and VCAM-1 in atherosclerotic lesion. ODN A151 significantly inhibited the primary signal transduction proteins for Th1 differentiation and Th1 cell functions, and skewed Th1/Th2 balance toward Th2 inflammation in vivo.Conclusions By inhibition of STAT1, 4 and T-bet pathway, suppressive ODN A151 can inhibit the development of atherosclerosis through modulation of Th1/Th2 balance in vivo.