faecalis infection, whereas all of the SCIDbgMN mice inoculated with Mϕs from burned WT mice died after the same infection.
Also, burned CCL2-knockout mice treated with rCCL2 were shown to be susceptible to E. faecalis infection, and M2Mϕs were isolated from these mice 25. In the present study, we tried to protect thermally injured mice orally infected with a lethal dose of E. faecalis by gene therapy utilizing phosphorothioate-CCL2 antisense oligodeoxynucleotides (ODNs). Antisense ODNs, ribozymes and small-interfering RNA have been used for cytokine knockdown therapy 26, 27. As compared with alternative technologies for blockage of CCL2, antisense ODNs have a higher specificity and probability of success 28. The advantage of antisense ODNs designed as phosphorothioates specifically to heterogeneous nuclear RNA or mature mRNA sequences is resistance to degradation by RNases this website 26. Therefore, for the blockage of CCL2 in severely burned mice orally infected with E. faecalis, Silmitasertib phosphorothioate-CCL2 antisense ODNs were utilized in this study. In our previous studies 23, 24, CCL2 produced in response to burn injury was shown to play a
major role on the M2Mϕ predominance in severely burned mice. Therefore, for the elimination of M2Mϕs; we tried to reduce serum CCL2 levels of severely burned mice by treatment with CCL2 antisense ODNs. Various concentrations of CCL2 antisense ODNs were administered
to mice 2 and 12 h after burn injury. Sera, obtained from these mice 24 h after burn injury, were assayed for CCL2 by ELISA. Serum specimens obtained from normal mice treated with saline and severely burned mice treated with scrambled ODNs were utilized as controls. CCL2 was not detected in the sera of normal mice, whereas the sera of severely burned mice treated with scrambled ODNs contained 1.3 ng/mL of CCL2. However, 77–100% of CCL2 was eliminated from the sera of severely burned mice after treatment with 1 μg/mouse (Fig. 1A) or more (10 and 100 μg/mouse, Fig. 1B) of CCL2 antisense ODNs. These results indicate that the gene therapy utilizing CCL2 antisense ODNs is feasible to decrease CCL2 levels in severely burned mice. The disappearance of MLN-M2Mϕs in severely burned mice treated Carnitine palmitoyltransferase II with CCL2 antisense ODNs was examined. Severely burned mice were treated twice with 10 μg/mouse of CCL2 antisense ODNs 2 and 12 h after burn injury. Mϕs isolated from mesenteric lymph nodes (MLN-Mϕs) of these mice 1–8 days after burn injury were cultured for 24 h without any stimulation. Culture fluids harvested were assayed for CCL17 as a biomarker of M2Mϕs. The amounts of CCL17 detected in the culture fluids were compared with those of CCL17 that were produced by the same MLN-Mϕs derived from controls (burned mice treated with scrambled ODNs).