IL-10 antisense oligodeoxynucleotides (ODN) improve the resistance of severely burned mice intradermally infected with MRSA (111.8)

Abstract

Abstract The effect of IL-10 antisense ODN on the susceptibility of burned mice to intradermal (i.d.) infection of MRSA was studied. IL-10 antisense ODN (6 μg/mouse) was administered to mice twice a day for 3 days beginning 1 day after burn injury (3rd degree, 25% TBSA flame burn). Two days after burn injury, these mice were infected i.d. with 108 CFU/mouse of MRSA. Abscess formation in the infection site and mortality rates of these mice were tested. Also, F4/80+ Mϕ isolated from tissues surrounding the infection sites of these mice were biophysically characterized. In the results, sepsis caused by MRSA i.d. infection did not develop and abscess formation was demonstrated in burned mice treated with IL-10 antisense ODN. However, all burned mice treated with scrambled ODN (control group) died from sepsis, and abscess formation was not shown in these mice. Mϕ isolated from the infection site tissues of burned mice treated with IL-10 antisense ODN were identified as M1Mϕ, while those from control mice were shown to be M2Mϕ. Abscess formation was demonstrated in burned mice inoculated with M1Mϕ (but not M2Mϕ), and these mice resisted a lethal dose of MRSA i.d. infection. These results indicate that burned mice treated with IL-10 antisense ODN are resistant against i.d. infection of MRSA. M1Mϕ appearing in the infection site tissues of burned mice that are treated with IL-10 antisense ODN may play a role on abscess formation and inhibiting sepsis caused by MRSA i.d. infection.