Anti-Bacterial Effect of CpG-DNA Involves Enhancement of the Complement Systems

• Published in: International journal of molecular sciences Vol. 20; no. 14; p. 3397
• Main Authors: Kim, Te Ha, Park, Joongwon, Kim, Dongbum, Gautam, Avishekh, Akauliya, Madhav, Kim, Jinsoo, Lee, Hanseul, Park, Sangkyu, Lee, Younghee, Kwon, Hyung-Joo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.07.2019; MDPI
• Subjects: Alternative pathway; Animals; Anti-Bacterial Agents - administration & dosage; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antibiotics; Antiinfectives and antibacterials; Bacteria; Bacterial infections; Classical pathway; cobra venom factor; complement; Complement activation; Complement Activation - drug effects; Complement Activation - immunology; Complement component C3; Complement component C3a; Complement component C3b; Complement System Proteins - drug effects; Complement System Proteins - immunology; CpG islands; CpG-DNA; Cytokines; Damage detection; Dendritic cells; Deoxyribonucleic acid; DNA; E coli; E. coli K1; Escherichia coli - drug effects; Escherichia coli - immunology; Escherichia coli Infections - drug therapy; Escherichia coli Infections - immunology; Escherichia coli Infections - microbiology; Gram-positive bacteria; Histopathology; Immune system; Immunologic Factors - administration & dosage; Immunologic Factors - chemistry; Immunologic Factors - pharmacology; infection; Infusions, Parenteral; Investigations; Lungs; Mice; Multidrug resistance; Oligodeoxyribonucleotides - administration & dosage; Oligodeoxyribonucleotides - chemistry; Oligodeoxyribonucleotides - pharmacology; Organs; Peritoneum; Phagocytosis - drug effects; Phagocytosis - immunology; Pneumonia; Pretreatment; Rodents; Spleen; Staphylococcus infections; Vaccines; infection; CpG-DNA; E. coli K1; complement; cobra venom factor
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20143397

CpG-DNA activates the host immune system to resist bacterial infections. In this study, we examined the protective effect of CpG-DNA in mice against ( ) K1 infection. Administration of CpG-DNA increased the survival of mice after K1 infection, which reduces the numbers of bacteria in the organs. Pre-injection of mice with CpG-DNA before K1 infection increased the levels of the complement C3 but not C3a and C3b. The survival of the mice after K1 infection was significantly decreased when the mice were pre-injected with the cobra venom factor (CVF) removing the complement compared to the non-CVF-treated mice group. It suggests that the complement has protective roles against K1 infection. In addition, the survival of complement-depleted mice was increased by CpG-DNA pre-administration before K1 infection. Therefore, we suggest that CpG-DNA enhances the anti-bacterial activity of the immune system by augmenting the levels of complement systems after K1 infection and triggering other factors as well. Further studies are required to investigate the functional roles of the CpG-DNA-induced complement regulation and other factors against urgent bacterial infection.