Complement is a rat natural resistance factor to amoebic liver infection

• Published in: Bioscience reports Vol. 38; no. 5
• Main Authors: Olivos-García, Alfonso, Nequiz, Mario, Liceaga, Scarlet, Mendoza, Edith, Zúñiga, Porfirio, Cortes, Azucena, López-Velázquez, Gabriel, Enríquez-Flores, Sergio, Saavedra, Emma, Pérez-Tamayo, Ruy
• Format: Journal Article
• Language: English
• Published: England Portland Press Ltd 31-10-2018
• Subjects: Animals; Complement Factor H - antagonists & inhibitors; Complement Factor H - genetics; Complement Hemolytic Activity Assay; Cricetinae; Disease Models, Animal; Entamoeba histolytica - pathogenicity; Humans; Immunity, Innate - genetics; Infection - genetics; Infection - parasitology; Infection - pathology; Liver Abscess, Amebic - blood; Liver Abscess, Amebic - genetics; Liver Abscess, Amebic - parasitology; Rats; Receptors, Complement 3b - antagonists & inhibitors; Receptors, Complement 3b - genetics; Trophozoites - pathogenicity; Trypan Blue; Entamoeba histolytica; innate immunity; complement; resistance to amoebiasis
• ISSN: 0144-8463; 1573-4935
• DOI: 10.1042/BSR20180713

Amoebiasis is a parasitic disease caused by
This illness is prevalent in poor countries causing 100,000 deaths worldwide. Knowledge of the natural resistance mechanisms of rats to amoebic liver abscess (ALA) development may help to discover new pathogenic factors and to design novel therapeutic strategies against amoebiasis. In this work, histologic analyses suggested that the complement system may play a central role in rat natural resistance to ALA.
trophozoites disappeared from rat liver within 6 h post-infection with minimal or no inflammatory infiltrate.
findings indicate that rat complement was lethal for the parasite. Furthermore, hamsters became resistant to ALA by intravenous administration of fresh rat serum before infection. The amoebicidal potency of rat complement was 10 times higher than hamster complement and was not related to their respective CH50 levels. The alternative pathway of complement plays a central role in its toxicity to
since trypan blue, which is a C3b receptor inhibitor, blocks its amoebicidal activity. These results suggest that amoebic membrane affinity, high for C3b and/or low for Factor H, in comparison with the hamster ones, may result in higher deposition of membrane complex attack on parasite surface and death.