Recombinant mouse IL-6 boosts specific serum anti-plasmodial IgG subtype titres and suppresses parasitaemia in Plasmodium chabaudi chabaudi infection.
C57BL/6 mice which were treated with recombinant mouse interleukin-6 (rmIL-6), 75 ng in 0.2 ml saline, i.p., 24 h before inoculation with Plasmodium chabaudi chabaudi and on days one, two and three could not control the primary acute parasitaemia but were able to suppress secondary parasitaemia significantly, peak of 3% and to reduce parasitaemia to subpatent levels within three weeks. Control C57BL/6 mice, which received saline injections only, developed two identical peaks of parasitaemia of at least 21% each, typical of a primary P. chabaudi chabaudi infection and cleared parasitaemia by day 28 post-inoculation. Serum levels of IL-6 measured in the first week by enzyme-linked immunosorbent assay were significantly higher (two-fold) in recipients compared to control mice. Anti-plasmodial IgG1, 2a and 2b titres were four to 16 times higher in rmIL-6 recipients than in the control mice. Reduction of parasitaemia to subpatency during the secondary phase of P. chabaudi chabaudi infection in C57BL/6 mice is primarily antibody-mediated and rmIL-6 accelerates this process by boosting the levels of the required specific anti-plasmodial IgG subclasses of antibodies.
Akanmori
B D
BD
Department of Parasitology, Gunma University School of Medicine, Maebashi, Japan.
Kawai
S
S
Suzuki
M
M
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood*; D000918:Antibody Specificity; D005260:Female; D007074:Immunoglobulin G / Q000097:blood* / Q000145:classification; D007167:Immunotherapy; D015850:Interleukin-6 / Q000097:blood / Q000494:pharmacology*; D008288:Malaria / Q000276:immunology* / Q000469:parasitology / Q000628:therapy*; D051379:Mice; D008810:Mice, Inbred C57BL; D018512:Parasitemia / Q000276:immunology* / Q000469:parasitology / Q000628:therapy*; D016788:Plasmodium chabaudi / Q000276:immunology*; D011994:Recombinant Proteins / Q000494:pharmacology; D013997:Time Factors
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D015850:Interleukin-6; D011994:Recombinant Proteins