Cytokines inhibit the development of liver schizonts of the malaria parasite Plasmodium berghei in vivo.
The effect of induction of an acute-phase response and its mediators on the development of liver schizonts of the rodent malaria parasite Plasmodium berghei was investigated in Brown Norway rats. Subcutaneous injection of turpentine oil 24 h or 5 min before inoculation of sporozoites resulted in 80% and 35% reduction of schizont development, respectively. Turpentine oil induced high plasma levels of interleukin-6 (IL-6). Intraperitoneal administration of IL-1, IL-6 or both, significantly reduced liver schizont development. This reduction was also present if IL-6 had been administered 24 h after sporozoite inoculation. Inhibition induced by IL-1 could be prevented by simultaneous administration of polyclonal anti-IL-6. Administration of polyclonal anti-IL-6 without IL-1 resulted in a 40% increase of liver schizonts compared to control animals. We conclude that induction of an acute-phase response during experimental Plasmodium berghei infections in Brown Norway rats, strongly inhibits liver schizont development and that IL-6 is a key mediator in this process.
Vreden
S G
SG
Department of Medical Microbiology, University Hospital Nijmegen, The Netherlands.
van den Broek
M F
MF
Oettinger
M C
MC
Verhave
J P
JP
Meuwissen
J H
JH
Sauerwein
R W
RW
D000210:Acute-Phase Reaction; D000818:Animals; D007375:Interleukin-1 / Q000494:pharmacology / Q000627:therapeutic use*; D015850:Interleukin-6 / Q000494:pharmacology / Q000627:therapeutic use*; D008099:Liver / Q000469:parasitology*; D008288:Malaria / Q000517:prevention & control*; D008297:Male; D051379:Mice; D010962:Plasmodium berghei / Q000187:drug effects; D011817:Rabbits; D051381:Rats; D011914:Rats, Inbred BN; D014425:Turpentine / Q000494:pharmacology
D007375:Interleukin-1; D015850:Interleukin-6; D014425:Turpentine