Kinetics of interleukin-6 production after experimental infection of mice with Schistosoma mansoni.
It has been reported that interleukin-6 (IL-6) is expressed in cells of acute inflammatory granulomas experimentally induced in mice by eggs of Schistosoma mansoni. Moreover, in vitro IL-6 was shown to enhance the cytotoxic activity of human platelets against larvae of S. mansoni. To elucidate further a proposed biological significance of this cytokine during the course of schistosomiasis, we studied the kinetics of IL-6 production and concomitantly performed a histopathological analysis of the livers in BALB/c mice subcutaneously infected with S. mansoni cercariae. Over a period of 24 weeks postinfection (p.i.) we monitored serum IL-6 levels, IL-6 production in vitro by pokeweed mitogen (PWM)-stimulated spleen cells as well as IL-6 mRNA expression in livers, spleens and kidneys. We found significantly elevated IL-6 levels in PWM-stimulated spleen cell-conditioned media (SCM) at weeks 6 to 20 p.i., peaking at week 10 p.i. In contrast, serum IL-6 concentrations started to rise not before week 8 but remained significantly elevated above normal control values until week 24 p.i. The time pattern of enhanced IL-6 mRNA expression detected in spleens and livers, but not in kidneys, as well as the rises of IL-6 in SCM and with a delay of 2 weeks in serum samples correlated with the onset of the egg-induced inflammatory reactions as well as the incidence and the number of the granulomas observed histopathologically in the livers of infected mice. Our data emphasize both a local and a systemic role of IL-6 in the host immune response following infection of mice with S. mansoni.
Khalil
R M
RM
GSF-Institute für Experimentelle Hämatologie, München, Germany.
Hültner
L
L
Mailhammer
R
R
Luz
A
A
Moeller
J
J
Mohamed
A A
AA
Omran
S
S
Dörmer
P
P
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D005260:Female; D006099:Granuloma / Q000276:immunology*; D015850:Interleukin-6 / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000276:immunology; D008099:Liver / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011043:Pokeweed Mitogens / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D012555:Schistosomiasis mansoni / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D013268:Stimulation, Chemical
D015850:Interleukin-6; D011043:Pokeweed Mitogens; D012333:RNA, Messenger