Interleukin-7 in the skin of Schistosoma mansoni-infected mice is associated with a decrease in interferon-gamma production and leads to an aggravation of the disease.
The effect of recombinant interleukin-7 (rIL-7) on the course of murine schistosomiasis and the development of the accompanying immune response were investigated. We demonstrated that IL-7 expression could be detected in the skin of infected mice from 1 to 21 days following infection. We here report that intradermal injection of exogenous human IL-7, prior to the penetration of the parasite into the skin, leads to a more severe liver pathology and an increased number of surviving adult parasites. In addition, injection of rIL-7 alters parasite migration (estimation of burdens of young larvae in lungs and liver). Administration of rIL-7 led to a decrease of IL-12 and interferon-gamma-(IFN-gamma) specific messengers RNA in skin and, more markedly, in skin-draining lymph nodes. The number of B220 expressing cells was increased, and T-cell number was reduced, in IL-7-treated infected mice. In addition, levels of IFN-gamma and IL-4 in sera were significantly reduced, whereas there was a shift from a Th1 to a Th2 type associated humoral response towards the egg antigens. Our experimental observation illustrate that the exogenous administration of rIL-7 affects both the development of the host's immune response and the behaviour of the parasite within the infected host. The early and specific production of IL-7 in the host skin, following infection with Schistosoma mansoni, raises fascinating questions concerning the relationships between the parasite and its host at the very beginning of their interaction.
Wolowczuk
I
I
Institut Pasteur de Lille, CNRS U.R.A. 1854, France.
Delacre
M
M
Roye
O
O
Giannini
S L
SL
Auriault
C
C
D000818:Animals; D005260:Female; D006790:Host-Parasite Interactions / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000235:genetics; D018664:Interleukin-12 / Q000096:biosynthesis / Q000235:genetics; D015847:Interleukin-4 / Q000097:blood; D015851:Interleukin-7 / Q000276:immunology* / Q000378:metabolism; D008099:Liver / Q000469:parasitology; D008168:Lung / Q000469:parasitology; D008198:Lymph Nodes / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D012555:Schistosomiasis mansoni / Q000276:immunology* / Q000378:metabolism / Q000469:parasitology; D012867:Skin / Q000276:immunology* / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000276:immunology
D015851:Interleukin-7; D012333:RNA, Messenger; D011994:Recombinant Proteins; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma