Enhanced expression of the decoy receptor IL-13Ralpha2 in macrophages of Schistosoma japonicum-infected mice.
BACKGROUND
Type 2 cytokine interleukin (IL)-13 and its decoy receptor, IL-13 receptor (R) alpha2 appear to play a major role in tissue fibrosis of schistosomiasis and asthma. IL-13 is a key regulator of the extracellular matrix (ECM). It is known to signal to cells by binding to the IL-13Ralpha1, which then heterodimerizes with IL-4Ralpha. In contrast, IL-13Ralpha2 binds IL-13 with high affinity but does not signal. IL-13Ralpha2 is known to down-regulate granulomatous inflammation and prolong host survival in Schistosoma mansoni (S. mansoni) infection, but little is known about the location and expression level of IL-13Ralpha2 in the context of S. japonicum infection.


METHODS
We established S. japonicum-infected mouse models. Kinetic serum levels of IL-13Ralpha2 were examined with ELISA. IL-13Ralpha2 mRNA and protein of liver tissues were determined by PCR and immunoblotting analysis, respectively. Detection of IL-13Ralpha2 expression and location in macrophages was performed by TaqMan PCR and fluorescent immunocytochemistry technique, respectively.


RESULTS
A marked elevation of mRNA and protein expression of IL-13Ralpha2 was observed in mice during S. japonicum infection. An enhanced expression of IL-13Ralpha2 was further demonstrated in primary macrophages of murine schistosomiasis.


CONCLUSIONS
IL-13Ralpha2 in macrophages may be a critical contributor to pathogenesis of schistosomiasis. The data highlight the potential importance of cell signaling and antifibrotic gene therapeutics in T helper 2 cell (Th2)-mediated diseases.
Wang
Wei
W
Department of Epidemiology and Biostatistics, Anhui Medical University, Hefei, China.
Shen
Yu-xian
YX
Li
Jing
J
Zhang
Shi-hai
SH
Luo
Qing-li
QL
Zhong
Zhen-rong
ZR
Jiang
Zuo-jun
ZJ
Shen
Ji-long
JL
D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D053663:Interleukin-13 Receptor alpha2 Subunit / Q000378:metabolism*; D008264:Macrophages / Q000276:immunology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011897:Random Allocation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012549:Schistosoma japonicum / Q000472:pathogenicity*; D012554:Schistosomiasis japonica / Q000276:immunology* / Q000382:microbiology
D053663:Interleukin-13 Receptor alpha2 Subunit