Endogenous IL-17 does not play a significant role in the development of experimental murine allergic conjunctivitis.
BACKGROUND
Endogenous IL-17 is needed for the Ag sensitization that results in murine allergic asthma, a Th2-mediated disease. Here, we aimed to investigate the role IL-17 plays in the development of murine experimental allergic conjunctivitis (EC) which is also a Th2-mediated disease.


METHODS
To induce EC, wild-type (WT) and IL-17-deficient (IL-17 KO) mice on the BALB/c and C57BL/6 backgrounds were immunized with ragweed (RW) in alum and challenged with RW in eye drops. Alternatively, EC was induced by adoptively transferring RW-primed splenocytes followed by challenge with RW-containing eye drops. Twenty-four hours after the RW challenge, the conjunctivas and spleens were harvested for histological analyses and cytokine assays, respectively.


RESULTS
The WT and IL-17 KO mice on both backgrounds did not differ in terms of the severity of actively induced EC, as evaluated by the conjunctival eosinophil infiltration. They also did not differ with regard to the phenotypes of the inflammatory cells infiltrating the conjunctivas, although primed IL-17 KO splenocytes stimulated in vitro with RW extract did produce significantly higher amounts of IL-4, IL-13 and IFN-gamma than WT splenocytes. Reciprocal adoptive transfer experiments also demonstrated that the IL-17 from both the donor splenocytes and the recipient mice is not involved in the development of EC.


CONCLUSIONS
Endogenous IL-17 does not appear to play a significant role in the development of EC.
Fukushima
Atsuki
A
Department of Ophthalmology, Kochi Medical School, Nankoku, Japan. fukusima@kochi-u.ac.jp
Sumi
Tamaki
T
Ishida
Waka
W
Yamada
Jun
J
Iwakura
Yoichiro
Y
Ueno
Hisayuki
H
D019264:Adoptive Transfer; D031164:Ambrosia / Q000009:adverse effects / Q000276:immunology; D000818:Animals; D003228:Conjunctiva / Q000276:immunology; D003233:Conjunctivitis, Allergic / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology*; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D004804:Eosinophils / Q000276:immunology*; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
D016207:Cytokines; D020381:Interleukin-17