Roles of CD4+CD25+ T cells in the development of experimental murine allergic conjunctivitis.
BACKGROUND
CD25+ regulatory T (T reg) cells play a suppressive role in experimental autoimmune uveoretinitis as well as experimental airway inflammation but their involvement in the development of allergic conjunctivitis (AC) remains unclear. We therefore investigated whether T reg cells play a role in the development of experimental AC (EC).


METHODS
BALB/c and C57BL/6 mice were actively immunized with ragweed (RW). The mice were treated with an anti-CD25 Ab (PC61) or control normal rat IgG (nrIgG) either 2 days prior to active immunization or during the induction phase (days 0, 2, 4, 6 and 8). Ten days after active immunization, the mice were challenged with RW-containing drops. Twenty-four hours after the challenge, the conjunctivas were harvested for histological analysis of eosinophil infiltration, and the spleens were harvested for cell culture for splenocyte transfer. Cultured splenocytes were transferred into syngeneic mice, and 4 days after the transfer, the recipient mice were challenged with RW. Twenty-four hours after the challenge, conjunctivas were collected for histological analysis.


RESULTS
Pretreatment with PC61 did not affect EC in either strain of mice; however, treatment with PC61 during the induction phase significantly suppressed EC in C57BL/6 mice. In contrast, transfer of RW-primed splenocytes from mice treated with PC61 induced EC that was significantly more severe regardless of strain and treatment protocol.


CONCLUSIONS
The finding that T reg cells play a suppressive role in the development of EC in splenocyte transfer experiments suggests that modulation of T reg cells may be a possible therapy for AC.
Fukushima
Atsuki
A
Department of Ophthalmology, Kochi Medical School, Kohasu, Oko-cho, Nankoku-city, 783-8505, Japan. fukusima@med.kochi-u.ac.jp
Yamaguchi
Tomoko
T
Sumi
Tamaki
T
Fukuda
Ken
K
Kumagai
Naoki
N
Nishida
Teruo
T
Takeuchi
Masaru
M
Taguchi
Osamu
O
Ueno
Hisayuki
H
D019264:Adoptive Transfer; D000485:Allergens; D031164:Ambrosia; D000818:Animals; D015704:CD4 Antigens / Q000276:immunology*; D003233:Conjunctivitis, Allergic / Q000209:etiology* / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D005434:Flow Cytometry; D007074:Immunoglobulin G / Q000627:therapeutic use; D053645:Interleukin-2 Receptor alpha Subunit / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013154:Spleen / Q000166:cytology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*; D014611:Vaccination
D000485:Allergens; D015704:CD4 Antigens; D016207:Cytokines; D007074:Immunoglobulin G; D053645:Interleukin-2 Receptor alpha Subunit