[Expressional changes of Th1 and Th2 cells in retina of a rat glaucoma model vaccinated by Cop-1].
OBJECTIVE
To explore the morphological and expressional changes of Th1 cells and Th2 cells in retina of a rat model of glaucoma vaccinated by Cop-1 (Copolymer-1) and elucidate the possible neuroprotection roles played by Th1/Th2.


METHODS
After modeling, the aqueous outflow from the right eyes was blocked by a ligation of three of four episcleral veins. There were 48 rats with elevated IOP (intraocular pressure) immunized by Cop-1 (Cop-1 group), 48 rats with elevated IOP immunized by PBS (phosphate-buffered saline) (PBS group) and 10 rats without any treatment (normal group). The experimental rats were immunized with Cop-1/PBS emulsified in a total volume of 0.4 ml complete Freund's adjuvant. The immunization was administered subcutaneously at the base of tail. Immunofluorescence was employed to test the distribution and activation of Th1 and Th2 cells in retina at Days 3, 7, 10, 17, 24 and 31 post-immunization respectively for each group. Western blot was selectively performed according to the results of immunofluorescence to verify if there was a similar variation of the retinal expression of IL-4 protein.


RESULTS
The results of immunofluorescence showed the numbers of Th1 cells peaked at Day 7 in both Cop-1 ((216 ± 21)/mm(2)) and PBS groups ((194 ± 27)/mm(2)). And no statistical significance existed between two groups (P > 0.05). The numbers of Th2 cells in the experimental groups peaked at Day 7 with statistical significance (Cop-1 group: 300 ± 28/mm(2) vs PBS group: 129 ± 27/mm(2)) (P < 0.01). With the prolongation of experimental period, the number of Th2 cells decreased gradually in the Cop-1 group but remained greater than that of the PBS group afterward (P < 0.05). The Western blot results showed that the expression of IL-4 in the Cop-1 group (1.91 ± 0.05) was significantly higher than that of the PBS group (0.51 ± 0.04) from Day 3 and peaked at Day 7 (2.11 ± 0.06 vs 0.57 ± 0.05). Then the IL-4 expression decreased gradually in the COP-1 group but still represented statistical significance versus the PBS group until Day 31 post-immunization (P < 0.001).


CONCLUSIONS
The retinal activation and accumulation of IL-4 are found in a rat model of chronic glaucoma immunized by Cop-1. Thus Th2 cells may play vital roles in the Cop-1-induced neuroprotective autoimmune responses.
Department of Ophthalmology, Fudan University, Shanghai, China.
Li-na
LN
Cheng
Shao-hong
SH
Qian
Xing-huai
XH
Sun
Jie
J
Tian
Ya-ting
YT
Tang
Yang
Y
Wang
D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D000068717:Glatiramer Acetate; D005901:Glaucoma / Q000276:immunology*; D015847:Interleukin-4 / Q000276:immunology; D010455:Peptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000276:immunology*; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018417:Th1 Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D018418:Th2 Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*
D010455:Peptides; D015847:Interleukin-4; D000068717:Glatiramer Acetate