Complex antibody profile changes in an experimental autoimmune glaucoma animal model.
OBJECTIVE
Increased serum antibodies against heat shock protein 27 (HSP27) have been identified in patients with glaucoma. Immunization with HSP27 caused retinal ganglion cell (RGC) loss in animals. The authors analyzed whether HSP27 immunization not only causes RGC loss but also affects systemic antibody patterns.


METHODS
Rats were immunized with HSP27 and were surveyed for 4, 5, and 6 weeks (groups 1-3). Control animals were humanely killed after 6 weeks (group 4). Intraocular pressure was measured before and 2 and 4 weeks after immunization. Fundus images were taken at the same time. Retinal flatmounts were prepared, and Brn-3a labeled RGCs were counted. Serum was collected during the study to detect antibody patterns against retinal antigens through Western blot analysis and mass spectrometry techniques. Patterns were analyzed by multivariate statistical techniques, and biomarkers were identified with the use of mass spectrometry.


RESULTS
No significant changes in intraocular pressure were observed, and no fundus abnormalities were noted. The animals immunized with HSP27 showed lower RGC density than controls (P < 0.05). Two and 4 weeks after immunization, we detected a significant difference in antibody profiles between groups 1 and 4 (P < 0.05) and groups 3 and 4 (P < 0.05). Proteins with different antibody level expression after immunization included heat shock protein 90, alpha-enolase, and glyceraldehyde-3-phosphate dehydrogenase.


CONCLUSIONS
After immunization with HSP27, animals showed IOP-independent RGC loss and changes in serum antibody patterns. Thus, this model might be a beneficial approach to study the development and effects of anti-retinal antibodies and their involvement in RGC loss.
Joachim
Stephanie C
SC
Experimental Ophthalmology, Department of Ophthalmology, Johannes Gutenberg University, Mainz, Germany.
Grus
Franz H
FH
Kraft
Daniela
D
White-Farrar
Kisha
K
Barnes
George
G
Barbeck
Mike
M
Ghanaati
Shahram
S
Cao
Shutong
S
Li
Byron
B
Wax
Martin B
MB
D000818:Animals; D001323:Autoantibodies / Q000097:blood*; D001327:Autoimmune Diseases / Q000276:immunology* / Q000473:pathology; D015551:Autoimmunity / Q000276:immunology; D015153:Blotting, Western; D002452:Cell Count; D004195:Disease Models, Animal; D005901:Glaucoma / Q000276:immunology* / Q000473:pathology; D055551:HSP27 Heat-Shock Proteins / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood; D007429:Intraocular Pressure; D008297:Male; D013058:Mass Spectrometry; D051381:Rats; D011917:Rats, Inbred Lew; D012165:Retinal Ganglion Cells / Q000473:pathology
D001323:Autoantibodies; D055551:HSP27 Heat-Shock Proteins; D007074:Immunoglobulin G