title: Retinal ganglion cell loss is accompanied by antibody depositions and increased levels of microglia after immunization with retinal antigens.
abstract: BACKGROUND
  Antibodies against retinal and optic nerve antigens are detectable in glaucoma patients. Recent studies using a model of experimental autoimmune glaucoma demonstrated that immunization with certain ocular antigens causes an immun-mediated retinal ganglion cell loss in rats.
  
  
  RESULTS
  Rats immunized with a retinal ganglion cell layer homogenate (RGA) had a reduced retinal ganglion cell density on retinal flatmounts (p = 0.007) and a lower number of Brn3(+) retinal ganglion cells (p = 0.0001) after six weeks. The autoreactive antibody development against retina and optic nerve was examined throughout the study. The levels of autoreactive antibodies continuously increased up to 6 weeks (retina: p = 0.004; optic nerve: p = 0.000003). Additionally, antibody deposits were detected in the retina (p = 0.02). After 6 weeks a reactive gliosis (GFAP density: RGA: 174.7±41.9; CO: 137.6±36.8, p = 0.0006; %GFAP(+) area: RGA: 8.5±3.4; CO: 5.9±3.6, p = 0.006) as well as elevated level of Iba1(+) microglia cells (p = 0.003) was observed in retinas of RGA animals.
  
  
  CONCLUSIONS
  Our findings suggest that these antibodies play a substantial role in mechanisms leading to retinal ganglion cell death. This seems to lead to glia cell activation as well as the invasion of microglia, which might be associated with debris clearance.
authors: Experimental Eye Research Institute, Ruhr University Eye Hospital, Bochum, Germany. stephanie.joachim@rub.de
authors: Stephanie C
authors: SC
authors: Joachim
authors: Oliver W
authors: OW
authors: Gramlich
authors: Panagiotis
authors: P
authors: Laspas
authors: Heiko
authors: H
authors: Schmid
authors: Sabine
authors: S
authors: Beck
authors: Harald D
authors: HD
authors: von Pein
authors: H Burkhard
authors: HB
authors: Dick
authors: Norbert
authors: N
authors: Pfeiffer
authors: Franz H
authors: FH
authors: Grus
mesh_terms: D000818:Animals; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects / Q000276:immunology; D005901:Glaucoma / Q000276:immunology* / Q000473:pathology; D007114:Immunization; D008297:Male; D017628:Microglia / Q000276:immunology* / Q000473:pathology; D051381:Rats; D011917:Rats, Inbred Lew; D012165:Retinal Ganglion Cells / Q000276:immunology* / Q000473:pathology
chemical_list: D001323:Autoantibodies; D001324:Autoantigens