Apoptotic retinal cell death induced by antirecoverin autoantibodies of cancer-associated retinopathy.
Invest Ophthalmol Vis Sci
; 38(2): 283-91, 1997 Feb.
Article
em En
| MEDLINE
| ID: mdl-9040460
ABSTRACT
PURPOSE:
Recoverin has been identified as a target autoantigen for antirecoverin antibodies found in the sera of some patients with cancer-associated retinopathy. The aim of this study was to investigate the role of antirecoverin antibodies in cancer-associated retinopathy.METHODS:
Human, rat, and rabbit antirecoverin antibodies were purified using a recoverin-affinity column. Purified biotinylated antibodies were cultured with recoverin-positive rat retinal cells E1A.NR3. Antibody uptake by retinal cells in vitro was analyzed by immunocytochemistry. Cytotoxic effect of antibodies on retinal cells was measured by the MTT colorimetric method. Apoptosis was shown by the ladder DNA fragmentation method and by fluorescent dye chromatin fragmentation analysis.RESULTS:
Antirecoverin antibodies obtained either from sera from five cancer-associated retinopathy patients or from sera of immunized animals were internalized by E1A.NR3 cells. Only specific, antirecoverin antibodies produced destruction of the cells in a dose- and time-dependent manner. Normal immunoglobulin G did not have such effects on retinal cells. No additional cell destruction was observed in the presence of complement as compared with cultures incubated with antirecoverin antibodies alone. Internucleosomal DNA fragmentation and presence of apoptotic cells was observed throughout the culture treated with recoverin specific antibodies but not with normal antibodies. Cells not expressing recoverin (Y79, PC12, and GH3) were not susceptible to cell destruction because of antirecoverin antibody action.CONCLUSIONS:
These studies showed that antibodies specific to recoverin are able to enter and cause death of cells expressing recoverin. In humans, autoantibodies originally elicited against recoverin expressed in tumor cells may damage retinal photoreceptors and play a role in the pathogenesis of cancer-associated retinopathy. Results suggest that autoantibody to recoverin, when given access to recoverin in the retina through the blood-retina barrier, could initiate photoreceptor degeneration leading to blindness. Such mechanism may be common for other paraneoplastic disorders or autoimmune diseases where antibodies interfere with the normal cell physiology.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Retina
/
Autoanticorpos
/
Proteínas de Ligação ao Cálcio
/
Apoptose
/
Proteínas do Olho
/
Lipoproteínas
/
Antígenos de Neoplasias
/
Proteínas do Tecido Nervoso
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Invest Ophthalmol Vis Sci
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos