alphaB-crystallin protects retinal tissue during Staphylococcus aureus-induced endophthalmitis.
Bacterial infections of the eye highlight a dilemma that is central to all immune-privileged sites. On the one hand, immune privilege limits inflammation to prevent bystander destruction of normal tissue and loss of vision. On the other hand, bacterial infections require a robust inflammatory response for rapid clearance of the pathogen. We demonstrate that the retina handles this dilemma, in part, by activation of a protective heat shock protein. During Staphylococcus aureus-induced endophthalmitis, the small heat shock protein alphaB-crystallin is upregulated in the retina and prevents apoptosis during immune clearance of the bacteria. In the absence of alphaB-crystallin, mice display increased retinal apoptosis and retinal damage. We found that S. aureus produces a protease capable of cleaving alphaB-crystallin to a form that coincides with increased retinal apoptosis and tissue destruction. We conclude that alphaB-crystallin is important in protecting sensitive retinal tissue during destructive inflammation that occurs during bacterial endophthalmitis.
Whiston
Emily A
EA
The Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, Massachusetts 02114, USA.
Sugi
Norito
N
Kamradt
Merideth C
MC
Sack
Coralynn
C
Heimer
Susan R
SR
Engelbert
Michael
M
Wawrousek
Eric F
EF
Gilmore
Michael S
MS
Ksander
Bruce R
BR
Gregory
Meredith S
MS
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001426:Bacterial Proteins / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D009877:Endophthalmitis / Q000382:microbiology*; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010447:Peptide Hydrolases / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000378:metabolism* / Q000382:microbiology; D013203:Staphylococcal Infections / Q000378:metabolism* / Q000382:microbiology; D013211:Staphylococcus aureus; D015854:Up-Regulation; D038203:alpha-Crystallin B Chain / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; C525420:Cryab protein, mouse; D038203:alpha-Crystallin B Chain; D010447:Peptide Hydrolases; D053148:Caspase 3