alphaB-crystallin protects retinal tissue during Staphylococcus aureus-induced endophthalmitis

Infect Immun. 2008 Apr;76(4):1781-90. doi: 10.1128/IAI.01285-07. Epub 2008 Jan 28.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Bacterial Proteins / metabolism
  • Caspase 3 / genetics
  • Caspase 3 / metabolism
  • Endophthalmitis / microbiology*
  • Female
  • Gene Expression Regulation, Enzymologic
  • Male
  • Mice
  • Mice, Knockout
  • Peptide Hydrolases / metabolism
  • Retina / cytology
  • Retina / metabolism*
  • Retina / microbiology
  • Staphylococcal Infections / metabolism*
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus*
  • Up-Regulation
  • alpha-Crystallin B Chain / genetics
  • alpha-Crystallin B Chain / metabolism*

Substances

  • Bacterial Proteins
  • Cryab protein, mouse
  • alpha-Crystallin B Chain
  • Peptide Hydrolases
  • Caspase 3