Qa-1, a nonclassical MHC molecule with immunomodulatory functions, is ubiquitously expressed in the immune-privileged anterior chamber of the eye.
OBJECTIVE
To determine whether the MHC class Ib gene, Qa-1, is expressed in the tissues that surround the immune-privileged anterior chamber (AC) of the murine eye.


METHODS
Transcription of Qa-1 mRNA in BALB/c ocular tissues was analyzed by reverse transcription-polymerase chain reaction. Expression of Qa-1 protein was assessed on ocular frozen tissue sections by immunohistochemistry, and within aqueous humor by western blotting.


RESULTS
Transcription of Qa-1 was found in all tissues surrounding the AC of the eye. Immunohistological staining revealed Qa-1 expression on corneal endothelium, corneal epithelium, and lens epithelium. No soluble Qa-1 was detected in aqueous humor.


CONCLUSIONS
Qa-1, unlike other MHC class I molecules, is ubiquitously expressed in tissues surrounding the AC of the eye, raising the possibility that Qa-1 plays a role in creating and maintaining ocular immune privilege.
Kim
Charles Y
CY
Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA. cykim@vision.eri.harvard.edu
Masli
Sharmila
S
Streilein
J Wayne
JW
D000818:Animals; D000867:Anterior Chamber / Q000276:immunology; D015153:Blotting, Western; D002460:Cell Line; D002472:Cell Transformation, Viral; D002924:Ciliary Body / Q000378:metabolism; D004728:Endothelium, Corneal / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism*; D019573:Epithelium, Corneal / Q000378:metabolism*; D015870:Gene Expression; D006183:H-2 Antigens / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry; D007498:Iris / Q000378:metabolism; D007908:Lens, Crystalline / Q000166:cytology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D006183:H-2 Antigens; D015395:Histocompatibility Antigens Class I; C032907:Q surface antigens; D012333:RNA, Messenger