TGF-beta 2 and TGF-beta 3 immunoreactivity within the ciliary epithelium [corrected].

PURPOSE: To determine whether the ciliary epithelium exhibits immunoreactivity for antibodies to transforming growth factor beta (TGF-beta) 2 and TGF-beta 3. The hypothesis was that because the aqueous humor contains mainly biologically active TGF-beta 2, with little TGF-beta 1, the epithelium largely responsible for its composition would also contain this isoform of TGF-beta. The authors anticipated TGF-beta 3 immunoreactivity because TGF-beta 3 often co-localizes with TGF-beta 2.

METHODS

The authors followed a standard immunohistochemical protocol using the avidin-biotin complex and newly available rabbit antibodies to synthetic peptide sequences of TGF-beta 2 and TGF-beta 3. Formalin-fixed, paraffin-embedded samples of freshly obtained rabbit and human autopsy eyes were studied. Specificity was supported by specific peptide absorption of antisera before tissue incubation.

RESULTS

The pigmented and nonpigmented ciliary epithelia of rabbit and human eyes were stained by antibodies to both TGF-beta 2 and TGF beta-3, and the staining was inhibited by preabsorption of antibodies by peptides of TGF-beta 2 and TGF-beta 3.

CONCLUSIONS

The authors conclude that the ciliary epithelium exhibits TGF-beta 2- and TGF-beta 3-like immunoreactivity that, based upon complementary work from other laboratories, is probably synthesized by this epithelium and is not simply absorbed by it from the aqueous humor.