TY - JOUR
T1 - Interferon-γ immunoreactivity in rat iris nerve fibres during endotoxin-induced uveitis
AU - De Vos, Alex F.
AU - Yang, Peizeng
AU - Kijlstra, Aize
PY - 1996/2/15
Y1 - 1996/2/15
N2 - Purpose. Previous studies by us and others have revealed that interferon-γ (IFN-γ) mRNA expression is upregulated in the anterior uvea during endotoxin/LPS-induced uveitis (EIU) in the rat. In the present study, we have investigated the source of IFN-γ in the iris during EIU. Methods. Iris wholemounts were isolated from Lewis rats before and at 4, 8, 16, 24, 48, 96 hours and 7, 10 or 14 cays after foot pad injection of 200 μg LPS. Immunohistology was performed using monoclonal antibodies DB12 and DB13, specific to rat IFN-γ. RT-PCR analysis was used to determine mRNA expression of IFN-γ and (activated) T cell markers, including CD-3, interleukin 2 (IL-2), IL-4, IL-10 and lymphotoxin (LT) at 48 hours. Results. IFN-γ immunoreactive cells were not detected in iris wholemounts of control rats. Strikingly, nerve fibres stained for IFN-γ from 4 hours until 10 days after LPS injection, with maximal staining at 24 to 48 hours. Although nerve fibres in all iris wholemounts stained at 48 hours, only a minor expression of IFN-γ mRNA was detected. Moreover, CD-3 and IL-2 mRNA expression was not found and only a slight signal for IL-4, IL-10 and LT mRNA was detected. Conclusions. These results indicate that iridal neurons may be an important source of intraocular IFN-γ during EIU in the rat and do not support the involvement of infiltrating activated T cells. The IFN-γ immunoreactive material in the iris nerve fibres may be identical to neuronal IFN-γ, a recently characterized cytokine with many properties of IFN-γ, and may contribute to the pathogenesis of EIU in the rat.
AB - Purpose. Previous studies by us and others have revealed that interferon-γ (IFN-γ) mRNA expression is upregulated in the anterior uvea during endotoxin/LPS-induced uveitis (EIU) in the rat. In the present study, we have investigated the source of IFN-γ in the iris during EIU. Methods. Iris wholemounts were isolated from Lewis rats before and at 4, 8, 16, 24, 48, 96 hours and 7, 10 or 14 cays after foot pad injection of 200 μg LPS. Immunohistology was performed using monoclonal antibodies DB12 and DB13, specific to rat IFN-γ. RT-PCR analysis was used to determine mRNA expression of IFN-γ and (activated) T cell markers, including CD-3, interleukin 2 (IL-2), IL-4, IL-10 and lymphotoxin (LT) at 48 hours. Results. IFN-γ immunoreactive cells were not detected in iris wholemounts of control rats. Strikingly, nerve fibres stained for IFN-γ from 4 hours until 10 days after LPS injection, with maximal staining at 24 to 48 hours. Although nerve fibres in all iris wholemounts stained at 48 hours, only a minor expression of IFN-γ mRNA was detected. Moreover, CD-3 and IL-2 mRNA expression was not found and only a slight signal for IL-4, IL-10 and LT mRNA was detected. Conclusions. These results indicate that iridal neurons may be an important source of intraocular IFN-γ during EIU in the rat and do not support the involvement of infiltrating activated T cells. The IFN-γ immunoreactive material in the iris nerve fibres may be identical to neuronal IFN-γ, a recently characterized cytokine with many properties of IFN-γ, and may contribute to the pathogenesis of EIU in the rat.
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M3 - Article
SN - 0146-0404
VL - 37
SP - S543
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 3
ER -