Expression of interleukin-15 and its receptor by human fetal retinal pigment epithelial cells.
OBJECTIVE
IL-15 and IL-15 receptor expression was measured in retinal pigment epithelial (RPE) cells to support a possible role of IL-15 in ocular inflammatory and immune responses.


METHODS
Reverse transcription-coupled polymerase chain reaction (RT-PCR) and Northern blot analysis of IL-15 mRNA in previously characterized non-transformed and simian virus (SV)-40 transformed human fetal RPE cells were carried out. Biological activities of IL-15 produced by the RPE cells were assayed by co-culture with IL-15 responsive cells. Expression of the IL-15 receptor (IL-15R) alpha, IL-2R beta and gamma chains were examined by RT-PCR.


RESULTS
Both non-transformed and SV-40 transformed human fetal RPE cells express IL-15, a T cell growth factor which has similar biological activities to IL-2, and the expression of IL-15 is enhanced by interferon-gamma (IFN-gamma) or tumor necrosis factor-alpha (TNF-alpha) stimulation. In addition, transcripts for all three IL-15 receptor components (IL-15R alpha, IL-2R beta and IL-2R gamma) were detected in these cells.


CONCLUSIONS
RPE cells produce IL-15, which may play an important role in ocular immune and inflammatory responses by stimulating infiltrated T cells and RPE cells via paracrine and autocrine loops, respectively.
Kumaki
N
N
Department of Ophthalmology, Tohoku University School of Medicine, Sendai, Japan.
Anderson
D M
DM
Cosman
D
D
Kumaki
S
S
D015152:Blotting, Northern; D015139:Blotting, Southern; D002461:Cell Line, Transformed / Q000378:metabolism; D017931:DNA Primers; D005333:Fetus; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D019409:Interleukin-15 / Q000096:biosynthesis*; D015345:Oligonucleotide Probes; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects / Q000196:embryology / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D053647:Receptors, Interleukin-15; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D015854:Up-Regulation
D017931:DNA Primers; C508024:IL15RA protein, human; D019409:Interleukin-15; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D053647:Receptors, Interleukin-15; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma