Activated retinitis pigmentosa peripheral lymphocytes adhere to and alter cultured human retinal pigment epithelial cells.
Interleukin-2 receptor (IL-2R) is an activation molecule that, when expressed on peripheral blood lymphocyte (PBL) membranes, indicates the secretion of IL-2 and initiation of an immune system activation cascade. Comparing the average of IL-2R expression in 34 patients with retinitis pigmentosa (RP) syndrome (561 +/- 282 cells/mm3; mean +/- standard deviation) with 35 age-matched normal subjects (194 +/- 39 cells/mm3), it was found that those with RP had greater numbers of IL-2R-positive cells (P less than 0.001). The increased amounts of IL-2R on PBL of 29 RP and the homotypic self-aggregation of RP PBL by phase and scanning electron microscopy led to the study of the interaction of RP PBL with cultured human postmortem retinal pigment epithelial cells (RPE). A direct correlation was found between the amount of IL-2R expression and the numbers of RP lymphocytes adhering to RPE monolayers. However, the adherence effect was not unique to RP syndrome but appeared to be a nonspecific result of lymphocyte activation. Greater adherence to RPE than normal also was observed in PBL from disease control subjects with elevated IL-2R values and in PBL stimulated by the mitogen, concanavalin A (Con-A). In addition, RPE monolayers were destroyed by Con-A-stimulated PBL that showed 95-98% IL-2R expression. Similar, but less serious effects, occurring in RPE cells after 1 wk's cocultivation with RP PBL, suggested that activated RP lymphocytes can be cytotoxic to RPE during prolonged contact. Because macrophage-like cells and class II major histocompatibility complex expression have been found in RP-affected retinas, immune-mediated cytopathologic effects may contribute to retinal degeneration in RP.
Williams
L L
LL
Department of Ophthalmology, Ohio State University College of Medicine, Columbus.
Lew
H M
HM
Shannon
B T
BT
Singley
C T
CT
Chambers
R B
RB
Davidorf
F H
FH
D000293:Adolescent; D000328:Adult; D000368:Aged; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002478:Cells, Cultured; D002648:Child; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism / Q000648:ultrastructure*; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010857:Pigment Epithelium of Eye / Q000378:metabolism / Q000648:ultrastructure*; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D012174:Retinitis Pigmentosa / Q000378:metabolism / Q000473:pathology
D015815:Cell Adhesion Molecules; D016169:Lymphocyte Function-Associated Antigen-1; D015375:Receptors, Interleukin-2