High levels of bcl-2 protein in circulating T lymphocytes, but not B lymphocytes, of patients with systemic lupus erythematosus.
OBJECTIVE
Defective regulation of programmed cell death (apoptosis) may play a role in the development of autoimmune diseases, and the proto-oncogene bcl-2 is involved in the control of apoptosis in immunocompetent cells. We therefore wished to investigate the expression of bcl-2 in the peripheral lymphocytes of patients with systemic lupus erythematosus (SLE), a prototypical autoimmune disease.


METHODS
Levels of bcl-2 expression in the lymphocytes of patients with SLE and, for comparison, in the lymphocytes of healthy controls and patients with rheumatoid arthritis (RA), systemic bacterial infections, and chronic B cell lymphocytic leukemia were studied by 2-color cytofluorography and RNA analysis.


RESULTS
In SLE patients, a significant proportion of T cells expressed increased amounts of bcl-2 protein. By fluorescence-activated cell sorter analysis, bcl-2--enriched lymphocytes were found in the CD45RO+ as well as in the CD45RO-, and also in the CD4+ and CD8+, lymphocyte subpopulations. Mononuclear cells of patients with SLE showed increased amounts of bcl-2 messenger RNA. An increased percentage of strongly bcl-2 positive peripheral T lymphocytes was found in patients with bacterial infections, but not in those with RA.


CONCLUSIONS
Although the occurrence of circulating T lymphocytes with abnormally high bcl-2 expression is not specific for SLE, it is evidence for a dysregulation of lymphocytic programmed cell death in this autoimmune disease.
Aringer
M
M
University of Vienna, Austria.
Wintersberger
W
W
Steiner
C W
CW
Kiener
H
H
Presterl
E
E
Jaeger
U
U
Smolen
J S
JS
Graninger
W B
WB
D000293:Adolescent; D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000737:chemistry*; D001483:Base Sequence; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood*; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger / Q000032:analysis; D012720:Severity of Illness Index; D013601:T-Lymphocytes / Q000737:chemistry*
C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger