Open AccessHigh levels of bcl ‐2 protein in circulating t lymphocytes, but not b lymphocytes, of patients with systemic lupus erythematosus
Author(s) -
Aringer Martin,
Wintersberger Winfried,
Steiner Carl W.,
Kiener Hans,
Presterl Elisabeth,
Jaeger Ulrich,
Smolen Josef S.,
Graninger Winfried B.
Publication year - 1994
Publication title -
arthritis & rheumatism
Language(s) - English
Resource type - Journals
eISSN - 1529-0131
pISSN - 0004-3591
DOI - 10.1002/art.1780371004
Subject(s) - immunology , autoimmune disease , peripheral blood mononuclear cell , cd8 , apoptosis , medicine , rheumatoid arthritis , lymphocyte , t cell , lupus erythematosus , autoimmunity , immune system , antibody , biology , biochemistry , in vitro
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. Conclusion . 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.