Anti-ribosomal and 'P-peptide'-specific autoantibodies bind to T lymphocytes.
Patients with systemic lupus erythematosus (SLE) frequently have anti-lymphocyte autoantibodies, some of which also bind to surfaces of neurons. Since anti-ribosomal P protein autoantibodies (anti-P) from SLE patients also bind to surfaces of neurons, we hypothesized that anti-P are anti-lymphocyte antibodies. A panel of human T lymphocytes was evaluated for anti-P binding by indirect immunofluorescence. Affinity-purified anti-ribosomal antibodies were used as a source of anti-P. These autoantibodies bound to the surfaces of all transformed T cell lines tested. This binding was not mediated by Fc receptors. It was inhibitable by ribosomes. Anti-P bound to circulating T lymphocytes from healthy adults and children. They also bound to thymocytes and cord blood T cells from normal neonates. Circulating T cells from SLE patients with anti-P bound less anti-P than cells from healthy controls. Two patients were studied on multiple occasions. The capacity of their T cells to bind anti-P correlated inversely with titres of anti-ribosomal antibodies. Anti-ribosomal antibodies, other than anti-P, also appear to bind to T cells. The surface of T cells contains a protein with the size and antigenicity of the ribosomal P protein, P0. We conclude that anti-ribosomal antibodies are a subset of anti-lymphocyte autoantibodies. Their possible role in the pathogenesis of lymphopenia or lymphocyte dysfunction in SLE has to be defined in further studies.
Stafford
H A
HA
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma Medical Research Foundation, Oklahoma City 73104, USA.
Chen
A E
AE
Anderson
C J
CJ
Paul
A G
AG
Wyatt
E L
EL
Lee
L A
LA
Neas
B R
BR
D000293:Adolescent; D000328:Adult; D000961:Antilymphocyte Serum / Q000032:analysis* / Q000276:immunology*; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D002846:Chromatography, Affinity; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007231:Infant, Newborn; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008231:Lymphopenia / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015800:Protozoan Proteins; D011961:Receptors, Fc / Q000276:immunology; D012269:Ribosomal Proteins / Q000276:immunology* / Q000302:isolation & purification; D012270:Ribosomes / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000961:Antilymphocyte Serum; C064601:L12E protein, Trypanosoma cruzi; D015800:Protozoan Proteins; D011961:Receptors, Fc; D012269:Ribosomal Proteins