Monoclonal antibodies against human ribosomal P proteins penetrate into living cells and cause apoptosis of Jurkat T cells in culture.
OBJECTIVE
This study was designed to determine the role of autoantibodies to the ribosomal P protein (anti-P Abs) in the pathogenesis of systemic lupus erythematosus (SLE) using monoclonal anti-P antibodies (anti-P mAbs).


METHODS
Anti-P mAbs were prepared by a standard hybridoma procedure using recombinant human P1 and P2 proteins as immunogens. We studied the reactivities of these mAbs to P proteins, their binding and penetration capabilities in different cell lines and their apoptotic effects on Jurkat T cells.


RESULTS
In addition to recognizing human P0, P1 and P2 proteins, the anti-P mAb 9B6-4 bound to 20-40% and penetrated 50-90% of astrocytes, Jurkat T cells and lung cancer cells via the P0 surface protein. Treatment with the mAb 9B6-4 also caused increases in the percentages of Jurkat T cells in the sub-G1 phase of the cell cycle (14.8%) and undergoing apoptosis (21.3%).


CONCLUSIONS
Anti-P autoantibodies may play a role in the pathogenesis of lymphopenia or lymphocyte dysfunction in SLE.
Sun
K H
KH
Faculty of Medical Technology and Institute of Biotechnology in Medicine, National Yang-Ming University, Taipei, Taiwan.
Tang
S J
SJ
Lin
M L
ML
Wang
Y S
YS
Sun
G H
GH
Liu
W T
WT
D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism* / Q000494:pharmacology; D017209:Apoptosis; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D001323:Autoantibodies / Q000378:metabolism* / Q000494:pharmacology; D015153:Blotting, Western; D002452:Cell Count; D002453:Cell Cycle / Q000187:drug effects; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D019169:Jurkat Cells / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008180:Lupus Erythematosus, Systemic / Q000378:metabolism*; D008565:Membrane Proteins / Q000276:immunology; D051379:Mice; D015800:Protozoan Proteins; D051381:Rats; D011994:Recombinant Proteins / Q000276:immunology; D012269:Ribosomal Proteins / Q000276:immunology*
D000911:Antibodies, Monoclonal; D001323:Autoantibodies; C064601:L12E protein, Trypanosoma cruzi; D008565:Membrane Proteins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; D003609:Dactinomycin