Kh. Sun et al., Monoclonal antibodies against human ribosomal P proteins penetrate into living cells and cause apoptosis of Jurkat T cells in culture, RHEUMATOLOG, 40(7), 2001, pp. 750-756
Objective. This study was designed to determine the role or autoantibodies
to the ribosomal P protein (anti-P Abs) in the pathogenesis of systemic lup
us 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 reactivi
ties of these mAbs to P proteins, their binding and penetration capabilitie
s 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 c
ells and lung cancer cells via the P0 surface protein. Treatment with the m
Ab 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%).
Conclusion. Anti-P autoantibodies may play a role in the pathogenesis of ly
mphopenia or lymphocyte dysfunction in SLE.