Monoclonal autoantibodies recognizing histone variants

Balb/c mice were immunized with affinity purified Ro(SS-A) from human origin in order to allow the preparation of monoclonal anti-Ro(SS-A) antibodies. After fusion of mouse myeloma cells (line Sp2/0 A914) with spleen cells from one of these mice, anti-Ro(SS-A) monoclonals were not obtained, but, instead, two IgM producing hybridomas reactive with histone H1 and one with histone H2B. The specificity of the anti-H1 monoclonals was investigated by means of immunoblotting of very lysine-rich histone variants from mouse which were separated by two-dimensional gelelectrophoresis. One of them (CLB-ANA 105) has H1 o specificity with respect to the histone variants of mouse and man, but recognizes H5 as well as H5 from Xenopus laevis Another monoclonal (CLB-ANA 108) reacts with the variant H1 c from mouse, exclusively. From the way these monoclonals were produced, we postulate that they were not the result of immunization, but comprise specifities of naturally occurring autoantibodies. © 1988 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted