C1q-binding immunoglobulin G in MRL/l mice consists of immune complexes containing antibodies to DNA.

Previous studies have shown that the majority of C1q-binding IgG in patients with systemic lupus erythematosus (SLE) is composed of autoantibodies to the collagen-like region of C1q. Mice of the MRL/l strain are considered as a murine model of human SLE and possess autoantibodies to nuclear antigens as well as IgM and IgG rheumatoid factors (RF). This study was undertaken to characterize the C1q-binding IgG in MRL/l mice.

The structural basis of germline-encoded VH3 immunoglobulin binding to staphylococcal protein A.

The ability of human VH3 immunoglobulins (Ig) to bind to staphylococcal protein A (SPA) via their Fab region is analogous to the binding of bacterial superantigens to T cell receptors. The present report establishes the structural basis for the interaction of SPA and VH3 Ig. We have studied a panel of 27 human monoclonal IgM that were derived from fetal B lymphocytes.

Emerging human B cell repertoire. Influence of developmental stage and interindividual variation.

In B cell precursors developing in fetal lymphopoietic tissue, the selection of VH, DH, and JH gene segments for initial H chain gene assembly is biased. The present study was designed to determine whether these biases persist in fully developed human fetal B cells and to examine specificities encoded by the favored elements. B cells were prepared from two sites representing different stages of development, i.

Sequence analysis and idiotypic relationships of BEG-2, a human fetal antibody reactive with DNA.

Monoclonal antibody (mAb) BEG-2 is a dsDNA binding IgM lambda derived from a 12-week human fetus. Two binding site idiotypes (BEG-2 Id alpha and BEG-2 Id beta) have been defined with the use of polyclonal rabbit anti-idiotypic anti-serum. BEG-2 Id alpha is located on the lambda light chain and has been described previously.

A vasculopathy with deposition of lambda light chain crystals.

An 82-year-old man and a 34-year-old woman developed subacute, obstructive, fatal vasculopathies characterized by extensive crystalline tissue deposits and monoclonal lambda light chain serum components. Cryocrystalglobulinemia was also present in one patient, and the purified crystals contained only lambda light chain dimers. Although the presentation of these patients resembled that of systemic necrotizing vasculitis, histologic evidence of inflammation was lacking and their subsequent rapid clinical deterioration was not altered by corticosteroid therapy, and in one case cyclophosphamide and plasmapheresis.