Tissue c-myc protein expression and immune response in systemic lupus erythematosus

Frozen sections of kidney tissue from 12 patients with systemic lupus erythematosus were examined for the expression of oncogene proteins. Polyclonal rabbit antibody to c-myc peptide or to whole 65,000 D c-myc protein, was used to identify c-myc protein within tissue sections. Patterns of nuclear staining in the Hep-2 cell line were similar to those seen with monospecific human SLE sera showing anti-Sm reactivity. In addition c-myc staining was not abolished by prior incubation of tissue sections with human serum containing anti-Sm antibodies. Five of 12 kidney biopsy tissues from patients with systemic lupus erythematosus (SLE) showed positive speckled c-myc protein staining within nuclei of monocyte/macrophage cells of glomerular tufts. Positive staining was in all instances completely abolished by prior absorption of anti-c-myc antibody with c-myc protein. No c-myc protein was identified within SLE immune complex deposits.