Antibody formation and transient immune complex glomerulopathy in A-strain mice with C1300 neuroblastoma tumors

One to three-month-old A-strain mice, inoculated subcutaneously with 2 x 10(6) viable syngeneic C1300 neuroblastoma cells (clone NB9R) developed a palpable tumor within 9-12 days and died within 28-30 days. A transient glomerulopathy developed after 16-24 days. Despite a normal histologic appearance, the nephropathy was clearly demonstrated by electron microscopy and was classified as a focal mesangiopathic glomerulonephritis. Deposits of host 7S-G immunoglobulins and C3 complement fragments were detected in these same kidneys by immunofluorescence. Radioimmunoprecipitin determinations on sera obtained from mice at different intervals from tumor cell inoculation, revealed that untreated mice contained circulating antibodies capable of reacting with 125I-labeled gp69-71 glycoprotein from Gross murine leukemia virus (MuLV). Antibodies to p30 MuLV antigen and to crude membrane antigen (s) (CMA) solubilized from NB9R cells were found in sera only after tumor cell inoculation. Circulating immune complexes formed by host 7S-G immunoglobulins were clearly detected from day 16 to 22. Antibodies eluted from kidneys with nephropathy were shown to react with NB9R cells in vitro and to react specifically with CMA and the p30 MuLV antigen.