Natural antibodies in human sera cross-reactive with type C RNA tumor viral P 30

Antibodies cross-reactive with type C viral p30 were concentrated from 105 samples of human plasma by affinity chromatography using Sepharose beads to which disrupted Simian sarcoma associated virus (SSAV) had been coupled. Eluates obtained from the affinity beads were tested for anti-p30 activity by performing radio-immunoprecipitations with 125I-labeled SSAV p30 and Rauscher murine leukemia viral (R-MuLV) p30. Forty six percent of the eluates were found positive when tested against SSAV p30. From 44 positive eluates for anti SSAV p30 activity, 20 (45%) were also found to be positive for anti-R-MuLV p30 activity. No significant difference was found in anti-p30 activity in eluates from normal controls and from patients with various kinds of malignancy.