Antibodies to the HIV-1 p17 protein cross-react with human superoxide dismutase-2

Antibodies reacting with the gag protein p17 of the human immunodeficiency virus type 1 (HIV-1) can occasionally be found in the serum of non-HIV-1-infected individuals. Conversely, anti-p17 antibodies can also react with human tissues from non-infected individuals. Here we report on the isolation from human liver of a molecule that is immunoreactive with anti-p17 antibodies. This molecule was purified to homogeneity and identified as superoxide dismutase-2 (manganese type SOD). Both human SOD-2 and HIV-1 p17 contain the LQPALK hexapeptide which may serve as a common antigenic determinant. This study indicates that human SOD-2 is a target for anti-p17 antibodies and suggests that HIV-1-negative individuals may possess SOD-2 auto-antibodies that cross-react with HIV-1 p17.