Production of antisera against porcine haptoglobin: potential for distinguishing haptoglobin subunits

Haptoglobin (Hp) is one of the acute phase proteins (APPs) that help to alleviate the immune oxidative damage. The present study expressed a truncated porcine Hp in Escherichia coli and produced rabbit and mouse antisera to the recombinant protein, in order to investigate Hp levels in sera from piglets infected with porcine reproduction and respiratory syndrome virus (PRRSV). Antisera prepared revealed both chains of porcine Hp in Western blot, and mouse antisera showed stronger binding activities than the rabbit antisera. With the combination of Hp monoclonal antibodies, this study confirmed that serum Hp was increased in piglets infected with PRRSV and offered a tool to know about subunit levels of Hp in porcine serum. But Hp itself could not be used as a specific biomarker for PRRSV infection, for elevated Hp levels were also obtained from pigs infected with other pathogens.