Human polyclonal antibodies (hPABs) are useful in the treatment of numerous diseases, but as they are currently only derived from human donors their use has been limited. However, in August 12 advanced online Nature Biotechnology, Yoshimi Kuroiwa and colleagues, from a joint venture between Hematech — a biotechnology company in Westport, Connecticut — and Kirin — a Japanese brewer with substantial pharmaceutical interests — show they have generated cloned calves that can produce significant amounts of human antibodies (Nat Biotechnol 2002, DOI:10.1038/nbt727).

Kuroiwa et al. prepared a human artificial chromosome (HAC) vector containing the entire unrearranged sequences of the human immunoglobulin (hIg) heavy-chain (H) and lambda (λ) light-chain loci. They used the HAC vector to produce cloned bovine fetuses, from which four healthy transchromosomic (Tc) calves were generated. They observed that the newborn Tc calves retained the HAC at a high rate (78–100% of cells) and of human immunoglobulin proteins could be detected in their blood.

"Therapeutic hPABs produced in a Tc bovine–based system may have broad application in the treatment and prevention of infectious disease (including antibiotic resistant infections), autoimmune disease and cancer," write the authors. But, "methods of reducing bovine Ig expression are probably needed before commercial production of hPABs can proceed in Tc cattle," they conclude.