Others, however, are closely studying the immune-system biochemistries of pigs and humans to find more classical, drug-based approaches to effective xenotransplantation. The first aim in both cases is the same -- to defeat the devastating and nearly immediate hyperacute rejection of pig organs by the human immune system, orchestrated by antibodies and involving powerful complement proteins, that otherwise occurs.
For example, T Cell Sciences Inc., a publicly traded biotech in Needham, Mass., is working on an injectable complement inhibitor, a substance the company calls sCR1, or soluble complement receptor type 1. This agent is a soluble form of the naturally occurring complement regulator CR1, which occurs on the surface of red cells. The soluble form has been liberated from the cell surface and can be administered intravenously.
LOOKING TOWARD TOLERANCE: Novel drug therapies could get xenotransplant patients over the organ-rejection "hump" to immune accommodation, syas T Cell Sciences' vice president ...