Immunity transplant boosts Aids research

Researchers in Switzerland have improved a technique of transplanting the human immune system into mice.

They say the advance could lead to new ways of diagnosing and treating disease, and solve the problem of rejection in organ transplants.

The team at the Institute for Research in Biomedicine in Bellinzona injected human blood-forming cells into the livers of mice that were born without immune systems.

The blood-forming stem cells developed into cells of the lymphatic system. The reconstituted human immune system generated responses against vaccinations and viral infections.

Group leader Markus Manz said the experiments built on previous attempts which have had only limited success.

“For 15 years, researchers have been looking at human immune responses in animals that have got injected human immune cells, and so far this did not really work.”

Aids research

The reconstituted immune system in the Bellinzona mice generated immune responses to both the tetanus vaccine and the Eppstein-Barr virus.

The development should help researchers study the effects of drugs and vaccines on the human immune system in the body of a living animal before performing such tests on humans.

“Looking at human cells and their immune response in a culture dish is insufficient,” Manz told swissinfo.

Meanwhile a huge challenge for Aids researchers has been the fact that HIV – like many viruses – does not cause disease in any other species except humans, and humans cannot be experimented on in the laboratory.

“It will also be very helpful in generating better vaccines,” said Manz.

New approach

Until now, researchers have transplanted human immune systems into mice in several different ways.

They have injected mature blood cells from human beings into immune-deficient mice or transplanted fetal tissue.

Another method has been to inject human haematopoietic stem cells into adult mice of a different type.

“They did not generate the mature B cells and mature T cells which formed structured lymphoid organs in the place where normally the mouse lymphoid system is sitting and that’s why probably those previous attempts had only a very limited success,” said Manz.

The research is published in the latest edition of the magazine Science.

swissinfo, Vincent Landon