A research project at a Harvard teaching hospital has produced a form of gene therapy that shows promise in fighting AIDS and cancer.

The findings of the research team at Dana-Farber Cancer Institute were published yesterday in the proceedings of the National Academy of Sciences.

The procedure involves genetically engineering human cells to produce antibodies that interfere with the production of a protein necessary for HIV, the virus which most commonly causes AIDS, to infect human cells.

Not only does this reduce the ability of virus to infect other cells, but it also protects many infected cells from cell death, according to team leader Wayne A. Marisco, an assistant professor in medicine at Harvard Medical School.

And the procedure is much easier than traditional gene therapy, since it does not require researchers to determine the nucleic acid sequence of the target cell in order to affect it with the altered gene.

"This is the first successful demonstration of a functional intra-cellular antibody," Marisco said. "It represents a significant technological breakthrough...to interfere with traditional functions through traditional gene therapy."

The antibody could also retard the growth of malignant tumors since it is retained in the endoplasmic reticulum, a part of the cell where proteins that produce mutated cancer cells are processed.

While side effects could arise during further testing, Marisco said, the antibodies had no toxic effect on healthy cells. "These experiments were done in human cells and the cultures," he said. "The next step will be to test this on human blood cells."

Marisco said his research team is currently conducting such tests. If these succeed, he said, they will probably apply to the Food and Drug Administration for permission to conduct small clinical trials of the therapy.

Though Marisco said he did not wish to be "near-sighted" about the possibilities of the treatment, he said he did not foresee it as acting as a vaccine.

Instead, he said it might be most effective for those already infected with HIV who have either not developed full-blown AIDS or are in the early stages of it. But he added that he was unsure as to what would be the best point in the course of the disease to apply the therapy.

Marisco emphasized that this strategy is not being seen as a cure for AIDS or any other disease.

"There are a great number of years of hard work to go before you say [there's] cure," he said