[Press kit]

NY, $130,000. Even when done in monkeys, vaccine experiments are very expensive
and slow. Dr. Littman is developing a system to allow the study of HIV infection in
mice, using genetic techniques to insert into mice the genes for the human proteins to
which the virus docks on the surface of cells. These cellular proteins are required for
the virus to penetrate inside target cells and establish infection. Dr. Littman will use such
mice to determine whether subsequent infection with HIV can elicit an immune response
and whether this response is protective. If he is successful, his mouse model will render
the process of anti-HIV vaccine testing much faster and cheaper.
* Lynda A. Morrison, Ph.D., St. Louis University, St. Louis, MO, $75,000. Dr.
Morrison proposes to compare immunization of mice with two different kinds of nonharmful viruses used as a means of introducing immune-enhancing proteins into body
cells to determine the best way to induce highly potent immune responses specific for
HIV. The use of herpes virus as one of these viral vectors also could lead to the
development of a combined vaccine to prevent, all at once, multiple sexually transmitted
diseases, for example, both HIV and herpes.
* Jack H. Nunberg, Ph.D., University of Montana, Missoula, MT, $142,456. Federal
funding for human trials of HIV envelope proteins, the part of the virus that attaches to
cells, as vaccine candidates was abruptly stopped several years ago because of
disappointing results. The types of antibodies that were produced by immunized
volunteers did inactivate laboratory strains of HIV, but virtually never neutralized virus
taken from patients, so-called "street virus." Dr. Nunberg believes this is because the
vaccine components were not presented in a physical structure capable of eliciting an
effective antibody response. He proposes constructing a fusion-competent vaccine, by
which HIV coat proteins are joined to the HIV receptor complex (CD4 + co-receptor).
This is a very novel approach.
* Melissa Pope, Ph.D., The Rockefeller University, New York, NY, $150,000. The
best response to why one believes a vaccine will some day be developed against HIV is
one very qualified success: deleting a single gene, known as nef, from the monkey AIDS
virus, SIV, and immunizing monkeys with this crippled or "attenuated" virus. This
completely protected most adult monkeys against strains of SIV normally capable of
causing disease. However, juvenile monkeys got AIDS from that vaccine, and even a
few of the adult monkeys developed viral infections and symptoms of disease from the
weakened strain of SIV. Dr. Pope correctly reasons that it is vital to find out why the
vaccine was so good - even if for a short period of time - and how these results can
be duplicated without the dangers of the previously tested "attenuated vaccine." Her
work focuses on an unusual white blood cell - the dendritic cell - and how it facilitates
immune responses to vaccines.
* Ruth M. Ruprecht, M.D., Ph.D., Dana-Farber Cancer Institute, Boston, MA,
$108,000. Encouraging results with DNA vaccination of chimpanzees against HIV have
been reported. Research by other investigators has implicated a small population of
white blood cells, the dendritic cells, as important antigen-presenting cells in DNA
vaccination. Recently, Dr. Ruprecht has found that human dendritic cells express