8th Conference on Retroviruses and Opportunistic Infections Chicago, IL - February 4 - 8, 2001

Conf Retroviruses Opportunistic Infect 2001 Feb 4-8; 8:97 (abstract no. 190)

Shibata R, Peterson M, Good J, Zaharias E, Lee S, Curd J, Francis D, Berman P, Sheppard H, Evans T; VaxGen, Brisbane, CA.

BACKGROUND: The saponin adjuvant QS21 is known to enhance induction of antibody to rgp120 in HIV-uninfected human volunteers.

METHODS: In an attempt to compare effects of QS21 and alum adjuvant administered with different doses of rgp120, serum samples from several related clinical trials were examined using assays that measure (1) binding to rgp120, (2) binding to V2 and V3 peptides, (3) neutralization of MN, and (4) binding to oligomeric gp120 on the surface of cells infected with primary HIV isolates.

RESULTS: Subjects immunized with 0.5 or 3 µg of rgp120 plus QS21 exhibited slightly higher antibody responses than those immunized with 600 µg of rgp120 plus alum, as measured by rgp120 or V2/V3 peptide ELISA, indicating that the dose-sparing effect of QS21 is about 1,000 fold. Essentially the same results were obtained with neutralizing antibodies against MN. Significant dose responses in neutralizing antibody titers were observed among subjects immunized with 3, 30, or 600 µg of rgp120 plus alum. In contrast, subjects immunized with 0.5, 3, or 30 µg of rgp120 plus QS21 all exhibited similar neutralization titers, which were slightly higher than those of subjects immunized with 600 µg of rgp120 plus alum.

CONCLUSIONS: These results confirmed that antibodies induced by low doses of rgp120 plus QS21 are functionally relevant. Breadth of antibody response measured by oligomeric gp120 binding assay using a variety of primary HIV-1 isolates will also be discussed.

Keywords: AEGIS, Adjuvants, Immunologic, Saponins, AIDS Vaccines, Vaccines, HIV-1, Alum Compounds, Vaccines, Synthetic, Viral Vaccines, QS 21, aluminum sulfate, Human, AIDS

2001-02-04
190

Copyright © 2001 - Foundation for Retrovirology and Human Health. Reproduction of this abstract (other than one copy for personal reference) must be cleared through the Foundation for Retrovirology and Human Health. Licensed (AIDSLINE) from National Library of Medicine.