Induction of cross-reactive cytotoxic T-lymphocyte responses specific for HIV-1 gp120 using saponin adjuvant (QS-21) supplemented subunit vaccine formulations

• Published in: Vaccine Vol. 15; no. 9; pp. 1001 - 1007
• Main Authors: Newman, M.J., Wu, J.-Y., Gardner, B.H., Anderson, C.A., Kensil, C.R., Recchia, J., Coughlin, R.T., Powell, M.F.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.1997; Elsevier
• Subjects: Adjuvants, Immunologic - chemistry; AIDS Vaccines - immunology; AIDS/HIV; Amino Acid Sequence; Animals; Antibody Specificity; Biological and medical sciences; CHO Cells; Cricetinae; Cross Reactions; cytotoxic T-lymphocyte (CTL); Epitopes, T-Lymphocyte - immunology; Female; Fundamental and applied biological sciences. Psychology; glycoprotein 120 (gp120); HIV Antibodies - biosynthesis; HIV Antibodies - immunology; HIV Envelope Protein gp120 - immunology; HIV-1 - immunology; human immunodeficiency virus 1; human immunodeficiency virus type-1 (HIV-1); Humans; Immunodominant Epitopes - immunology; Mice; Mice, Inbred BALB C; Microbiology; Molecular Sequence Data; Peptide Fragments - immunology; QS-21; Recombinant Proteins - immunology; saponin adjuvant; Saponins - chemistry; Saponins - immunology; subunit vaccine; T-Lymphocytes, Cytotoxic - immunology; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies; Vaccines, Synthetic - immunology; Virology; QS-21; saponin adjuvant; glycoprotein 120 (gp120); subunit vaccine; cytotoxic T-lymphocyte (CTL); human immunodeficiency virus type-1 (HIV-1); Immunopathology; Antigenic determinant; HIV-1 virus; Variable region; Rodentia; Retroviridae; AIDS; Immune deficiency; Property formulation relationship; Saponin; Infection; Virus; Vertebrata; Mammalia; Immunogenicity; Mouse; Viral disease; Immunological adjuvant; Antigenic variation; Lentivirinae; Human immunodeficiency virus; Virus envelope
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/S0264-410X(96)00293-9

The antigenic variation associated with Human Immunodeficiency Virus type-1 (HIV-1) envelope proteins could limit their utility in vaccines if the immune responses induced are specific for immunodominant variable epitopes. We evaluated the ability of experimental subunit vaccines, containing recombinant forms of the envelope glycoprotein (rgp120) from two HIV-1 variants, to induce immune responses capable of recognizing unrelated HIV-1 variants. A vaccine formulaion based on HIV-1 IIIB/LAI rgp120 and and supplemented with saponin adjuvant (QS-21) induced neutralizing antibodies specific for the HIV-1 IIIB/LAI variant. This antibody response was presumably specific for the variable principle neutralizing determinant (PND) of the third variable region of gp120, the V-3 region. This formulation induced cytotoxic T-lymphocytes (CTL) specific for the dominant V-3 epitope but also to an additional unidentified epitope outside of this region. The CTL specific for this second epitope also recognized gp120 from the HIV-1 MN and HIV-1 RF variants in a “cross-reactive” manner. A second vaccine formulation based on HIV-1 MN rgp120 and QS-21 adjuvant induced neutralizing antibodies that were again variant-specific but also CTL that recognized all three HIV-1 variants in a cross-reactive manner. These data demonstrate that CTL capable of recognizing different HIV-1 variants, which are presumed to be specific for a conserved HIV-1 gp120 epitope, can be induced using subunit vaccines with the appropriate adjuvant while variant-specific antibody responses are produced. These findings support further evaluation of this vaccine format.