Induction of HIV-1-specific T-helper responses and type 1 cytokine secretion following therapeutic vaccination of macaques with a recombinant fowlpoxvirus co-expressing interferon-gamma

• Published in: Journal of medical primatology Vol. 29; no. 3-4; pp. 240 - 247
• Main Authors: Dale, C. Jane, Anne, Zhao, Jones, Stephen L., Boyle, David B., Ramshaw, Ian A., Kent, Stephen J.
• Format: Journal Article
• Language: English
• Published: Copenhagen Munksgaard 01.08.2000
• Subjects: AIDS Vaccines - immunology; AIDS Vaccines - toxicity; Animals; Antigens, CD - blood; Antigens, Differentiation, T-Lymphocyte - blood; CD69; cellular immunity; ELISOT; Fowlpox virus - genetics; Fowlpox virus - immunology; Genes, gag; Genes, pol; HIV-1 - immunology; Humans; Interferon-gamma - blood; Interferon-gamma - genetics; Interferon-gamma - immunology; interferon-gamma assay; Lectins, C-Type; Macaca nemestrina; Safety; T-Lymphocytes - immunology; T-Lymphocytes, Helper-Inducer - immunology; T-Lymphocytes, Helper-Inducer - virology; Thymidine Kinase - genetics; Time Factors; vaccine vectors; Vaccines, Synthetic - immunology; Vaccines, Synthetic - toxicity
• ISSN: 0047-2565; 1600-0684
• DOI: 10.1034/j.1600-0684.2000.290317.x

Preventive and/or therapeutic vaccines against Human Immunodeficiency Virus (HIV‐1) are urgently required. Induction of cellular immunity is favoured since these responses correlate with control of HIV‐1. Recombinant fowlpoxvirus (FPV) vaccines encoding both HIV‐1 gag/pol and interferon‐gamma (FPV gag/pol‐IFNΓ) were hypothesised to enhance HIV‐specific cellular immunity and were further evaluated in macaques previously infected with HIV‐1. A novel assay to detect IFNΓ secretion following HIV antigen stimulation of whole blood was developed to further assess the safety and immunogenicity of the FPV gag/pol‐IFNΓ vaccine. Immunisation with FPV gag/pol‐IFNΓ safely enhanced HIV‐specific IFNΓ secretion following ex vivo stimulation of whole blood, greater than that observed following FPV gag/pol vaccination not co‐expressing IFNΓ. Both HIV‐specific IFNΓ‐spot‐forming cells by ELISPOT and CD69 expression by CD4+ lymphocytes were also enhanced following FPV gag/pol‐IFNΓ vaccination. Hence, the FPV‐HIV vaccine co‐expressing IFNΓ stimulated HIV‐specific T cell responses in macaques, and should be further evaluated as a therapeutic or preventive HIV vaccine.