Insect baculoviruses strongly potentiate adaptive immune responses by inducing type I IFN.
Baculoviruses (BVs) are dsDNA viruses that are pathogenic for insects. They have been used worldwide as selective bioinsecticides and for producing recombinant proteins in insect cells. Surprisingly, despite their widespread use in research and industry and their dissemination in the environment, the potential effects of these insect viruses on the immune responses of mammals remain totally unknown. We show in this study that BVs have strong adjuvant properties in mice, promoting potent humoral and CD8(+) T cell adaptive responses against coadministered Ag. BVs also induce the in vivo maturation of dendritic cells and the production of inflammatory cytokines. We demonstrate that BVs play a major role in the strong immunogenicity of virus-like particles produced in the BV-insect cell expression system. The presence of even small numbers of BVs among the recombinant proteins produced in the BV expression system may therefore strengthen the immunological properties of these proteins. This adjuvant behavior of BVs is mediated primarily by IFN-alphabeta, although mechanisms independent of type I IFN signaling are also involved. This study demonstrates that nonpathogenic insect viruses may have a strong effect on the mammalian immune system.
Hervas-Stubbs
Sandra
S
Institut Pasteur, Unité de Régulation Immunitaire et Vaccinologie, Paris, France.
Rueda
Paloma
P
Lopez
Lissette
L
Leclerc
Claude
C
D000276:Adjuvants, Immunologic; D000818:Animals; D000917:Antibody Formation / Q000276:immunology*; D000941:Antigens / Q000276:immunology*; D016367:Baculoviridae / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D018836:Inflammation Mediators / Q000276:immunology; D007313:Insecta / Q000821:virology; D007370:Interferon Type I / Q000276:immunology*; D051379:Mice
D000276:Adjuvants, Immunologic; D000941:Antigens; D018836:Inflammation Mediators; D007370:Interferon Type I