Preclinical evaluation of innate immunity to baculovirus gene therapy vectors in whole human blood.
Interactions of gene therapy vectors with human blood components upon intravenous administration have a significant effect on vector efficacy and patient safety. Here we describe methods to evaluate these interactions and their effects in whole human blood, using baculovirus vectors as a model. Opsonisation of baculovirus particles by binding of IgM and C3b was demonstrated, which is likely to be the cause of the significant blood cell-associated virus that was detected. Preventing formation of the complement C5b-9 (membrane attack) complex maintained infectivity of baculovirus particles as shown by studying the effects of two specific complement inhibitors, Compstatin and a C5a receptor antagonist. Formation of macroscopic blood clots after 4h was prevented by both complement inhibitors. Pro- and anti-inflammatory cytokines Il-1beta, IL-6, IL-8 and TNF-alpha were produced at variable levels between volunteers and complement inhibitors showed patient-specific effects on cytokine levels. Whilst both complement inhibitors could play a role in protecting patients from aggressive inflammatory reactions, only Compstatin maintained virus infectivity. We conclude that this ex vivo model, used here for the first time with infectious agents, is a valuable tool in evaluating human innate immune responses to gene therapy vectors or to predict the response of individual patients as part of a clinical trial or treatment. The use of complement inhibitors for therapeutic viruses should be considered on a patient-specific basis.
Georgopoulos
Lindsay J
LJ
YCR Cancer Research Unit, Department of Biology (Area 13), University of York, Heslington, York YO10 5DD, UK. ljs8@york.ac.uk
Elgue
Graciela
G
Sanchez
Javier
J
Dussupt
Vincent
V
Magotti
Paola
P
Lambris
John D
JD
Tötterman
Thomas H
TH
Maitland
Norman J
NJ
Nilsson
Bo
B
D016367:Baculoviridae / Q000235:genetics / Q000276:immunology*; D003179:Complement C3b / Q000276:immunology; D015936:Complement C5a / Q000494:pharmacology; D015938:Complement Membrane Attack Complex / Q000187:drug effects / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000097:blood* / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects; D007118:Immunoassay; D007075:Immunoglobulin M / Q000097:blood; D010456:Peptides, Cyclic / Q000494:pharmacology
C112335:C5aRAD; D015938:Complement Membrane Attack Complex; D016207:Cytokines; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; C111828:compstatin; D003179:Complement C3b; D015936:Complement C5a