cDNA microarray assays to evaluate immune responses following intracranial injection of baculoviral vectors in non‐human primates

Abstract

Recombinant insect baculoviral vectors efficiently transduce several types of cells in the brain and can possibly be used in gene therapy for brain disorders. However, together with contaminating insect cell proteins, they trigger immune responses that might damage host brain cells. To substantially reduce unwanted immune responses due to the insect cell impurities, we purified and concentrated baculoviral vectors by combining an ion-exchange membrane chromatography method with high-speed centrifugation and demonstrated reduced immune responses of the vector preparations in the mouse brain. To verify the suitability of using these viral vectors for gene therapy strategies in the brain, we evaluated immune reactions and vector toxicity upon acute administration of baculoviral vectors into the brains of cynomolgus macaques. We demonstrated that the virus inoculation caused no abnormalities to non-human primates but induced host anti-viral responses in the brain. With global cellular gene expression profiling, using cDNA microarray technology, we detected that the affected genes were mainly associated with innate immunity, involving the genes of RIG-1-like receptor signaling pathway as the major interferon production pathway. These findings in non-human primates, which share close physiological and genomic similarities with man, may better mimic the responses to baculoviral transduction in the human brain and should be useful in guiding rational therapeutic applications of baculoviral vectors to treat brain disorders.

Solutions against emerging infectious and noninfectious human diseases through the application of baculovirus technologies

“…Despite these definitive benefits, the usually short-expression time in vivo of the GOI in mammals (around 7-14 days postinoculation) should be considered, which timing limits readministrations (Luo et al 2013), mainly because of certain generic immunologic responses that baculoviruses trigger-those being more pronounced upon systematic administration, though lesser upon local inoculation (Ono et al 2014). Among such responses, the innate immune system is a clear example because the administration of BVs has been reported to upregulate the RIG-1-like receptor (Balasundaram et al 2017) and the Toll-like-receptor-9 signaling pathways (Abe et al 2009;Boulaire et al 2009), thus activating type-I interferon (Hervas-Stubbs et al 2007;Abe et al 2009) and natural-killer cells (Moriyama et al 2017). In addition, a few other genes are induced by baculoviruses, such as those encoding complement factors and adhesion molecules, or those involved in cytokine-cytokine receptor interaction ( Shin et al 2020).…”

“…We need to mention that certain studies were carried out in nonhuman primates (Balasundaram et al 2017) or using whole-human-blood samples (Georgopoulos et al 2009) and cells from human donors (Bak et al 2011;Paul et al 2011;Graves et al 2018;Wang et al 2019aWang et al , 2020. In addition, owing to the excellent transport capability of baculoviruses, new approaches in synthetic biology are being explored in vitro that enable, for example, the incorporation of complex gene circuits that can express a therapeutic gene in target cells and not in others (Lin et al 2018).…”