Impact of deletion of envelope-related genes of recombinant Sendai viruses on immune responses following pulmonary gene transfer of neonatal mice

Abstract

We demonstrated previously that the additive-type recombinant Sendai virus (rSeV) is highly efficient for use in pulmonary gene transfer; however, rSeV exhibits inflammatory responses. To overcome this problem, we tested newly developed non-transmissible constructs, namely, temperature-sensitive F-deleted vector, rSeV/dF (ts-rSeV/dF) and a rSeV with all the envelope-related genes deleted (rSeV/ dFdMdHN), for pulmonary gene transfer in neonatal mice, by assessing their toxicity and immune responses. The gene expression in the lungs of neonatal ICR mice peaked on day 2, then gradually decreased until almost disappearing at 14 days after infection in all constructs. Loss of body weight and mortality rate, however, were dramatically improved in mice treated with SeV/dFdMdHN (mortality ¼ 0%, n ¼ 41) and ts-rSeV/dF (24.2%, n ¼ 33) compared with additive rSeV (70.7%, n ¼ 58). Although the deletion of envelope-related genes of SeV had a small impact on the production of antibody and cytotoxic T-lymphocyte activity in both adults and neonates, a dramatic reduction was found in the events related to innate responses, including the production of proinflammatory cytokines, particularly in the case of neonates. These results indicate that pulmonary gene transfer using SeV/dFdMdHN warrants further investigation for its possible use in developing safer therapeutics for neonatal lung diseases, including cystic fibrosis.

Complete elimination of established neuroblastoma by synergistic action of γ-irradiation and DCs treated with rSeV expressing interferon-β gene

“…injection of rSeV-DCs without exposure to tumor antigen ex vivo evoked tumor-specific antitumor immunity. 14,15 On the basis of these findings, the present experimental study was performed to examine the potential of DC-based immunotherapy boosted by a newly developed rSeV/dF, the less cytotoxic, clinically available vector ts-rSeV/dF, 18 to treat less-immunogenic murine c1300 neuroblastoma.…”

“…With this background in mind, we here examined and optimized the antitumor effect of DC immunotherapy activated by a 'temperature-sensitive mutant' and F-gene-deleted non-transmissible rSeV (ts-rSeV/dF), an advanced vector design showing a less cytopathic effect, 18,21,22 that is now available for mass production according to the good manufacturing practice guidelines.…”

“…15 rSeV is a novel and powerful gene transfer modality as a cytoplasmic gene expression system [16][17][18] that leads DCs to highly activated/mature state through a DExD/H-box RNA helicase, retinoic acid-inducible gene-I (RIG-I). 19,20 Therefore, we hypothesized that rSeV-activated DCs might enhance antitumor immunity against less immunogenic c1300 neuroblastoma.…”

A Respiratory Syncytial Virus Replicon That Is Noncytotoxic and Capable of Long-Term Foreign Gene Expression

“…Because we have been able to mobilize the replicon as OSVs by providing the RSV G and F proteins in trans while retaining its native targeting ability, some form of the replicon may be useful as an attenuated vaccine for RSV and/or for expressing a foreign viral protein(s). The RSV replicon could also be useful as a self-limiting gene therapy vector, as recently demonstrated for Sendai virus replicons (3,17,18,22,30,31,51,58). The RSV replicon has the advantages of relative stability in a cell population over many cell divisions, a lack of cytotoxicity in nearly all the cell lines tested, the ability to express foreign genes, and as an RNA virus, the inability for its genome to be incorporated into the host DNA.…”

Viral and Synthetic RNA Vector Technologies and Applications

“…Importantly, deletion of enveloperelated genes attenuated both the strong cytopathogenicity and immunogenicity observed for wild-type recombinant SeV. [106][107][108][109] Transgene expression from SeVV is transient, strong and adjustable as a result of a natural transcription gradient by selecting different positions for transgene insertion within the vector genome (Figure 1d), 110 with greater expression of genes closer to the 3′ leader region. 95 A stably maintained SeVV system was established based on isolation of the noncytopathic persistent SeV strain Cl.151, which can escape interferon regulatory factor 3-mediated antiviral responses.…”