Widespread and efficient marker gene expression in the airway epithelia of fetal sheep after minimally invasive tracheal application of recombinant adenovirus in utero

A Novel Surgical Approach for Intratracheal Administration of Bioactive Agents in a Fetal Mouse Model

“…This procedure is in use in larger animal models such as rabbits and sheep 8 , and even in a clinical setting 9 , but has to date not been performed before in a mouse model. When studying the potential of fetal gene therapy for genetic diseases such as CF, the mouse model is very useful as a first proof-of-concept because of the wide availability of different transgenic mouse strains, the well documented embryogenesis and fetal development, less stringent ethical regulations, short gestation and the large litter size.…”

Lentiviral transduction of the murine lung provides efficient pseudotype and developmental stage-dependent cell-specific transgene expression

“…Intra-tracheal access at this developmental stage has not yet been shown to be feasible in the human foetus and, therefore, interpretations based on the mouse model must be made cautiously. Previous studies have shown transduction of the fetal lung with adenoviral and lentiviral vectors 3,7,47,48 but to our knowledge this is the first example of fetal and/or neonatal transduction of the murine airways using a lentivirus. Furthermore, we have presented preliminary evidence of possible stem-cell transduction with the presence of clusters of transduced cells in lung after fetal and neonatal vector administration and transgene expression beyond 1 year.…”

“…In a therapeutic context these considerations are of minimal relevance as dosing would most likely be performed by ultrasound-guided intratracheal administration or intra-luminal injection. 7,8 Macroscopic analysis of GFP expression in posttransduction lung, independent of pseudotype, suggests that adult and neonatal administrations are of equivalent efficiency and both show better overall transduction than in utero delivery owing to the fluid dilution factor as discussed above. The lack of significant transduction in the nasal epithelium may be due to minimal contact time, as the neonate rapidly inhales the virus and the majority of virus passes to the distal airways.…”

“…1,2 A number of groups have attempted in utero gene therapy approaches to CF in the mouse [3][4][5] and higher mammals [6][7][8][9] although the resultant expression was either at a low level or transient. Larson et al 10 reported controversial evidence of alleviation of meconium ileus in cftr-null mice following intra-amniotic injection of adenovirus expressing the CF transmembrane regulator (CFTR) cDNA.…”

Lentiviral-Mediated Fetal Gene Therapy for Monogenic Disorders: Development of an in vitro Rabbit Model

“…The principle advantages of a paradigm of prenatal (compared to post-natal) gene replacement, are: (1) genetic diagnosis and gene replacement before irreversible tissue or organ injury has occurred; (2) reduced likelihood of pre-existing immunity to viral 'vectors' responsible for gene transfer; (3) attenuated infl ammatory responses to viral vectors due to immune system immaturity, and (4) increased likelihood of transfection of pluripotent stem cells [1][2][3] . Amongst a substantial list of candidate metabolic, neurologic, immunologic and hematologic disorders which can be diagnosed prenatally, there is considerable experimental interest in a gene transfer strategy that could target respiratory and foregut epithelium and potentially treat a condition such as cystic fi brosis [4][5][6][7][8] . …”