No abstract

Cystic Fibrosis (CF) is a genetic disorder affecting multiple organs, including the pancreas, hepatobiliary system and reproductive organs however lung disease is responsible for the majority of morbidity and mortality. Management of CF involves CFTR modulator agents including corrector drugs to augment cellular trafficking of mutant CFTR as well as potentiators that open defective CFTR channels. These therapies are poised to help most individuals with CF, with the notable exception of individuals with class I mutations where full length CFTR protein is not produced. For these mutations, gene replacement has been suggested as a potential solution.In this work, we used a helper dependent adenoviral vector (HD-CFTR) to express CFTR in nasal epithelial cell cultures derived from CF subjects with class I CFTR mutations. CFTR function was significantly restored in CF cells by HD-CFTR and reached healthy control functional levels as detected by Ussing chamber and membrane potential (FLIPR) assay. A dose response relationship was observed between the amount of vector used and subsequent functional outcomes; small amounts of HD-CFTR were sufficient to correct CFTR function. At higher doses, HD-CFTR did not increase CFTR function in healthy control cells above baseline values. This latter observation allowed us to use this vector to benchmark in vitro efficacy testing of CFTR-modulator drugs. In summary, we demonstrate the potential for HD-CFTR to inform in vitro testing and to restore CFTR function to healthy control levels in airway cells with class I or CFTR nonsense mutations.

Background The ongoing COVID-19 pandemic has resulted in 185 million recorded cases and over 4 million deaths worldwide. Several COVID-19 vaccines have been approved for emergency use in humans and are being used in many countries. However, all the approved vaccines are administered by intramuscular injection and this may not prevent upper airway infection or viral transmission. Results Here, we describe a novel, intranasally delivered COVID-19 vaccine based on a helper-dependent adenoviral (HD-Ad) vector. The vaccine (HD-Ad_RBD) produces a soluble secreted form of the receptor binding domain (RBD) of the SARS-CoV-2 spike protein and we show it induced robust mucosal and systemic immunity. Moreover, intranasal immunization of K18-hACE2 mice with HD-Ad_RBD using a prime-boost regimen, resulted in complete protection of the upper respiratory tract against SARS-CoV-2 infection. Conclusion Our approaches provide a powerful platform for constructing highly effective vaccines targeting SARS-CoV-2 and its emerging variants.