AAV Exploits Subcellular Stress Associated with Inflammation, Endoplasmic Reticulum Expansion, and Misfolded Proteins in Models of Cystic Fibrosis

Barriers to infection act at multiple levels to prevent viruses, bacteria, and parasites from commandeering host cells for their own purposes. An intriguing hypothesis is that if a cell experiences stress, such as that elicited by inflammation, endoplasmic reticulum (ER) expansion, or misfolded proteins, then subcellular barriers will be less effective at preventing viral infection. Here we have used models of cystic fibrosis (CF) to test whether subcellular stress increases susceptibility to adeno-associated virus (AAV) infection. In human airway epithelium cultured at an air/liquid interface, physiological conditions of subcellular stress and ER expansion were mimicked using supernatant from mucopurulent material derived from CF lungs. Using this inflammatory stimulus to recapitulate stress found in diseased airways, we demonstrated that AAV infection was significantly enhanced. Since over 90% of CF cases are associated with a misfolded variant of Cystic Fibrosis Transmembrane Conductance Regulator (ΔF508-CFTR), we then explored whether the presence of misfolded proteins could independently increase susceptibility to AAV infection. In these models, AAV was an order of magnitude more efficient at transducing cells expressing ΔF508-CFTR than in cells expressing wild-type CFTR. Rescue of misfolded ΔF508-CFTR under low temperature conditions restored viral transduction efficiency to that demonstrated in controls, suggesting effects related to protein misfolding were responsible for increasing susceptibility to infection. By testing other CFTR mutants, G551D, D572N, and 1410X, we have shown this phenomenon is common to other misfolded proteins and not related to loss of CFTR activity. The presence of misfolded proteins did not affect cell surface attachment of virus or influence expression levels from promoter transgene cassettes in plasmid transfection studies, indicating exploitation occurs at the level of virion trafficking or processing. Thus, we surmised that factors enlisted to process misfolded proteins such as ΔF508-CFTR in the secretory pathway also act to restrict viral infection. In line with this hypothesis, we found that AAV trafficked to the microtubule organizing center and localized near Golgi/ER transport proteins. Moreover, AAV infection efficiency could be modulated with siRNA-mediated knockdown of proteins involved in processing ΔF508-CFTR or sorting retrograde cargo from the Golgi and ER (calnexin, KDEL-R, β-COP, and PSMB3). In summary, our data support a model where AAV exploits a compromised secretory system and, importantly, underscore the gravity with which a stressed subcellular environment, under internal or external insults, can impact infection efficiency

The Politics of Intergovernmental Relations: Assessing the Many Phases and Challenges of Nigeria’s Judicial System

The judiciary is an important organ of government as it functions as a counterbalancing institution in states. Notwithstanding the nature of the political system in place, either democratic or nondemocratic, the judiciary plays the essential role of interpreting the extant laws and adjudicating between competing interests whether domiciled in individuals, groups, institutions of government or the various arms of government. The stabilising role of the judiciary in modern governance is exemplified by its ingrained function of checking the excesses of individuals, groups and government institutions through the application of state laws. Since Nigeria’s independence, its judiciary has been discharging its constitutional responsibilities. The journey of the Nigerian judiciary has been quite explosive, considering that it traversed both the jackboot of military authoritarianism and democratic governance in diverse forms, with each presenting its own peculiar bouquet of challenges. This chapter examines the various phases and attendant challenges that the Nigerian judiciary has passed through. It chronicles its many challenges and triumphs as well as low points. In sum, the Nigerian judiciary has acquitted itself admirably in dealing with such challenges as judicial independence, judicial accountability and crisis of condence occasioned by judicial recklessness and corruption. However, Nigeria’s judicial system still has room for further improvement in order to continue to command the respect of the citizens and thus, deserve such epithets as “the last hope of the common man”, “the bulwark of the people’s liberty”, “the defender of the rights of the people” and “the bastion of constitutional democracy,” among others, which demonstrate public acceptance and confidence