Recombinant HIV-2 (ROD) Nef protein [His]

Objectives: Cigarette smoking is highly prevalent among persons with HIV (PWH), which is concerning due to their increased risk of developing smoking-related cancers compared to those without HIV. Smoking cessation rates are substantially lower among PWH compared to the general population and less than half report a goal of total abstinence. Given these factors, a switch to electronic cigarettes (ECs), as a form of tobacco harm reduction, may be a viable approach to decreasing tobacco-related morbidity and mortality in PWH. The US Food and Drug Administration has the authority to implement product standards for cigarettes, including ECs and flavors. Methods: This qualitative study enrolled 19 HIV-positive smokers into an EC switch study. At Week 12, qualitative interviews were conducted to examine EC perceptions and flavor preferences. Results: ECs were viewed as a less harmful, cost-effective method of reducing or eliminating CC smoking, and non-tobacco flavors were an essential part of EC appeal and use. Conclusions: Flavored EC liquid seems to enhance the user experience and may influence the user's ability to make a complete switch. Tobacco harm reduction, as a strategy, will only be effective if current evidence guides tobacco regulatory decisions.

Cdc-like kinase 1 (CLK1) is a dual-specificity kinase capable of autophosphorylation on tyrosine residues and Ser/Thr phosphorylation of its substrates. CLK1 belongs to the CLK kinase family that regulates alternative splicing through phosphorylation of serine-arginine rich (SR) proteins. Recent studies have demonstrated that CLK1 has an important role in the replication of influenza A and chikungunya viruses. Furthermore, CLK1 was found to be relevant for the replication of HIV-1 and the West Nile virus, making CLK1 an interesting cellular candidate for the development of a host-directed antiviral therapy that might be efficient for treatment of newly emerging viruses. We describe here our attempts and detailed procedures to obtain the recombinant kinase domain of CLK1 in suitable amounts for crystallization in complex with specific inhibitors. The key solution for the reproducibility of crystals resides in devising and refining expression and purification protocols leading to homogeneous protein. Co-expression of CLK1 with lambda-phosphatase and careful purification has yielded crystals of CLK1 complexed with the KH-CB19 inhibitor that diffracted to 1.65 angstrom. These results paved the path to the screening of more structures of CLK1 complexed compounds, leading to further optimization of their inhibitory activity. Moreover, since kinases are desired targets in numerous pathologies, the approach we report here, the co-expression of kinases with lambda-phosphatase, previously used in other kinases, can be adopted as a general protocol in numerous kinase targets for obtaining reproducible and homogenic non-phosphorylated (inactive) forms suitable for biochemical and structural studies thus facilitating the development of novel inhibitors.