4,552 publications from this institution
HIV-1 infection is a manageable chronic condition, with non-nucleoside HIV-1 reverse transcriptase inhibitors (NNRTIs) remaining a cornerstone of antiretroviral therapy. Nevertheless, drug resistance to existing therapeutics is a serious and immediate concern. Using structure-based and scaffold-hopping approaches, we designed evolved diarylpyrimidine analogs targeting reverse transcriptase (RT), exploiting chemical space surrounding the NNRTI-binding pocket. We identified compounds <b>5i3</b> and <b>5e2</b>, with robust antiviral efficacy against wild-type HIV-1 and rilpivirine-resistant strains. Encouragingly, in vitro selection of mutant strains with <b>5i3</b> took 39 passages to select resistance, with no phenotypic cross-resistance observed with known RT drugs. Co-crystal structures of wild-type and mutant RT with <b>5i3</b> and <b>5e2</b> revealed their resilience toward resistance mutations due to enhanced conformational flexibility and positional adaptability. <b>5i3</b> exhibited good pharmacokinetic properties and favorable safety profiles, without substantial cytochrome P450 inhibition, and excellent oral bioavailability. These derivatives represent a promising scaffold for the development of anti-HIV drugs.
A new class of acyclic adenosine analogues is described which exhibit broad-spectrum antiviral activity and are apparently targeted at S-adenosyl-L-homocysteine hydrolase. The compounds are all alkyl (i.e., methyl, ethyl, 1-propyl, 2-propyl, 1-butyl, 2-butyl, 2-methylpropyl, tert-butyl, 1-pentyl, 3-methylbutyl, 1-octyl, 2-hydroxyethyl, 2-methoxyethyl, furylmethyl, cyclohexyl) esters of (RS)-3-adenin-9-yl-2-hydroxypropanoic acid. They are inhibitory to a broad variety of viruses, including vesicular stomatitis, vaccinia, reo, parainfluenza, and measles, and, with one exception (the furylmethyl ester), nontoxic to the host cell at antivirally active concentrations. It is postulated that the alkyl esters are as such taken up by the cells and hydrolyzed within the cells to release the parent compound, 3-adenin-9-yl-2-hydroxypropanoic acid.
Stem cell-based gene therapy of HIV infection aims at inhibiting HIV replication and the progression to AIDS by the introduction of antiviral genes in primitive hematopoietic stem cells (HSC). Ideally, after differentiation into mature blood cells, these antiviral genes should create a host-cell population that is resistant to HIV infection. Although the current gene therapy clinical trials established the safety and provided proof-of-principle for gene therapy of HIV-1 infection, the overall results have been disappointing, and many issues still remain to be resolved before this approach can be efficiently used against HIV infection. Since a significant percentage of the stem cells in the patient have to be transduced to obtain a significant impact on HIV replication, the first prerequisite for successful gene therapy of HIV-1 infection consists of increasing the amount of transduced HSCs. Further improvements in gene transfer and gene therapy strategies will probably lead to future clinical successes. On the other hand, HIV-1 infection is a very complex disease, affecting various organs in addition to the T-cells, with an impact on T-cell homeostasis that is currently not fully understood. Even at low viral loads and before the advent of clinical symptoms, a high turnover of CD4+ cells exists in HIV-infected patients with functional implications for the homeostasis of the thymus, bone marrow and T-cell homeostasis which may hamper the CD34+ HSC approach. Hence, the extent to which these alterations hamper a gene therapy approach, or can be reversed upon HAART, will determine the feasibility of future gene therapy against AIDS.
