Long-acting anti-HIV products can substantively change the standard of care for patients with HIV/AIDS. To this end, hydrophobic antiretroviral drugs (ARVs) were recently developed for parenteral administration at monthly or longer intervals. While shorter-acting hydrophilic drugs can be made into nanocarrier-encased prodrugs, the nanocarrier encasement must be boosted to establish long-acting ARV depots. The mixed-lineage kinase 3 (MLK-3) inhibitor URMC-099 provides this function by affecting autophagy. Here, we have shown that URMC-099 facilitates ARV sequestration and its antiretroviral responses by promoting the nuclear translocation of the transcription factor EB (TFEB). In monocyte-derived macrophages, URMC-099 induction of autophagy led to retention of nanoparticles containing the antiretroviral protease inhibitor atazanavir. These nanoparticles were localized within macrophage autophagosomes, leading to a 4-fold enhancement of mitochondrial and cell vitality. In rodents, URMC-099 activation of autophagy led to 50-fold increases in the plasma drug concentration of the viral integrase inhibitor dolutegravir. These data paralleled URMC-099-mediated induction of autophagy and the previously reported antiretroviral responses in HIV-1-infected humanized mice. We conclude that pharmacologic induction of autophagy provides a means to extend the action of a long-acting, slow, effective release of antiretroviral therapy. Center for Neural Development and Disease, University of Rochester Medical Center (URMC), Rochester, New York, USA.
Conflict of interest:H.A. Gelbard and H.E. Gendelman are members of the scientific advisory board for WavoDyne Therapeutics Inc., which is developing URMC-099 as a firstin-class MLK-3 inhibitor for clinical trials. URMC-099 is owned by URMC (patent nos. US 8,846,909 B2;8,877,772;and 9,181,247 and associated international patents). tion of TFEB mRNA by approximately 4-to 8-fold under different treatment conditions ( Figure 2F). With HIV-1 infection, TFEB mRNA levels were reduced by 2-to 3-fold compared with levels in uninfected controls, and URMC-099 could recover the phenotype. Increased TFEB translocation was delayed and did not reach significant levels until day 7 after URMC-099 treatment (Supplemental Figure 2B). These data confirm that URMC-099 regulates TFEB nuclear translocation in an mTORC1-dependent manner. URMC-099 stimulates autophagy in human MDMs. On the basis of the preceding data sets, we theorized that nuclear translocation of TFEB induces autophagy and lysosomal biogenesis. TFEB serves as the master regulator of both autophagy and lysosomal biogenesis (26), and such regulation could have a profound role in nanoART intracellular sequestration in MDMs. Thus, we examined the autophagosome markers microtubule-associated protein 1 light chain 3 β (LC3B, also known as MAP1LC3B) and beclin 1 (BECN1). Using Western blot assays, we found that each marker was significantly upregulated by URMC-099 ( Figure 3, A-C and Supplemental Figure 3A). URMC-099 increased the expression ...