Pharmacogenetics of HIV therapy: State of the art in Latin American countries.

The use of combined antiretroviral therapy (cART) has resulted in a remarkable reduction in morbidity and mortality of people living with HIV worldwide. Nevertheless, interindividual variations in drug response often impose a challenge to cART effectiveness. Although personalized therapeutic regimens may help overcome incidence of adverse reactions and therapeutic failure attributed to host factors, pharmacogenetic studies are often restricted to a few populations. Latin American countries accounted for 2.1 million people living with HIV and 1.4 million undergoing cART in 2020-21. The present review describes the state of art of HIV pharmacogenetics in this region and highlights that such analyses remain to be given the required relevance. A broad analysis of pharmacogenetic markers in Latin America could not only provide a better understanding of genetic structure of these populations, but might also be crucial to develop more informative dosing algorithms, applicable to non-European populations.

Repression of HIV-1 reactivation mediated by CRISPR/dCas9-KRAB in lymphoid and myeloid cell models.

BACKGROUND: Despite antiretroviral treatment efficacy, it does not lead to the complete eradication of HIV infection. Consequently, reactivation of the virus from latently infected cell reservoirs is a major challenge toward cure efforts. Two strategies targeting viral latency are currently under investigation: the "shock and kill" and the "block and lock." The "Block and Lock" methodology aims to control HIV-1 latency reactivation, promoting a functional cure. We utilized the CRISPR/dCas9-KRAB platform, which was initially developed to suppress cellular genes transcription, to block drug-induced HIV-1 reactivation in latently infected T cells and myeloid cells. RESULTS: We identified a set of five sgRNAs targeting the HIV-1 proviral genome (LTR1-LTR5), having the lowest nominated off-target activity, and transduced them into the latently infected lymphoid (J-Lat 10.6) and myeloid (U1) cell lines. One of the sgRNAs (LTR5), which binds specifically in the HIV-1 LTR NFκB binding site, was able to promote robust repression of HIV-1 reactivation in latently infected T cells stimulated with Phorbol 12-Myristate 13-Acetate (PMA) and Ingenol B (IngB), both potent protein kinase C (PKC) stimulators. Reactivation with HDAC inhibitors, such as SAHA and Panobinostat, showed the same strong inhibition of reactivation. Additionally, we observed a hundred times reduction of HIV-1 RNA expression levels in the latently infected myeloid cell line, U1 induced with IngB. CONCLUSION: Taken together, our results show that the KRAB fused CRISPR/dCas9 system can robustly prevent the HIV-1 latency reactivation process, mediated by PMA or IngB and SAHA or Panobinostat, both in myeloid and lymphoid HIV-1 latently infected cells. In addition, we demonstrated that KRAB repressor protein is crucial to reactivation resistance phenotype, and we have identified some useful hotspots sequences in HIV-1 LTR for the design sgRNAs.