Ros3 (Lem3p/CDC50) Gene Dosage Is Implicated in Miltefosine Susceptibility in <i>Leishmania (Viannia) braziliensis</i> Clinical Isolates and in <i>Leishmania (Leishmania) major</i>

The Ros3 protein is a component of the MT-Ros3 transporter complex, considered as main route miltefosine entry in Leishmania. L. braziliensis clinical isolates presenting differences susceptibility and uptake were previously shown to differentially express ros3. In this work, we showed that ros3 gene copy number was increased isolate highest rates and, thus, drug. role dosage then investigated through modulation using two distinct approaches: an overexpression tolerant major by generating mono- diallelic knockouts clustered regularly interspaced short palindromic repeats (CRISPR) Cas9 (Cas = CRISPR-associated). Although levels mRNA at least 40-fold overexpressing clones, no significant reduction half-maximal effective concentration (EC50) for observed these parasites. partial or complete deletion major, turn, resulted increase 3 20 times, respectively, EC50 miltefosine. We unequivocally one factors involved differential