EK-16A liposomes enhance HIV replication in ACH2 or J-Lat 10.6 cell engrafted NSG mice

Background: Numbers of HIV latency reversal agents (LRAs) have been tested in clinical trials, but with limited effect. EK-16A is an ingenol derivative that isolated from Euphorbia kansui. Our prior studies have suggested that it could reactivate latent HIV and meanwhile inhibit HIV infection in vitro. Here, we further advanced the research in vivo. Methods: In vitro, the activity of EK-16A liposomes was measured in HIV latently infected cells. In serum pharmacology test, BALB/c mice were orally administered with EK-16A liposomes, serum was separated and co-cultured with cells, HIV reactivation was measured. In vivo, NSG mice were transplanted with human cells for 3 weeks and then administered with EK-16A liposomes for 3 days. In ACH2 cell engrafted NSG mice, P24 in plasma and cell-associated HIV RNA in tissues was measured. In J-Lat 10.6 cell engrafted NSG mice, GFP expression of J-Lat 10.6 cells in diverse tissues was measured. Hematoxylin and eosin (HE) staining was carried out for histopathological examination in both mice. Results: EK-16A liposomes can reactivate latent HIV in ACH2 and J-Lat 10.6 cells. Serum pharmacological test showed that EK-16A retained activity after oral administration. Importantly, in ACH2 cell engrafted NSG mice, EK-16A liposomes increased the secretion of P24 in plasma and the expression of cell-associated HIV RNA in tissues. In J-Lat 10.6 cell engrafted NSG mice, EK-16A liposomes increased the GFP expression of J-Lat 10.6 cells in diverse tissues, including the bone marrow, spleen, liver, lung and peripheral blood. Furthermore, there was no obvious histopathological change associated with the use of EK-16A liposomes in both mice. Conclusions: Our results confirmed the enhancing HIV replication activity and preliminary security of EK-16A in human cell engrafted NSG mice, laying the foundation for research in clinical trials.