The Combined Anti-HIV-1 Effect Of Chloroquineand Antiretroviral Drugs In Vitro

Objective:To evaluate the anti-HIV-1 effect of chloroquine in combination with anti-HIV drugs,and inhibition of pDC activation and type ? interferon production by TLR7 agonist stimulation.Methods:We investigated the anti-HIV-1?B,HIV-1KM018 activity of chloroquine and chloroquine combined with RAL,T-20,IDV and EFV in vitro by luciferase activity assay system and ELISA method for p24 antigen.We tested which stage that chloroquine and T-20 combination is more active than monotherapy by adding drugs at different time points after virus infection.We measured the effect of chloroquine on the activation of pDC in combination with RAL and IDV,respectively.Quantitative PCR was used to evaluate the inhibition of chloroquine in combination with RAL and IDV on the upregulation of IFN-a and IFN-?.Results:Chloroquine showed less cytotoxicity to C8166,TZM-bl and PBMC cells,and the CC50 values were 85.02 � 0.28?M,73.67 �5.1?M and 91.84 � 4.?M,respectively.Chloroquine has a certain anti-HIV-1 activity,EC50 of chloroquine against HIV-1?B infection in C8166 and TZM-bl cells were 11.83�0.5 ?M,10.68�2.7 ?M,respectively.Chloroquine inhibited HIV-1 KM0118 replication in PBMC with EC5013.64 � 0.8?M The synergism/antagonism volumes of chloroquine with RAL,T-20,IDV and EFV were 99.24�19.33/0�0 nM2%,104.72�17.83/-10.13 � 7.55nM2%,24.74� 1.29/-6.115 � 0.13nM2%,0.495� 0.7/-63.4�19.94nM2%,indicating the anti-HIV-1?B activity of these combination were moderate synergy,strong synergy,additive and moderate antagonism,respectively.The anti-HIV-1KM018 activity of chloroquine in combination with RAL,IDV were moderate synergy,minor synergy with the synergism/antagonism volumes 63.46�15.93/-44.83/12.7 nM2%,27.01�8.07/-7.33�0.32 nM2%.Compared to chloroquine alone,chloroquine in combination with T-20 is more active during virus entry stage.There was no statistically significant difference between the chloroquine monotherapy and chloroquine combined with RAL,IDV in the down-regulation of pDC activation and IFN-a,IFN-? expression levels.Conclusion:We have successfully found that chloroquine combined with different anti-HIV drugs represent different degrees of synergism,antagonism or additive anti-HIV-1 effect,we further found that chloroquine and T-20 synergy mainly occured in the virus entry stage.Chloroquine in combination with RAL and IDV did not have influence on the inhibitory effect of chloroquine on pDC activation and type I interferon secretion induced by TLR7 agonist,We hope we can provide a reference to the use of chloroquine on anti-HIV treatment and promote chloroquine better and more widely used in clinical research and treatment.