Novel Technique Improves Investigation of Interactions Between HIV and Malaria Parasite

Due to their extensive overlap in some developing regions, especially Sub-Saharan Africa, coinfections with malaria and HIV-1 are common, but the interplay between the two diseases is poorly understood and a systematic analysis of the interactions in different relevant human primary cell populations is critically needed. Each disease affects the immune system differently and by studying coinfection at different phases of each disease in vitro, scientists can better understand how different stages of malaria infection and HIV reproduction affect the onset and severity of the other disease.

In this study, an in vitro Plasmodium-HIV-1 coinfection model was developed and used to investigate the impact of P. falciparum-infected red blood cells on the HIV-1 replicative cycle in human primary monocyte-derived macrophages (MDMs). The impact of parasite exposure on HIV-1 transcriptional/translational events was monitored by using single cycle pseudotyped viruses in which a luciferase reporter gene has replaced the Env gene, while the effect on the quantity of progeny virus released by the infected macrophages is determined by measuring the HIV-1 capsid protein p24 by ELISA in cell supernatants. The researchers observed that exposure of P. falciparum to MDMs, decreases their susceptibility to HIV-1 infection, exerting a clear detrimental effect on the HIV-1 replicative cycle in macrophages (not excluding the possibility of other effects under different conditions).

The new technique, developed and applied by the laboratory led by Dr. David Richard of the Centre Hospitalier Universitaire de Quebec (CHUQ; Quebec City, Quebec, CA; www.chuq.qc.ca), was published August 15, 2012, in the online video Journal of Visualized Experiments (JoVE). "By publishing in JoVE, you really see what is happening in the experiment. The visual representation helps succinctly explain a long procedure, and gives you a fuller picture of the schematic complexity," said Dr. Richards. He hopes that this publication will give the scientific community an important additional tool to look at the interactions of the coinfection encounter on a cellular level and to more thoroughly dissect these interactions in a simplified system. This versatile system can also be adapted to monitor other factors and to use other primary cell types susceptible to HIV-1 infection. "Publication of the protocol in JoVE will allow researchers around the world to see a detailed demonstration of this system, which will help bring the technology to their laboratories," said JoVE editor Dr. Charlotte Frank Sage.

Related Links:
Centre Hospitalier Universitaire de Quebec
Journal of Visualized Experiments