Schistosomiasis, a disease caused by the infestation of parasitic flatworms, afflicts more than 200 million people worldwide, mostly in developing countries. Researchers hope to expand existing medication options by developing new treatments that target key genes in the parasite. However, a complex life cycle makes parasitic flatworms difficult to maintain in a lab, thwarting efforts to determine the function of specific genes.
Sutas Suttiprapa of the George Washington University, Washington, D.C., and colleagues are working towards new methods to elucidate gene function by manipulating the genomes of parasitic flatworms, which are also known as schistosomes.
In their new study published in PLOS Pathogens, the researchers infected Schistosoma mansoni, a major species of schistosomiasis-causing flatworm, with a strain of HIV-1 whose outer shell had been modified to aid infection. Next-generation DNA sequencing revealed that HIV-1 genetic material had integrated itself throughout the schistosome genome, including in sex chromosomes. This is the first demonstration of HIV-1 integration into the genome of an invertebrate.
“The report,” the authors explain, “reveals that HIV-1 is active with cells of schistosomes, causative agent of the major neglected tropical disease schistosomiasis. The report also demonstrated, for the first time, the integration of HIV-1 into the chromosomes of an invertebrate.”
In the future, Suttiprapa and colleagues will attempt to infect S. mansoni eggs with the same modified HIV-1 virus in order to create a line of flatworms that can pass down virus-derived genomic integrations to their offspring. This could open up the possibility of using virus-based methods to block expression of specific flatworm genes, reveal their function and affect viability and fertility of the worms.
Research Article: Suttiprapa S, Rinaldi G, Tsai IJ, Mann VH, Dubrovsky L, Yan H-b, et al. (2016) HIV-1 Integrates Widely throughout the Genome of the Human Blood Fluke Schistosoma mansoni. PLoS Pathog 12(10): e1005931. doi:10.1371/journal.ppat.1005931
Image Credit: Sergey Iordanskiy