Latest research has discovered that the malaria parasite can switch on and off the expression of some of the proteins it uses to enter its victim’s red blood cells. Alfred Cortes, an ICREA researcher working at IRB Barcelona and an expert in molecular parasitology, together with researchers from the National Institute for Medical Research (NIMR) in London, believe that this ability of Plasmodium falciparum makes it more adaptable when attempting to attack the cells.
30 genes are known to be involved in the process of invasion. Now, the scientists have found that P. falciparum can turn on and turn off the expression of 7 of these genes (and their corresponding proteins) without compromising the parasite's ability to enter normal or modified red blood cells.
According to Cortes, this suggests that the varied expression of these genes may help the parasite to break away from the host organism's immune responses, although the researcher points out that this is yet to be confirmed.
The researchers discovered that the silencing mechanism happens at the epigenetic level, meaning that the parasite stops expressing a certain gene without changing the basic genetic information, and that the mechanism is flexible, adjustable and easily reversible. This means that the parasite can re-express the proteins comparatively easily when infecting another individual or silence them again in a different host, explains Cortes.
"We are talking about a very sophisticated adaptation system to the host and our challenge is to find out how this mechanism works at molecular level; that is, we need to figure out which specific epigenetic modifications are associated to activity or to silencing," says Cortes.
"Thanks to this study we have been able to identify 7 genes in 4 different genetic families that may be silenced in a specific P. falciparum strain; we suspect, however, that other genes may also be silenced, and we'll follow this up with studies on wild strains of the parasite," he adds.