Impairment of invasion and maturation and decreased selectivity of Plasmodium falciparum in G6PD Viangchan and Mahidol variants.
Palasuwan D., Palasuwan A., Boonpeng K., Ketprasit N., Imwong M., Kulkeaw K.
Protection against Plasmodium falciparum is observed in a population deficient in glucose-6-phosphate dehydrogenase (G6PD), particularly in African and Mediterranean regions. However, such protection remains unknown among G6PD-deficient individuals in Southeast Asia. Here, we assessed the invasion and maturation of P. falciparum K1 in a culture of erythrocytes isolated from Thai subjects carrying Viangchan (871G>A) and Mahidol (487G>A). We found that the parasites lost their ability to invade hemizygous and homozygous G6PD-deficient erythrocytes of Viangchan and Mahidol variants in the second and third cycles of intraerythrocytic development. Interestingly, P. falciparum parasites selectively grew in erythrocytes from hemi- and homozygous genotypes with normal G6PD activity. Moreover, externalization of phosphatidylserine upon P. falciparum infection was significantly increased only in Viangchan hemizygous variant cells. This study is the first to show that blockage of invasion in long-term culture and potentially enhanced removal of parasitized erythrocytes were observed for the first time in erythrocytes from Viangchan and Mahidol G6PD-deficient individuals.