Plasmodium falciparum Choline Kinase Inhibition Leads to a Major Decrease in Phosphatidylethanolamine Causing Parasite Death

This work was supported by Agencia Aragonesa para la Investigación y Desarrollo (ARAID), Ministerio de Economía y Competitividad (CTQ2013-44367-C2-2-P to R.H.-G.) and Diputación General de Aragón (DGA; B89 to R.H.-G.) and the EU Seventh Framework Programme (2007–2013) under BioStruct-X (grant agreement 283570 and BIOSTRUCTX 5186, to R.H.-G.). T.K.S. was supported by the Wellcome Trust grant 093228 and European Community’s Seventh Framework Programme under grant agreement No. 602773 (Project KINDRED).Malaria is a life-threatening disease caused by different species of the protozoan parasite Plasmodium, with P. falciparum being the deadliest. Increasing parasitic resistance to existing antimalarials makes the necessity of novel avenues to treat this disease an urgent priority. The enzymes responsible for the synthesis of phosphatidylcholine and phosphatidylethanolamine are attractive drug targets to treat malaria as their selective inhibition leads to an arrest of the parasite’s growth and cures malaria in a mouse model. We present here a detailed study that reveals a mode of action for two P. falciparum choline kinase inhibitors both in vitro and in vivo. The compounds present distinct binding modes to the choline/ethanolamine-binding site of P. falciparum choline kinase, reflecting different types of inhibition. Strikingly, these compounds primarily inhibit the ethanolamine kinase activity of the P. falciparum choline kinase, leading to a severe decrease in the phosphatidylethanolamine levels within P. falciparum, which explains the resulting growth phenotype and the parasites death. These studies provide an understanding of the mode of action, and act as a springboard for continued antimalarial development efforts selectively targeting P. falciparum choline kinase.Publisher PDFPeer reviewe

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 April 2011-31 May 2011.

This article documents the addition of 92 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anopheles minimus, An. sinensis, An. dirus, Calephelis mutica, Lutjanus kasmira, Murella muralis and Orchestia montagui. These loci were cross-tested on the following species: Calephelis arizonensi, Calephelis borealis, Calephelis nemesis, Calephelis virginiensis and Lutjanus bengalensis

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 April 2011-31 May 2011.

This article documents the addition of 92 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Anopheles minimus, An. sinensis, An. dirus, Calephelis mutica, Lutjanus kasmira, Murella muralis and Orchestia montagui. These loci were cross-tested on the following species: Calephelis arizonensi, Calephelis borealis, Calephelis nemesis, Calephelis virginiensis and Lutjanus bengalensis

Severe Infections in HIV-Exposed Uninfected Infants Born in a European Country.

Several studies indicate that HIV-exposed uninfected (HEU) children have a high infectious morbidity. We previously reported an increased incidence of group B streptococcus (GBS) infections in HEU infants born in Belgium.This study was undertaken to evaluate the incidence and risk factors of all cause severe infections in HEU infants born in Belgium between 1985 and 2006, including the pre-antiretroviral (ARV) prophylaxis era (1985 to 1994). The medical charts of 537 HEU infants followed in a single center were reviewed.The incidence rate of severe infections during the first year of life was 16.8/100 HEU infant-years. The rates of invasive S. pneumoniae (0.62/100 infant-years) and GBS infections (1.05/100 infant-years) were, respectively, 4 and 13-fold higher in HEU infants than in the general infant population. Preterm birth was a risk factor for severe infections in the neonatal period (aOR = 21.34, 95%CI:7.12-63.93) and post-neonatal period (aHR = 3.00, 95%CI:1.53-5.88). As compared to the pre-ARV prophylaxis era, infants born in the ARV prophylaxis era (i.e., after April 1994) had a greater risk of severe infections (aHR = 2.93; 95%CI:1.07-8.05). This risk excess was present in those who received ARV prophylaxis (aHR 2.01, 95%CI 0.72-5.65) and also in those born in the ARV prophylaxis era who did not benefit from ARV prophylaxis as a result of poor access to antenatal care or lack of compliance (aHR 3.06, 95%CI 0.88-10.66).In HEU infants born in an industrialized country, preterm birth and being born during the ARV prophylaxis era were risk factors of severe infections throughout the first year of life. These observations have important implications for the clinical management of HIV-infected mothers and their infants