Towards a Vaccine against Plasmodium vivax Malaria

The authors discuss a new study that suggests thatPlasmodium vivax Duffy-binding protein could be a candidate antigen for developing aP. vivax vaccine

Development of fluorescent Plasmodium falciparum for in vitro growth inhibition assays

<p>Abstract</p> <p>Background</p> <p><it>Plasmodium falciparum </it><it>in vitro </it>growth inhibition assays are widely used to evaluate and quantify the functional activity of acquired and vaccine-induced antibodies and the anti-malarial activity of known drugs and novel compounds. However, several constraints have limited the use of these assays in large-scale population studies, vaccine trials and compound screening for drug discovery and development.</p> <p>Methods</p> <p>The D10 <it>P. falciparum </it>line was transfected to express green fluorescent protein (GFP). <it>In vitro </it>growth inhibition assays were performed over one or two cycles of <it>P. falciparum </it>asexual replication using inhibitory polyclonal antibodies raised in rabbits, an inhibitory monoclonal antibody, human serum samples, and anti-malarials. Parasitaemia was evaluated by microscopy and flow cytometry.</p> <p>Results</p> <p>Transfected parasites expressed GFP throughout all asexual stages and were clearly detectable by flow cytometry and fluorescence microscopy. Measurement of parasite growth inhibition was the same when determined by detection of GFP fluorescence or staining with ethidium bromide. There was no difference in the inhibitory activity of samples when tested against the transfected parasites compared to the parental line. The level of fluorescence of GFP-expressing parasites increased throughout the course of asexual development. Among ring-stages, GFP-fluorescent parasites were readily separated from uninfected erythrocytes by flow cytometry, whereas this was less clear using ethidium bromide staining. Inhibition by serum and antibody samples was consistently higher when tested over two cycles of growth compared to one, and when using a 1 in 10 sample dilution compared to 1 in 20, but there was no difference detected when using a different starting parasitaemia to set-up growth assays. Flow cytometry based measurements of parasitaemia proved more reproducible than microscopy counts.</p> <p>Conclusions</p> <p>Flow cytometry based assays using GFP-fluorescent parasites proved sensitive and highly reproducible for quantifying the growth-inhibitory activity of antibodies and anti-malarials, with superior reproducibility to light microscopy, and are suitable for high-throughput applications.</p

Truncation of Plasmodium berghei merozoite surface protein 8 does not affect in vivo blood-stage development

Merozoite surface protein 8 (MSP8) has shown promise as a vaccine candidate in the Plasmodium yoelii rodent malaria model and has a proposed role in merozoite invasion of erythrocytes. However, the temporal expression and localisation of MSP8 are unusual for a merozoite antigen. Moreover, in Plasmodium falciparum the MSP8 gene could be disrupted with no apparent effect on in vitro growth. To address the in vivo function of full-length MSP8, we truncated MSP8 in the rodent parasite Plasmodium berghei. Pb&Delta;MSP8 disruptant parasites displayed a normal blood-stage growth rate but no increase in reticulocyte preference, a phenomenon observed in P. yoelii MSP8 vaccinated mice. Expression levels of erythrocyte surface antigens were similar in P. berghei wild-type and Pb&Delta;MSP8-infected erythrocytes, suggesting that a parasitophorous vacuole function for MSP8 does not involve global trafficking of such antigens. These data demonstrate that a full-length membrane-associated form of PbMSP8 is not essential for blood-stage growth.<br /

Promising Functional Readouts of Immunity in a Blood-Stage Malaria Vaccine Trial

The authors discuss results from an early trial of a vaccine based on Plasmodium MSP-3 protein reported by Pierre Druilhe and colleagues

Quantifying the Importance of MSP1-19 as a Target of Growth-Inhibitory and Protective Antibodies against Plasmodium falciparum in Humans

BACKGROUND: Antibodies targeting blood stage antigens are important in protection against malaria, but the key targets and mechanisms of immunity are not well understood. Merozoite surface protein 1 (MSP1) is an abundant and essential protein. The C-terminal 19 kDa region (MSP1-19) is regarded as a promising vaccine candidate and may also be an important target of immunity. METHODOLOGY/FINDINGS: Growth inhibitory antibodies against asexual-stage parasites and IgG to recombinant MSP1-19 were measured in plasma samples from a longitudinal cohort of 206 children in Papua New Guinea. Differential inhibition by samples of mutant P. falciparum lines that expressed either the P. falciparum or P. chabaudi form of MSP1-19 were used to quantify MSP1-19 specific growth-inhibitory antibodies. The great majority of children had detectable IgG to MSP1-19, and high levels of IgG were significantly associated with a reduced risk of symptomatic P. falciparum malaria during the 6-month follow-up period. However, there was little evidence of PfMSP1-19 specific growth inhibition by plasma samples from children. Similar results were found when testing non-dialysed or dialysed plasma, or purified antibodies, or when measuring growth inhibition in flow cytometry or microscopy-based assays. Rabbit antisera generated by immunization with recombinant MSP1-19 demonstrated strong MSP1-19 specific growth-inhibitory activity, which appeared to be due to much higher antibody levels than human samples; antibody avidity was similar between rabbit antisera and human plasma. CONCLUSIONS/SIGNIFICANCE: These data suggest that MSP1-19 is not a major target of growth inhibitory antibodies and that the protective effects of antibodies to MSP1-19 are not due to growth inhibitory activity, but may instead be mediated by other mechanisms. Alternatively, antibodies to MSP1-19 may act as a marker of protective immunity

Tradisi panangat pra nikah oleh wali perempuan dalam perspektif hukum Islam: studi kasus di Desa Sadulang Kecamatan Sapeken Kabupaten Sumenep

Skripsi dengan judul “Tradisi Panangat Pra Nikah Oleh Wali Perempuan Dalam Perspektif Hukum Islam (Studi Kasus di Desa Sadulang Kecamatan Sapeken Kabupaten Sumenep. Penelitian ini bertujuan untuk menjawab pertanyaan: 1. Bagaimana tradisi panangat pra nikah oleh wali perempuan dalam di Desa Sadulang Kecamatan Sapeken Kabupaten Sumenep? 2. Bagaimana analisis hukum Islam terhadap tradisi panangat pra nikah oleh wali perempuan di Desa Sadulang Kecamatan Sapeken Kabupaten Sumenep? Jenis penelitian ini adalah dengan menggunakan metode penelitian lapangan, yaitu sebuah penelitian yang dilakukan secara langsung terhadap peristiwa data-data ada di lapangan. Teknik pengumpulan data yang penulis gunakan adalah wawancara. Setelah data terkumpul, maka penulis melakukan analisis dengan metode analisis kualitatif. Dari data-data yang telah diperoleh, pemberian panangat ini telah dilakukan oleh masyarakat Desa Sadulang sudah menjadi turun-temurun sejak dahulu sampai sekarang. Pemberian panangat di Desa Sadulang merupakan sebagai syarat wajibnya sebelum melaksanakan perkawinan. Adapun tujuannya adalah untuk menghormati atau menghargai wanita yang ingin dinikahi. Proses penentuan panangat tersebut dilakukan dengan cara musyawarah antara pihak laki-laki dengan pihak perempuan, sehingga setelah ada kata sepakat maka perkawinan akan dilangsungkan. Menurut analisis hukum Islam, adat tentang pemberian panangat ada dua yaitu: 1. Di bolehkan selama permintaan panangat tidak memberatkan. 2. Tidak boleh jika permintaan panangat mempersulit atau memberatkan, karena hal itu sangat bertentangan dengan syariat Islam. Berdasarkan hasil penelitian di atas hendaknya pemberian panangat di Desa Sadulang yang diminta oleh pihak perempuan tidak memberatkan pihak lika-laki, sehingga bagi pemuda yang ingin menyempurnakan separuh agamanya yaitu menikah bisa melangsungkannya, jangan sampai gara-gara permintaan panangat yang terlalu tinggi bisa menghalangi niat baik seseorang yang ingin menikah. Kepada para tokoh agama, tokoh masyarakat hendaknya memberikan pemahaman kepada masyarakat Desa Sadulang tentang pelaksanaan panangat yang tidak bertentangan dengan ajaran Islam, karena pada dasarnya masyarakat Desa Sadulang 100% (seratus persen) beragama Islam. Sehingga adat yang berlaku harus sesuai dengan ajaran Islam

Risk factors and knowledge associated with high unintended pregnancy rates and low family planning use among pregnant women in Papua New Guinea

Unintended pregnancy is a major driver of poor maternal and child health in resource-limited settings. Data on pregnancy intention and use of family planning (FP) is scarce in Papua New Guinea (PNG), but are needed to inform public health strategies to improve FP accessibility and uptake. Data from a facility-based cross-sectional sample of 699 pregnant women assessed prevalence and predictors of unintended pregnancy and modern FP use among pregnant women in East New Britain Province, PNG. More than half (55%) the women reported their pregnancy as unintended. Few (18%) reported ever having used a modern FP method, and knowledge of different methods was low. Being single, separated or divorced (AOR 9.66; 95% CI 3.27-28.54), educated to a tertiary or vocational level (AOR 1.78 CI 1.15-2.73), and gravidity>1 (AOR 1.43 for each additional pregnancy CI 1.29-1.59) were associated with unintended pregnancy; being accompanied by a male partner to ANC was associated with a reduced unintended pregnancy (0.46 CI 0.30-0.73). Factors associated with modern FP use included male partner involvement (AOR 2.26 CI 1.39-3.67) and gravidity>1 (AOR 1.54 for each additional pregnancy CI 1.36-1.74). FP use also varied by the facility women attended. Findings highlight an urgent need for targeted interventions to improve FP knowledge, uptake and access, and male partner involvement, to reduce unintended pregnancies and their complications

Low knowledge of newborn danger signs among pregnant women in Papua New Guinea and implications for health seeking behaviour in early infancy – findings from a longitudinal study

Background: Globally, 2.5 million babies die in the first 28 days of life each year with most of these deaths occurring in low- and middle-income countries. Early recognition of newborn danger signs is important in prompting timely care seeking behaviour. Little is known about women’s knowledge of newborn danger signs in Papua New Guinea. This study aims to assess this knowledge gap among a cohort of women in East New Britain Province. Methods: This study assessed knowledge of newborn danger signs (as defined by the World Health Organization) at three time points from a prospective cohort study of women in East New Britain Province, factors associated with knowledge of danger signs after childbirth were assessed using logistic regression. This study includes quantitative and qualitative interview data from 699 pregnant women enrolled at their first antenatal clinic visit, followed up after childbirth (n = 638) and again at one-month post-partum (n = 599). Results: Knowledge of newborn danger signs was very low. Among the 638 women, only 9.4% knew three newborn danger signs after childbirth and only one knew all four essential danger signs defined by Johns Hopkins University ‘Birth Preparedness and Complication Readiness’ Index. Higher knowledge scores were associated with higher gravidity, income level, partner involvement in antenatal care, and education. Conclusion: Low levels of knowledge of newborn danger signs among pregnant women are a potential obstacle to timely care-seeking in rural Papua New Guinea. Antenatal and postnatal education, and policies that support enhanced education and decision-making powers for women and their families, are urgently needed

Mutations in KEOPS-Complex Genes Cause Nephrotic Syndrome with Primary Microcephaly

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms