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Genes Aug 2023Malaria in pregnancy (MiP) is a public health problem in malaria-endemic areas, contributing to detrimental outcomes for both mother and fetus. Primigravida and...
Malaria in pregnancy (MiP) is a public health problem in malaria-endemic areas, contributing to detrimental outcomes for both mother and fetus. Primigravida and second-time mothers are most affected by severe anemia complications and babies with low birth weight compared to multigravida women. Infected erythrocytes (IE) reach the placenta, activating the immune response by placental monocyte infiltration and inflammation. However, specific markers of MiP result in poor outcomes, such as low birth weight, and intrauterine growth restriction for babies and maternal anemia in women infected with are limited. In this study, we identified the plasma proteome signature of a mouse model infected with ANKA and pregnant women infected with infection using quantitative mass spectrometry-based proteomics. A total of 279 and 249 proteins were quantified in murine and human plasma samples, of which 28% and 30% were regulated proteins, respectively. Most of the regulated proteins in both organisms are involved in complement system activation during malaria in pregnancy. CBA anaphylatoxin assay confirmed the complement system activation by the increase in C3a and C4a anaphylatoxins in the infected plasma compared to non-infected plasma. Moreover, correlation analysis showed the association between complement system activation and reduced head circumference in newborns from -infected mothers. The data obtained in this study highlight the correlation between the complement system and immune and newborn outcomes resulting from malaria in pregnancy.
Topics: Infant, Newborn; Pregnancy; Infant; Female; Humans; Animals; Mice; Mice, Inbred CBA; Placenta; Complement Activation; Malaria; Biomarkers
PubMed: 37628675
DOI: 10.3390/genes14081624 -
Molecular and Biochemical Parasitology Sep 2023The parasite responsible for causing malaria infection, Plasmodium, is known to exhibit resistance to a number of already available treatments. This has prompted the...
The parasite responsible for causing malaria infection, Plasmodium, is known to exhibit resistance to a number of already available treatments. This has prompted the continue search for new antimalarial drugs ranging from medicinal plant parts to synthetic compounds. In lieu of this, the mitigative action of the bioactive compound, eugenol towards P. berghei-induced anaemia and oxidative organ damage was investigated following a demonstration of in vitro and in vivo antiplasmodial effects. Mice were infected with chloroquine-sensitive strain of P. berghei and thereafter treated with eugenol at doses of 10 and 20 mg/kg body weight (BW) for seven days. The packed cell volume and redox sensitive biomarkers in the liver, brain and spleen were measured. Our result demonstrated that eugenol significantly (p < 0.05) ameliorated the P. berghei-associated anaemia at a dose of 10 mg/kg BW. In addition, the compound, at a dose of 10 mg/kg BW, significantly (p < 0.05) alleviated the P. berghei-induced organ damage. This evidently confirmed that eugenol plays an ameliorative role towards P. berghei-related pathological alterations. Hence, the study opens up a new therapeutic use of eugenol against plasmodium parasite.
Topics: Mice; Animals; Plasmodium berghei; Eugenol; Plant Extracts; Antimalarials; Oxidative Stress; Anemia
PubMed: 37329986
DOI: 10.1016/j.molbiopara.2023.111577 -
MSphere Aug 2023During invasion, parasites secrete proteins from rhoptry and microneme apical end organelles, which have crucial roles in attaching to and invading target cells. A...
During invasion, parasites secrete proteins from rhoptry and microneme apical end organelles, which have crucial roles in attaching to and invading target cells. A sporozoite stage-specific gene silencing system revealed that rhoptry neck protein 2 (RON2), RON4, and RON5 are important for sporozoite invasion of mosquito salivary glands. Here, we further investigated the roles of RON4 during sporozoite infection of the liver . Following intravenous inoculation of RON4-knockdown sporozoites into mice, we demonstrated that sporozoite RON4 has multiple functions during sporozoite traversal of sinusoidal cells and infection of hepatocytes. infection experiments using a hepatoma cell line revealed that secreted RON4 is involved in sporozoite adhesion to hepatocytes and has an important role in the early steps of hepatocyte infection. In addition, motility assays indicated that RON4 is required for sporozoite attachment to the substrate and the onset of migration. These findings indicate that RON4 is crucial for sporozoite migration toward and invasion of hepatocytes via attachment ability and motility.IMPORTANCEMalarial parasite transmission to mammals is established when sporozoites are inoculated by mosquitoes and migrate through the bloodstream to infect hepatocytes. Many aspects of the molecular mechanisms underpinning migration and cellular invasion remain largely unelucidated. By applying a sporozoite stage-specific gene silencing system in the rodent malarial parasite, , we demonstrated that rhoptry neck protein 4 (RON4) is crucial for sporozoite infection of the liver . Combined with investigations, it was revealed that RON4 functions during a crossing of the sinusoidal cell layer and invading hepatocytes, at an early stage of liver infection, by mediating the sporozoite capacity for adhesion and the onset of motility. Since RON4 is also expressed in merozoites and tachyzoites, our findings contribute to understanding the conserved invasion mechanisms of parasites.
Topics: Animals; Mice; Plasmodium berghei; Liver; Malaria; Sporozoites; Protozoan Proteins; Hepatocytes
PubMed: 37272704
DOI: 10.1128/msphere.00587-22 -
Molecular Microbiology Mar 2024Plasmodium parasites, the eukaryotic pathogens that cause malaria, feature three distinct invasive forms tailored to the host environment they must navigate and invade...
Plasmodium parasites, the eukaryotic pathogens that cause malaria, feature three distinct invasive forms tailored to the host environment they must navigate and invade for life cycle progression. One conserved feature of these invasive forms is the micronemes, apically oriented secretory organelles involved in egress, motility, adhesion, and invasion. Here we investigate the role of GPI-anchored micronemal antigen (GAMA), which shows a micronemal localization in all zoite forms of the rodent-infecting species Plasmodium berghei. ∆GAMA parasites are severely defective for invasion of the mosquito midgut. Once formed, oocysts develop normally, however, sporozoites are unable to egress and exhibit defective motility. Epitope-tagging of GAMA revealed tight temporal expression late during sporogony and showed that GAMA is shed during sporozoite gliding motility in a similar manner to circumsporozoite protein. Complementation of P. berghei knockout parasites with full-length P. falciparum GAMA partially restored infectivity to mosquitoes, indicating conservation of function across Plasmodium species. A suite of parasites with GAMA expressed under the promoters of CTRP, CAP380, and TRAP, further confirmed the involvement of GAMA in midgut infection, motility, and vertebrate infection. These data show GAMA's involvement in sporozoite motility, egress, and invasion, implicating GAMA as a regulator of microneme function.
Topics: Animals; Culicidae; Parasites; Protozoan Proteins; Oocysts; Plasmodium berghei; Sporozoites
PubMed: 37314965
DOI: 10.1111/mmi.15078 -
Nature Communications Dec 2023Gametogenesis in Plasmodium spp. occurs within the Anopheles mosquito and is essential for sexual reproduction / differentiation and onwards transmission to mammalian...
Gametogenesis in Plasmodium spp. occurs within the Anopheles mosquito and is essential for sexual reproduction / differentiation and onwards transmission to mammalian hosts. To better understand the 3D organisation of male gametogenesis, we used serial block face scanning electron microscopy (SBF-SEM) and serial-section cellular electron tomography (ssET) of P. berghei microgametocytes to examine key structures during male gamete formation. Our data reveals an elaborate organisation of axonemes coiling around the nucleus in opposite directions forming a central axonemal band in microgametocytes. Furthermore, we discover the nucleus of microgametes to be tightly coiled around the axoneme in a complex structure whose formation starts before microgamete emergence during exflagellation. Our discoveries of the detailed 3D organisation of the flagellated microgamete and the haploid genome highlight some of the atypical mechanisms of axoneme assembly and haploid genome organisation during male gamete formation in the malaria parasite.
Topics: Male; Animals; Plasmodium berghei; Haploidy; Germ Cells; Anopheles; Flagella; Mammals
PubMed: 38092766
DOI: 10.1038/s41467-023-43877-w -
Frontiers in Cellular and Infection... 2023Coronavirus disease 2019 (COVID-19) and malaria, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and parasites, respectively, share geographical...
Coronavirus disease 2019 (COVID-19) and malaria, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and parasites, respectively, share geographical distribution in regions where the latter disease is endemic, leading to the emergence of co-infections between the two pathogens. Thus far, epidemiologic studies and case reports have yielded insufficient data on the reciprocal impact of the two pathogens on either infection and related diseases. We established novel co-infection models to address this issue experimentally, employing either human angiotensin-converting enzyme 2 (hACE2)-expressing or wild-type mice, in combination with human- or mouse-infective variants of SARS-CoV-2, and the rodent malaria parasite. We now show that a primary infection by a viral variant that causes a severe disease phenotype partially impairs a subsequent liver infection by the malaria parasite. Additionally, exposure to an attenuated viral variant modulates subsequent immune responses and provides protection from severe malaria-associated outcomes when a blood stage infection was established. Our findings unveil a hitherto unknown host-mediated virus-parasite interaction that could have relevant implications for disease management and control in malaria-endemic regions. This work may contribute to the development of other models of concomitant infection between and respiratory viruses, expediting further research on co-infections that lead to complex disease presentations.
Topics: Humans; Mice; Animals; SARS-CoV-2; COVID-19; Rodentia; Coinfection; Malaria; Disease Models, Animal
PubMed: 38156320
DOI: 10.3389/fcimb.2023.1307553 -
Nature Communications Jan 2024Excessive host immune responses contribute to severe malaria with high mortality. Here, we show that PRL2 in innate immune cells is highly related to experimental...
Excessive host immune responses contribute to severe malaria with high mortality. Here, we show that PRL2 in innate immune cells is highly related to experimental malaria disease progression, especially the development of murine severe malaria. In the absence of PRL2 in myeloid cells, Plasmodium berghei infection results in augmented lung injury, leading to significantly increased mortality. Intravital imaging revealed greater neutrophilic inflammation and NET formation in the lungs of PRL2 myeloid conditional knockout mice. Depletion of neutrophils prior to the onset of severe disease protected mice from NETs associated lung injury, and eliminated the difference between WT and PRL2 CKO mice. PRL2 regulates neutrophil activation and NET accumulation via the Rac-ROS pathway, thus contributing to NETs associated ALI. Hydroxychloroquine, an inhibitor of PRL2 degradation alleviates NETs associated tissue damage in vivo. Our findings suggest that PRL2 serves as an indicator of progression to severe malaria and ALI. In addition, our study indicated the importance of PRL2 in NET formation and tissue injury. It might open a promising path for adjunctive treatment of NET-associated disease.
Topics: Animals; Mice; Acute Lung Injury; Extracellular Traps; Lung; Malaria; Mice, Inbred C57BL; Mice, Knockout; Neutrophils; Protein Tyrosine Phosphatases; Immediate-Early Proteins
PubMed: 38286811
DOI: 10.1038/s41467-024-45210-5 -
Indian Journal of Microbiology Sep 2023Malaria in pregnancy causes a dual brunt on the mother as well as the foetus. Upregulation of T-regulatory cells (Tregs) during pregnancy allows tolerance towards the...
INTRODUCTION
Malaria in pregnancy causes a dual brunt on the mother as well as the foetus. Upregulation of T-regulatory cells (Tregs) during pregnancy allows tolerance towards the growing foetus, their suppression predisposes the mother to infections. This study analyzed the levels of CD3CD4CD25Fox-p3 Tregs, parasitaemia, maternal and foetal outcomes in BALB/c mice infected with NK65 during early-, mid-, and late-pregnancy.
METHODOLOGY
Total of 114 mice, non-pregnant non-infected (n = 6), non-pregnant infected (n = 12), pregnant non-infected (n = 48) and pregnant infected (n = 48) were included in the study. Infected groups were inoculated intra-peritoneally with 1 × 10 infected RBCs during early-, mid-, and late- pregnancy (D6, D10, and D14 respectively). Six mice from each stage were sacrificed on the 5th and 7th day post-infection (DPI) to evaluate parasitaemia (staining) and Tregs from splenocytes (by flow cytometry).
RESULTS
The parasitaemia was significantly higher among early pregnancy infected mice (≥ 70%) than mid-pregnancy infected (40-70%), late pregnancy infected (50-65%), and non-pregnant infected mice (≤ 50%) ( < 0.05). The level of Tregs was significantly higher among non-pregnant infected mice as compared to non-pregnant non-infected mice (%Tregs 0.86 vs. 0.44). Among pregnant mice, the levels of Tregs in infected mice were lower than in non-infected mice during all stages of pregnancy. None of the mice infected during early- and mid-pregnancy survived at 6DPI and 7DPI, respectively, and those infected during late-pregnancy delivered premature pups.
CONCLUSION
In contrast to non-pregnant mice, the levels of Tregs among pregnant mice decrease when malaria infection is acquired thereby leading to adverse pregnancy outcomes.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s12088-023-01089-2.
PubMed: 37781008
DOI: 10.1007/s12088-023-01089-2 -
ELife Dec 2023Lipophorin is an essential, highly expressed lipid transport protein that is secreted and circulates in insect hemolymph. We hijacked the gene to make it co-express a...
Lipophorin is an essential, highly expressed lipid transport protein that is secreted and circulates in insect hemolymph. We hijacked the gene to make it co-express a single-chain version of antibody 2A10, which binds sporozoites of the malaria parasite . The resulting transgenic mosquitoes show a markedly decreased ability to transmit expressing the circumsporozoite protein to mice. To force the spread of this antimalarial transgene in a mosquito population, we designed and tested several CRISPR/Cas9-based gene drives. One of these is installed in, and disrupts, the pro-parasitic gene and also cleaves wild-type causing the anti-malarial modified version to replace the wild type and hitch-hike together with the drive. Although generating drive-resistant alleles and showing instability in its gRNA-encoding multiplex array, the -based gene drive reached high levels in caged mosquito populations and efficiently promoted the simultaneous spread of the antimalarial allele. This combination is expected to decrease parasite transmission via two different mechanisms. This work contributes to the design of novel strategies to spread antimalarial transgenes in mosquitoes, and illustrates some expected and unexpected outcomes encountered when establishing a population modification gene drive.
Topics: Animals; Mice; Anopheles; Gene Drive Technology; Antimalarials; Mosquito Vectors; RNA, Guide, CRISPR-Cas Systems; Plasmodium falciparum; Plasmodium berghei; Lipoproteins
PubMed: 38051195
DOI: 10.7554/eLife.93142 -
Molecules (Basel, Switzerland) Jul 2023Malaria remains a life-threatening health problem and is responsible for the high rates of mortality and morbidity in the tropical and subtropical regions of the world....
Malaria remains a life-threatening health problem and is responsible for the high rates of mortality and morbidity in the tropical and subtropical regions of the world. The increasing threat of drug resistance to available artemisinin-based therapy warrants an urgent need to develop new antimalarial drugs that are safer, more effective, and have a novel mode of action. Natural plants are an excellent source of inspiration in searching for a new antimalarial agent. This research reports a systematic investigation for determining the antimalarial potential of the seeds of . The study shows that the crude seed extract (CSE), protein, saponin, and the oily fractions of the seeds were nontoxic at a 2000 mg/kg body weight dose when tested in Wistar rats, thus revealing high safety is classified as class 5. The oily fraction, Annomaal, demonstrated pronounced antimalarial activity with low IC (1.25 ± 0.183 μg/mL) against in vitro. The CSE and Annomaal significantly inhibited the growth of parasites in vivo with 58.47% and 61.11% chemo suppression, respectively, while the standard drug artemether showed chemo suppression of 66.75%. Furthermore, the study demonstrated that oral administration of Annomaal at a daily dose of 250 mg/kg/day for 3 days was adequate to provide a complete cure to the -infected mice. Annomaal thus holds promise as being patient-compliant due to the shorter treatment schedule, eliminating the need for frequent dosing for extended time periods as required by several synthetic antimalarial drugs. Further studies are needed to determine the active compounds in the oily fraction responsible for antimalarial activity.
Topics: Rats; Animals; Mice; Antimalarials; Plasmodium falciparum; Plasmodium berghei; Annona; Plant Extracts; Rats, Wistar; Malaria, Falciparum; Seeds
PubMed: 37513343
DOI: 10.3390/molecules28145472