An MFS-Domain Protein Pb115 Plays a Critical Role in Gamete Fertilization of the Malaria Parasite Plasmodium berghei

In this study, we characterized the functions of a conserved cell membrane protein P115 in the rodent malaria parasite Plasmodium berghei ANKA. Pb115 was expressed in both asexual stages (schizonts) and sexual stages (gametocytes, gametes, and ookinetes), and was localized on the plasma membrane of gametes and ookinetes. In P. berghei, genetic deletion of Pb115 (Δpb115) did not affect asexual multiplication, nor did it affect gametocyte development or exflagellation of the male gametocytes. However, mosquitoes fed on Δpb115-infected mice showed 74% reduction in the prevalence of infection and 96.5% reduction in oocyst density compared to those fed on wild-type P. berghei-infected mice. The Δpb115 parasites showed significant defects in the interactions between the male and female gametes, and as a result, very few zygotes were formed in ookinete cultures. Cross fertilization with the male-defective Δpbs48/45 line and the female-defective Δpfs47 line further indicated that the fertilization defects of the Δpb115 lines were present in both male and female gametes. We evaluated the transmission-blocking potential of Pb115 by immunization of mice with a recombinant Pb115 fragment. In vivo mosquito feeding assay showed Pb115 immunization conferred modest, but significant transmission reducing activity with 44% reduction in infection prevalence and 39% reduction in oocyst density. Our results described functional characterization of a conserved m...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research

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Conclusions: Naturally acquired sexual stage immunity, as detected by antibodies to Pfs230 and Pfs48/45, was present in most studies analyzed. Significant between-study heterogeneity was seen, and methodological factors were a major contributor to this, and prevented further analysis of epidemiological and biological factors. This demonstrates a need for standardized protocols for conducting and reporting seroepidemiological analyses.
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
Conclusions: ivA was highly efficacious in this pediatric cohort. We observed episodes of mild to moderate posttreatment hemolysis in approximately one-third of patients. The legal status and usage of potentially lifesaving ivA should be evaluated in Europe.
Source: The Pediatric Infectious Disease Journal - Category: Infectious Diseases Tags: Original Studies Source Type: research
In conclusion, the overall results present the molecular characterization of annexin B30, annexin B5a, annexin B7a and annexin B5b from S. mansoni in host-parasite interactions and strongly suggest that the molecules could be useful candidates for vaccine or diagnostic development.
Source: Molecular and Biochemical Parasitology - Category: Parasitology Source Type: research
The level of human group IIA secreted phospholipase A2 (hGIIA sPLA2) is increased in the plasma of malaria patients, but its role is unknown. In parasite culture with normal plasma, hGIIA is inactive against Plasmodium falciparum, contrasting with hGIIF, hGV, and hGX sPLA2s, which readily hydrolyze plasma lipoproteins, release nonesterified fatty acids (NEFAs), and inhibit parasite growth. Here, we revisited the anti-Plasmodium activity of hGIIA under conditions closer to those of malaria physiopathology where lipoproteins are oxidized. In parasite culture containing oxidized lipoproteins, hGIIA sPLA2 was inhibitory, with ...
Source: Infection and Immunity - Category: Infectious Diseases Authors: Tags: Molecular Pathogenesis Source Type: research
Authors: Szuster-Ciesielska A, Wawiórka L, Krokowski D, Grankowski N, Jarosz Ł, Lisiecka U, Tchórzewski M Abstract Malaria remains one the most infectious and destructive protozoan diseases worldwide. Plasmodium falciparum, a protozoan parasite with a complex life cycle and high genetic variability responsible for the difficulties in vaccine development, is implicated in most malaria-related deaths. In the course of study, we prepared a set of antigens based on P-proteins from P. falciparum and determined their immunogenicity in an in vivo assay on a mouse model. The pentameric complex P0-(P1-P2)2 wa...
Source: Journal of Immunology Research - Category: Allergy & Immunology Tags: J Immunol Res Source Type: research
Malaria elimination requires diagnostic methods able to detect parasite levels well below what is currently possible with microscopy and rapid diagnostic tests. This is particularly true in surveillance of mal...
Source: Malaria Journal - Category: Infectious Diseases Authors: Tags: Research Source Type: research
by Angela Nalwoga, Emily L. Webb, Belinda Chihota, Wendell Miley, Bridgious Walusimbi, Jacent Nassuuna, Richard E. Sanya, Gyaviira Nkurunungi, Nazzarena Labo, Alison M. Elliott, Stephen Cose, Denise Whitby, Robert Newton We investigated the impact of helminths and malaria infection on Kaposi’s sarcoma associated herpesvirus (KSHV) seropositivity, using samples and data collected from a cluster-randomised trial of intensive versus standard anthelminthic treatment. The trial was carried out in 2012 to 2016 among f ishing communities on Lake Victoria islands in Uganda. Plasma samples from 2881 participants from two hou...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research
A gene enabled the malaria parasite to infect both gorillas and humans for a limited time, explaining how the jump was made at a molecular level, researchers say.
Source: CBC | Health - Category: Consumer Health News Tags: News/Health Source Type: news
Discovery of mutation 50,000 years ago could help in the fight against malaria.
Source: BBC News | Health | UK Edition - Category: Consumer Health News Source Type: news
Scientists who resurrected a 50,000-year-old gene sequence have analyzed it to figure out how the world's deadliest malaria parasite jumped from gorillas to humans - giving insight into the origins of one of human history's biggest killers.
Source: Reuters: Health - Category: Consumer Health News Tags: healthNews Source Type: news
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