A Plasmodium berghei putative serine-threonine kinase 2 (PBANKA_0311400) is required for late liver stage development and timely initiation of blood stage infection

Malaria starts with Plasmodium sporozoites infection of the host's liver, where development into blood stage parasites occurs. It is not clear why natural infections do not induce protection against the initial liver stage and generate low CD8+ T cell responses. Using a rodent malaria model, we show that Plasmodium blood stage infection suppresses CD8+ T cell immune responses that were induced against the initial liver stage. Blood stage Plasmodium affects dendritic cell (DC) functions, inhibiting maturation and the capacity to initiate immune responses and inverting the interleukin (IL)-12/IL-10 secretion pattern. The interaction of blood stage parasites with DCs induces the secretion of soluble factors that inhibit the activation of CD8+ T cells in vitro and the suppression of protective CD8+ T cell responses against the liver stage in vivo. We propose that blood stage infection induces DCs to suppress CD8+ T cell responses in natural malaria infections. This evasion mechanism leaves the host unprotected against reinfection by inhibiting the immune response against the initial liver stage of the disease.

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Differential interleukin-10 expression in interferon regulatory factor-1 deficient mice during Plasmodium berghei blood-stage infection

Parasite Immunology ◽

10.1046/j.1365-3024.2000.00312.x ◽

2000 ◽

Vol 22 (9) ◽

pp. 425-435 ◽

Cited By ~ 12

Author(s):

Rosemary S.-P. Tan ◽

Anna U. Kara ◽

Chiguang Feng ◽

Yoshihiro Asano ◽

Raja Sinniah

Keyword(s):

Plasmodium Berghei ◽

Interleukin 10 ◽

Interferon Regulatory Factor ◽

Blood Stage ◽

Regulatory Factor ◽

Interferon Regulatory Factor 1 ◽

Blood Stage Infection ◽

Deficient Mice ◽

Stage Infection

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Chemical Attenuation of Plasmodium berghei Sporozoites Induces Sterile Immunity in Mice

Infection and Immunity ◽

10.1128/iai.01399-07 ◽

2008 ◽

Vol 76 (3) ◽

pp. 1193-1199 ◽

Cited By ~ 42

Author(s):

Lisa A. Purcell ◽

Stephanie K. Yanow ◽

Moses Lee ◽

Terry W. Spithill ◽

Ana Rodriguez

Keyword(s):

Plasmodium Falciparum ◽

Plasmodium Berghei ◽

Alkylating Agent ◽

Blood Stage ◽

Wild Type ◽

Vaccine Strategy ◽

Liver Stage ◽

Stage Development

ABSTRACT Radiation and genetic attenuation of Plasmodium sporozoites are two approaches for whole-organism vaccines that protect against malaria. We evaluated chemical attenuation of sporozoites as an alternative vaccine strategy. Sporozoites were treated with the DNA sequence-specific alkylating agent centanamycin, a compound that significantly affects blood stage parasitemia and transmission of murine malaria and also inhibits Plasmodium falciparum growth in vitro. Here we show that treatment of Plasmodium berghei sporozoites with centanamycin impaired parasite function both in vitro and in vivo. The infection of hepatocytes by sporozoites in vitro was significantly reduced, and treated parasites showed arrested liver stage development. Inoculation of mice with sporozoites that were treated in vitro with centanamycin failed to produce blood stage infections. Furthermore, BALB/c and C57BL/6 mice vaccinated with treated sporozoites were protected against subsequent challenge with wild-type sporozoites. Our findings demonstrate that chemically attenuated sporozoites could be a viable alternative for the production of an effective liver stage vaccine for malaria.

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A dual fluorescent Plasmodium cynomolgi reporter line reveals in vitro malaria hypnozoite reactivation

Communications Biology ◽

10.1038/s42003-019-0737-3 ◽

2020 ◽

Vol 3 (1) ◽

Cited By ~ 4

Author(s):

Annemarie M. Voorberg-van der Wel ◽

Anne-Marie Zeeman ◽

Ivonne G. Nieuwenhuis ◽

Nicole M. van der Werff ◽

Els J. Klooster ◽

...

Keyword(s):

Cell Infection ◽

Liver Stage ◽

Plasmodium Cynomolgi ◽

Prolonged Culture ◽

Blood Stage Infection ◽

Transgenic Parasites ◽

Stage Development ◽

Green Fluorescent ◽

Stage Infection

AbstractPlasmodium vivax malaria is characterized by repeated episodes of blood stage infection (relapses) resulting from activation of dormant stages in the liver, so-called hypnozoites. Transition of hypnozoites into developing schizonts has never been observed. A barrier for studying this has been the lack of a system in which to monitor growth of liver stages. Here, exploiting the unique strengths of the simian hypnozoite model P. cynomolgi, we have developed green-fluorescent (GFP) hypnozoites that turn on red-fluorescent (mCherry) upon activation. The transgenic parasites show full liver stage development, including merozoite release and red blood cell infection. We demonstrate that individual hypnozoites actually can activate and resume development after prolonged culture, providing the last missing evidence of the hypnozoite theory of relapse. The few events identified indicate that hypnozoite activation in vitro is infrequent. This system will further our understanding of the mechanisms of hypnozoite activation and may facilitate drug discovery approaches.

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Proteomic Analysis ofPlasmodiumMerosomes: The Link Between Liver and Blood Stages in Malaria

10.1101/580266 ◽

2019 ◽

Author(s):

Melanie J Shears ◽

Raja Sekhar Nirujogi ◽

Kristian E Swearingen ◽

Santosh Renuse ◽

Satish Mishra ◽

...

Keyword(s):

Proteomic Analysis ◽

Life Cycle Stage ◽

Blood Stage ◽

Quantitative Detection ◽

List Type ◽

Liver Stage ◽

Core Set ◽

Blood Stage Infection ◽

Malaria Model ◽

Stage Infection

SummaryThe pre-erythrocytic liver stage of the malaria parasite, comprising sporozoites and the liver stages into which they develop, remains one of the least understood parts of the lifecycle, in part owing to the low numbers of parasites. Nonetheless, it is recognized as an important target for anti-malarial drugs and vaccines. Here we provide the first proteomic analysis of merosomes, which define the final phase of the liver stage and are responsible for initiating the blood stage of infection. We identify a total of 1879 parasite proteins, and a core set of 1188 proteins quantitatively detected in every biological replicate, providing an extensive picture of the protein repertoire of this stage. This unique dataset will allow us to explore key questions about the biology of merosomes and hepatic merozoites.HighlightsFirst proteome of the merosome stage of malaria parasitesQuantitative detection of 1188 parasite proteins across 3 biological replicatesComparison to blood stage proteomes identifies shared and unique proteinsDiscovery of cleaved PEXEL motifs highlights liver stage protein exportIn BriefThe merosome stage that links malaria liver and blood stage infection is poorly understood. Here we provide the first proteome of this life cycle stage using thePlasmodium bergheirodent malaria model.Graphical Abstract

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Resolving the cause of recurrent Plasmodium vivax malaria probabilistically

Nature Communications ◽

10.1038/s41467-019-13412-x ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 8

Author(s):

Aimee R. Taylor ◽

James A. Watson ◽

Cindy S. Chu ◽

Kanokpich Puaprasert ◽

Jureeporn Duanguppama ◽

...

Keyword(s):

Plasmodium Vivax ◽

Vivax Malaria ◽

Blood Stage ◽

High Dose ◽

Time To Event ◽

Liver Stage ◽

Plasmodium Vivax Malaria ◽

Blood Stage Infection ◽

Stage Infection

AbstractRelapses arising from dormant liver-stage Plasmodium vivax parasites (hypnozoites) are a major cause of vivax malaria. However, in endemic areas, a recurrent blood-stage infection following treatment can be hypnozoite-derived (relapse), a blood-stage treatment failure (recrudescence), or a newly acquired infection (reinfection). Each of these requires a different prevention strategy, but it was not previously possible to distinguish between them reliably. We show that individual vivax malaria recurrences can be characterised probabilistically by combined modelling of time-to-event and genetic data within a framework incorporating identity-by-descent. Analysis of pooled patient data on 1441 recurrent P. vivax infections in 1299 patients on the Thailand–Myanmar border observed over 1000 patient follow-up years shows that, without primaquine radical curative treatment, 3 in 4 patients relapse. In contrast, after supervised high-dose primaquine only 1 in 40 relapse. In this region of frequent relapsing P. vivax, failure rates after supervised high-dose primaquine are significantly lower (∼3%) than estimated previously.

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A Plasmodium falciparum Host-Targeting Motif Functions in Export during Blood Stage Infection of the Rodent Malarial Parasite Plasmodium berghei

PLoS ONE ◽

10.1371/journal.pone.0002405 ◽

2008 ◽

Vol 3 (6) ◽

pp. e2405 ◽

Cited By ~ 14

Author(s):

Julia J. MacKenzie ◽

Noé D. Gómez ◽

Souvik Bhattacharjee ◽

Shaina Mann ◽

Kasturi Haldar

Keyword(s):

Plasmodium Falciparum ◽

Plasmodium Berghei ◽

Blood Stage ◽

Malarial Parasite ◽

Parasite Plasmodium ◽

Blood Stage Infection ◽

Stage Infection

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A Plasmodium Parasite with Complete Late Liver Stage Arrest Protects against Preerythrocytic and Erythrocytic Stage Infection in Mice

Infection and Immunity ◽

10.1128/iai.00088-18 ◽

2018 ◽

Vol 86 (5) ◽

pp. e00088-18 ◽

Cited By ~ 14

Author(s):

Ashley M. Vaughan ◽

Brandon K. Sack ◽

Dorender Dankwa ◽

Nana Minkah ◽

Thao Nguyen ◽

...

Keyword(s):

Inbred Mice ◽

Specific Protein ◽

Plasmodium Yoelii ◽

Blood Stage ◽

Susceptible Mouse ◽

Liver Stage ◽

Content Type ◽

Synthetic Lethal ◽

Stage Development ◽

Stage Infection

ABSTRACT Genetically attenuated malaria parasites (GAP) that arrest during liver stage development are powerful immunogens and afford complete and durable protection against sporozoite infection. Late liver stage-arresting GAP provide superior protection against sporozoite challenge in mice compared to early live stage-arresting attenuated parasites. However, very few late liver stage-arresting GAP have been generated to date. Therefore, identification of additional loci that are critical for late liver stage development and can be used to generate novel late liver stage-arresting GAPs is of importance. We further explored genetic attenuation in Plasmodium yoelii by combining two gene deletions, PlasMei2 and liver-specific protein 2 (LISP2), that each cause late liver stage arrest with various degrees of infrequent breakthrough to blood stage infection. The dual gene deletion resulted in a synthetic lethal phenotype that caused complete attenuation in a highly susceptible mouse strain. P. yoelii plasmei2− lisp2− arrested late in liver stage development and did not persist in livers beyond 3 days after infection. Immunization with this GAP elicited robust protective antibody responses in outbred and inbred mice against sporozoites, liver stages, and blood stages as well as eliciting protective liver-resident T cells. The immunization afforded protection against both sporozoite challenge and blood stage challenge. These findings provide evidence that completely attenuated late liver stage-arresting GAP are achievable via the synthetic lethal approach and might enable a path forward for the creation of a completely attenuated late liver stage-arresting P. falciparum GAP.

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Plasmodium vivax Latent Liver Stage Infection and Relapse: Biological Insights and New Experimental Tools

Annual Review of Microbiology ◽

10.1146/annurev-micro-032421-061155 ◽

2021 ◽

Vol 75 (1) ◽

Author(s):

Carola Schäfer ◽

Gigliola Zanghi ◽

Ashley M. Vaughan ◽

Stefan H.I. Kappe

Keyword(s):

Plasmodium Vivax ◽

Blood Stage ◽

Annual Review ◽

Publication Date ◽

Liver Stage ◽

Human Malaria Parasite ◽

Treatment And Prevention ◽

Parasite Stage ◽

Blood Stage Infection ◽

Stage Infection

Plasmodium vivax is the most widespread human malaria parasite, in part because it can form latent liver stages known as hypnozoites after transmission by female anopheline mosquitoes to human hosts. These persistent stages can activate weeks, months, or even years after the primary clinical infection; replicate; and initiate relapses of blood stage infection, which causes disease and recurring transmission. Eliminating hypnozoites is a substantial obstacle for malaria treatment and eradication since the hypnozoite reservoir is undetectable and unaffected by most antimalarial drugs. Importantly, in some parts of the globe where P. vivax malaria is endemic, as many as 90% of P. vivax blood stage infections are thought to be relapses rather than primary infections, rendering the hypnozoite a major driver of P. vivax epidemiology. Here, we review the biology of the hypnozoite and recent discoveries concerning this enigmatic parasite stage. We discuss treatment and prevention challenges, novel animal models to study hypnozoites and relapse, and hypotheses related to hypnozoite formation and activation. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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