Plasmodium falciparum: Modifications of the In vitro Culture Conditions Improving Parasitic Yields

Zolg, J. Werner; MacLeod, Alexander J.; Dickson, Ida H.; Scaife, John

doi:10.2307/3281094

Cited by 81 publications

(44 citation statements)

References 19 publications

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“…Mosquitoes were reared at 27°C and 80% humidity on a 12-h light to dark cycle under standard laboratory conditions. The four P. falciparum strains used (NF54, 3D7, GB4 and 7G8) were maintained in O+ human erythrocytes using RPMI medium 1640 supplemented with 25 mM Hepes, 50 mg/L hypoxanthine, 25 mM NaHCO3, and 10% (vol/vol) heat-inactivated type O+ human serum at 37°C and a gas mixture of 5% O 2 , 5% CO 2 , and balance N 2 (21,22).…”

Section: Methodsmentioning

confidence: 99%

Some strains of Plasmodium falciparum , a human malaria parasite, evade the complement-like system of Anopheles gambiae mosquitoes

Molina-Cruz

DeJong

Ortega

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

112

116

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Plasmodium falciparum lines differ in their ability to infect mosquitoes. The Anopheles gambiae L3-5 refractory (R) line melanizes most Plasmodium species, including the Brazilian P. falciparum 7G8 line, but it is highly susceptible to some African P. falciparum strains such as 3D7, NF54, and GB4. We investigated whether these lines differ in their ability to evade the mosquito immune system. Silencing key components of the mosquito complement-like system [thioester-containing protein 1 (TEP1), leucine-rich repeat protein 1, and Anopheles Plasmodium-responsive leucine-rich repeat protein 1] prevented melanization of 7G8 parasites, reverting the refractory phenotype. In contrast, it had no effect on the intensity of infection with NF54, suggesting that this line is able to evade TEP1-mediated lysis. When R females were coinfected with a line that is melanized (7G8) and a line that survives (3D7), the coinfection resulted in mixed infections with both live and encapsulated parasites on individual midguts. This finding shows that survival of individual parasites is parasite-specific and not systemic in nature, because parasites can evade TEP1-mediated lysis even when other parasites are melanized in the same midgut. When females from an extensive genetic cross between R and susceptible A. gambiae (G3) mosquitoes were infected with P. berghei, encapsulation was strongly correlated with the TEP1-R1 allele. However, P. falciparum 7G8 parasites were no longer encapsulated by females from this cross, indicating that the TEP1-R1 allele is not sufficient to melanize this line. Evasion of the A. gambiae immune system by P. falciparum may be the result of parasite adaptation to sympatric mosquito vectors and may be an important factor driving malaria transmission.immune evasion | mosquito immunity | refractory mosquito | thioester-containing protein 1 activation

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Section: Methodsmentioning

confidence: 99%

Some strains of Plasmodium falciparum , a human malaria parasite, evade the complement-like system of Anopheles gambiae mosquitoes

Molina-Cruz

DeJong

Ortega

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

112

116

View full text Add to dashboard Cite

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“…Mosquitoes were reared at 27°C and 80% humidity on a 12-h lightdark cycle under standard laboratory conditions. The Plasmodium falciparum strains used-NF54, SenTh015.04 (MRA-1181) from Senegal, 7G8 from Brazil, IPC 3445 Pailin Cambodia 2010 (MRA-1236), IPC 4912 Mondolkiri Cambodia 2011 (MRA-1241), NF54-Pfs47KO and Pfs47KO complemented lines (Pfs47 Africa-Nf54, Pfs47 Asia MRA-1241, and Pfs47 America-7G8)-were maintained in O+ human erythrocytes using RPMI medium 1640 supplemented with 25 mM Hepes, 10 mg/L hypoxanthine, 25 mM NaHCO 3 , and 10% (vol/vol) heat-inactivated type O+ human serum (Interstate Blood Bank) at 37°C and with a gas mixture of 5% O 2 , 5% CO 2 , and balance N 2 (28,29). Tables S3 and S4).…”

Section: Methodsmentioning

confidence: 99%

Plasmodium evasion of mosquito immunity and global malaria transmission: The lock-and-key theory

Molina-Cruz

Canepa

Kamath

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

119

167

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Plasmodium falciparum malaria originated in Africa and became global as humans migrated to other continents. During this journey, parasites encountered new mosquito species, some of them evolutionarily distant from African vectors. We have previously shown that the Pfs47 protein allows the parasite to evade the mosquito immune system of Anopheles gambiae mosquitoes. Here, we investigated the role of Pfs47-mediated immune evasion in the adaptation of P. falciparum to evolutionarily distant mosquito species. We found that P. falciparum isolates from Africa, Asia, or the Americas have low compatibility to malaria vectors from a different continent, an effect that is mediated by the mosquito immune system. We identified 42 different haplotypes of Pfs47 that have a strong geographic population structure and much lower haplotype diversity outside Africa. Replacement of the Pfs47 haplotypes in a P. falciparum isolate is sufficient to make it compatible to a different mosquito species. Those parasites that express a Pfs47 haplotype compatible with a given vector evade antiplasmodial immunity and survive. We propose that Pfs47-mediated immune evasion has been critical for the globalization of P. falciparum malaria as parasites adapted to new vector species. Our findings predict that this ongoing selective force by the mosquito immune system could influence the dispersal of Plasmodium genetic traits and point to Pfs47 as a potential target to block malaria transmission. A new model, the "lock-and-key theory" of P. falciparum globalization, is proposed, and its implications are discussed. malaria globalization | immune evasion | anopheles immunity | Plasmodium selection | Pfs47

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“…Suspension cultures of parasites have also been tried. Zolg et al (100) reported improved yields with shaking of cultures, but these claims have been disputed (39). Fragility of the infected red blood cells is an important factor in agitated cultures, but this has been countered to some extent by the use of methylcellulose in agitated cultures (47, 100).…”

Section: Erythrocytic Stagesmentioning

confidence: 99%

Cultivation of Plasmodium spp

Schuster

2002

Clin Microbiol Rev

102

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Cultivation of both human and non-human species of Plasmodium spp., the causal agent of malaria, has been a major research success, leading to a greater understanding of the parasite. Efforts at cultivating the organisms in vitro are complicated by the parasites' alternating between a human host and an arthropod vector, each having its own set of physiological, metabolic, and nutritional parameters. Life cycle stages of the four species that infect humans have been established in vitro. Of these four, P. falciparum remains the only species for which all stages have been cultured in vitro; different degrees of success have been achieved with the other human Plasmodium spp. The life cycle includes the exoerythrocytic stage (within liver cells), the erythrocytic stage (within erythrocytes or precursor reticulocytes), and the sporogonic stage (within the vector). Culture media generally consist of a basic tissue culture medium (e.g., minimal essential medium or RPMI 1640) to which serum and erythrocytes are added. Most of the efforts have been directed toward the stage found in the erythrocyte. This stage has been cultivated in petri plates or other growth vessels in a candle jar to generate elevated CO2 levels or in a more controlled CO2 atmosphere. Later developments have employed continuous-flow systems to reduce the labor-intensive nature of medium changing. The exoerythrocytic and sporogonic life cycle stages have also been cultivated in vitro. A number of avian, rodent, and simian malarial parasites have also been established in vitro. Although cultivation is of great help in understanding the biology of Plasmodium, it does not lend itself to use for diagnostic purposes

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Plasmodium falciparum: Modifications of the In vitro Culture Conditions Improving Parasitic Yields

Cited by 81 publications

References 19 publications

Some strains of Plasmodium falciparum , a human malaria parasite, evade the complement-like system of Anopheles gambiae mosquitoes

Some strains of Plasmodium falciparum , a human malaria parasite, evade the complement-like system of Anopheles gambiae mosquitoes

Plasmodium evasion of mosquito immunity and global malaria transmission: The lock-and-key theory

Cultivation of Plasmodium spp

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