Hemolytic CType Lectin CELIII from Sea

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Hemolytic C-Type Lectin CEL-III from Sea
Cucumber Expressed in Transgenic Mosquitoes
Impairs Malaria Parasite Development Shigeto
Yoshida, Yohei Shimada, Daisuke Kondoh, Yoshiaki
Kouzuma, Anil K. Ghosh, Marcelo Jacobs-Lorena,
and Robert E. Sinden. PLoS Pathogens, December
2007 volume 3, Issue 12, pp. 1962-1970 Presented
by Jan Boitz February 13, 2008
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• CEL-III
• Ca2-dependent, galactose-specific lectin
• Exhibits hemolytic and hemagglutinating
  activities
• Purified from the sea cucumber
• Cucumaria echinata

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• CEL-III
• 6 molecules of CEL-III oligomerize to form an
  ion permeable pore in the cell membrane
• Three domains
• Two N-terminal carbohydrate-binding domains
  which  are highly homologous to ricin and
  abrin
• Unique C-terminal domain

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Model for CEL-III Pore Formation in
Cell Membranes
Peptide 332 KGVIFAKASVSVKVTASLSK
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Peptide 332 strongly active against Gram
bacteria
Mutated all K--gt R Mutated all V--gt L
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Efforts regarding Transgenic Mosquito
production 2002 First transgenic mosquitoes
made using peptide that blocks transmission of
Plasmodium across the midgut epithelium 2002
Bee venom phospholipase inhibits Plasmodium
development 2007 CEL-III exhibits cytotoxicity
against Malaria parasites within infected
mosquitoes
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Plasmodium Lifecycle Within the Mosquito Vector
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Figure 1
Hemolytic activity /- FBS CEL-III has high
activity against human and rat erythrocytes at
low concentrations (FBS)
Abs at 550 nm, detecting free hemoglobin
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CEL-III has no hemagglutination activity against
mouse erythrocytes
CEL-III does not bind the surface of mouse
erythrocytes
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Figure 2
CEL-III binds to ookinetes
CEL-III inhibits ookinete development
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Figure 3
CEL-III is secreted into the mosquito midgut and
has hemolytic activity
Blood meal induces CEL-III mRNA induction
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Figure 4
Western blot analysis of CEL-III protein in
mosquito midgut. Native CEL-III is from the sea
cucumber.
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Figure 5
Red blood cells are lysed in midguts of
mosquitoes expressing CEL-III
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Tables 12
Rat and mouse Transmission blockade of intensity
(TBi) Prevalence number of infected
mosquitoes TBpPrevalence of (CEL-III/WT) Tbi
100-(CEL-III/WT)1000
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Table 3
CEL-III transgenic mosquitoes have decreased
ability to infect mice
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Table 4
CEL-III transgenic mosquitoes have fewer
sporozoites in salivary glands
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Table 5
Oocyst production is decreased in CEL-III
expressing mosquitoes
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• Conclusions
• CEL-III has hemolytic activity against human and
  rat erythrocytes
• CEL-III binds to ookinetes
• CEL-III appears to inhibit ookinete development
  by decreasing progress to oocyst and sporozoite
  formation
• CEL-III expression does not appear to cause any
  fitness issues in moquitoes thus far

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• Considerations for Releasing Transgenic (GMO)
  Mosquitoes into the Environment
• Mosquito fitness
• Genetic drive
• Efficiency
• Effect on other organisms
• DISCUSSION

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