“MALARIA” Binding of Malaria Parasites to Host cells Advanced cell biology II, class presentation Kedar Ghimire, April 5, 2006 EM of a plasmodium

Why do we need to concern about Malaria and the tiny mosquito? Infects million people every year! Infects million people every year! Kills 1-3 million people!!! Kills 1-3 million people!!! Kills one child every 30 seconds!!!!! Kills one child every 30 seconds!!!!!

Originated in Africa Originated in Africa In 1898, Ronald Ross discovered plasmodium in Anopheles mosquitoes In 1898, Ronald Ross discovered plasmodium in Anopheles mosquitoes In past, common in the whole world and mostly in Rome, name derived from the Italian (male-aria) In past, common in the whole world and mostly in Rome, name derived from the Italian (male-aria) Brief History of Malaria

Malarial parasite Caused by four species of Plasmodium Caused by four species of Plasmodium Transmitted by any of 60 species of Anopheles among 400 species Transmitted by any of 60 species of Anopheles among 400 species Plasmodium Falciparum- the most dangerous species and luckily,the intensely studied one Plasmodium Falciparum- the most dangerous species and luckily,the intensely studied one

Life cycle of Plasmodium The life cycle of Plasmodium is extraordinarily complex The life cycle of Plasmodium is extraordinarily complex Life cycle of Plasmodium Falciparum

Binding of parasite to mosquito cells Parasites tend to attack specific tissues of mosquito Parasites tend to attack specific tissues of mosquito Hypothesis, specific ligands- specific receptors binding Hypothesis, specific ligands- specific receptors binding Specific recognition event, evidence is there to support it. Specific recognition event, evidence is there to support it. Sporozoites have surface protein called CS protein and TRAP. Sporozoites have surface protein called CS protein and TRAP. The protein Saglin- a salivary-gland receptor for parasites (its ability to bind the sporozoite surface protein TRAP The protein Saglin- a salivary-gland receptor for parasites (its ability to bind the sporozoite surface protein TRAP Laminins expressed in the midgut epithelial cells thought to bind malaria parasites Laminins expressed in the midgut epithelial cells thought to bind malaria parasites

Merozoite invasion of red blood cells Bannister et al., 1975, Parasitology, 71, Apical adhesion

Binding of parasite to mammalian host cells Plasmodium sporozoites successfully invades liver Plasmodium sporozoites successfully invades liver They also express a surface protein CS and TRAP(SSP2)- sporozoite ligands, (STARP, LSA-3) They also express a surface protein CS and TRAP(SSP2)- sporozoite ligands, (STARP, LSA-3) CS binds to hepatocyte microvilli on HSPG and CSPG CS binds to hepatocyte microvilli on HSPG and CSPG

Change in Rbc‘s shape: knob formation Entry into red blood cells

Possible explanation for binding of sporozoites to hepatocytes trc.ucdavis.edu/mjguinan/apc100/modules/Digestive/mammal/liver5/liver.html

Plasmodium and problems for immune system Toxins released during growth, reproduction or rupture of red blood cells Toxins released during growth, reproduction or rupture of red blood cells Malaria parasites hide from immune system (Nature, 2005) Malaria parasites hide from immune system (Nature, 2005) Plasmodium falciparum constantly changes the appearance of a protein pfEMP1 it deposits on infected RBCs Plasmodium falciparum constantly changes the appearance of a protein pfEMP1 it deposits on infected RBCs They mainly damage Red blood cells They mainly damage Red blood cells

Prospects for Anti malarial vaccines, drugs, genetic methods???? Anti-malarial vaccines- not yet Anti-malarial vaccines- not yet Chloroquine, mefloquine etc- resistance and side effects Chloroquine, mefloquine etc- resistance and side effects Genetically engineered mosquitoes Genetically engineered mosquitoes Organisations funding the malarial research- UNDP, WHO, The Wellcome trust, Gates foundation etc Organisations funding the malarial research- UNDP, WHO, The Wellcome trust, Gates foundation etc

References Sultan AA, Molecular mechanisms of malaria sporozoite motility and invasion of host cells,1999, Int Microbiol Sultan AA, Molecular mechanisms of malaria sporozoite motility and invasion of host cells,1999, Int Microbiol Cerami C. et al (1992), The basolateral domain of the hepatocyte plasma membrane bears receptors for the circumsporozoite protein, Cell, Cell press Cerami C. et al (1992), The basolateral domain of the hepatocyte plasma membrane bears receptors for the circumsporozoite protein, Cell, Cell press Kappe S. et al (2001), Exploring the transcriptome of the malaria sporozoite stage, PNAS Kappe S. et al (2001), Exploring the transcriptome of the malaria sporozoite stage, PNAS Fidock DA, Bottius E, Brahimi K, Moelans II, Aikawa M, Konings RN, Certa U, Olafsson P, Kaidoh T, Asavanich A, et al.,1994, Mol Biochem parasitol Fidock DA, Bottius E, Brahimi K, Moelans II, Aikawa M, Konings RN, Certa U, Olafsson P, Kaidoh T, Asavanich A, et al.,1994, Mol Biochem parasitol Fidock DABottius EBrahimi KMoelans IIAikawa MKonings RNCerta UOlafsson P Kaidoh TAsavanich A Fidock DABottius EBrahimi KMoelans IIAikawa MKonings RNCerta UOlafsson P Kaidoh TAsavanich A Daubersies P, Thomas AW, Millet P, Brahimi K, Langermans JA, Ollomo B, BenMohamed L, Slierendregt B, Eling W, Van Belkum A, Dubreuil G, Meis JF, Guerin-Marchand C, Cayphas S, Cohen J, Gras-Masse H, Druilhe P.et al, 2000, Nature-Medicine Daubersies P, Thomas AW, Millet P, Brahimi K, Langermans JA, Ollomo B, BenMohamed L, Slierendregt B, Eling W, Van Belkum A, Dubreuil G, Meis JF, Guerin-Marchand C, Cayphas S, Cohen J, Gras-Masse H, Druilhe P.et al, 2000, Nature-Medicine Daubersies PThomas AWMillet PBrahimi KLangermans JAOllomo BBenMohamed LSlierendregt BEling WVan Belkum ADubreuil GMeis JFGuerin-Marchand C Cayphas SCohen JGras-Masse HDruilhe P Daubersies PThomas AWMillet PBrahimi KLangermans JAOllomo BBenMohamed LSlierendregt BEling WVan Belkum ADubreuil GMeis JFGuerin-Marchand C Cayphas SCohen JGras-Masse HDruilhe P Consuelo Pinzon-Ortiz. Et al, 2005, The binding of the circumsporozoite protein to cell surface proteoglycans is required for plasmodium sporozoite attachment to target cells, J. Biol. Chem Consuelo Pinzon-Ortiz. Et al, 2005, The binding of the circumsporozoite protein to cell surface proteoglycans is required for plasmodium sporozoite attachment to target cells, J. Biol. Chem alariawebpage.htm alariawebpage.htm alariawebpage.htm alariawebpage.htm THANK YOU ALL FOR YOUR KIND ATTENTION, QUESTIONS?