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Glycocalyx shedding by cercariae of bird schistosomes
Chaloupecká, Jana ; Mikeš, Libor (advisor) ; Štěrba, Ján (referee)
Trichobilharzia spp. are avian schistosomes related to medically important human parasites of the genus Schistosoma. Penetrating cercariae are well known as causative agent of cercarial dermatitis in humans. Cercariae actively penetrate the skin of definitive hosts and transform into schistosomula. This process is preceded by cercarial tail detachment and includes emptying of penetration glands and extensive surface changes. One of these changes is the loss of highly immunogenic glycocalyx which represents a protective coat in the aquatic environment. The glycocalyx has specific composition of saccharide molecules which are bound to lipids or proteins on the membrane of cercarial tegument. There is only limited information about the mechanism of shedding. Hypotheses based on indirect evidences suggest that peptidases or (phospho)lipases from penetration glands could be involved. This work describes the changes in surface glycosylation during transformation of cercariae into schistosomula by fluorescently labelled lectins and monoclonal antibodies against Lewis X antigen. Lectins UEA-I, LTA and PNA have been chosen as markers of transformation of T. regenti. Further, our experiments have been focused on shedding of cercarial glycocalyx. During in vitro induction of penetration gland emptying and...
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Features and functions of glycocalyx of trematode cercariae
Chaloupecká, Jana ; Mikeš, Libor (advisor) ; Kašný, Martin (referee)
Trematodes are parasites from phylum Platyhelminthes which have compex life cycles involving two to four hosts. This work focuses especially on trematodes of the family Schistosomatidae. Their cercariae which leave the snail intermediate host, actively penetrate the skin of definitive hosts and transform into schistosomula. This is accompanied by detachment of cercarial tail and emptying of penetration glands. During transformation, cercarial bodies undergo extensive ultrastructural and molecular changes. One of these changes is the loss of surface glycocalyx which represents a protective coat in the aquatic environment. In glycocalyx shedding, participation of proteolytic enzymes from cercarial penetration glands is expected during invasion of the host. Glycocalyx has specific composition of saccharide molecules which are bound to lipids or proteins on the membrane of cercarial tegument. This work describes the origin, ultrastructure, saccharide composition, function and shedding mechanism of cercarial glycocalyx.
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In vitro cultivation of the trematode species Trichobilharzia regenti
Vrbová, Kristýna ; Kašný, Martin (advisor) ; Skelly, Patrick (referee)
The class Trematoda includes many pathogenic representatives. Main subject of this thesis, avian schistosome Trichobilharzia regenti, is a close relative to the important human pathogen Schistosoma mansoni (family Schistosomatidae). In vitro cultivation of trematodes enables closer understanding of their biology and parasite- host interactions; however, no trematode species has been successfully kept in vitro from the egg stage to the adults producing eggs. Many studies are focused on the problematic of S. mansoni cultivation, but data concerning T. regenti cultivation remain scarce. Only the ability of T. regenti cercariae to transform into schistosomula in vitro was documented, with following survival in a culture medium for a few days. Comparison of eight transformation methods was performed with T. regenti cercariae. Based on the number of tailless cercarial bodies obtained, five transformation methods were selected for further evaluation of the early schistosomula characteristics (glycocalyx shedding, penetration glands emptying and survival in vitro). It was observed that the largest quantity of cercarial bodies can be obtained by using a syringe needle or the BeadBeater cell disrupter. The largest quantity of schistosomula meeting the criteria of early schistosomulum was recorded after...
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Glycocalyx shedding by cercariae of bird schistosomes
Chaloupecká, Jana ; Mikeš, Libor (advisor) ; Štěrba, Ján (referee)
Trichobilharzia spp. are avian schistosomes related to medically important human parasites of the genus Schistosoma. Penetrating cercariae are well known as causative agent of cercarial dermatitis in humans. Cercariae actively penetrate the skin of definitive hosts and transform into schistosomula. This process is preceded by cercarial tail detachment and includes emptying of penetration glands and extensive surface changes. One of these changes is the loss of highly immunogenic glycocalyx which represents a protective coat in the aquatic environment. The glycocalyx has specific composition of saccharide molecules which are bound to lipids or proteins on the membrane of cercarial tegument. There is only limited information about the mechanism of shedding. Hypotheses based on indirect evidences suggest that peptidases or (phospho)lipases from penetration glands could be involved. This work describes the changes in surface glycosylation during transformation of cercariae into schistosomula by fluorescently labelled lectins and monoclonal antibodies against Lewis X antigen. Lectins UEA-I, LTA and PNA have been chosen as markers of transformation of T. regenti. Further, our experiments have been focused on shedding of cercarial glycocalyx. During in vitro induction of penetration gland emptying and...
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Features and functions of glycocalyx of trematode cercariae
Chaloupecká, Jana ; Mikeš, Libor (advisor) ; Kašný, Martin (referee)
Trematodes are parasites from phylum Platyhelminthes which have compex life cycles involving two to four hosts. This work focuses especially on trematodes of the family Schistosomatidae. Their cercariae which leave the snail intermediate host, actively penetrate the skin of definitive hosts and transform into schistosomula. This is accompanied by detachment of cercarial tail and emptying of penetration glands. During transformation, cercarial bodies undergo extensive ultrastructural and molecular changes. One of these changes is the loss of surface glycocalyx which represents a protective coat in the aquatic environment. In glycocalyx shedding, participation of proteolytic enzymes from cercarial penetration glands is expected during invasion of the host. Glycocalyx has specific composition of saccharide molecules which are bound to lipids or proteins on the membrane of cercarial tegument. This work describes the origin, ultrastructure, saccharide composition, function and shedding mechanism of cercarial glycocalyx.
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