Parasitic Flatworms : Molecular Biology, Biochemistry, Immunology and Physiology

by A. G. Maule; N. J. Marks

• ISBN13: 9780851990279
• ISBN10: 0851990274
• Edition: 1st
• Format: Hardcover
• Copyright: 2006-09-18
• Publisher: Cab Intl

Summary

This book examines recent research into the molecular biology, genomics and transcriptomics of, and novel control strategies for, flatworm parasites. These include Cestodes (tapeworms) and Trematodes (flukes, schistosomes etc), which are the cause of a number of diseases of medical and veterinary importance. The book explores three main areas: phylogeny, genetics and transcriptomes; immunobiology, host-parasite interaction and control; and protein function, metabolism and physiology. Where appropriate, comparisons are made between different parasitic flatworms and between parasitic and free-living species. The book concludes by exploring future avenues for research. Contributors to the book include leading authorities from Europe, North and South America, and Australia.

Table of Contents

Contributors	xv
Preface	xix
Access to Colour Illustrations	xx
PART I PHYLOGENY, GENETICS AND TRANSCRIPTOMES
The Evolution of Parasitism in Flatworms	1	(36)
D.T.J. Littlewood
Introduction	1	(6)
Parasitism in the Platyhelminthes	6	(1)
The Origins of Obligate Parasitism -- The Appearance of the Neodermata	7	(8)
When did the Neodermata appear?	12	(1)
The Neodermata -- advantages of a new skin	13	(2)
The Radiation of the Parasitic Flatworms	15	(12)
Radiation of the Monogenea	16	(4)
Radiation of the Cestoda	20	(3)
Radiation of the Aspidogastrea	23	(1)
Radiation of the Digenea	24	(3)
Concluding Remarks	27	(3)
Acknowledgements	30	(1)
References	31	(6)
Genomes and Genomics of Parasitic Flatworms	37	(44)
D.A. Johnston
Introduction	38	(2)
Genome Features	40	(10)
Genome size	40	(2)
Genome composition	42	(1)
DNA methylation	42	(1)
Repeat sequences	43	(3)
Integration of host DNA sequences	46	(1)
Genome instability	47	(1)
Gene processing	48	(2)
Karyotype Features	50	(4)
Chromosome number	50	(1)
Ploidy	50	(2)
Sex chromosomes	52	(1)
Recombination frequency	53	(1)
Telomeres	54	(1)
Mitochondrial Genomes	54	(10)
General characteristics	54	(4)
Gene order	58	(1)
Genetic code	59	(2)
Maternal inheritance	61	(3)
Flatworm Genomics	64	(3)
Rationale	64	(1)
Gene discovery and transcriptome analysis	64	(2)
Physical mapping	66	(1)
Chromosome mapping	66	(1)
Genome sequencing	67	(1)
Concluding Remarks	67	(1)
Acknowledgements	68	(1)
References	68	(13)
Genetic Discrimination of Echinococcus Species and Strains	81	(15)
D.P. McManus
Introduction	81	(1)
Genetic Variation in Echinococcus	82	(2)
Identification of Echinococcus Isolates Using Molecular Genetic Techniques	84	(1)
RFLP/RAPD analysis	84	(1)
PCR-amplified DNA sequences	84	(1)
Mutation scanning methods	85	(1)
Microsatellite markers	85	(1)
Molecular Identification of E. granulosus Strains	85	(5)
Sheep--dog (Genotype 1) and horse--dog (Genotype 4 -- E. equinus) strains	85	(2)
Cattle--dog strain (Genotype 5 -- E. ortleppi)	87	(2)
Camel--dog strain (Genotype 6)	89	(1)
Pig--dog strains (Genotypes 7 and 9)	89	(1)
Cervid strains (Genotypes 8 and 10)	89	(1)
Detection of Echinococcus Nucleic Acids in Clinical Samples	90	(1)
DNA Detection of Infection in Definitive and Intermediate Hosts	90	(1)
Concluding Remarks	91	(1)
Acknowledgements	92	(1)
References	92	(4)
Ribosomal DNA Variation in Parasitic Flatworms	96	(28)
D. Blair
Introduction	96	(2)
Nuclear Ribosomal Operons	98	(11)
Intergenic spacers	100	(2)
Internal transcribed spacers (ITSs)	102	(1)
Intra-individual variation and repeat sequences	103	(4)
Intra- and interspecific variation	107	(1)
Functional motifs	108	(1)
Secondary structure	108	(1)
Small and Large Subunit Genes	109	(6)
Mitochondrial Ribosomal Genes	115	(1)
Hybrids	116	(1)
Concluding Remarks	117	(1)
References	117	(7)
Genetic Studies on Monogeneans with Emphasis on Gyrodactylus	124	(14)
C.O. Cunningham
I. Matejusova
Introduction	124	(1)
Difficulties in Molecular Studies of Monogenea	125	(1)
Molecular Markers for Monogenean Species	126	(4)
The rRNA genes and spacers	126	(1)
The SSU (18S) rRNA gene	127	(1)
The rRNA internal transcribed spacer (ITS)	127	(2)
The rRNA intergenic spacer (IGS)	129	(1)
Large Subunit (LSU) (28S) rRNA gene	129	(1)
Other Regions of the Monogenean Genome	130	(1)
Monogenean Species Concept and Species Complexes	130	(1)
Molecular Analysis within Monogenean Species	131	(1)
Other Genetic Studies in Monogenea	132	(1)
Concluding Remarks	133	(1)
References	133	(5)
The Schistosome Transcriptome	138	(11)
S. Verjovski-Almeida
R. DeMarco
Introduction	138	(1)
The Transcriptome Projects	139	(1)
Transcriptome Comparisons	139	(2)
Evolutionary Implications	141	(1)
Novel Transcripts	141	(1)
Receptors and Host--Parasite Interaction	142	(1)
Immune Evasion	142	(1)
Sex Differences	143	(1)
Genome Data	143	(1)
Novel Drug Targets	143	(1)
Vaccines	144	(1)
Trans-splicing	145	(1)
Retrotransposable Elements	145	(1)
Functional Genomics	145	(1)
Concluding Remarks	146	(1)
References	146	(3)
Transgenic Flatworms	149	(25)
C.G. Grevelding
Introduction	149	(1)
The Planarian Model	150	(1)
Trematodes and Cestodes	151	(2)
Transformation Techniques for Schistosomes	153	(11)
Particle bombardment	153	(2)
The PDS-1000/He particle bombardment system	155	(1)
Reporter gene activity in bombarded schistosomes	156	(6)
Stable Transformation	162	(2)
Cestodes, on the Way to Transgenesis	164	(1)
Concluding Remarks	165	(1)
Acknowledgements	166	(1)
References	166	(8)
PART II IMMUNOBIOLOGY, HOST--PARASITE INTERACTION AND CONTROL
Immunobiology of Schistosomes	174	(19)
S.G. Forrester
E.J. Pearce
Introduction	174	(1)
Host--Parasite Molecular Interactions	175	(1)
How Schistosomes Evade the Host Immune System	176	(3)
Skin stage parasites	176	(2)
Lung stage parasites	178	(1)
Adult parasites	178	(1)
Host Immune Response to Schistosome Infection (Th1 versus Th2)	179	(2)
Potential Players in Th2 Response Induction during a Schistosome Infection	181	(2)
Chemotherapy -- An Integral Role for the Immune Response	183	(1)
Immunotherapy	183	(1)
Concluding Remarks	184	(1)
Acknowledgements	185	(1)
References	185	(8)
Cestode Infection: Immunological Considerations from Host and Tapeworm Perspectives	193	(17)
D.M. McKay
R.A. Webb
Introduction	193	(1)
Cestode Parasites	194	(1)
Immunology -- The Basics	195	(2)
The Intestine and Immune Responses	197	(2)
Create an inhospitable environment	197	(1)
Mobilize an active immune response	198	(1)
Specifics of the Host Response to Cestode Infection	199	(3)
Parenteral infections of cestodes	199	(1)
Host response to the oncosphere	199	(1)
Resistance to parenteral metacestodes	200	(2)
Lumenal Infections: The Immune Response to Hymenolepidid Cestodes	202	(1)
Cestode Infections and the Immune Response -- Where Do We Go from Here?	203	(1)
Evasion and Subversion of the Host Response	204	(1)
The Beneficial Tapeworm	204	(1)
Concluding Remarks	205	(1)
Acknowledgements	206	(1)
References	206	(4)
Signal Transduction at the Host--Parasite Interface	210	(18)
T.P. Yoshino
J.J. Vermeire
J.E. Humphries
Introduction	210	(1)
Tegumental Involvement in Signal Transduction: Perception and Reality	211	(2)
Elements of Platyhelminth Signal Transduction Systems	213	(5)
Molecular and EST data	213	(1)
Platyhelminth signalling proteins	214	(4)
Platyhelminth Signal Transduction Pathways: Tegument and Beyond	218	(5)
Transforming growth factor receptor (TGFR) pathway	218	(1)
TGF-β receptor signalling in schistosomes	219	(1)
Epidermal growth factor receptor (EGFR) pathway	220	(1)
EGFR signalling: roles in the host--parasite relationship	220	(2)
G Protein-coupled receptors (GPCRs)	222	(1)
GPCRs in parasitic platyhelminths	222	(1)
Concluding Remarks	223	(1)
Acknowledgements	223	(1)
References	224	(4)
Parasite Effects on the Snail Host Transcriptome	228	(15)
M. Knight
N. Raghavan
Introduction	228	(2)
Effect of Parasite Infection on the Snail Host: Towards a Molecular Understanding	230	(8)
Innate immunity	230	(1)
Biochemical involvement	231	(2)
Parasite-induced changes in gene expression	233	(4)
Parasite-induced changes in snail neurobiology	237	(1)
Concluding Remarks	238	(1)
Acknowledgements	238	(1)
References	239	(4)
Developments in the Chemotherapy of Parasitic Flatworms	243	(13)
G.C. Coles
Introduction	243	(1)
Parasites of Animals	244	(1)
Infections of Humans	245	(2)
Adult tapeworms	246	(1)
Larval tapeworms	246	(1)
Taenia solium	246	(1)
Echinococcus granulosus	246	(1)
Echinococcus multilocularis	247	(1)
New Anti-parasitics: Nitazoxanide	247	(1)
Mode of Action of Fasciolicides and Cestodicides	247	(1)
Resistance	248	(2)
Resistance in Fasciola	249	(1)
Resistance in monogeneans	249	(1)
Resistance in cestodes	249	(1)
Detection of resistance	250	(1)
Concluding Remarks	250	(1)
References	251	(5)
Drug Resistance in Schistosomes	256	(13)
T.A. Day
S. Botros
Introduction	256	(1)
Schistosomiasis Chemotherapy	257	(1)
Impact of Praziquantel	257	(1)
Challenges to Detecting and Monitoring Anti-schistosomal Resistance	258	(2)
There is a high background of drug failure	258	(1)
Methods for detecting infection are variable	258	(1)
Factors other than resistance can produce drug failure	258	(1)
It is difficult to substantiate a decreased response in the worms	259	(1)
Praziquantel's mechanism of action is not known	259	(1)
Defining resistance	260	(1)
Cases of Drug Resistance in Schistosomes	260	(4)
Resistance to Hycanthone and Oxamniquine	260	(1)
Resistance to Praziquantel	261	(1)
Senegal	261	(1)
Egypt	262	(2)
Concluding Remarks	264	(1)
References	265	(4)
Praziquantel: Mechanism of Action	269	(13)
R.M. Greenberg
Introduction	269	(1)
Praziquantel Mode of Action	270	(2)
Voltage-gated Ca2+ Channels	272	(2)
Schistosome and Flatworm Ca2+ Currents	274	(1)
Schistosome Ca2+ Channel Subunits	275	(2)
Concluding Remarks	277	(1)
Acknowledgements	278	(1)
References	278	(4)
Cestode Vaccine Development	282	(21)
M.W. Lightowlers
Introduction	282	(2)
Immunity -- Basic Principles	284	(1)
Vaccination -- Historical Perspectives	285	(1)
Defined Vaccines	286	(5)
Taenia ovis	287	(1)
Taenia saginata	288	(1)
Taenia solium	289	(1)
Echinococcus granulosus	290	(1)
Echinococcus multilocularis	290	(1)
Towards Practical Application of Cestode Vaccines	291	(1)
Protective Immune Responses and Epitope Identification	292	(1)
Predicted Protein Structure and Function of Oncosphere Antigens	293	(2)
Structure of Genes Encoding Oncosphere Antigens	295	(1)
Potential Practical Impact of Vaccination Against Cestode Parasites	296	(1)
Concluding Remarks	297	(1)
References	297	(6)
The Development of a Schistosome Vaccine	303	(24)
R.A. Wilson
P.S. Coulson
Introduction	303	(1)
Approaches to Schistosomiasis Vaccine Development	304	(1)
What Is Meant by Protective Immunity?	304	(1)
Attenuated Parasites Can Induce Protective Immunity	305	(1)
Routes to Antigen Identification	306	(5)
Mining crude parasite extracts for antigens	306	(1)
Protective monoclonal antibodies	307	(1)
TPI	307	(1)
9B-Ag	308	(1)
Sm23	308	(1)
Anti-idiotypic antibodies	308	(1)
Expression library screening with sera from putatively protected hosts	308	(1)
IrV5	309	(1)
GADPH	309	(1)
Antigens identified on the basis of their immunogenicity	309	(1)
GSTs	309	(1)
Sm14	310	(1)
An Antigen Cocktail Does Not Improve Vaccine Efficacy	311	(1)
Antigen Formulation	311	(1)
The WHO vaccine trials	312	(1)
Clinical Trials	312	(1)
Why Are High Levels of Protection Difficult to Achieve?	313	(1)
Secreted and Tegument Antigens as Vaccine Targets	314	(1)
Calpain	315	(1)
The 20--22 kDa family	315	(1)
Future Prospects	315	(2)
The genome	316	(1)
The transcriptome	316	(1)
The proteome	316	(1)
Concluding Remarks	317	(1)
References	317	(10)
PART III PROTEIN FUNCTION, METABOLISM AND PHYSIOLOGY
Flatworm Parasite Proteomics	327	(21)
R.M. Morphew
J. Barrett
P.M. Brophy
Introduction	327	(1)
Parasitic Flatworm Sample Preparation	328	(5)
Protein collection	329	(1)
Solubilization of proteins	330	(2)
Removal of contaminating substances	332	(1)
Protein Separation before Two-dimensional Electrophoresis	333	(1)
Separating Proteins by Two-dimensional Protein Electrophoresis	334	(3)
Isoelectric focusing	334	(1)
SDS--PAGE the second dimension	335	(1)
Staining and extraction	335	(1)
Image analysis	336	(1)
Mass Spectrometry to Unravel the Flatworm Proteome	337	(1)
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI ToF) for parasite analysis	337	(3)
Electrospray ionization time-of-flight mass spectrometry (ESI ToF MS)	338	(1)
Analysis of post-translational modifications	339	(1)
Peptide sequencing via post-source decay and tandem mass spectrometry	339	(1)
Database Mining and Protein Identification	340	(2)
Useful databases	341	(1)
Proteomics without Two-dimensional Electrophoresis	342	(2)
Multi-dimensional protein identification technology (MuDPIT)	342	(1)
Isotope-coded affinity tagging	343	(1)
Concluding Remarks	344	(1)
Acknowledgements	344	(1)
References	344	(4)
Proteases in Trematode Biology	348	(21)
J.P. Dalton
C.R. Caffrey
M. Sajid
C. Stack
S. Donnelly
A. Loukas
T. Don
J. McKerrow
D.W. Halton
P.J. Brindley
Introduction	349	(1)
The Trematode Gut	349	(1)
Schistosomes	349	(1)
Fasciola hepatica	350	(1)
Blood as a Source of Amino Acids	350	(2)
Prevention of Blood Clotting	352	(1)
Lysis of Blood Cells	352	(1)
Peptidases Involved in the Digestion of Blood and Tissue Proteins	353	(2)
Digestion in schistosomes	353	(2)
Digestion in liver flukes	355	(1)
Regulation of the Digestive Process	355	(1)
Non-feeding Functions Attributed to Peptidases	356	(2)
Invasion and migration through host tissue	356	(1)
Excystment of juvenile parasites	357	(1)
Hatching of eggs	358	(1)
Protease Phylogeny	358	(3)
Cathepsin B	358	(1)
Cathepsins L and F	359	(2)
Aspartic proteases	361	(1)
Gene Structure, Orthology and Molecular Evolution	361	(1)
Concluding Remarks	362	(1)
References	363	(6)
Signalling Molecules and Nerve--Muscle Function	369	(18)
A.G. Maule
N.J. Marks
T.A. Day
Introduction	369	(1)
Nervous System Structure	370	(1)
Muscle Structure and Organization	371	(1)
Neuronal Signalling Molecules	372	(9)
Classical transmitters, their synthesis, degradation and receptors	372	(1)
Acetylcholine	372	(1)
5-Hydroxytryptamine (5-HT; serotonin)	373	(1)
Catecholamines	374	(1)
Histamine	374	(1)
γ-Aminobutyric acid (GABA)	375	(1)
Glutamate	375	(1)
Octopamine	376	(1)
Nitric oxide	376	(1)
Neuropeptides	376	(1)
Neuropeptide F	376	(2)
FMRFamide-related peptides	378	(1)
Neuropeptide processing enzymes	379	(2)
Concluding Remarks	381	(1)
Acknowledgement	381	(1)
References	381	(6)
Unusual Aspects of Metabolism in Flatworm Parasites	387	(21)
A.G.M. Tielens
J.J. van Hellemond
Introduction	387	(1)
Parasitic versus Free-living Stages	388	(1)
Nutrition	388	(2)
Free-living stages	388	(1)
Parasitic stages	389	(1)
Energy Metabolism	390	(11)
Substrates of energy metabolism	390	(1)
Free-living versus parasitic stages	391	(1)
Anaerobic glycolysis versus malate dismutation	391	(3)
Unusual aspects of glycolysis	394	(1)
Unusual aspects of mitochondrial metabolism	395	(1)
Succinate dehydrogenase versus fumarate reductase	396	(1)
Ubiquinone versus rhodoquinone	396	(1)
Acetate:succinate CoA-transferase (ASCT)	397	(1)
Evolutionary origin of anaerobic mitochondria	398	(1)
Transitions in energy metabolism during the life cycle	399	(2)
Biosynthetic Capacities	401	(3)
Lipids	402	(1)
Purines, pyrimidines and polyamines	403	(1)
Concluding Remarks	404	(1)
References	405	(3)
Glycoconjugate Structures	408	(15)
M. Wuhrer
R. Geyer
Introduction	408	(1)
Trematodes (Digenea)	408	(7)
Schistosoma	408	(1)
Glycosphingolipids of schistosomes	409	(2)
Protein glycosylation of schistosomes	411	(1)
Cercarial stage	411	(1)
Adult stage	411	(1)
Egg stage	412	(1)
The Lewis X-epitope and the host--parasite relationship	413	(1)
Fasciola	413	(2)
Cestodes	415	(3)
Pseudophyllida	415	(1)
Cyclophyllida	415	(1)
Glycosphingolipids	415	(2)
Glycoproteins	417	(1)
Concluding Remarks	418	(1)
References	418	(5)
Gene Silencing in Flatworms Using RNA Interference	423	(12)
P.J. Skelly
Introduction	423	(1)
Molecular Mechanisms of Silencing	424	(1)
Biological Functions of Gene Silencing	424	(2)
RNAi as a Molecular and Therapeutic Tool	426	(1)
RNAi Protocols	426	(2)
RNAi in Flatworms	428	(3)
Planaria	428	(1)
Schistosomes	429	(2)
Concluding Remarks	431	(1)
Acknowledgements	431	(1)
References	431	(4)
Index	435