High polymorphism in genes encoding antigen B from human infecting strains of Echinococcus granulosus

Kamenetzky, Laura; Muzulin, Patricia M.; Gutierrez, Ariana M.; Angel, Sérgio O.; Zaha, Arnaldo; Guarnera, Eduardo; Rosenzvit, Mara Cecília

doi:10.1017/s0031182005008474

Cited by 56 publications

(40 citation statements)

References 33 publications

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“…Kamenetzky et al [19] mentioned that no polymorphism in AgB2 genes was found in each strain but there was a substantial level of inter-strain variation in AgB2 related genes and that cysts from the same strain shared more genomic DNA than cysts from different strains. The high genetic similarity between the human and sheep isolates were confirmed by Jaccard's similarity coefficient and the dendrogram.…”

Section: Discussionmentioning

confidence: 99%

“…Using PCR and RT-PCR, followed by cloning and sequencing, Arend et al [3] characterized a high degree of AgB2 sequence polymorphism between strains. Kamenetzky et al [19] using PCR-SSCP (single strand conformation polymorphism) followed by DNA sequencing to evaluate sequence variation and transcription profile of AgB2-coding genes in several human infecting strains of E. granulosus found a substantial level of inter-strain variation in AgB2-related genes between G1/G2 strain on one hand and G6/G7 and G5 on the other hand. Their finding was supported by a previous study using mitochondrial or nuclear markers which also grouped G1/G2 strains and G6/G7 strains as 2 separate groups leaving G5 strain outside but closer to the G6/G7 group [21].…”

Section: Discussionmentioning

confidence: 99%

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Genetic Variability of Antigen B among Echinococcus granulosus Egyptian Isolates

et al. 2009

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Genetic polymorphisms of encoding antigen B2 gene (AgB2) in Echinococcus granulosus were studied using PCR-RFLP and DNA sequencing among 20 Egyptian isolates. Five isolates from different host origins (humans, camels, pigs, and sheep) were collected and used. All examined isolates of each host group gave very similar patterns of PCR-RFLP after restriction enzyme digestion with AluI, with the gene size of approximately 140 bp and 240 bp for sheep and human isolates, and approximately 150 bp and 250 bp for pig and camel isolates. No digestion pattern was obtained after incubation of all studied isolates with EcoRI. These results reveal high intra-group homogeneity. DNA sequence analysis highlighted that human infecting strain showed 100% identity with respect to sheep infecting isolate, 96% and 99% with pig and camel infecting isolates, respectively.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Genetic Variability of Antigen B among Echinococcus granulosus Egyptian Isolates

et al. 2009

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“…E. granulosusspecific EgAgB is likely to be a key factor in the process of immune evasion, as the antigen is secreted and variable 34 . Encoded by a gene family, we found seven EgAgB genes in the genome, similar to in a previous report 13 .…”

Section: Evading Immune Recognition and Regulation Of Host Immunologimentioning

confidence: 99%

The genome of the hydatid tapeworm Echinococcus granulosus

et al. 2013

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A r t i c l e sThe dog tapeworm E. granulosus is one of a group of medically important parasitic helminths of the family Taeniidae (Platyhelminthes; Cestoda; Cyclophyllidea) that infect at least 50 million people globally 1 . Its life cycle involves two mammals, including an intermediate host, usually a domestic or wild ungulate (humans are accidental intermediate hosts) and a canine-definitive host, such as the domestic dog. The larval (metacestode) stage causes hydatidosis (cystic hydatid disease; cystic echinococcosis), a chronic cyst-forming disease in the intermediate (human) host. Currently, up to 3 million people are infected with E. granulosus 2,3 , and, in some areas, 10% of the population has detectable hydatid cysts by abdominal ultrasound and chest X-ray 4,5 .E. granulosus has no gut, circulatory or respiratory organs. It is monoecious, producing diploid eggs that give rise to ovoid embryos, the oncospheres. Strobilization is a notable feature of cestode biology, whereby proglottids bud distally from the anterior scolex, resulting in the production of tandem reproductive units exhibiting increasing degrees of development. A unique characteristic of the larvae (protoscoleces, PSCs) within the hydatid cyst is an ability to develop bidirectionally into an adult worm in the dog gastrointestinal tract or into a secondary hydatid cyst in the intermediate (human) host, a process triggered by bile acids 6 . Another distinct feature of E. granulosus is its capacity to infect and adapt to a large number of mammalian species as intermediate hosts, which has contributed to its cosmopolitan global distribution.Here we report the sequence and analysis of the E. granulosus genome. Comprising nine pairs of chromosomes 7 , it is one of the first cestode genomes to be sequenced and complements the recent publication by Tsai et al. 8 of a high-quality genome for Echinococcus multilocularis (the cause of alveolar echinococcosis), together with draft genomes of three other tapeworm species including E. granulosus. Our study provides insights into the biology, development, differentiation, evolution and host interaction of E. granulosus and has identified a range of drug and vaccine targets that can facilitate the development of new intervention tools for hydatid treatment and control. Cystic echinococcosis (hydatid disease), caused by the tapeworm E. granulosus, is responsible for considerable human morbidity and mortality. This cosmopolitan disease is difficult to diagnose, treat and control. We present a draft genomic sequence for the worm comprising 151.6 Mb encoding 11,325 genes. Comparisons with the genome sequences from other taxa show that E. granulosus has acquired a spectrum of genes, including the EgAgB family, whose products are secreted by the parasite to interact and redirect host immune responses. We also find that genes in bile salt pathways may control the bidirectional development of E. granulosus, and sequence differences in the calcium channel subunit EgCa v b 1 may be associated with praziquantel sens...

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“…After establishment in the host, the hydatid cyst produces a large amount of AgB , which can alter the Th1/Th2 ratio from a predominant Th1 response in the early stage of infection to a Th2 response (Rigano et al, 2001), indicating that AgB is a modulator of the T cell response benefiting parasite survival. A number of studies have shown that AgB is encoded by a gene family and the antigen exhibits a high degree of genetic polymorphism (Haag et al, 2006;Rosenzvit et al, 2006;Kamenetzky et al, 2005), suggesting that the Echinococcus organisms have evolved antigenic variation-type mechanisms for escaping the host immune response.…”

Section: Regulatory T Cellsmentioning

confidence: 99%