Molecular Mimicry: Parasite Evasion and Host Defense

Damian, Raymond T.

doi:10.1007/978-3-642-74594-2_9

Cited by 51 publications

(43 citation statements)

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“…Larval parasite killing mechanisms include the release of oxidants by eosinophils, neutrophils, and macrophages potentiated by antibodies and/or cytokines (8,12,16,31,32). However, to establish itself in the host, the parasite has evolved a number of immune evasion mechanisms (17,39,51,60), such as antioxidant enzymes (7,11,30,37). These are essential enzymes involved in the prevention of reactive oxygen species-derived damage.…”

mentioning

confidence: 99%

Cross-Reactivity ofSchistosoma mansoniCytosolic Superoxide Dismutase, a Protective Vaccine Candidate, with Host Superoxide Dismutase and Identification of Parasite-Specific B Epitopes

Carvalho-Queiroz¹,

Cook²,

Wang

et al. 2004

Infect Immun

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Schistosoma mansoni, an intravascular parasite, has evolved a number of immune evasion mechanisms to establish itself in the host, such as antioxidant enzymes. Our laboratory has demonstrated that the highest levels of certain antioxidant enzymes are found in adult worms, which are the least susceptible to immune killing. Vaccination of mice with naked DNA constructs containing the gene encoding Cu/Zn cytosolic superoxide dismutase (SmCT-SOD) showed significant levels of protection compared to a control group, and our data demonstrate that the adult worms are a target of the immune response that confers resistance in SmCT-SOD DNA-vaccinated mice. Because SmCT-SOD shows significant identity with the human homologue, we evaluated the reactivity of anti-SmCT-SOD antibodies derived from SmCT-SOD-immunized mice and rabbits and from S. mansoni-infected individuals to human superoxide dismutase (hSOD) and SmCT-SOD parasite-specific peptides to assess the potential for autoimmune responses from immunization with the recombinant molecule. In addition, we evaluated the ability of various SmCT-SOD adjuvant-delivered immunizations to induce cross-reactive antibodies. Both mouse and rabbit antibodies generated against SmCT-SOD recognized the denatured form of hSOD. The same antibodies did not recognize nondenatured hSOD. Sera from infected individuals with different clinical forms of schistosomiasis recognized SmCT-SOD but not hSOD. Antibodies from mice immunized with different SmCT-SOD-containing formulations of both DNA and protein were able to recognize SmCT-SOD-derived peptides but not soluble hSOD. All together, these findings serve as a basis for developing a subunit vaccine against schistosomiasis.Schistosomiasis remains an endemic problem in over 76 countries, although approaches to reduce transmission and morbidity as well as to improve sanitation, mollusciciding and mass chemotherapy, have been attempted (3, 13). Vaccine development to control schistosomiasis is a high priority, as it would offer the potential of cost-efficient, long-lasting prophylaxis (2, 65). Schistosoma mansoni, an intravascular parasite, lives in a hostile environment in close contact with host humoral and cellular cytotoxic factors. Larval parasite killing mechanisms include the release of oxidants by eosinophils, neutrophils, and macrophages potentiated by antibodies and/or cytokines (8,12,16,31,32). However, to establish itself in the host, the parasite has evolved a number of immune evasion mechanisms (17,39,51,60), such as antioxidant enzymes (7,11,30,37). These are essential enzymes involved in the prevention of reactive oxygen species-derived damage. Evidence for the involvement of schistosome antioxidant enzymes, such as cytosolic superoxide dismutase (SmCT-SOD) and glutathione peroxidase (SmGPX), in immune evasion has been presented elsewhere (39). SmCT-SOD and GPX localize to the host-parasite interface (worm tegument and gut epithelium of the adult but not the larval schistosome) (41) and show developmental regulation (29,41,42) wit...

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confidence: 99%

Cross-Reactivity ofSchistosoma mansoniCytosolic Superoxide Dismutase, a Protective Vaccine Candidate, with Host Superoxide Dismutase and Identification of Parasite-Specific B Epitopes

Carvalho-Queiroz¹,

Cook²,

Wang

et al. 2004

Infect Immun

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“…In addition to parasite-specific glycan motifs, schistosomes express also mammalian-type carbohydrate structures. Therefore, the question arises as to whether the worm might utilize sugar-based molecular mimicry (Damian 1989) as an additional survival strategy.…”

Section: Introductionmentioning

confidence: 99%

Structural characterization of N-glycans from the freshwater snail Biomphalaria glabrata cross-reacting with Schistosoma mansoni glycoconjugates

et al. 2006

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The human parasitic trematode Schistosoma mansoni has a complex life cycle that includes the freshwater snail Biomphalaria glabrata as intermediate host. Within each stage, the parasite synthesizes a wide array of glycoconjugates, exhibiting, in part, unique carbohydrate structures. In addition, the parasite expresses definitive host-like sugar epitopes, such as Lewis X determinants, supporting the concept of carbohydrate-mediated molecular mimicry as an invasion and survival strategy. In the present study, we investigated whether common carbohydrate determinants occur also at the level of the intermediate host. To this end, a structural characterization of hemolymph glycoprotein-N-glycans of B. glabrata was performed. N-glycans were released from tryptic glycopeptides and labeled with 2-aminopyridine. Sugar chains serologically cross-reacting with S. mansoni glycoconjugates were isolated by immunoaffinity chromatography using a polyclonal antiserum directed against schistosomal egg antigens and fractionated by Aleuria aurantia lectin affinity chromatography and high-performance liquid chromatography. Obtained glycans were analyzed by different mass spectrometric techniques as well as by monosaccharide constituent and linkage analysis. The results revealed a highly heterogeneous oligosaccharide pattern. Cross-reacting species represented about 5% of the total glycans and exhibited a terminal Fuc(a1-3)GalNAc unit, a (1-2)-linked xylosyl residue, or both types of structural motifs. In conclusion, our study demonstrates the presence of common carbohydrate epitopes also at the level of S. mansoni and its intermediate host.

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“…Taennids can also exploit the hormonal microenvironment within the host in their favor (Escobedo et al, 2005;Locksley, 1997). Taennids have evolved structures similar to the steroid and protein hormone receptors expressed in upper vertebrates, with binding properties and terminal effects similar to the hormonal metabolites synthesized by the host (Damian, 1989;Salzet et al, 2000). In the next paragraphs, we summarize the findings on the role of sex steroids in two cestodes: Taenia crassiceps and Taenia solium.…”

Section: The Case Of Cestodesmentioning

confidence: 97%