Characterization of Haemonchus contortus calreticulin suggests its role in feeding and immune evasion by the parasite

Suchitra, S.; Joshi, Pallavi

doi:10.1016/j.bbagen.2004.12.020

Cited by 77 publications

(72 citation statements)

References 32 publications

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“…This finding is consistent with hematophagous parasites having complement escape mechanisms (10). Both Necator americanus and Hemonchus contortus express a calreticulin-like protein that binds C1q (29,30). Ticks such as Ixodes scapularis and Ixodes ricinus express proteins preventing deposition of C3b, such as Isac (26) and IRACs/IxACs (31,32).…”

Section: Discussionsupporting

confidence: 70%

Scabies Mite Inactivated Serine Protease Paralogs Inhibit the Human Complement System

Bergström

Reynolds

Johnstone

et al. 2009

The Journal of Immunology

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Infestation of skin by the parasitic itch mite Sarcoptes scabiei afflicts 300 million people worldwide and there is a need for novel and efficient therapies. We have previously identified a multigene family of serine proteases comprising multiple catalytically inactive members (scabies mite-inactivated protease paralogs (SMIPPs)), which are secreted into the gut of S. scabiei. SMIPPs are located in the mite gut and in feces excreted into the upper epidermis. Scabies mites feed on epidermal protein, including host plasma; consequently, they are exposed to host defense mechanisms both internally and externally. We found that two recombinantly expressed SMIPPs inhibited all three pathways of the human complement system. Both SMIPPs exerted their inhibitory action due to binding of three molecules involved in the three different mechanisms which initiate complement: C1q, mannose-binding lectin, and properdin. Both SMIPPs bound to the stalk domains of C1q, possibly displacing or inhibiting C1r/C1s, which are associated with the same domain. Furthermore, we found that binding of both SMIPPs to properdin resulted in prevention of assembly of the alternative pathway convertases. However, the SMIPPs were not able to dissociate already formed convertases. Immunohistochemical staining demonstrated the presence of C1q in the gut of scabies mites in skin burrows. We propose that SMIPPs minimize complement-mediated gut damage and thus create a favorable environment for the scabies mites.

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Section: Discussionsupporting

confidence: 70%

Scabies Mite Inactivated Serine Protease Paralogs Inhibit the Human Complement System

Bergström

Reynolds

Johnstone

et al. 2009

The Journal of Immunology

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“…Calreticulin was the first molecule shown to be secreted via the nematode stylet into the feeding site . Calreticulins secreted by animal eukaryotic parasites have been identified as key modulators of host immune defenses (Kasper Suchitra and Joshi, 2005). However, the function of RKN calreticulin in the modulation of plant responses remains unclear and it is thought that this molecule may also be involved in calcium signaling and cell cycle regulation (Borisjuk et al, 1998;Ghiran et al, 2003) during giant cell formation.…”

Section: Nematode Parasitism Genesmentioning

confidence: 99%

Root-knot nematodes manipulate plant cell functions during a compatible interaction

Caillaud

Dubreuil

Quentin

et al. 2008

Journal of Plant Physiology

240

177

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“…Full-length r Eh CRT and N- and C-terminal-domain proteins were expressed and purified as previously described [8, 22]. Briefly, the plasmid pBluescript-KS+ (pbKS+) was used to clone PCR products.…”

Section: Methodsmentioning

confidence: 99%

“…CRT genes from a number of parasites ( Trypanosoma , Leishmania , Entamoeba , Onchocerca , Schistosoma , and Haemonchus ) have been cloned and sequenced, revealing approximately 50% identity with CRT human gene [3–8]. …”

Section: Introductionmentioning

confidence: 99%

“…We also reported the cloning of CRT gene in E. histolytica and the preparation of monospecific antibodies against recombinant CRT (r Eh CRT); the immunohistochemical assays on trophozoites show that Eh CRT is located in the cytoplasmic vesicles and in vesicles in close contact with the inner cytoplasmic membrane. In histopathological studies, on sections of experimental ALA in hamsters, Eh CRT was clearly detected into the trophozoites and seems to be neither exposed in the surface of trophozoites nor exported into the hepatic tissue [8]. The binding of C1q to CRT in the surface of E. histolytica trophozoites has been recently reported after its activation in cell-to-cell interaction with Jurkat cells; authors mention that during erytrophagocytosis the CRT is located in the surface of trophozoites and in the phagocytic cups [17].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Entamoeba histolyticaandE. disparCalreticulin: Inhibition of Classical Complement Pathway and Differences in the Level of Expression in Amoebic Liver Abscess

Ximénez

González

Nieves

et al. 2014

BioMed Research International

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The role of calreticulin (CRT) in host-parasite interactions has recently become an important area of research. Information about the functions of calreticulin and its relevance to the physiology of Entamoeba parasites is limited. The present work demonstrates that CRT of both pathogenic E. histolytica and nonpathogenic E. dispar species specifically interacted with human C1q inhibiting the activation of the classical complement pathway. Using recombinant EhCRT protein, we demonstrate that CRT interaction site and human C1q is located at the N-terminal region of EhCRT. The immunofluorescence and confocal microscopy experiments show that CRT and human C1q colocalize in the cytoplasmic vesicles and near to the surface membrane of previously permeabilized trophozoites or are incubated with normal human serum which is known to destroy trophozoites. In the presence of peripheral mononuclear blood cells, the distribution of EhCRT and C1q is clearly over the surface membrane of trophozoites. Nevertheless, the level of expression of CRT in situ in lesions of amoebic liver abscess (ALA) in the hamster model is different in both Entamoeba species; this molecule is expressed in higher levels in E. histolytica than in E. dispar. This result suggests that EhCRT may modulate some functions during the early moments of the host-parasite relationship.

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Characterization of Haemonchus contortus calreticulin suggests its role in feeding and immune evasion by the parasite

Cited by 77 publications

References 32 publications

Scabies Mite Inactivated Serine Protease Paralogs Inhibit the Human Complement System

Scabies Mite Inactivated Serine Protease Paralogs Inhibit the Human Complement System

Root-knot nematodes manipulate plant cell functions during a compatible interaction

Entamoeba histolyticaandE. disparCalreticulin: Inhibition of Classical Complement Pathway and Differences in the Level of Expression in Amoebic Liver Abscess

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