A Schistosoma mansoni 62-KDA Band Is Identified as an Irradiated Vaccine T-Cell Antigen and Characterized as Calreticulin

Gengehi, Naglaa El; Ridi, Rashika El; Tawab, Nagwa Abdel; Demellawy, Maha El; Mangold, Beverly L.

doi:10.2307/3284811

Cited by 11 publications

(11 citation statements)

References 15 publications

(37 reference statements)

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“…In contrast, with other parasite infection models (Rokeach et al 1994;El-Gengehi et al 2000), we did not detect EhCRT in the hepatic tissue. This may indicate that E. histolytica trophozoites do not secrete or export CRT into the liver parenchyma.…”

Section: Discussioncontrasting

confidence: 84%

Entamoeba histolytica calreticulin: an endoplasmic reticulum protein expressed by trophozoites into experimentally induced amoebic liver abscesses

et al. 2010

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Entamoeba histolytica calreticulin (EhCRT) is remarkably immunogenic in humans (90-100% of invasive amoebiasis patients). Nevertheless, the study of calreticulin in this protozoan is still in its early stages. The exact location, biological functions, and its role in pathogenesis are yet to be fully understood. The aim of the present work is to determine the location of EhCRT in virulent trophozoites in vivo and the expression of the Ehcrt gene during the development of experimentally induced amoebic liver abscesses (ALA) in hamsters. Antibodies against recombinant EhCRT were used for the immunolocalization of EhCRT in trophozoites through confocal microscopy; immunohistochemical assays were also performed on tissue sections of ALAs at different times after intrahepatic inoculation. The expression of the Ehcrt gene during the development of ALA was estimated through both in situ RT-PCR and real-time RT-PCR. Confocal assays of virulent trophozoites showed a distribution of EhCRT in the cytoplasmic vesicles of different sizes. Apparently, EhCRT is not exported into the hepatic tissue. Real-time RT-PCR demonstrated an over-expression of the Ehcrt gene at 30 min after trophozoite inoculation, reaching a peak at 1-2 h; thereafter, the expression fell sharply to its original levels. These results demonstrate for the first time in an in vivo model of ALA, the expression of Ehcrt gene in E. histolytica trophozoites and add evidence that support CRT as a resident protein of the ER in E. histolytica species. The in vivo experiments suggest that CRT may play an important role during the early stages of the host-parasite relationship, when the parasite is adapting to a new environment, although the protein seems to be constitutively synthesized. Moreover, trophozoites apparently do not export EhCRT into the hepatic tissue in ALA.

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Section: Discussioncontrasting

confidence: 84%

Entamoeba histolytica calreticulin: an endoplasmic reticulum protein expressed by trophozoites into experimentally induced amoebic liver abscesses

et al. 2010

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“…Similar erratic protection data were obtained in our laboratory with other antigens such as calreticulin [10] and S. mansoni glucose transporter protein, SGTP4 [12], and in many other laboratories using a diversity of well-characterized subunit antigens [9]. No solid, reproducible protection was obtained with any schistosome antigen, at variance from the significant and consistent protection achieved in the RA vaccine model, where the target of immune resistance was identified as the lung-stage schistosomula [9,13].…”

Section: Introductionsupporting

confidence: 71%

“…It was recently shown that a 42 kDa soluble adult worm antigen band, identified as S. mansoni glyceraldehyde 3-phosphate dehydrogenase (SG3PDH), is a target of cellular and humoral immune responses in subjects resistant to infection with schistosomes [7,8]. Additionally, several schistosomular and adult worm antigens were detected by sera from mice immunized with radiation-attenuated cercariae (RA), among which Sm23, glutathione S-transferase, triose phosphate isomerase, Sm32, heat shock protein, calreticulin, and paramyosin are the best studied [9,10].…”

Section: Introductionmentioning

confidence: 98%

Impact of interleukin-1 and interleukin-6 in murine primary schistosomiasis

Ridi¹,

Wagih²,

Salem³

et al. 2006

International Immunopharmacology

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“…has been suggested (El Gengehi et al 2000;Khalife et al 1994;Pritchard et al 1999). And the exhibition of necrotic lesions in the tick bite sites in A. americanum CRTimmunized rabbits indicates that immune reaction could disrupt the feeding cycle (Jaworski et al 1995).…”

Section: Discussionmentioning

confidence: 97%

Cloning and characterization of a cDNA clone encoding calreticulin from Haemaphysalis qinghaiensis (Acari: Ixodidae)

et al. 2007

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The application of anti-tick vaccine has been shown to be the most promising alternative strategy compared to the current use of acaricides that suffer from a number of serious limitations. The success of this method is dependent upon identification and cloning of potential tick vaccine antigens. Previously, we have cloned 21 positive clones (named from Hq02 to Hq22) by immunoscreening complimentary DNA (cDNA) libraries of Haemaphysalis qinghaiensis; however, some of those clones did not contain open reading frames (ORF). In this study, we amplified the entire sequence of Hq07 by using rapid amplification of the cDNA ends. Hq07 contains an ORF of 1,233 bp that encodes for 410 amino acid residues with a coding capacity of 47 kDa. Search of the cloned sequences against GenBank revealed that Hq07 is a calreticulin (CRT)-similar clone and designated HqCRT. Expression analysis by reverse transcription-polymerase chain reaction showed that this gene is ubiquitously expressed at different developmental stages and in different tissues of H. qinghaiensis. The gene was expressed as glutathione S-transferase-fused proteins in a prokaryotic system. Western blot analysis revealed that native HqCRT was secreted into their hosts by ticks during blood sucking. Vaccination of sheep with rHqCRT conferred protective immunity against ticks, resulting in 54.3% mortality in adult ticks, compared to the 38.7% death rate in the control group. These results demonstrated that rHqCRT might be a useful vaccine candidate antigen for biological control of H. qinghaiensis.

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A Schistosoma mansoni 62-KDA Band Is Identified as an Irradiated Vaccine T-Cell Antigen and Characterized as Calreticulin

Cited by 11 publications

References 15 publications

Entamoeba histolytica calreticulin: an endoplasmic reticulum protein expressed by trophozoites into experimentally induced amoebic liver abscesses

Entamoeba histolytica calreticulin: an endoplasmic reticulum protein expressed by trophozoites into experimentally induced amoebic liver abscesses

Impact of interleukin-1 and interleukin-6 in murine primary schistosomiasis

Cloning and characterization of a cDNA clone encoding calreticulin from Haemaphysalis qinghaiensis (Acari: Ixodidae)

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