Humoral immune response against a 70-kilodalton heat shock protein of Entamoeba histolytica in a group of patients with invasive amoebiasis

Ortner, Stephan; Plaimauer, Barbara; Binder, Marina; Wiedermann, G; Scheiner, Otto; Duchêne, Michael

doi:10.1016/0166-6851(92)90110-6

Cited by 27 publications

(14 citation statements)

References 30 publications

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“…The HSPs of some protozoan parasites, including Entamoeba histolytica (Ortner et al 1992), Leishmania donovani chagasi, and Trypanosoma cruzi (Nafziger et al 1991), are also antigenic. Not only are the HSPs of Plasmodium falciparum antigenic, but T-cells reactive to the P. falciparum HSP70-1 protein have been described (Behr et al 1992).…”

Section: Discussionmentioning

confidence: 99%

Antigenicity of Trichomonas vaginalis heat-shock proteins in human infections

Davis-Hayman

Shah

Finley

et al. 2000

Parasitology Research

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Patients infected with Trichomonas vaginalis mount humoral and cellular immune responses that often do not protect against reinfection. The oxidative stressors produced by leukocytes may trigger a heat-shock-like response in T. vaginalis trophozoites, helping the parasite to survive host immune defenses. The antigenicity of T. vaginalis heat-shock proteins (HSPs) was examined by immunoprecipitation of T. vaginalis heat-induced proteins with sera from infected patients and controls. When T. vaginalis was heat-shocked, HSPs of 169-167 and 140-137 kDa were specifically recognized by sera from infected male and female patients. However, the majority of T. vaginalis HSPs were also immunoprecipitated by control sera; all sera recognized 72- to 71-kDa, 47- to 45-kDa, 38- to 37-kDa, 35-kDa, and 31-kDa heat-induced proteins. At least 15 proteins from non-heat-shocked T. vaginalis were immunoprecipitated by sera from infected patients and controls, indicating that natural or cross-reacting antibodies could participate in host responses to trichomoniasis. Molecules of 158, 135, 89, and 74-72 kDa were immunoprecipitated from some non-heat-shocked parasites only by patients' sera. A 38-kDa T. vaginalis protein was immunoprecipitated only by sera from infected females and may be specific for infection in women.

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Section: Discussionmentioning

confidence: 99%

Antigenicity of Trichomonas vaginalis heat-shock proteins in human infections

Davis-Hayman

Shah

Finley

et al. 2000

Parasitology Research

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“…A single HSP70 homologue was detected in Entamoeba histolytica (Ortner et al 1992), which is most similar to higher eukaryote HSP70 cytoplasmic sequences (SSPA scores, 74-77), with significantly lower similarity scores to other protist (Giardia lamblia, Trichomonas vaginalis, and Plasmodium falciparum) sequences (61-69) and ER sequences (55-61). The ENTHI sequence alignments to Archaea, mitochondria, and chloroplasts show much lower SSPA scores, in the range 40-49.…”

Section: Evolutionary Implicationsmentioning

confidence: 99%

Heat Shock Protein 70 Family: Multiple Sequence Comparisons, Function, and Evolution

1998

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The heat shock protein 70 kDa sequences (HSP70) are of great importance as molecular chaperones in protein folding and transport. They are abundant under conditions of cellular stress. They are highly conserved in all domains of life: Archaea, eubacteria, eukaryotes, and organelles (mitochondria, chloroplasts). A multiple alignment of a large collection of these sequences was obtained employing our symmetric-iterative ITERALIGN program (Brocchieri and Karlin 1998). Assessments of conservation are interpreted in evolutionary terms and with respect to functional implications. Many archaeal sequences (methanogens and halophiles) tend to align best with the Gram-positive sequences. These two groups also miss a signature segment [about 25 amino acids (aa) long] present in all other HSP70 species (Gupta and Golding 1993). We observed a second signature sequence of about 4 aa absent from all eukaryotic homologues, significantly aligned in all prokaryotic sequences. Consensus sequences were developed for eight groups [Archaea, Gram-positive, proteobacterial Gram-negative, singular bacteria, mitochondria, plastids, eukaryotic endoplasmic reticulum (ER) isoforms, eukaryotic cytoplasmic isoforms]. All group consensus comparisons tend to summarize better the alignments than do the individual sequence comparisons. The global individual consensus "matches" 87% with the consensus of consensuses sequence. A functional analysis of the global consensus identifies a (new) highly significant mixed charge cluster proximal to the carboxyl terminus of the sequence highlighting the hypercharge run EEDKKRRER (one-letter aa code used). The individual Archaea and Gram-positive sequences contain a corresponding significant mixed charge cluster in the location of the charge cluster of the consensus sequence. In contrast, the four Gram-negative proteobacterial sequences of the alignment do not have a charge cluster (even at the 5% significance level). All eukaryotic HSP70 sequences have the analogous charge cluster. Strikingly, several of the eukaryotic isoforms show multiple mixed charged clusters. These clusters were interpreted with supporting data related to HSP70 activity in facilitating chaperone, transport, and secretion function. We observed that the consensus contains only a single tryptophan residue and a single conserved cysteine. This is interpreted with respect to the target rule for disaggregating misfolded proteins. The mitochondrial HSP70 connections to bacterial HSP70 are analyzed, suggesting a polyphyletic split of Trypanosoma and Leishmania protist mitochondrial (Mt) homologues separated from Mt-animal/fungal/plant homologues. Moreover, the HSP70 sequences from the amitochondrial Entamoeba histolytica and Trichomonas vaginalis species were analyzed. The E. histolytica HSP70 is most similar to the higher eukaryotic cytoplasmic sequences, with significantly weaker alignments to ER sequences and much diminished matching to all eubacterial, mitochondrial, and chloroplast sequences. This appears to be at variance with the hypoth...

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“…In contrast, RT-PCR products of mRNAs for amebapore A, which is a lysosomal protein involved in killing bacteria and/or host cells, remained constant during the temperature shift from 37 to 42°C. By similar methods, we determined that amebic mRNAs encoding homologues of Hsp70 (also known as BiP), Hsc70, and inositol kinase were also increased with heat shock (unpublished data) (33). Two-dimensional protein gels of heat-shocked parasites versus controls without heat shock showed increased expression of a 56-kDa protein, which coincided with that of amebae transfected with their own hsp60 gene under an actin gene promoter (Fig.…”

Section: Resultsmentioning

confidence: 93%

Hsp60 Is Targeted to a Cryptic Mitochondrion-Derived Organelle (“Crypton”) in the Microaerophilic Protozoan Parasite Entamoeba histolytica

Mai¹,

Ghosh²,

Frisardi³

et al. 1999

Molecular and Cellular Biology

173

113

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Entamoeba histolytica is a microaerophilic protozoan parasite in which neither mitochondria nor mitochondrion-derived organelles have been previously observed. Recently, a segment of an E. histolytica gene was identified that encoded a protein similar to the mitochondrial 60-kDa heat shock protein (Hsp60 or chaperonin 60), which refolds nuclear-encoded proteins after passage through organellar membranes. The possible function and localization of the amebic Hsp60 were explored here. Like Hsp60 of mitochondria, amebic Hsp60 RNA and protein were both strongly induced by incubating parasites at 42°C. 5 and 3 rapid amplifications of cDNA ends were used to obtain the entire E. histolytica hsp60 coding region, which predicted a 536-aminoacid Hsp60. The E. histolytica hsp60 gene protected from heat shock Escherichia coli groEL mutants, demonstrating the chaperonin function of the amebic Hsp60. The E. histolytica Hsp60, which lacked characteristic carboxy-terminal Gly-Met repeats, had a 21-amino-acid amino-terminal, organelle-targeting presequence that was cleaved in vivo. This presequence was necessary to target Hsp60 to one (and occasionally two or three) short, cylindrical organelle(s). In contrast, amebic alcohol dehydrogenase 1 and ferredoxin, which are bacterialike enzymes, were diffusely distributed throughout the cytosol. We suggest that the Hsp60-associated, mitochondrion-derived organelle identified here be named "crypton," as its structure was previously hidden and its function is still cryptic.

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Humoral immune response against a 70-kilodalton heat shock protein of Entamoeba histolytica in a group of patients with invasive amoebiasis

Cited by 27 publications

References 30 publications

Antigenicity of Trichomonas vaginalis heat-shock proteins in human infections

Antigenicity of Trichomonas vaginalis heat-shock proteins in human infections

Heat Shock Protein 70 Family: Multiple Sequence Comparisons, Function, and Evolution

Hsp60 Is Targeted to a Cryptic Mitochondrion-Derived Organelle (“Crypton”) in the Microaerophilic Protozoan Parasite Entamoeba histolytica

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