Expression of a recombinant protein immunochemically equivalent to the major Anisakis simplex allergen Ani s 1.

Abstract

BACKGROUND:

Anisakis simplex is a nematode which can parasitize humans, producing anisakiasis and can induce immunoglobulin-(Ig)-E-mediated allergic symptoms. Parasite recombinant proteins, such as the major allergen Ani s 1, may be useful tools to avoid misdiagnosis of A simplex allergy due to cross-reactivity when whole parasite extracts are used.

OBJECTIVE:

To obtain Ani s 1 allergen as a recombinant protein with IgE-binding properties similar to its natural counterpart.

METHODS:

Ani s 1-encoding cDNA was amplified by polymerase chain reaction and cloned. The allergen was expressed in Escherichia coli as a nonfusion protein. Natural and recombinant Ani s 1 were investigated by means of Western blotting, enzyme allergosorbent test, enzyme-linked immunosorbent assay (ELISA), and ELISA inhibition using sera from 53 patients with A simplex allergy.

RESULTS:

Residues of the amino acid sequence of the encoded protein were 99.4% identical to the reported one. Purified rAni s 1 was obtained with a yield of 2 mg/L of culture while the yield of the natural counterpart was only 50 micro/g of larvae. rAni s 1 reactivity was not significantly different from that of the natural allergen; the correlation was excellent (p = 0.92, P < .001). ELISA-inhibition experiments showed that the dose-response inhibition curve obtained with rAni s 1 overlapped with that of nAni s 1. In an enzyme allergosorbent analysis, 86.8% of the A simplex-allergic patient sera reacted to rAni s 1.

CONCLUSION:

Recombinant Ani s 1 is immunochemically equivalent to its natural counterpart and therefore might be useful for the in vitro diagnosis of anisakiasis and A simplex-mediated allergy.

• Authors: I Ibarrola, M C Arilla, M D Herrero, M I Esteban, A Martínez, J A Asturias
• Journal: Journal of investigational allergology & clinical immunology (J Investig Allergol Clin Immunol) Vol. 18 Issue 2 Pg. 78-83 ( 2008) ISSN: 1018-9068 [Print] Spain
• PMID: 18447135 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Allergens
• Antibodies, Helminth
• Antigens, Helminth
• Calcium-Binding Proteins
• DNA, Helminth
• Helminth Proteins
• Recombinant Proteins
• troponin-like protein, Anisakis simplex
• Immunoglobulin E

Topics

• Allergens (biosynthesis, genetics, immunology)
• Animals
• Anisakiasis (blood, diagnosis, immunology)
• Anisakis
• Antibodies, Helminth (blood, genetics, immunology)
• Antigens, Helminth (biosynthesis, genetics, immunology)
• Calcium-Binding Proteins (biosynthesis, genetics, immunology)
• DNA, Helminth (genetics, immunology)
• Escherichia coli
• Helminth Proteins (biosynthesis, genetics, immunology)
• Humans
• Hypersensitivity, Immediate (diagnosis, parasitology)
• Immunochemistry
• Immunoglobulin E (blood, genetics)
• Recombinant Proteins (biosynthesis, genetics, immunology)