Production of recombinant PSA and HK2 and analysis of their immunologic cross-reactivity

• Measurements of prostate-specific antigen (PSA) in serum are widely used to monitor patients with prostate cancer, but the attenuation of the assay response by PSA complexed to protease inhibitors has been shown to affect the results in certain assay designs. Moreover, the human glandular kallikrein-2 (hK2), a kallikrein-like serine protease that is 80% similar to PSA, might interfere with the specific detection of PSA by immunological cross-reactivity. We have expressed hK2 and PSA in eucaryotic cells using the Semliki Forest Virus expression system and studied the reactivity of 18 monoclonal anti-PSA IgGs. Five of them cross-reacted with identical affinities to recombinant hK2 whereas 13 recognized PSA alone. The antibodies that recognized both PSA and hK2 bind to a region of the protein that is exposed when PSA is complexed to alpha-1-antichymotrypsin.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Läkemedelskemi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Medicinal Chemistry (hsv//eng)

Keyword

Kallikreins/*genetics/immunology

Humans

Cross Reactions

Molecular

Cloning

Monoclonal/immunology

Antibodies

Antigen-Antibody Reactions

Prostate-Specific Antigen/*genetics/immunology

Recombinant Proteins/genetics/immunology

Research Support

Non-U.S. Gov't

Semliki forest virus/genetics

Tissue Kallikreins

Publication and Content Type

art (subject category)

ref (subject category)