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Immunohistochemical definition of antigenic determinants of pregnancy‐associated α 2 ‐glycoprotein (α 2 ‐PAG) using monoclonal antibodies
Author(s) -
Smith Nicholas M.,
Horne Charles H. W.,
Carpenter Frederick H.,
Stigbrand Torgny,
CarlssonBostedt Lena
Publication year - 1988
Publication title -
the journal of pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.964
H-Index - 184
eISSN - 1096-9896
pISSN - 0022-3417
DOI - 10.1002/path.1711540408
Subject(s) - epitope , monoclonal antibody , polyclonal antibodies , immunohistochemistry , immunoperoxidase , antibody , antigen , glycoprotein , biology , monoclonal , microbiology and biotechnology , immunology , pathology , medicine
Abstract Human pregnancy‐associated α 2 ‐glycoprotein (α 2 ‐PAG) is a high molecular weight glycoprotein present in normal sera. The protein is present in high concentration in the sera of pregnant females and in abnormally low concentration in association with conditions connected with abnormalities of mucosal immunity. Indirect immunoperoxidase techniques using poly‐ and monoclonal antibodies were employed to identify pregnancy‐associated α 2 ‐PAG in different tissues. Four monoclonal antibodies were selected from a battery of antibodies with defined specificities in order to ascertain reactivity with various epitopes of the antigen. The antibodies were applied to paraffin sections of breast, colon, salivary gland, and tonsil, and different fixation regimes were used in the preparation of the tissues. The polyclonal antibodies were found to stain plasma cells and epithelial lumina evenly in all the tissues included whereas the monoclonal antibodies were shown to stain certain components selectively. In breast and salivary glands, all four monoclonal antibodies could identify α 2 ‐PAG, but in tonsil and colon, only two were reactive. This difference in epitope expression might reflect the internal processing of α 2 ‐PAG, and lack of availability of certain epitopes may be indicative of functional blocking of certain domains.