Prostasome antigens as targets for sperm agglutinating antibodies demonstrated by 1‐D gel electrophoresis and immunoblottings

Abstract

Many immunoinfertile men have sperm agglutinating antibodies that are directed against prostasome-derived antigens, but these antigens have not been defined so far. We selected serum samples with high ELISA titres against prostasomes from a group of immunoinfertile patients with sperm agglutinating antibodies and used the sera for immunoblottings on 1-D SDS-PAGE of prostasomes and sperm cells. The immunoblottings with individual antiprostasome antisera on 1-D SDS-PAGE of prostasomes, revealed three to 10 bands for each serum. Eighty-five per cent of the serum samples contained bands in the 70-75 kDa region and 80% of the samples contained bands in the 50-55 kDa region. Immunoblottings of extracted sperm cells, revealed one to six bands in the molecular weight range 25-82 kDa and two of the samples recognized two bands with molecular weights (50 and 43 kDa) similar to immunoblottings of prostasomes. The prostasomal antigens recognized by the high titre-antisera of immunoinfertile men were generally different from the sperm antigens recognized by the same sera. This suggests that prostasomes offer a new set of antigens available for research on male immunoinfertility and immunocontraception.

Mode of Growth Determines Differential Expression of Prostasomes in Cultures of Prostate Cancer Cell Lines and Opens for Studies of Prostasome Gene Expression

“…The prostasomes are complex structures and exert several abilities, which are associated with both reproduction and prostate cancer development (1). This has made them interesting in our research on immunocontraception (2) and prostate cancer metastases (3). As a further step in these studies, we have work in progress to find ways to map the prostasome genes.…”

Antiprostasome antibodies are not an appropriate prognostic marker for prostate cancer

“…Larsson et al describe their method as ''sensitive and specific'' on the basis of positive and negative standard preparations prepared by Immunosystem AB [22]. No false-positive results were found in a cohort of 10 subjects of proven fertility [23]. Furthermore, of 116 infertile patients, 97% (113) had antibodies reacting with prostasomal antigens [23].…”

“…No false-positive results were found in a cohort of 10 subjects of proven fertility [23]. Furthermore, of 116 infertile patients, 97% (113) had antibodies reacting with prostasomal antigens [23]. The assay characteristically produced results with standard deviations for patient samples Â1/10th of the mean (e.g.…”

Prostasomes: Their Characterisation: Implications for Human Reproduction

“…As already mentioned, prostasomes have the ability to adhere to sperm cells albeit that both prostasomes and sperm cells have a net negative surface charge of their membranes favouring repulsive forces. This propensity of sperm cells to carry attached prostasomes, allowed us to regard prostasomes as a new category of sperm antigens (Carlsson et al 2004a). In a study of the reactivity of ASA-positive sera from 116 suspected immunoinfertile patients, a binding of IgG antibodies to prostasomes was clearly visible in 113 patient sera (97 %) (Carlsson et al 2004b).…”