Increase of lymphocytes expressing Fc-receptor class III (CD16) by exposure to human seminal plasma.
OBJECTIVE
To characterize conditions for the seminal plasma-induced increase of lymphocytes that express immunoglobulin G-Fc receptor class III (Fc gamma RIII).


METHODS
Peripheral blood lymphocytes were incubated in diluted seminal plasma or control media. Cells expressing Fc gamma RIII were quantified by using flow cytometry and fluorochrome-labeled monoclonal antibodies specific for Fc gamma RIII. The influence of incubation time, temperature, and seminal plasma concentration was investigated. Physical properties of the active seminal plasma substance were characterized by studying effects of dialysis and ultracentrifugation. The origin of the active seminal plasma substance was investigated by studying activity of autopsy materials from male accessory glands. Identity of cells that are influenced by seminal plasma activity was investigated by using two-color flow cytometry with monoclonal antibodies specific for Fc gamma RIII and different phenotypic markers of leukocytes.


RESULTS
Incubation of lymphocytes in seminal plasma significantly increased percentages of cells expressing Fc gamma RIII. Maximal increases were observed after seminal plasma incubation at 37 degrees C for 90 to 120 minutes and increases were significantly correlated with seminal plasma concentration. Seminal plasma activity was not altered by ultracentrifugation (100,000 x g for 30 minutes) but completely removed by dialysis (12,000 to 14,000 pore size). Fc gamma RIII-positive lymphocytes markedly increased after incubation in prostatic but not in seminal vesicle secretions. Two-color flow cytometry showed that increases of Fc gamma RIII-expressing cells occurred within the subset of CD56-positive natural killer (NK) cells.


CONCLUSIONS
Dialyzable compounds of prostatic origin induce significant increases of NK cells expressing Fc gamma RIII. These findings might reflect a novel regulatory mechanism acting on CD56-positive cells within the female reproductive tract after insemination.
Thaler
C J
CJ
Frauenklinik im Klinikum Grosshadern, Ludwig-Maximilians-Universität, Munich, Germany.
Boldt
H D
HD
McIntyre
J A
JA
Faulk
W P
WP
D000704:Analysis of Variance; D015703:Antigens, CD / Q000096:biosynthesis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis; D019002:CD56 Antigen; D002478:Cells, Cultured; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D011467:Prostate / Q000276:immunology; D017452:Receptors, IgG / Q000096:biosynthesis* / Q000276:immunology; D012661:Semen / Q000276:immunology*; D013997:Time Factors; D014461:Ultracentrifugation
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; D017452:Receptors, IgG