Phagocytosis of immunoglobulin G and C3-bound human sperm by human polymorphonuclear leukocytes is not associated with the release of oxidative radicals.
Antisperm antibody (ASA)- and complement (C)-mediated immune injury to human sperm is thought to be caused in part by phagocytic neutrophils. To investigate this process, we co-cultured purified human polymorphonuclear leukocytes (PMN) with swim-up sperm in the presence of ASA-positive and ASA-negative sera and assayed for PMN respiratory burst activity, monitored by the release of superoxide anion (O2-) and hydrogen peroxide (H2O2). Phorbol myristate acetate (PMA) and opsonized zymosan were used as positive controls. Phagocytosis of ASA-positive and C-bound sperm by PMN did not enhance O2- production when compared to incubation of sperm with ASA-negative sera. Phagocytosis of ASA-positive and C-bound sperm also resulted in minimal release of H2O2 when compared with ASA-positive and C-negative sperm that were not phagocytosed. In contrast, PMN were maximally stimulated to release O2- in response to either opsonized zymosan or PMA. The kinetics of PMA-induced O2- release was unaffected by the presence of ASA-positive and C-bound sperm. Cytocentrifuge preparations of PMN incubated with ASA-positive and C-bound sperm revealed limited O2- release at the site of PMN/sperm contact. These results indicated that 1) phagocytosis of motile sperm by PMN requires the binding of both ASA and C to the sperm surface; 2) phagocytosis of ASA-positive and C-positive sperm by PMN fails to release reactive oxygen species; and 3) metabolic processes associated with PMN respiratory burst activity may not be coupled to the ingestion of ASA-positive and C-bound sperm.
D'Cruz
O J
OJ
Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City 73190.
Wang
B L
BL
Haas
G G
GG
D000328:Adult; D002450:Cell Communication / Q000502:physiology; D003176:Complement C3 / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D007074:Immunoglobulin G / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D010587:Phagocytosis / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology
D003176:Complement C3; D005609:Free Radicals; D007074:Immunoglobulin G; D013481:Superoxides; D015054:Zymosan; D006861:Hydrogen Peroxide; D013755:Tetradecanoylphorbol Acetate