Phagocytic Function of Human Blood Polymorphonuclear Leukocytes in the Presence of Carrageenan, a Potential Vaginal Microbicide
Carrageenan is currently undergoing clinical trials as the active constituent of a vaginal gel product for use as a female-controlled option to prevent the transmission of HIV during sexual intercourse. Here we show that in the presence of 0.5 mg/ml of carrageenan, human blood polymorphonuclear leukocytes (PMN) do not ingest this material, as evidenced by a lack of progressive vacuolization, but can ingest microorganisms present in the medium, excluding adjacent carrageenan. Moreover, PMN move at normal speeds, respond chemotactically, and reduce netroblue tetrazolium (NBT) to formazan on stimulation. Hence, in the presence of carrageenan the phagocytic response appears to remain intact.
Key wordsmotility chemotaxis neutrophils phagocytes AIDS vaginal microbicide
We are ever grateful to the late Professor Marcel Bessis, who made this work possible. Dr. David M. Phillips of The Population Council supplied the carrageenan and provided advice on its use. Dr. Sheldon J. Segal assisted in the preparation of the manuscript.
This study was supported in part by the USPHS (AR-10493, AI-43558; AR 48513), the G. Harold & Leila Y. Mathers Charitable Foundation, and the Eshe Fund. Dr. Malawista was a Fellow of the John Simon Guggenheim Memorial Foundation.
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