Differences in Innate Immunologic Response to Group BStreptococcus Between Colonized and Noncolonized Women

[摘要] Objective:To evaluate the functional capacity of granulocytes and monocytes from pregnant and nonpregnant women in relation to group B streptococcus (GBS) colonization status.Methods:Engulfment of fluorescent GBS by peripheral blood phagocytes from GBS-colonized and noncolonizedwomen was measured by flow cytometry. Intracellular superoxiode generated in response to GBS challenge tomonocytes and granulocytes enriched from peripheral blood of these women was also measured by flowcytometry, and extracellular superoxide was determined by colorimetric assay.Results:Monocytes and granulocytes from pregnant, GBS-colonized women engulfed significantly greaternumbers of GBS than phagocytes from pregnant, noncolonized women. No difference in intracellular superoxideproduction was detected between any of the groups of women; however, monocytes from pregnant, colonizedwomen released significantly more superoxide into the extracellular milieu than did granulocytes from the samewomen. No differences in extracellular release of superoxide were observed among noncolonized womenwhether they were pregnant or not.Conclusions:Monocytes from pregnant, colonized women engulf more GBS and release more of the superoxideinto the extracellular environment, where it is unlikely to be an effective defense mechanism against intracellularbacteria. This suggests that components of the innate immune system that should serve in a protective role mayfunction suboptimally, thereby contributing to the colonization process by GBS.

[学科分类] 妇产科学