Survival of group B streptococcus type III in mononuclear phagocytes: differential regulation of bacterial killing in cord macrophages by human recombinant gamma interferon and granulocyte-macrophage colony-stimulating factor.
Phagocytic and killing capacities of resident and cytokine-activated human macrophages against group B Streptococcus (GBS) type III were studied. Evidence is presented that monocyte-derived macrophages from cord and adults ingest serum-opsonized GBS but that killing of bacteria was negligible in resident cells. Treatment of adult macrophages with recombinant human gamma interferon (rhIFN-gamma; 100 U/ml) or recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF; 200 U/ml) resulted in significant increases of killing of GBS (P < 0.01 for each). The killing capacity of cord macrophages treated with rhGM-CSF was also enhanced compared to that of untreated cells (P < 0.01). However, treatment with rhIFN-gamma resulted in only a moderate increase in the capacity of cord macrophages to kill GBS (P > 0.1). These results mirrored the effect of rhIFN-gamma on candidacidal capacities of cord and adult macrophages, reported earlier from our laboratory. These data indicate differential modulation of neonatal macrophages by rhGM-CSF and rhIFN-gamma. We suggest that administration of rhGM-CSF to neonates with invasive GBS disease may enhance host resistance to these bacteria.
Maródi
L
L
Department of Infectology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary. LMarodi@jaguar.dote.hu
Káposzta
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Nemes
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D000328:Adult; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology*; D006098:Granulocytes / Q000382:microbiology; D006801:Humans; D007231:Infant, Newborn; D007371:Interferon-gamma / Q000494:pharmacology*; D007963:Leukocytes, Mononuclear / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology*; D009895:Opsonin Proteins / Q000378:metabolism; D010586:Phagocytes / Q000382:microbiology*; D010587:Phagocytosis / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology*; D013292:Streptococcus agalactiae / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors; D014470:Umbilical Cord / Q000382:microbiology*
D009895:Opsonin Proteins; D011994:Recombinant Proteins; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor