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Peripheral Blood Mononuclear Leukocytes Release a Mediator(s) That Induces Phagocytosis of C‐Reactive Protein‐Coated Cells by Polymorphonuclear Leukocytes
Author(s) -
Kilpatrick J. Michael,
Gresham Hattie D.,
Griffin Frank M.,
Volanakis John E.
Publication year - 1987
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.41.2.150
Subject(s) - phagocytosis , peripheral blood mononuclear cell , immunology , biology , ingestion , granulocyte , stimulation , lymphokine , immune system , endocrinology , in vitro , biochemistry
We studied the phagocytosis by human polymorphonuclear leukocytes (PMN) of sheep erythrocytes (E) passively sensitized with pneumococcal C‐polyseccharidc (E‐PnC), E‐PnC coated with C‐resctive protein (E‐PnC‐CRP), and E coated with rabbit antisheep E IgG (E‐lgG). PMN isolated from the blood of normal individuals failed to ingest either E‐PnC or E‐PnC‐CRP; however, after incubation with supernatents from stimulated peripheral blood mononuclear leukocytes, glass adherent PMN ingested E‐PnC‐CRP with a mean phagocytic index of 47.8 ± 14.9 (means ± SD, n = 9) and E‐PnC to a lesser extent with a phagocytic index of 9.6 ± 2.9 (mean ± SD, n = 4). We also observed a statistically significant increase in the ingestion of E‐lgG by lymphokine‐stimulated PMN with phagocytic indices of 85.2 ± 21.2 (mean ± SD, n = 12) for unstimulated PMN and 158 ± 37.1 (mean ± SO, n = 9) for stimulated PMN. The best conditions for stimulating release of this phagocytosis‐promoting mediator included exposure to Phytohemagglutinin (PHA) in the presence of monocytes that had ingested lgG‐coated sheep erythrocytes. The induction of phagocytosis of E‐PnC‐CRP was rapid, reaching a maximal level after stimulation of the adherent PMN with the conditioned media for 30 min. The factor(s) responsible for the induction of the ingestion of E‐PnC‐CRP was lees than 10,000 dations and was heat stable (56°C for 45 min). These data are similar to earlier results obtained with PMN activated by 12‐0‐tetradecanoyt‐phoboi‐13‐acetale (PMA), an important contrast being that in the current studies PMN were activated by a soluble factor released from stimulated mononuclear cells under conditions simulating those in vivo.