Modulation of pokeweed mitogen-induced B cell differentiation by polymorphonuclear cells: effects of bacterial lipopolysaccharides.
The capacity of polymorphonuclear (PMN) cells to release several cytokines stresses the potential immunomodulatory role of these cells. The effects mediated by purified PMN cell suspensions on pokeweed mitogen (PWM)-driven B cell differentiation was investigated. Results showed that the addition of increasing concentrations of resting PMN cells to peripheral blood mononuclear cell (PBMC) cultures gave rise to inhibition of immunoglobulin (Ig) production. At the same time, similar results were obtained using lipopolysaccharide (LPS)-pretreated PMN cells. In contrast, when LPS, at different concentrations, and PMN cells were both added to PBMC cultures an enhancement of IgG or IgM release in comparison with cultures treated with PMN cells only occurred at low PMN cell/PBMC ratios (1:20 and 1:10), which was maximal in the presence of 10 or 100 ng/ml LPS. This effect was probably mediated by LPS-induced monocyte stimulation, since the supplementation of LPS-activated monocyte supernatants to PMN cell/PBMC cocultures led to an Ig synthesis which mimicked that seen in similarly-treated PBMC cultures. These data suggest the occurrence of various in vitro modulatory effects in the interactions between PMN, LPS and lymphocytes in a PWM-induced B cell polyclonal responsiveness system.
Tortorella
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C
Department of Internal Medicine, University of Bari Medical Faculty, Italy.
Ottolenghi
A
A
Testa
A
A
Decandia
P
P
Jirillo
E
E
Antonaci
S
S
D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D002454:Cell Differentiation; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D007075:Immunoglobulin M / Q000096:biosynthesis; D007963:Leukocytes, Mononuclear / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D009000:Monocytes / Q000187:drug effects / Q000502:physiology; D009504:Neutrophils / Q000502:physiology*; D011043:Pokeweed Mitogens / Q000494:pharmacology*
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008070:Lipopolysaccharides; D011043:Pokeweed Mitogens