Enhancement of eosinophil survival by lipopolysaccharide through releasing granulocyte-macrophage colony stimulating factor from mononuclear cells from patients with bronchial asthma.
BACKGROUND
The mechanism of bronchoobstruction in asthmatics following inhalation of lipopolysaccharide (LPS) is unclear.


OBJECTIVE
In this study we have investigated the effects of the LPS on eosinophil survival rate in stimulating peripheral blood mononuclear cells (PBMCs) from patients with asthma.


METHODS
PBMC supernatants from 10 asthmatic patients and 4 healthy subjects were compared for eosinophil survival rate using the same purified eosinophils. Two x 10(6) cells/ml of PBMCs were cultured for 24 hours in RPMI 1640 containing 10% fetal bovine serum along with 10 micrograms/ml of LPS. 10(6) cells/ml of eosinophils were incubated for 96 hours in the presence of PBMC-derived culture supernatants at 75% in volume.


RESULTS
The viability of eosinophils incubated with PBMC supernatants from asthmatic patients stimulated with LPS was higher, 62.5% +/- 10.6% (mean +/- SD), than that without LPS, 26.9% +/- 10.8%, and also higher than that of PBMCs from healthy subjects with LPS, 40.0% +/- 15.4%. This increasing activity of asthmatic PBMC stimulated with LPS was markedly inhibited from 72.2% +/- 9.7% to 38.5% +/- 6.8% by addition of mouse anti-human GM-CSF antibody to the PBMC supernatant but not mouse anti-human IL-5 antibody.


CONCLUSIONS
These results suggest that LPS enhances eosinophil survival in asthmatics by increasing the production of GM-CSF from PBMCs.
Saitou
M
M
Department of Internal Medicine II, Fukushima Medical College, Japan.
Kida
S
S
Kaise
S
S
Suzuki
S
S
Ohara
M
M
Kasukawa
R
R
D000328:Adult; D000368:Aged; D000818:Animals; D001249:Asthma / Q000097:blood*; D002470:Cell Survival / Q000187:drug effects; D004804:Eosinophils / Q000187:drug effects* / Q000502:physiology; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008875:Middle Aged
D008070:Lipopolysaccharides; D016178:Granulocyte-Macrophage Colony-Stimulating Factor