Alteration of membrane oligosaccharides by castanospermine, an alpha glucosidase inhibitor, enhances immunoglobulin production in Staphylococcus aureus Cowan I-stimulated lymphocyte culture.
Castanospermine (CSP) inhibits alpha-glucosidase, which is involved in the initial step of N-linked oligosaccharide processing of secretory and membrane glycoproteins. In Staphylococcus aureus Cowan I (SAC)-stimulated human lymphocyte culture, CSP at a dose of 20 micrograms/ml caused a twofold increase in immunoglobulin G (IgG) release after 7 days. An initial 48-h exposure to CSP sufficed for this enhancing effect. Plaque-forming cell assays on the seventh day disclosed that CSP caused an increase in the number of IgG-, IgA- and IgM-secreting cells. In cross-culture experiments, only a mixture of B cells pretreated with CSP and untreated T cells showed an increase in IgG production. Tritiated thymidine incorporation studies revealed that CSP enhanced B-cell responses to T cell-derived soluble factor (TSF). When incubated with CSP for 18 h, B cells showed an increased surface binding on [3H]concanavalin A (Con A). These results indicate that the alteration in B-cell membrane oligosaccharides enhances the response to TSF at an early stage of SAC culture, leading to an increase in Ig-secreting cell number at later stages. The present study provides evidence that cell-surface oligosaccharides of B cells play an important role in the responses of B cells to lymphokines.
Karasuno
T
T
Second Department of Internal Medicine, Osaka University Medical School, Japan.
Kanayama
Y
Y
Nishiura
T
T
Nakao
H
H
Kurata
Y
Y
Yonezawa
T
T
Tarui
S
S
D000470:Alkaloids / Q000494:pharmacology*; D000917:Antibody Formation / Q000187:drug effects*; D000921:Antibody-Producing Cells / Q000187:drug effects; D001402:B-Lymphocytes / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D065089:Glycoside Hydrolase Inhibitors; D006801:Humans; D007212:Indolizines; D007958:Leukocyte Count; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D008934:Mitogens; D009844:Oligosaccharides / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000276:immunology; D054836:Indolizidines
D000470:Alkaloids; D065089:Glycoside Hydrolase Inhibitors; D007212:Indolizines; D008934:Mitogens; D009844:Oligosaccharides; C037806:castanospermine; D054836:Indolizidines