Isolation and Characterization of Antibodies Induced by Immunization with TNF-α Inducible Globotetraosylceramide.

Glycosphingolipids containing very-long-chain fatty acids (VLCFAs) regulate several immune responses, such as cytokine production, immune signaling, and antibody induction. We previously reported that stimulation with an inflammatory mediator, TNF-α, promotes the expression of glycosphingolipids in vascular endothelial cells. The major component is globotetraosylceramide containing VLCFAs (Gb4Cer-VLCFAs), but its role in inflammatory responses has not been fully investigated. In this study, the antibody-inducing properties of Gb4Cer-VLCFAs were analyzed using serum and hybridoma cells generated from Gb4Cer-VLCFA-immunized mice. The reactivity of serum antibodies against Gb4Cer indicated that immunization with Gb4Cer-VLCFAs immediately induced the production of anti-Gb4Cer antibodies. Over 81% of hybridomas generated from the splenocytes of an immunized mouse produced anti-Gb4Cer antibodies, a subset of which recognized an epitope shared by Gb4Cer and its precursor globotriaosylceramide (Gb3Cer). Further biochemical analyses of established monoclonal antibodies revealed that these antibodies included IgM and IgG3, which specifically react with Gb4Cer and Gb3Cer. These results indicate that immunization with Gb4Cer-VLCFAs can efficiently induce the production of anti-Gb4Cer and -Gb3Cer antibodies by B cells.