[Modulation of the level of sphingomyelin cycle products and expression of the CD3 receptor in immunocompetent organs by fumonisin B1].
The fungi (Fusarium moniliforme) residing on cereals produce a broad range of mycotoxins, among which fumonisins display a high toxicity alongside with carcinogenic and teratogenic activities. Taking into account the ability of fumonisins to inhibit sphingolipid synthesis, the role of sphingomyelin cycle products in immune reactions was studied with the view of establishing the correlation between the expression of the surface receptor CD3 in immunocompetent organs (spleen, thymus) (T-cell mediated immunity) and the degree of sphingomyelin cycle activation (changes in the activities of sphingomyelinase and sphingomyelin and ceramide content) in the spleen, thymus and liver 2.5 hours after intraperitoneal injection of fumonisin B1 (FB1) (5 and 20 micrograms/animal). Significant sphingomyelinase activation was found in the thymus of animals injected with 20 micrograms of fumonisin. It coincides with a loss of the sphingomyelin and ceramide content. The changes in the sphingomyelinase activity and sphingomyelin content in the spleen and in the liver caused by fumonisin were insignificant, while the ceramide content dropped drastically. Fumonisin decreased the receptor CD3 expression on the surface of thymus cells "in vitro" and "in vivo", which is consistent with the sharp decrease of the ceramide content in this organ. Ceramide accumulation in thymus and spleen cells treated with sphingomyelinase in vitro correlates with the increased affinity of receptor CD3. The putative role of ceramide in the expression of receptors modulating T-cell mediated immunity under the influence of fumonisin is discussed.
Martynova
E A
EA
Solov'ev
A S
AS
Khrenov
A V
AV
Zabotina
T N
TN
Alesenko
A V
AV
D000818:Animals; D017252:CD3 Complex / Q000378:metabolism*; D002518:Ceramides / Q000378:metabolism; D037341:Fumonisins; D051379:Mice; D008807:Mice, Inbred BALB C; D009183:Mycotoxins / Q000494:pharmacology*; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D013109:Sphingomyelins / Q000378:metabolism*; D013154:Spleen / Q000201:enzymology / Q000378:metabolism*; D013950:Thymus Gland / Q000201:enzymology / Q000378:metabolism*
D017252:CD3 Complex; D002518:Ceramides; D037341:Fumonisins; D009183:Mycotoxins; D013109:Sphingomyelins; C056933:fumonisin B1; D013108:Sphingomyelin Phosphodiesterase
Moduliatsiia fumonizinom B1 soderzhaniia produktov sfingomielinovogo tsikla i ékspressii retseptora CD3 v immunokompetentnykh organakh.