Sialated glycosphingolipids (gangliosides) were recently shown to induce internalisation of the CD4 Ag in lymphoid cells and dissociation of p56(lck) from CD4 (Repke et al. (1992) J. Immunol. 149, 2585-2591; Saggioro et al. (1993) J. Biol. Chem. 268, 1368-1375). The findings presented in this paper show that GM1 induces internalisation and the eventual degradation of the CD4 Ag also in the monocytic cell line U937. GM1 effects are independent of a possible activation of protein kinase C, as enzyme inhibitors which effectively blocked phorbol esters effects did not prevent GM1-induced CD4 internalisation and degradation. GM1 effects were also independent of a possible action on a CD4 associated kinase activity as we show that U937 cells lack any CD4-associated kinase activity.
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 1993|
ASJC Scopus subject areas
- Molecular Biology