Jp. Zanetta et al., HUMAN LYMPHOCYTE-ACTIVATION IS ASSOCIATED WITH THE EARLY AND HIGH-LEVEL EXPRESSION OF THE ENDOGENOUS LECTIN CSL AT THE CELL-SURFACE, Biochemical journal, 311, 1995, pp. 629-636
Lymphocytes undergo activation in response to antigens, cytokines, lec
tins and antibodies interacting with specific cell-surface molecules o
r through substances influencing signal transduction pathways. This st
udy shows that human T- and B-cells stimulated using phorbol eaters or
plant lectins express early (2 h using phorbol esters and 24 h using
plant lectins) a high level of a polyvalent carbohydrate-binding prote
in, the cerebellar soluble lectin (CSL), which is in part externalized
. The lectin, immunologically related to CDw70, interacts with specifi
c glycoprotein ligands of the lymphocyte surface, including CD3 on T-c
ells and CD24 on B-cells. Major changes in phosphorylations associated
with activation appear as largely CSL-dependent since they are specif
ically inhibited by anti-CSL Fab fragments. It is suggested that the l
ectin induces the clustering of specific cell-surface glycoproteins an
d plays the role of an endogenous amplifier of activation signals.