TY - JOUR
T1 - Expression and function of CD22, a B-cell restricted molecule
AU - Moyron-QuirOz, J. E.
AU - Partida-Sánchez, S.
AU - Donís-Hernández, R.
AU - Sandoval-Montes, C.
AU - Santos-Argumedo, L.
PY - 2002
Y1 - 2002
N2 - In this work, we studied the expression and function of CD22 in murine B cells. CD22 has been previously characterized as an activation marker of mature B lymphocytes. However, we found that CD22 is expressed early during the ontogeny of B cells in the bone marrow and spleen, and was found on B cells isolated from all the different lymphoid compartments. We also found that B cells stimulated through the B-cell antigen receptor (BCR), CD38 and CD40, upregulated CD22 expression to maximal levels within 24 h after stimulation, but that the levels of CD22 declined at later times (48 and 72 h). CD22 is rapidly phosphorylated after BCR signal transduction, and is believed to downregulate B-cell activation. In this study, we did not detect CD22 phosphorylation in activated B cells after CD38 or CD40 cross-linking, even though CD22 was clearly phosphorylated in the BCR-stimulated B cells. Consistent with this, we found no evidence of physical association between CD38 or CD40 and CD22 in B cells. The lack of association or phosphorylation of CD22 induced by CD38 and CD40 cross-linking indicates that CD22 may not downregulate the activation induced by these two molecules.
AB - In this work, we studied the expression and function of CD22 in murine B cells. CD22 has been previously characterized as an activation marker of mature B lymphocytes. However, we found that CD22 is expressed early during the ontogeny of B cells in the bone marrow and spleen, and was found on B cells isolated from all the different lymphoid compartments. We also found that B cells stimulated through the B-cell antigen receptor (BCR), CD38 and CD40, upregulated CD22 expression to maximal levels within 24 h after stimulation, but that the levels of CD22 declined at later times (48 and 72 h). CD22 is rapidly phosphorylated after BCR signal transduction, and is believed to downregulate B-cell activation. In this study, we did not detect CD22 phosphorylation in activated B cells after CD38 or CD40 cross-linking, even though CD22 was clearly phosphorylated in the BCR-stimulated B cells. Consistent with this, we found no evidence of physical association between CD38 or CD40 and CD22 in B cells. The lack of association or phosphorylation of CD22 induced by CD38 and CD40 cross-linking indicates that CD22 may not downregulate the activation induced by these two molecules.
UR - http://www.scopus.com/inward/record.url?scp=0036225852&partnerID=8YFLogxK
U2 - 10.1046/j.1365-3083.2002.01063.x
DO - 10.1046/j.1365-3083.2002.01063.x
M3 - Artículo
SN - 0300-9475
VL - 55
SP - 343
EP - 351
JO - Scandinavian Journal of Immunology
JF - Scandinavian Journal of Immunology
IS - 4
ER -