Ligation of tumour-produced mucins to CD22 dramatically impairs splenic marginal zone B-cells.
Biochem J
; 417(3): 673-83, 2009 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-18925876
ABSTRACT
CD22 [Siglec-2 (sialic acid-binding, immunoglobulin-like lectin-2)], a negative regulator of B-cell signalling, binds to alpha2,6- sialic acid-linked glycoconjugates, including a sialyl-Tn antigen that is one of the typical tumour-associated carbohydrate antigens expressed on various mucins. Many epithelial tumours secrete mucins into tissues and/or the bloodstream. Mouse mammary adenocarcinoma cells, TA3-Ha, produce a mucin named epiglycanin, but a subline of them, TA3-St, does not. Epiglycanin binds to CD22 and inhibits B-cell signalling in vitro. The in vivo effect of mucins in the tumour-bearing state was investigated using these cell lines. It should be noted that splenic MZ (marginal zone) B-cells were dramatically reduced in the mice bearing TA3-Ha cells but not in those bearing TA3-St cells, this being consistent with the finding that the thymus-independent response was reduced in these mice. When the mucins were administered to normal mice, a portion of them was detected in the splenic MZ associated with the MZ B-cells. Furthermore, administration of mucins to normal mice clearly reduced the splenic MZ B-cells, similar to tumour-bearing mice. These results indicate that mucins in the bloodstream interacted with CD22, which led to impairment of the splenic MZ B-cells in the tumour-bearing state.
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Base de dados:
MEDLINE
Assunto principal:
Baço
/
Linfócitos B
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Adenocarcinoma
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Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico
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Mucinas
Limite:
Animals
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article