The cytoplasmic tail of CD45 is released from activated phagocytes and can act as an inhibitory messenger for T cells.
Blood
; 112(4): 1240-8, 2008 Aug 15.
Article
en En
| MEDLINE
| ID: mdl-18511809
ABSTRACT
CD45 is the prototypic transmembrane protein tyrosine phosphatase (PTP), which is expressed on all nucleated hematopoietic cells and plays a central role in the integration of environmental signals into immune cell responses. Here we report an alternative function for the intracellular domain of CD45. We dis-covered that CD45 is sequentially cleaved by serine/metalloproteinases and gamma-secretases during activation of human monocytes and granulocytes by fungal stimuli or phorbol 12-myristate 13-acetate but not by other microbial stimuli. Proteolytic processing of CD45 occurred upon activation of monocytes or granulocytes but not of T cells, B cells, or dendritic cells and resulted in a 95-kDa fragment of the cytoplasmic tail of CD45 (ct-CD45). ct-CD45 was released from monocytes and granulocytes upon activation-induced cell death. Binding studies with ct-CD45 revealed a counter-receptor on preactivated T cells. Moreover, T-cell proliferation induced by dendritic cells or CD3 antibodies was inhibited in the presence of ct-CD45. Taken together, the results of our study demonstrate that fragments of the intracellular domain of CD45 from human phagocytes can function as intercellular regulators of T-cell activation.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fragmentos de Péptidos
/
Fagocitos
/
Linfocitos T
/
Antígenos Comunes de Leucocito
Límite:
Humans
Idioma:
En
Revista:
Blood
Año:
2008
Tipo del documento:
Article
País de afiliación:
Austria