Increased expression of CD152 (CTLA-4) by normal T lymphocytes in untreated patients with B-cell chronic lymphocytic leukemia.
Leukemia
; 19(10): 1788-93, 2005 Oct.
Article
em En
| MEDLINE
| ID: mdl-16094420
ABSTRACT
Patients with chronic lymphocytic leukemia (CLL) have defects in both cellular and humoral immunity. Since CD152 (CTLA-4) plays a critical role in downregulating T-cell responses, we studied the expression of surface and cytoplasmic CD152 (sCD152 and cCD152, respectively) in freshly isolated T cells from treatment-naïve patients with CLL. CD4+ and CD8+ T cells from these patients demonstrated significantly increased sCD152 and cCD152 compared to normal donors. Furthermore, these patients had an increased proportion of the regulatory CD4(+)/CD25(+)/CD152+ subset that correlated with advanced Rai stage, unfavorable cytogenetics and low serum IgG and IgA levels. The expression of sCD152 by T cells also correlated with ZAP-70 expression by CLL B cells. The proportion of CD4(+)/CD25+ cells was also correlated with unmutated immunoglobulin heavy chain variable gene status. Blockade of CD152 with monoclonal antibody (mAb) in proliferation assays was associated with potent T-cell proliferation in response to autologous and allogeneic CD40-activated CLL B cells. In summary, T cells from patients with CLL may be primed for anergy by expressing increased amounts of CD152; anti-CD152 mAb may represent a therapeutic opportunity to enhance an immune response against autologous leukemia cells.
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Base de dados:
MEDLINE
Assunto principal:
Linfócitos T
/
Leucemia Linfocítica Crônica de Células B
/
Antígenos de Diferenciação
/
Regulação Neoplásica da Expressão Gênica
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article