Requirements for the functional expression of OX40 ligand on human activated CD4+ and CD8+ T cells.
Hum Immunol
; 68(7): 563-71, 2007 Jul.
Article
em En
| MEDLINE
| ID: mdl-17584577
Interaction between OX40 expressed on activated T cells and its ligand (OX40L) on antigen presenting cells (APC) provides a co-stimulatory signal for T cells to promote acquired immunity. In the present study, we have examined various culture conditions for optimum OX40L expression on T cells stimulated with immobilized anti-CD3/CD28 monoclonal antibodies (mAbs). Although the day 3 primed T cells expressed minimal OX40L, after repeated stimulations both the CD4+ and CD8+ T cells became OX40L positive as determined by flow cytometry. Interleukin (IL)-12 interfered with the OX40L expression. Among activated T cells, a higher frequency of CD8+ T cells expressed OX40L than CD4+ T cells. By blocking OX40L-OX40 interaction by an anti-OX40 mAb, the number of OX40L+ T cells significantly increased. Screening of various cytokines showed that transforming growth factor (TGF)-beta1 was capable of induction of OX40L on the activated T cells within 3 days. The OX40L expressed on T cells was functional, as they bound soluble OX40 and stimulated human immunodeficiency virus-1 (HIV-1) production from cell lines chronically infected with HIV-1 and expressing OX40. Altogether the present study findings indicate that functional OX40L is inducible on human activated CD4+ and CD8+ T cells, and that the expression is enhanced by TGF-beta1.
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Base de dados:
MEDLINE
Assunto principal:
Linfócitos T CD4-Positivos
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Linfócitos T CD8-Positivos
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Fator de Crescimento Transformador beta1
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Ligante OX40
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Receptores OX40
Limite:
Humans
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article