Inhibition of Activation of Transcription Factor Ap-1 by Cd28 Signaling

• Co-stimulation of T-lymphocytes by T-cell receptor (TcR) occupancy and activation of the CD28 surface molecule results in enhanced proliferation and interleukin 2 (IL-2) production. The increase in IL-2 gene expression triggered by CD28 involves a KB-like sequence in the 5'-regulatory region of the IL-2 promoter, called CD28-responsive element. Stimulation of T-cells by agonistic anti-CD28 antibodies in conjunction with phorbol 12-myristate 13-acetate (PMA)- or TcR-derived signals induces the enhanced activation of the transcription factor NF-B-K. Here we report that CD28 engagement, however, exerts opposite effects on the transcription factor AP-1. Whereas anti-CD28 together with PMA increased the DNA binding and trans-activation activity of NF-B-K, PMA-induced activation of AP-1 was significantly suppressed. The inhibitory effect exerted by anti-CD38 was observed at the level of DNA binding as well as in functional reporter-gene assays. These results suggest that the two transcription factors are independently regulated and may perform different functions during T-cell activation.

Ämnesord

NATURVETENSKAP  -- Biologi -- Cellbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Cell Biology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

antigen

c-fos

death

expression

interleukin-2 gene

lymphocytes

nf-kappa-b

pathway

phosphorylation

receptor

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)