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Rapid TNFR1-dependent Lymphocyte Depletion in Vivo With a Selective Chemical Inhibitor of IKKbeta

Kumiko Nagashima, Vito G Sasseville, Danyi Wen, Andrew Bielecki, Hua Yang, Chris Simpson, Ethan Grant, Michael Hepperle, Gerry Harriman, Bruce Jaffee, Tim Ocain, Yajun Xu, Christopher C Fraser

Blood. 2006 Jun 1;107(11):4266-73.

PMID: 16439676

Abstract:

The transcription factor NF-kappaB plays a central role in regulating inflammation and apoptosis, making it a compelling target for drug development. We identified a small molecule inhibitor (ML120B) that specifically inhibits IKKbeta, an Ikappa-B kinase that regulates NF-kappaB. IKKbeta and NF-kappaB are required in vivo for prevention of TNFalpha-mediated apoptosis. ML120B sensitized mouse bone marrow progenitors and granulocytes, but not mature B cells to TNFalpha killing in vitro, and induced apoptosis in vivo in the bone marrow and spleen within 6 hours of a single oral dose. In vivo inhibition of IKKbeta with ML120B resulted in depletion of thymocytes and B cells in all stages of development in the bone marrow but did not deplete granulocytes. TNF receptor-deficient mouse thymocytes and B cells were resistant to ML120B-induced depletion in vivo. Surprisingly, surviving bone marrow granulocytes expressed TNFR1 and TNFR2 after dosing in vivo with ML120B. Our results show that inhibition of IKKbeta with a small molecule in vivo leads to rapid TNF-dependent depletion of T and B cells. This observation has several implications for potential use of IKKbeta inhibitors for the treatment of inflammatory disease and cancer.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP783348367 ML120B ML120B 783348-36-7 Price
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