Transactivation of the Interleukin-1 Alpha Promoter by Human T-cell Leukemia Virus

Abstract

The expression of interleukin-I a (IL-1 a) appears to be tightly regulated, as the levels of constitutive expression in normal cells is extremely low. In contrast to normal hematopoietic cells, human T-cell leukemia virus type I (HTLV-I)-infected T-cell lines constitutively produce high levels of IL-1 a mRNA and secret this cytokine into the culture medium. IL-1-a mRNA is also expressed in fresh leukemic cells of adult T-cell leukemia/lymphoma (ATLL) patients. HTLV-I-induced IL-1 a might explain some symptoms observed in ATLL. In this regard, molecular dissection of the IL-1 a gene transcriptional regulation is of primary importance. In this review, the transcriptional regulation of IL-1 a gene expression and the possible role of the NF-K B pathway are discussed in the light of our current understanding of IL-1 a gene regulation by HTLV-I and HTLV-II Tax proteins, which are viral transcriptional transactivators.

Key Words:

• Interleukin-1 α
• human T-cell leukemia virus Tax
• NF-K B
• adult T-cell leukemidlymphoma