HBZ, a new important player in the mystery of adult T-cell leukemia

• Published in: Blood 2006-12, Vol.108 (13), p.3979-3982
• Main Authors: Mesnard, Jean-Michel, Barbeau, Benoît, Devaux, Christian
• Format: Article
• Language: English
• Subjects: Animals; Basic-Leucine Zipper Transcription Factors; Basic-Leucine Zipper Transcription Factors - genetics; Basic-Leucine Zipper Transcription Factors - immunology; Biological and medical sciences; Cancer; Cell Proliferation; Cell Transformation, Viral; Cell Transformation, Viral - genetics; Cell Transformation, Viral - immunology; Disease Models, Animal; Gene Products, tax; Gene Products, tax - deficiency; Gene Products, tax - immunology; Hematologic and hematopoietic diseases; Human T-lymphotropic virus 1; Human T-lymphotropic virus 1 - genetics; Human T-lymphotropic virus 1 - immunology; Humans; Leukemia-Lymphoma, Adult T-Cell - genetics; Leukemia-Lymphoma, Adult T-Cell - immunology; Leukemia-Lymphoma, Adult T-Cell - pathology; Leukemia-Lymphoma, Adult T-Cell - physiopathology; Leukemia-Lymphoma, T-Cell, Acute, HTLV-I-Associated; Leukemias. Malignant lymphomas. Malignant reticulosis. Myelofibrosis; Life Sciences; Medical sciences; Microbiology and Parasitology; Protein Isoforms; Protein Isoforms - genetics; Protein Isoforms - immunology; Retroviridae Proteins; RNA, Messenger; RNA, Messenger - genetics; RNA, Messenger - immunology; RNA, Viral; RNA, Viral - genetics; RNA, Viral - immunology; T-Lymphocytes; T-Lymphocytes - immunology; T-Lymphocytes - pathology; T-Lymphocytes - virology; Viral Proteins; Viral Proteins - genetics; Viral Proteins - immunology; Virology; Virus Replication; Virus Replication - genetics; Virus Replication - immunology
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2006-03-007732

Adult T-cell leukemia (ATL) was first described in 1977. A link between ATL and human T-cell leukemia virus type 1 (HTLV-1) was clearly established in the early 1980s. Over the years, many aspects of HTLV-1–induced cellular dysfunctions have been clarified. However, the detailed mechanism behind ATL occurrence remains unsolved. Presently, we are still unable to explain the absence of viral Tax protein (thought to play a central role in T-cell transformation) in more than 50% of ATL cells. A novel HTLV-1 HBZ protein, encoded on the negative strand, was characterized by our group and is currently the subject of intensive research efforts to determine its function in viral replication and/or pathophysiology. Recently, 4 studies reported on the existence of different HBZ isoforms and have investigated on their function in both ATL cells or animal models. One report suggests that the HBZ gene might have a bimodal function (at the mRNA and protein levels), which could represent an uncharacterized strategy to regulate viral replication and proliferation of infected T cells.