scholarly journals Activation of AID by human T-cell leukemia virus Tax oncoprotein and the possible role of its constitutive expression in ATL genesis

2010 ◽  
Vol 32 (1) ◽  
pp. 110-119 ◽  
Author(s):  
C. Ishikawa ◽  
S. Nakachi ◽  
M. Senba ◽  
M. Sugai ◽  
N. Mori
Keyword(s):  
T Cell ◽  
Leukemia Virus ◽  
Constitutive Expression ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Human T Cell ◽  
T Cell Leukemia Virus

scholarly journals The Role of ITCH Protein in Human T-cell Leukemia Virus Type 1 Release

2011 ◽  
Vol 286 (36) ◽  
pp. 31092-31104 ◽  
Author(s):  
Batsukh Dorjbal ◽  
David Derse ◽  
Patricia Lloyd ◽  
Ferri Soheilian ◽  
Kunio Nagashima ◽  
...  
Keyword(s):  
T Cell ◽  
Virus Type ◽  
Leukemia Virus ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Leukemia Virus Type ◽  
Human T Cell ◽  
T Cell Leukemia Virus

scholarly journals Role of miRNAs (miR‐93 and miR‐130b) in Human T‐cell Leukemia Virus‐1 (HTLV‐1) Transformation of Cells through Tumor Suppressor TP53INP1 Downregulation

2007 ◽  
Vol 21 (6) ◽  
Author(s):  
Man Lung Yeung ◽  
Jun‐ichirou Yasunaga ◽  
Yamina Bennasser ◽  
Dusetti Nelson ◽  
Masao Matsuoka ◽  
...  
Keyword(s):  
T Cell ◽  
Tumor Suppressor ◽  
Leukemia Virus ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Human T Cell ◽  
T Cell Leukemia Virus

scholarly journals Induction of Bcl-xL Expression by Human T-Cell Leukemia Virus Type 1 Tax through NF-κB in Apoptosis-Resistant T-Cell Transfectants with Tax

1999 ◽  
Vol 73 (10) ◽  
pp. 7981-7987 ◽  
Author(s):  
Tomonori Tsukahara ◽  
Mari Kannagi ◽  
Takashi Ohashi ◽  
Hirotomo Kato ◽  
Masaaki Arai ◽  
...  
Keyword(s):  
T Cell ◽  
Virus Type ◽  
Leukemia Virus ◽  
Constitutive Expression ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Leukemia Virus Type ◽  
Human T Cell ◽  
T Cell Leukemia Virus

ABSTRACT Human T-cell leukemia virus type 1 (HTLV-1) Tax is thought to play a pivotal role in immortalization of T cells. We have recently shown that the expression of Tax protected the mouse T-cell line CTLL-2 against apoptosis induced by interleukin-2 (IL-2) deprivation and converted its growth from being IL-2 dependent to being IL-2 independent. In this study, we demonstrate that constitutive expression of bcl-xl but not bcl-2, bcl-xs,bak, bad, or bax was associated with apoptosis resistance after IL-2 deprivation in CTLL-2 cells that expressed Tax. Transient-transfection assays showed thatbcl-x promoter was transactivated by wild-type Tax. Similar effects were observed in mutant Tax retaining transactivating ability through NF-κB. Deletion or substitution of a putative NF-κB binding site identified in the bcl-x promoter significantly decreased Tax-induced transactivation. This NF-κB-like element was able to form a complex with NF-κB family proteins in vitro. Furthermore, Tax-induced transactivation of the bcl-xpromoter was also diminished by the mutant IκBα, which specifically inhibits NF-κB activity. Our findings suggest that constitutive expression of Bcl-xL induced by Tax through the NF-κB pathway contributes to the inhibition of apoptosis in CTLL-2 cells after IL-2 deprivation.

scholarly journals Biochemical Characterization, Specificity and Inhibition Studies of HTLV-1, HTLV-2, and HTLV-3 Proteases

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 127
Author(s):  
Norbert Kassay ◽  
János András Mótyán ◽  
Krisztina Matúz ◽  
Mária Golda ◽  
József Tőzsér
Keyword(s):  
T Cell ◽  
Biochemical Characterization ◽  
Leukemia Virus ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Cell Leukemia Virus Type ◽  
Adult T Cell Leukemia ◽  
Human T Cell ◽  
T Cell Leukemia Virus

The human T-lymphotropic viruses (HTLVs) are causative agents of severe diseases including adult T-cell leukemia. Similar to human immunodeficiency viruses (HIVs), the viral protease (PR) plays a crucial role in the viral life-cycle via the processing of the viral polyproteins. Thus, it is a potential target of anti-retroviral therapies. In this study, we performed in vitro comparative analysis of human T-cell leukemia virus type 1, 2, and 3 (HTLV-1, -2, and -3) proteases. Amino acid preferences of S4 to S1′ subsites were studied by using a series of synthetic oligopeptide substrates representing the natural and modified cleavage site sequences of the proteases. Biochemical characteristics of the different PRs were also determined, including catalytic efficiencies and dependence of activity on pH, temperature, and ionic strength. We investigated the effects of different HIV-1 PR inhibitors (atazanavir, darunavir, DMP-323, indinavir, ritonavir, and saquinavir) on enzyme activities, and inhibitory potentials of IB-268 and IB-269 inhibitors that were previously designed against HTLV-1 PR. Comparative biochemical analysis of HTLV-1, -2, and -3 PRs may help understand the characteristic similarities and differences between these enzymes in order to estimate the potential of the appearance of drug-resistance against specific HTLV-1 PR inhibitors.

scholarly journals Transformed T lymphocytes infected by a novel isolate of human T cell leukemia virus type II

Blood ◽  
1985 ◽  
Vol 66 (6) ◽  
pp. 1336-1342 ◽  
Author(s):  
TL Chorba ◽  
R Brynes ◽  
VS Kalyanaraman ◽  
M Telfer ◽  
R Ramsey ◽  
...  
Keyword(s):  
T Cell ◽  
Leukemia Virus ◽  
Type Ii ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
T Helper ◽  
Cell Leukemia Virus Type ◽  
Human T Cell ◽  
Viral Particles ◽  
T Cell Leukemia Virus

Abstract Human T cell leukemia virus type II (HTLV-II) has been isolated from a patient (Mo) with features of leukemic reticuloendotheliosis (LRE) and from a patient with acquired immunodeficiency syndrome (AIDS). We have obtained another isolate of HTLV-II from a patient (CM) with severe hemophilia A, pancytopenia, and a 14-year history of staphylococcal and candidal infections but no evidence of T cell leukemia/lymphoma, AIDS, or LRE. Fresh mononuclear cells and cultured lymphocytes from CM express retroviral antigens indistinguishable by molecular criteria from HTLV-IIMo. Leukocyte cultures from CM yield hyperdiploid (48,XY, +2, +19) continuous lymphoid lines; human fetal cord blood lymphocytes (CBL) are transformed by cocultivation with these CM cell cultures but retain normal cytogenetic constitution. Electron microscopic examination of the CM cultures and transformed CBL reveals budding of extracellular viral particles, intracellular tubuloreticular structures, and viral particles contained within intracellular vesicles. CM cell cultures and the transformed CBL do not require exogenous interleukin 2, have T cell cytochemical features and mature T helper phenotypes, and exhibit minimal T helper and profound T suppressor activity on pokeweed mitogen-stimulated differentiation of normal B cells. These characteristics, which are similar to those observed with the first HTLV-II isolate, may represent properties of all HTLV-II-infected T cells.

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