Abstract
[en] Alteration of early haematopoietic development is thought to be responsible for the onset of immature leukemias and lymphomas. We have previously demonstrated that Tax(HTLV-1) interferes with ss-selection, an important checkpoint of early thymopoiesis, indicating that human T-cell leukemia virus type 1 (HTLV-1) infection has the potential to perturb thymic human alphabeta T-cell development. To verify that inference and to clarify the impact of HTLV-1 infection on human T-cell development, we investigated the in vivo effects of HTLV-1 infection in a textquotedblHuman Immune Systemtextquotedbl (HIS) Rag2(-)/(-)gamma(c)(-)/(-) mouse model. These mice were infected with HTLV-1, at a time when the three main subpopulations of human thymocytes have been detected. In all but two inoculated mice, the HTLV-1 provirus was found integrated in thymocytes; the proviral load increased with the length of the infection period. In the HTLV-1-infected mice we observed alterations in human T-cell development, the extent of which correlated with the proviral load. Thus, in the thymus of HTLV-1-infected HIS Rag2(-)/(-)gammac(-)/(-) mice, mature single-positive (SP) CD4(+) and CD8(+) cells were most numerous, at the expense of immature and double-positive (DP) thymocytes. These SP cells also accumulated in the spleen. Human lymphocytes from thymus and spleen were activated, as shown by the expression of CD25: this activation was correlated with the presence of tax mRNA and with increased expression of NF-kB dependent genes such as bfl-1, an anti-apoptotic gene, in thymocytes. Finally, hepato-splenomegaly, lymphadenopathy and lymphoma/thymoma, in which Tax was detected, were observed in HTLV-1-infected mice, several months after HTLV-1 infection. These results demonstrate the potential of the HIS Rag2(-)/(-)gamma(c)(-)/(-) animal model to elucidate the initial steps of the leukemogenic process induced by HTLV-1.
Original language | English |
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Pages (from-to) | e1002231 |
Journal | Plos Pathogens |
Volume | 7 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2011 |
Externally published | Yes |
Keywords
- Sciences de la santé humaine => Oncologie
- Animals
- DNA-Binding Proteins/genetics
- Disease Models, Animal
- HTLV-I Infections/immunology/pathology
- Hematopoietic Stem Cell Transplantation
- Human T-lymphotropic virus 1/physiology
- Humans
- Leukemia-Lymphoma, Adult T-Cell/etiology
- Mice
- Thymocytes/physiology/virology
- Transplantation Chimera/immunology
- Transplantation, Heterologous
- Viral Load