Insights on the pathogenicity of human T-lymphotropic/leukemia virus types I and II.
Human T-lymphotropic/leukemia virus types I and II (HTLV-I and HTLV-II) are phylogenetically and immunologically related viruses that differ in their pathogenicity in vivo. HTLV-I is the etiologic agent of adult T-cell leukemia/lymphoma, as well as a chronic progressive myelopathy, HTLV-I-associated myelopathy/tropical spastic paraparesis. In contrast, HTLV-II has not been conclusively associated with specific diseases. Both HTLV-I and HTLV-II transform CD4+ T-cells in vitro, but their in vivo target cells appear to differ. HTLV-I is found mainly in CD4+ cells, whereas HTLV-II has been demonstrated mainly in CD8+ cells. Clearly the definition of the viral genetic determinants responsible for the different tropism and pathogenicity in vivo may provide the basis of our understanding of the HTLV-I oncogenicity. In this short review we emphasize two aspects of viral infection of T cells: (1) the influence of viral infection on the major proteins involved in the G0-G1 phase of the cell cycle and (2) the effect of viral infection on the S phase of the cell cycle, i.e., the interleukin-2 receptor pathway.
Cereseto
A
A
Laboratory of Tumor Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892-4255, USA.
Mulloy
J C
JC
Franchini
G
G
D017398:Alternative Splicing / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology / Q000821:virology; D002472:Cell Transformation, Viral; D016193:G1 Phase / Q000502:physiology; D016355:Genes, pX / Q000502:physiology; D015490:HTLV-I Infections / Q000235:genetics / Q000821:virology*; D015491:HTLV-II Infections / Q000235:genetics / Q000821:virology*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000472:pathogenicity*; D015367:Human T-lymphotropic virus 2 / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D015375:Receptors, Interleukin-2 / Q000502:physiology; D016192:Resting Phase, Cell Cycle / Q000502:physiology; D016196:S Phase / Q000502:physiology; D015398:Signal Transduction
D015375:Receptors, Interleukin-2