Temporal dynamics of human T-lymphotropic virus type I tax mRNA and proviral DNA load in peripheral blood mononuclear cells of human T-lymphotropic virus type I-associated myelopathy patients.
Human T-cell lymphotropic virus type I (HTLV-I) is the etiologic agent of HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). High HTLV-I provirus load and tax mRNA level have been suggested as predictors of disease progression in patients with HAM/TSP, but little is known about the temporal variation in patients. To clarify the role of high proviral and tax mRNA loads and their fluctuations in the pathogenesis of HAM/TSP, we measured proviral load and tax mRNA in serially collected peripheral blood mononuclear cells (PBMCs) from nine patients with HAM/TSP during a long-term follow-up, by use of real-time polymerase chain reaction using tax primers. The real-time PCR quantitation revealed a wide range of variation of proviral loads (7.82-97.13 copies per 100 PBMCs) and tax mRNA (0.20-245.30 copies) among HAM/TSP patients. Patients showed three different patterns of HTLV-I tax mRNA loads during the course of the disease. Tax mRNA load showed a separate evolution with respect to the disease. The dynamic patterns of proviral load and mRNA Tax expression suggest that only the permanent presence of a basal level of tax mRNA, rather than the tax mRNA load, is related to the development of HAM/TSP. To our knowledge, this is the first longitudinal study to determine tax mRNA expression at different clinical stages.
Ramirez
Eugenio
E
Department of Virology, Instituto de Salud Publica de Chile, Santiago, Chile. eramirez@ispch.cl
Cartier
Luis
L
Torres
Mauricio
M
Barria
Marcelo
M
D000328:Adult; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D016356:Gene Products, tax / Q000235:genetics*; D015368:Human T-lymphotropic virus 1 / Q000235:genetics* / Q000502:physiology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000821:virology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015493:Paraparesis, Tropical Spastic / Q000821:virology*; D011533:Proviruses / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis*; D012367:RNA, Viral / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D013997:Time Factors; D019562:Viral Load
D004279:DNA, Viral; D016356:Gene Products, tax; D012333:RNA, Messenger; D012367:RNA, Viral