HTLV-1: A real pathogen or a runaway guest of a diseased cell?

Abstract

The human T-cell lymphotropic virus type 1 (HTLV-1) is a deltaretrovirus claimed to be aetiologically linked to the adult T-cell leukaemia/lymphoma (ATLL) and associated myelopathy/tropical spastic paraparesis (HAM/TSP) besides other minor pathologies. HTLV-1 infection is worldwide distributed, despite its heterogeneous prevalence. Environmental factors and host-genetic background are very likely to determine the epidemiological profile of HTLV-1 prevalence and related disease confinement in distinct human ethnic populations and geographical coordinates, which raises the question if the virus is a real pathogen or a runaway well-organized packed genome of a burden host cell near death process. New methodological approaches need to be proposed and applied in order to prove or discard the hypotheses emerged in the present review.

Putative oncogenic viruses: Some data on Brazilian subjects

“…As commonly substantiated, cervix uterine cancer is etiologically linked to HPV persistent infection but, both HTLV-1/2 and HPV are mainly sexually transmitted, and mostly by promiscuous behavior, despite HTLV-1/2 infection be usually circumscribed to nuclear families. In addition, radiotherapy procedures represent an important variable among cancer uterine patients that could contribute to HTLV-1/2 expression [69,75,76], furthermore we still reported HTLV-1 positivity among health care workers exposed to ionizing radiation as already discussed elsewhere [77]. Based on these findings, of HTLV-1 and HTLV-2 expression, it could be reinforced the hypothesis of ionizing radiation protagonism in the activation of host cell integrated HTLV-1/2 genes [77].…”

“…In addition, radiotherapy procedures represent an important variable among cancer uterine patients that could contribute to HTLV-1/2 expression [69,75,76], furthermore we still reported HTLV-1 positivity among health care workers exposed to ionizing radiation as already discussed elsewhere [77]. Based on these findings, of HTLV-1 and HTLV-2 expression, it could be reinforced the hypothesis of ionizing radiation protagonism in the activation of host cell integrated HTLV-1/2 genes [77]. In vitro and ex vivo studies aim to explain in vivo phenomena which accounts for Koch postulates [78] that is under review, so it would infer, for example, that virus associated cytopathology and related dysregulated cell signaling, not necessarily and definitively prove the etiological role played by some viruses in cancer etiology.…”

What Is Adult T-Cell Leukemia Pathogenesis? System Virology as a Solution of This Puzzle

“…Human T-cell leukemia virus type 1 (HTLV-1) is a causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and the adult T-cell leukemia/lymphoma (ATLL) (1). There are 20 million HTLV-1 infected individuals worldwide.…”