Human T-Cell Leukemia Virus Type 1 Oncogenesis between Active Expression and Latency: A Possible Source for the Development of Therapeutic Targets

Abstract

The human T-cell leukemia virus type 1 (HTLV-1) is the only known human oncogenic retrovirus. HTLV-1 can cause a type of cancer called adult T-cell leukemia/lymphoma (ATL). The virus is transmitted through the body fluids of infected individuals, primarily breast milk, blood, and semen. At least 5–10 million people in the world are infected with HTLV-1. In addition to ATL, HTLV-1 infection can also cause HTLV-I-associated myelopathy (HAM/TSP). ATL is characterized by a low viral expression and poor prognosis. The oncogenic mechanism triggered by HTLV-1 is extremely complex and the molecular pathways are not fully understood. However, viral regulatory proteins Tax and HTLV-1 bZIP factor (HBZ) have been shown to play key roles in the transformation of HTLV-1-infected T cells. Moreover, several studies have shown that the final fate of HTLV-1-infected transformed Tcell clones is the result of a complex interplay of HTLV-1 oncogenic protein expression with cellular transcription factors that subvert the cell cycle and disrupt regulated cell death, thereby exerting their transforming effects. This review provides updated information on the mechanisms underlying the transforming action of HTLV-1 and highlights potential therapeutic targets to combat ATL.

HTLV-1 Tax Tug-of-War: Cellular Senescence and Death or Cellular Transformation

“…Therefore, understanding how the virus prevents CTL activity is essential. Indeed, the findings that infected cells with extremely low levels of Tax expression can be targeted by high-avidity CTLs in vitro raises the possibility of developing therapeutic vaccines for the treatment of HTLV-I-associated diseases [132]. Notably, the adoptive transfer of Tax-specific CTLs is sufficient to prevent HTLV-I-associated disease in animal models [133].…”

Заболевания, Ассоциированные С Т-Лимфотропным Вирусом Типа 1 Человека (HTLV-1)

“…Вирус передается через биологические жидкости инфицированных людей. Описаны случаи передачи вируса через грудное молоко, кровь и сперму [3].…”